import { spawn, spawnSync } from "node:child_process";
import { createHash, randomBytes } from "node:crypto";
import { appendFileSync, mkdirSync, writeFileSync } from "node:fs";
import { tmpdir } from "node:os";
import { join } from "node:path";
import { type UniDeskConfig, repoRoot } from "./config";
import {
  decodeApplyPatchV2BulkRead,
  formatApplyPatchV2BulkReplacementPayload,
  isApplyPatchV2HelpArgs,
  runApplyPatchV2,
  type ApplyPatchV2BulkReplacementWritePlan,
  type ApplyPatchV2Executor,
  type ApplyPatchV2FileSystem,
} from "./apply-patch-v2";
import {
  isSshFileTransferOperation,
  runSshFileTransferOperation,
  type SshRemoteCommandExecutor,
  type SshRemoteCommandStreamHandlers,
} from "./ssh-file-transfer";

export interface ParsedSshArgs {
  remoteCommand: string | null;
  requiresStdin: boolean;
  invocationKind: SshInvocationKind;
  stdinPrefix?: string;
  stdinSuffix?: string;
  requiredHelpers?: SshHelperName[];
}

export type SshInvocationKind = "interactive" | "argv" | "helper" | "ssh-like";
export type SshHelperName = "apply_patch" | "glob" | "skill-discover";

export interface ParsedSshRoute {
  providerId: string;
  plane: "host" | "k3s" | "win";
  entry: string | null;
  namespace: string | null;
  resource: string | null;
  container: string | null;
  workspace: string | null;
  raw: string;
}

export interface ParsedSshInvocation {
  providerId: string;
  route: ParsedSshRoute;
  parsed: ParsedSshArgs;
}

export interface SshCaptureResult {
  exitCode: number;
  stdout: string;
  stderr: string;
}

export type SshCaptureBackend = "local-backend-core-broker" | "remote-frontend-websocket";

export interface SshCaptureBackendPlan {
  backend: SshCaptureBackend;
  remoteHost: string | null;
  reason: string;
  localBackendCore: {
    dockerExecutable: boolean;
    backendCoreContainer: boolean;
    error: string | null;
  };
}

export interface SshFailureHint {
  code: "ssh-like-command-friction";
  providerId: string;
  trigger: "timeout-or-kex" | "exit-255";
  exitCode: number;
  message: string;
  try: string;
  triage: string;
  note: string;
}

export interface SshRuntimeTimingHint {
  code: "ssh-runtime-timing";
  level: "info" | "warning";
  providerId: string;
  route: string;
  transport: "backend-core-broker" | "frontend-websocket";
  invocationKind: SshInvocationKind;
  exitCode: number;
  elapsedMs: number;
  elapsedSeconds: number;
  thresholdMs: number;
  slow: boolean;
  message: string;
  note: string;
}

export interface SshRuntimeTimeoutHint {
  code: "ssh-runtime-timeout";
  level: "warning";
  providerId: string;
  route: string;
  transport: "backend-core-broker" | "frontend-websocket";
  invocationKind: SshInvocationKind;
  timeoutMs: number;
  timeoutSeconds: number;
  message: string;
  action: string;
  note: string;
}

export interface SshStdoutTruncationHint {
  code: "ssh-stdout-truncated";
  level: "warning";
  providerId: string;
  route: string;
  transport: "backend-core-broker" | "frontend-websocket";
  invocationKind: SshInvocationKind;
  thresholdBytes: number;
  observedBytesAtTruncation: number;
  dumpPath: string | null;
  dumpError: string | null;
  message: string;
  action: string;
  note: string;
}

const argvQuotedSshSubcommands = new Set(["git", "rg", "grep", "sed", "nl", "stat", "du", "ls", "cat", "head", "tail", "wc", "pwd"]);
const nativeK3sKubeconfig = "/etc/rancher/k3s/k3s.yaml";
const windowsBridgeCwd = "/mnt/c/Windows";
const windowsPowerShellExePath = "/mnt/c/Windows/System32/WindowsPowerShell/v1.0/powershell.exe";
const windowsCmdExeNativePath = "C:\\Windows\\System32\\cmd.exe";
const defaultSshSlowWarningMs = 10_000;
const defaultSshRuntimeTimeoutMs = 60_000;
const maxSshRuntimeTimeoutMs = 60_000;
const defaultSshStdoutStreamMaxBytes = 256 * 1024;
const minSshStdoutStreamMaxBytes = 4 * 1024;
const maxSshStdoutStreamMaxBytes = 16 * 1024 * 1024;
const sshStdoutDumpDir = join(tmpdir(), "unidesk-cli-output");
export const sshShellCompatibilityPrelude = 'printf(){ if [ "${1+x}" = x ] && [ "$1" = "-v" ] && [ -n "${BASH_VERSION:-}" ]; then command printf "$@"; return $?; fi; if [ "${1+x}" = x ] && [ "$1" = "--" ]; then shift; fi; command printf -- "$@"; }';
export const sshUserToolPathPrelude = [
  'for unidesk_path_dir in "$HOME/.bun/bin" "$HOME/.local/bin" "$HOME/bin" "/root/.bun/bin"; do',
  '  [ -d "$unidesk_path_dir" ] || continue',
  '  case ":$PATH:" in',
  '    *":$unidesk_path_dir:"*) ;;',
  '    *) PATH="$unidesk_path_dir:$PATH" ;;',
  "  esac",
  "done",
  "export PATH",
].join("\n");
const k3sResourceKindAliases = new Set(["pod", "po", "pods", "deployment", "deploy", "deployments", "statefulset", "sts", "daemonset", "ds", "job", "jobs"]);
const k3sPodRoutePrefixes = ["pod:", "po:", "pods:"];
const legacyK3sOperationRouteSegments = new Set([
  "guard",
  "kubectl",
  "exec",
  "script",
  "apply-patch",
  "apply-patch-v1",
  "patch",
  "patch-v1",
  "v2",
  "logs",
  "get",
  "describe",
  "top",
  "rollout",
  "wait",
  "config",
  "version",
  "cluster-info",
  "auth",
  "api-resources",
  "api-versions",
]);

export const remoteApplyPatchSource = String.raw`#!/bin/sh
set -eu

allow_loose=0

die() {
  printf 'apply_patch: %s\n' "$*" >&2
  exit 1
}

mk_temp() {
  mktemp "${"$"}{TMPDIR:-/tmp}/unidesk-apply-patch.XXXXXX" || exit 1
}

ensure_parent() {
  case "$1" in
    */*)
      dir=${"$"}{1%/*}
      [ -n "$dir" ] || dir=/
      mkdir -p "$dir"
      ;;
  esac
}

read_text_preserve_newlines() {
  marker="__UNIDESK_APPLY_PATCH_EOF_$$__"
  text=$(cat "$1"; printf '%s' "$marker") || die "failed to read $1"
  printf '%s' "${"$"}{text%"$marker"}"
}

write_file() {
  target=$1
  source=$2
  ensure_parent "$target"
  cp "$source" "$target" || die "failed to write $target"
}

line_number_for_prefix() {
  newline_count=$(printf '%s' "$1" | tr -cd '\n' | wc -c | tr -d ' ')
  printf '%s\n' $((newline_count + 1))
}

replace_once_with_perl() {
  command -v perl >/dev/null 2>&1 || return 127
  perl -0777 -e '
use strict;
use warnings;

sub fail {
  print STDERR "apply_patch: ", @_, "\n";
  exit 1;
}

sub read_all {
  my ($path, $label) = @_;
  open my $fh, "<", $path or fail("failed to read $label");
  binmode $fh;
  local $/;
  my $data = <$fh>;
  close $fh;
  return defined $data ? $data : "";
}

my ($target, $search_file, $replace_file, $hunk_id, $allow_loose, $out) = @ARGV;
my $old = read_all($target, $target);
my $search = read_all($search_file, "hunk search");
my $replacement = read_all($replace_file, "hunk replacement");
my $new;

if ($search eq "") {
  fail("hunk $hunk_id in $target has no context; add unchanged/deleted anchor lines or pass --allow-loose after manual review") if $allow_loose ne "1";
  print STDERR "apply_patch: hunk $hunk_id matched $target:1 (loose)\n";
  $new = $replacement . $old;
} else {
  my $pos = -1;
  my $offset = 0;
  my $count = 0;
  while (1) {
    my $found = index($old, $search, $offset);
    last if $found < 0;
    $pos = $found if $count == 0;
    $count += 1;
    last if $count > 1 && $allow_loose ne "1";
    $offset = $found + length($search);
  }
  fail("hunk $hunk_id context not found in $target") if $count == 0;
  fail("hunk $hunk_id context matched multiple locations in $target; add more unchanged context or pass --allow-loose after manual review") if $count > 1 && $allow_loose ne "1";
  my $prefix = substr($old, 0, $pos);
  my $suffix = substr($old, $pos + length($search));
  my $line = ($prefix =~ tr/\n//) + 1;
  print STDERR "apply_patch: hunk $hunk_id matched $target:$line\n";
  $new = $prefix . $replacement . $suffix;
}

open my $ofh, ">", $out or fail("failed to render patched file");
binmode $ofh;
print $ofh $new or fail("failed to render patched file");
close $ofh or fail("failed to render patched file");
' "$@"
}

replace_once() {
  target=$1
  search_file=$2
  replace_file=$3
  hunk_id=$4
  [ -e "$target" ] || die "file not found: $target"

  fast_out=$(mk_temp)
  if replace_once_with_perl "$target" "$search_file" "$replace_file" "$hunk_id" "$allow_loose" "$fast_out"; then
    write_file "$target" "$fast_out"
    rm -f "$fast_out"
    return 0
  else
    status=$?
  fi
  rm -f "$fast_out"
  [ "$status" = 127 ] || exit "$status"

  marker="__UNIDESK_APPLY_PATCH_EOF_$$__"
  old=$(cat "$target"; printf '%s' "$marker") || die "failed to read $target"
  old=${"$"}{old%"$marker"}
  search=$(cat "$search_file"; printf '%s' "$marker") || die "failed to read hunk search"
  search=${"$"}{search%"$marker"}
  replacement=$(cat "$replace_file"; printf '%s' "$marker") || die "failed to read hunk replacement"
  replacement=${"$"}{replacement%"$marker"}

  if [ -z "$search" ]; then
    [ "$allow_loose" = 1 ] || die "hunk $hunk_id in $target has no context; add unchanged/deleted anchor lines or pass --allow-loose after manual review"
    printf 'apply_patch: hunk %s matched %s:1 (loose)\n' "$hunk_id" "$target" >&2
    new=$replacement$old
  else
    case "$old" in
      *"$search"*)
        prefix=${"$"}{old%%"$search"*}
        suffix=${"$"}{old#*"$search"}
        case "$suffix" in
          *"$search"*)
            [ "$allow_loose" = 1 ] || die "hunk $hunk_id context matched multiple locations in $target; add more unchanged context or pass --allow-loose after manual review"
            ;;
        esac
        printf 'apply_patch: hunk %s matched %s:%s\n' "$hunk_id" "$target" "$(line_number_for_prefix "$prefix")" >&2
        new=$prefix$replacement$suffix
        ;;
      *)
        die "hunk $hunk_id context not found in $target"
        ;;
    esac
  fi

  out=$(mk_temp)
  printf '%s' "$new" > "$out" || die "failed to render patched file"
  write_file "$target" "$out"
  rm -f "$out"
}

apply_update() {
  target=$1
  body=$2
  in_hunk=0
  search_file=
  replace_file=
  changed=0
  hunk_number=0
  has_add=0
  has_delete=0
  seen_add=0
  anchor_before_add=0
  anchor_after_add=0
  explicit_eof=0

  finish_hunk() {
    [ "$in_hunk" = 1 ] || return 0
    if [ "$allow_loose" != 1 ]; then
      [ -s "$search_file" ] || die "hunk $hunk_number in $target has no context; add unchanged/deleted anchor lines or pass --allow-loose after manual review"
      if [ "$has_add" = 1 ] && [ "$has_delete" = 0 ]; then
        if [ "$anchor_before_add" != 1 ] || { [ "$anchor_after_add" != 1 ] && [ "$explicit_eof" != 1 ]; }; then
          die "hunk $hunk_number in $target is insert-only without both leading and trailing context; include nearby unchanged lines after the insertion or pass --allow-loose after manual review"
        fi
      fi
    fi
    replace_once "$target" "$search_file" "$replace_file" "$hunk_number"
    rm -f "$search_file" "$replace_file"
    search_file=
    replace_file=
    in_hunk=0
    changed=1
  }

  while IFS= read -r line || [ -n "$line" ]; do
    case "$line" in
      "*** End of File"*)
        continue
        ;;
      "@@"*)
        finish_hunk
        search_file=$(mk_temp)
        replace_file=$(mk_temp)
        hunk_number=$((hunk_number + 1))
        has_add=0
        has_delete=0
        seen_add=0
        anchor_before_add=0
        anchor_after_add=0
        explicit_eof=0
        in_hunk=1
        continue
        ;;
    esac
    [ "$in_hunk" = 1 ] || die "expected hunk header in $target"
    case "$line" in
      " "*)
        text=${"$"}{line#?}
        printf '%s\n' "$text" >> "$search_file"
        printf '%s\n' "$text" >> "$replace_file"
        if [ "$seen_add" = 1 ]; then anchor_after_add=1; else anchor_before_add=1; fi
        ;;
      "-"*)
        text=${"$"}{line#?}
        printf '%s\n' "$text" >> "$search_file"
        has_delete=1
        if [ "$seen_add" = 1 ]; then anchor_after_add=1; else anchor_before_add=1; fi
        ;;
      "+"*)
        text=${"$"}{line#?}
        printf '%s\n' "$text" >> "$replace_file"
        has_add=1
        seen_add=1
        ;;
      "\\ No newline at end of file")
        ;;
      "*** End of File"*)
        explicit_eof=1
        ;;
      *)
        die "bad hunk line in $target: $line"
        ;;
    esac
  done < "$body"

  finish_hunk
  [ "$changed" = 1 ] || [ -e "$target" ] || die "file not found: $target"
}

is_top_header() {
  case "$1" in
    "*** Add File: "*|"*** Update File: "*|"*** Delete File: "*|"*** End Patch")
      return 0
      ;;
    *)
      return 1
      ;;
  esac
}

pushed=0
pushed_line=
next_patch_line() {
  if [ "$pushed" = 1 ]; then
    line=$pushed_line
    pushed=0
    pushed_line=
    return 0
  fi
  if IFS= read -r line; then
    return 0
  fi
  [ -n "${"$"}{line:-}" ]
}

push_patch_line() {
  pushed_line=$1
  pushed=1
}

parse_add_file() {
  target=$1
  [ ! -e "$target" ] || die "file already exists: $target"
  tmp=$(mk_temp)
  while next_patch_line; do
    if is_top_header "$line"; then
      push_patch_line "$line"
      break
    fi
    case "$line" in
      "+"*)
        printf '%s\n' "${"$"}{line#?}" >> "$tmp"
        ;;
      *)
        rm -f "$tmp"
        die "add file lines must start with + for $target"
        ;;
    esac
  done
  write_file "$target" "$tmp"
  rm -f "$tmp"
}

parse_update_file() {
  target=$1
  move_to=
  body=$(mk_temp)
  if next_patch_line; then
    case "$line" in
      "*** Move to: "*)
        move_to=${"$"}{line#"*** Move to: "}
        ;;
      *)
        push_patch_line "$line"
        ;;
    esac
  fi
  while next_patch_line; do
    if is_top_header "$line"; then
      push_patch_line "$line"
      break
    fi
    case "$line" in
      "*** Move to: "*)
        rm -f "$body"
        die "move marker must appear before update hunks"
        ;;
      *)
        printf '%s\n' "$line" >> "$body"
        ;;
    esac
  done
  if [ -s "$body" ]; then
    apply_update "$target" "$body"
  elif [ -z "$move_to" ] && [ ! -e "$target" ]; then
    rm -f "$body"
    die "file not found: $target"
  fi
  rm -f "$body"
  if [ -n "$move_to" ]; then
    [ -e "$target" ] || die "file not found: $target"
    [ ! -e "$move_to" ] || die "target file already exists: $move_to"
    ensure_parent "$move_to"
    mv "$target" "$move_to" || die "failed to move $target to $move_to"
  fi
}

main() {
  while [ "$#" -gt 0 ]; do
    case "${"$"}1" in
      -h|--help)
        printf 'apply_patch: sh-only helper; reads *** Begin Patch format from stdin; --allow-loose bypasses low-context hunk guards\n'
        return 0
        ;;
      --allow-loose)
        allow_loose=1
        shift
        ;;
      *)
        die "unsupported option: ${"$"}1"
        ;;
    esac
  done
  next_patch_line || die "patch must start with *** Begin Patch"
  [ "$line" = "*** Begin Patch" ] || die "patch must start with *** Begin Patch"
  while next_patch_line; do
    case "$line" in
      "*** End Patch")
        printf 'Done!\n'
        return 0
        ;;
      "*** Add File: "*)
        parse_add_file "${"$"}{line#"*** Add File: "}"
        ;;
      "*** Delete File: "*)
        target=${"$"}{line#"*** Delete File: "}
        rm -f "$target" || die "failed to delete $target"
        ;;
      "*** Update File: "*)
        parse_update_file "${"$"}{line#"*** Update File: "}"
        ;;
      *)
        die "unexpected patch line: $line"
        ;;
    esac
  done
  die "missing *** End Patch"
}

main "$@"
`;

const remoteGlobSource = String.raw`#!/usr/bin/env python3
import argparse
import glob
import os
import sys


def main():
    parser = argparse.ArgumentParser(description="remote glob helper for UniDesk ssh passthrough")
    parser.add_argument("patterns", nargs="*", help="glob patterns relative to --root unless absolute")
    parser.add_argument("--root", default=".", help="base directory for relative patterns")
    parser.add_argument("--pattern", action="append", default=[], help="additional glob pattern")
    parser.add_argument("--contains", action="append", default=[], help="match path names containing text")
    parser.add_argument("--icontains", action="append", default=[], help="case-insensitive contains match")
    parser.add_argument("--type", choices=["any", "f", "d"], default="any", help="filter by any/file/dir")
    parser.add_argument("--limit", type=int, default=0, help="maximum number of rows to print")
    parser.add_argument("--sort", action="store_true", help="sort output")
    parser.add_argument("--absolute", action="store_true", help="print absolute paths")
    args = parser.parse_args()

    if args.limit < 0:
        print("glob: --limit must be >= 0", file=sys.stderr)
        return 2

    root = os.path.abspath(args.root)
    patterns = list(args.patterns) + list(args.pattern)
    for text in args.contains:
        patterns.append(f"**/*{text}*")
    for text in args.icontains:
        # Python glob is case-sensitive on Linux, so filter from a broad recursive scan.
        patterns.append("**/*")
    if not patterns:
        patterns = ["*"]

    seen = set()
    rows = []
    lowered_contains = [text.lower() for text in args.icontains]
    for pattern in patterns:
        effective = pattern if os.path.isabs(pattern) else os.path.join(root, pattern)
        for path in glob.iglob(effective, recursive=True):
            full = os.path.abspath(path)
            if full in seen:
                continue
            if lowered_contains and not any(text in os.path.basename(full).lower() or text in full.lower() for text in lowered_contains):
                continue
            if args.type == "f" and not os.path.isfile(full):
                continue
            if args.type == "d" and not os.path.isdir(full):
                continue
            seen.add(full)
            rows.append(full if args.absolute else os.path.relpath(full, root))

    if args.sort:
        rows.sort()
    if args.limit > 0:
        rows = rows[:args.limit]
    for row in rows:
        print(row)
    return 0


if __name__ == "__main__":
    raise SystemExit(main())
`;

const remoteSkillDiscoverSource = String.raw`#!/usr/bin/env python3
import argparse
import getpass
import json
import os
import platform
import socket
import sys
from datetime import datetime, timezone
from pathlib import Path


SKIP_PARTS = {"node_modules", ".git", ".state", "logs", "references", "__pycache__"}


def is_wsl():
    try:
        release = Path("/proc/sys/kernel/osrelease").read_text(errors="ignore").lower()
    except Exception:
        release = ""
    return "microsoft" in release or "wsl" in release or "WSL_INTEROP" in os.environ


def to_windows_path(path):
    text = str(path)
    if text.startswith("/mnt/") and len(text) >= 7 and text[5].isalpha() and text[6] == "/":
        drive = text[5].upper()
        rest = text[7:].replace("/", "\\")
        return drive + ":\\" + rest
    return None


def read_bounded(path, limit=16384):
    try:
        data = path.read_bytes()[:limit]
        return data.decode("utf-8", errors="replace")
    except Exception:
        return ""


def frontmatter_value(line):
    if ":" not in line:
        return None
    key, value = line.split(":", 1)
    return key.strip().lower(), value.strip().strip("\"'")


def parse_skill_metadata(skill_md):
    text = read_bounded(skill_md)
    name = skill_md.parent.name
    description = ""
    lines = text.splitlines()
    if lines and lines[0].strip() == "---":
        for line in lines[1:]:
            if line.strip() == "---":
                break
            item = frontmatter_value(line)
            if item is None:
                continue
            key, value = item
            if key == "name" and value:
                name = value
            if key == "description" and value:
                description = value
    if not description:
        for line in lines:
            stripped = line.strip()
            if stripped and not stripped.startswith("---") and not stripped.startswith("#"):
                description = stripped
                break
    return name, description


def iter_skill_files(root, max_depth):
    try:
        iterator = root.rglob("SKILL.md")
        for skill_md in iterator:
            try:
                rel = skill_md.relative_to(root)
            except ValueError:
                continue
            directory_parts = rel.parts[:-1]
            if len(directory_parts) == 0 or len(directory_parts) > max_depth:
                continue
            if any(part in SKIP_PARTS for part in directory_parts):
                continue
            yield skill_md
    except Exception as exc:
        raise RuntimeError(str(exc)) from exc


def unique_paths(paths):
    seen = set()
    output = []
    for raw in paths:
        path = Path(raw).expanduser()
        key = str(path)
        if key in seen:
            continue
        seen.add(key)
        output.append(path)
    return output


def default_wsl_roots():
    home = Path.home()
    roots = [home / ".agents" / "skills", home / ".codex" / "skills"]
    for raw in ("/root/.agents/skills", "/root/.codex/skills"):
        path = Path(raw)
        if str(path) not in {str(item) for item in roots}:
            roots.append(path)
    return roots


def default_windows_roots():
    if not is_wsl():
        return []
    users = Path("/mnt/c/Users")
    roots = []
    try:
        children = list(users.iterdir()) if users.exists() else []
    except Exception:
        children = []
    for child in children:
        try:
            if not child.is_dir():
                continue
        except Exception:
            continue
        lower = child.name.lower()
        if lower in {"all users", "default", "default user", "public"}:
            continue
        roots.append(child / ".agents" / "skills")
        roots.append(child / ".codex" / "skills")
    return roots


def scan_root(scope, root, max_depth):
    try:
        root_exists = root.exists()
        root_error = None
    except Exception as exc:
        root_exists = False
        root_error = str(exc)
    record = {
        "scope": scope,
        "path": str(root),
        "windowsPath": to_windows_path(root),
        "exists": root_exists,
        "skillCount": 0,
        "error": root_error,
    }
    skills = []
    if not record["exists"]:
        return record, skills
    try:
        for skill_md in iter_skill_files(root, max_depth):
            name, description = parse_skill_metadata(skill_md)
            skill = {
                "scope": scope,
                "name": name,
                "description": description,
                "path": str(skill_md.parent),
                "skillMd": str(skill_md),
                "windowsPath": to_windows_path(skill_md.parent),
                "root": str(root),
            }
            skills.append(skill)
    except Exception as exc:
        record["error"] = str(exc)
    record["skillCount"] = len(skills)
    return record, skills


def main():
    parser = argparse.ArgumentParser(description="discover WSL/Linux and Windows skill directories from a UniDesk ssh passthrough session")
    parser.add_argument("--scope", choices=["all", "wsl", "windows"], default="all", help="which skill roots to scan")
    parser.add_argument("--max-depth", type=int, default=4, help="maximum directory depth below each skill root")
    parser.add_argument("--limit", type=int, default=0, help="maximum skill rows to return; 0 means unlimited")
    parser.add_argument("--root", action="append", default=[], help="extra WSL/Linux skill root")
    parser.add_argument("--windows-root", action="append", default=[], help="extra Windows skill root, expressed as /mnt/<drive>/...")
    args = parser.parse_args()

    if args.max_depth <= 0:
        print(json.dumps({"ok": False, "error": "--max-depth must be positive"}, ensure_ascii=False))
        return 2
    if args.limit < 0:
        print(json.dumps({"ok": False, "error": "--limit must be >= 0"}, ensure_ascii=False))
        return 2

    roots = []
    if args.scope in ("all", "wsl"):
        roots.extend(("wsl", path) for path in default_wsl_roots())
        roots.extend(("wsl", Path(raw).expanduser()) for raw in args.root)
    if args.scope in ("all", "windows"):
        roots.extend(("windows", path) for path in default_windows_roots())
        roots.extend(("windows", Path(raw).expanduser()) for raw in args.windows_root)

    seen = set()
    unique = []
    for scope, path in roots:
        key = (scope, str(path))
        if key in seen:
            continue
        seen.add(key)
        unique.append((scope, path))

    root_records = []
    skills = []
    for scope, root in unique:
        record, found = scan_root(scope, root, args.max_depth)
        root_records.append(record)
        skills.extend(found)

    scope_order = {"wsl": 0, "windows": 1}
    skills.sort(key=lambda item: (scope_order.get(str(item["scope"]), 9), str(item["name"]).lower(), str(item["path"])))
    total_before_limit = len(skills)
    if args.limit > 0:
        skills = skills[:args.limit]

    counts = {"total": len(skills), "totalBeforeLimit": total_before_limit, "wsl": 0, "windows": 0}
    for skill in skills:
        scope = str(skill["scope"])
        if scope in counts:
            counts[scope] += 1

    payload = {
        "ok": True,
        "command": "unidesk ssh skills",
        "generatedAt": datetime.now(timezone.utc).isoformat(),
        "node": {
            "hostname": socket.gethostname(),
            "user": getpass.getuser(),
            "home": str(Path.home()),
            "platform": platform.platform(),
            "isWsl": is_wsl(),
            "python": sys.version.split()[0],
        },
        "counts": counts,
        "roots": root_records,
        "skills": skills,
    }
    print(json.dumps(payload, ensure_ascii=False, indent=2))
    return 0


if __name__ == "__main__":
    raise SystemExit(main())
`;

const sshOptionsWithValue = new Set([
  "-B", "-b", "-c", "-D", "-E", "-e", "-F", "-I", "-i", "-J", "-L", "-l", "-m", "-O", "-o", "-p", "-Q", "-R", "-S", "-W", "-w",
]);

export function isSshSkillDiscoveryArgs(args: string[]): boolean {
  const subcommand = args[0] ?? "";
  return subcommand === "skills" || subcommand === "skill-discover" || subcommand === "discover-skills" || (subcommand === "skill" && args[1] === "discover");
}

export function parseSshArgs(args: string[]): ParsedSshArgs {
  const subcommand = args[0] ?? "";
  if (isSshFileTransferOperation(args)) {
    return { remoteCommand: null, requiresStdin: false, invocationKind: "helper" };
  }
  if (isSshSkillDiscoveryArgs(args)) {
    const toolArgs = subcommand === "skill" ? ["skill-discover", ...args.slice(2)] : ["skill-discover", ...args.slice(1)];
    return { remoteCommand: shellArgv(toolArgs), requiresStdin: false, invocationKind: "helper", requiredHelpers: ["skill-discover"] };
  }
  if (subcommand === "apply-patch") {
    if (isApplyPatchV2HelpArgs(args.slice(1))) {
      return { remoteCommand: null, requiresStdin: false, invocationKind: "helper" };
    }
    return { remoteCommand: null, requiresStdin: true, invocationKind: "helper" };
  }
  if (subcommand === "apply-patch-v1") {
    const toolArgs = ["apply_patch", ...args.slice(1)];
    return { remoteCommand: shellArgv(toolArgs), requiresStdin: true, invocationKind: "helper", requiredHelpers: ["apply_patch"] };
  }
  if (subcommand === "patch" || subcommand === "patch-v1" || subcommand === "v2") {
    throw new Error("remote patch entrypoints are `apply-patch` for the default v2 engine and `apply-patch-v1` for the legacy helper");
  }
  if (subcommand === "py") {
    return { remoteCommand: buildPythonStdinCommand(args.slice(1)), requiresStdin: true, invocationKind: "helper" };
  }
  if (subcommand === "script" || subcommand === "sh") {
    return buildShellCommand(args.slice(1));
  }
  if (subcommand === "shell") {
    return buildShellStringCommand(args.slice(1));
  }
  if (subcommand === "argv" || subcommand === "exec") {
    const toolArgs = args.slice(1);
    if (toolArgs.length === 0) throw new Error(`ssh ${subcommand} requires a command`);
    validateDirectArgvCommand(subcommand, toolArgs);
    return { remoteCommand: shellArgv(toolArgs), requiresStdin: false, invocationKind: "argv" };
  }
  if (subcommand === "find") {
    return { remoteCommand: buildFindCommand(args.slice(1)), requiresStdin: false, invocationKind: "helper" };
  }
  if (subcommand === "glob") {
    return { remoteCommand: shellArgv(["glob", ...args.slice(1)]), requiresStdin: false, invocationKind: "helper", requiredHelpers: ["glob"] };
  }
  if (subcommand === "k3s") {
    throw new Error("ssh k3s shorthand is unsupported; put k3s in the route, for example: trans D601:k3s kubectl get nodes");
  }
  if (argvQuotedSshSubcommands.has(subcommand)) {
    return { remoteCommand: shellArgv(args), requiresStdin: false, invocationKind: "argv" };
  }
  const remote: string[] = [];
  let remoteStarted = false;
  for (let index = 0; index < args.length; index += 1) {
    const arg = args[index] ?? "";
    if (remoteStarted) {
      remote.push(arg);
      continue;
    }
    if (arg === "--") {
      remoteStarted = true;
      continue;
    }
    if (arg.startsWith("-") && arg !== "-") {
      if (sshOptionsWithValue.has(arg) && index + 1 < args.length) index += 1;
      continue;
    }
    remoteStarted = true;
    remote.push(arg);
  }
  return {
    remoteCommand: remote.length === 0 ? null : remote.join(" "),
    requiresStdin: false,
    invocationKind: remote.length === 0 ? "interactive" : "ssh-like",
  };
}

export function normalizeSshOperationArgs(args: string[]): string[] {
  return args[0] === "--" ? args.slice(1) : args;
}

export function sshRouteSeparatorCompatibilityHint(rawArgs: string[], normalizedArgs: string[]): string {
  if (rawArgs === normalizedArgs || rawArgs[0] !== "--") return "";
  const operation = normalizedArgs[0] ?? "";
  const operationText = operation.length === 0 ? "operation" : `operation \`${operation}\``;
  return `UNIDESK_SSH_HINT route-level -- is ignored before ${operationText}; canonical form is \`trans <route> ${normalizedArgs.join(" ")}\`. Keep -- only inside operations such as \`script -- <command>\` or \`exec -- <command>\`.\n`;
}

function validateDirectArgvCommand(commandName: string, toolArgs: string[]): void {
  if (toolArgs.length !== 1) return;
  const command = toolArgs[0] ?? "";
  if (!looksLikeShellCommandString(command)) return;
  throw new Error(
    `ssh ${commandName} received one shell-like command string; ${commandName} executes a single process and treats that string as the executable path. ` +
    `Use \`trans <route> script -- ${shellQuote(command)}\` for one-line shell logic, or split argv tokens, for example \`trans <route> ${commandName} ls -la\`.`
  );
}

function looksLikeShellCommandString(value: string): boolean {
  return /\s/u.test(value) || /&&|\|\||[;|<>]/u.test(value);
}

export function parseSshInvocation(target: string, args: string[]): ParsedSshInvocation {
  const route = parseSshRoute(target);
  const operationArgs = normalizeSshOperationArgs(args);
  if (route.plane === "k3s") {
    return { providerId: route.providerId, route, parsed: parseK3sRouteArgs(route, operationArgs) };
  }
  if (route.plane === "win") {
    return { providerId: route.providerId, route, parsed: parseWinRouteArgs(route, operationArgs) };
  }
  if ((operationArgs[0] ?? "") === "k3s") {
    throw new Error(`ssh k3s shorthand is unsupported; use route syntax instead: trans ${route.providerId}:k3s ${operationArgs.slice(1).join(" ")}`.trim());
  }
  return { providerId: route.providerId, route, parsed: parseSshArgs(operationArgs) };
}

export function parseSshRoute(target: string): ParsedSshRoute {
  if (!target) throw new Error("ssh requires provider id, for example: trans D601");
  const firstColon = target.indexOf(":");
  if (firstColon < 0) {
    return hostSshRoute(target, target, null);
  }
  const providerId = target.slice(0, firstColon);
  const tail = target.slice(firstColon + 1);
  if (!providerId) throw new Error("ssh route requires a provider id before ':'");
  if (tail.length === 0) {
    return hostSshRoute(providerId, target, null);
  }
  if (tail.startsWith("/")) {
    return hostSshRoute(providerId, target, tail);
  }
  if (tail === "win32" || tail.startsWith("win32/") || tail.startsWith("win32:")) {
    throw new Error(`unsupported ssh route plane: win32; use ${providerId}:win or ${providerId}:win/c/path`);
  }
  if (tail === "win" || tail.startsWith("win/")) {
    return winSshRoute(providerId, target, parseWinRouteWorkspace(providerId, tail));
  }
  if (tail.startsWith("win:")) {
    throw new Error(`ssh win workspace route uses slash syntax, for example: trans ${providerId}:win/c/test cmd cd`);
  }
  const [plane, ...rest] = tail.split(":");
  if (plane === undefined || plane.length === 0 || plane === "host") {
    const workspace = rest.length > 0 ? rest.join(":") : null;
    if (workspace !== null && !workspace.startsWith("/")) throw new Error("ssh host workspace route requires an absolute path after provider:host:");
    return hostSshRoute(providerId, target, workspace);
  }
  if (plane !== "k3s") throw new Error(`unsupported ssh route plane: ${plane}`);
  const normalizedRest = normalizeK3sRouteRestSegments(rest);
  const [first, second, third, fourth] = normalizedRest;
  const operationInRoute = [first, second, third].map((segment) => segment === undefined ? undefined : routeSegmentHead(segment)).find((segment) => segment !== undefined && legacyK3sOperationRouteSegments.has(segment));
  if (operationInRoute !== undefined) throw new Error(k3sOperationInRouteMessage(target, operationInRoute));
  if (fourth !== undefined) throw new Error("ssh k3s target route supports at most provider:k3s:namespace:resource:container");
  const targetRoute = parseK3sRouteTargetSegments(second ?? null, third ?? null);
  return {
    providerId,
    plane: "k3s",
    entry: null,
    namespace: first && first.length > 0 ? first : null,
    resource: targetRoute.resource,
    container: targetRoute.container,
    workspace: targetRoute.workspace,
    raw: target,
  };
}

function hostSshRoute(providerId: string, raw: string, workspace: string | null): ParsedSshRoute {
  return { providerId, plane: "host", entry: null, namespace: null, resource: null, container: null, workspace, raw };
}

function winSshRoute(providerId: string, raw: string, workspace: string | null): ParsedSshRoute {
  return { providerId, plane: "win", entry: null, namespace: null, resource: null, container: null, workspace, raw };
}

function parseWinRouteWorkspace(providerId: string, tail: string): string | null {
  if (tail === "win") return null;
  const suffix = tail.slice("win/".length);
  const slashIndex = suffix.indexOf("/");
  const drive = slashIndex < 0 ? suffix : suffix.slice(0, slashIndex);
  if (!/^[A-Za-z]$/u.test(drive)) {
    throw new Error(`ssh win workspace route requires a drive letter, for example: ssh ${providerId}:win/c/test cmd cd`);
  }
  const rest = slashIndex < 0 ? "" : suffix.slice(slashIndex + 1);
  const segments = rest.split("/").filter((segment) => segment.length > 0);
  return `${drive.toUpperCase()}:\\${segments.join("\\")}`;
}

function parseWinRouteArgs(route: ParsedSshRoute, args: string[]): ParsedSshArgs {
  const operation = args[0] ?? "";
  if (operation.length === 0) {
    throw new Error(`ssh ${route.raw} requires a Windows operation, for example: ssh ${route.providerId}:win cmd ver or ssh ${route.providerId}:win skills`);
  }
  if (operation === "upload" || operation === "download") {
    return { remoteCommand: null, requiresStdin: false, invocationKind: "helper" };
  }
  if (operation === "apply-patch") {
    if (isApplyPatchV2HelpArgs(args.slice(1))) {
      return { remoteCommand: null, requiresStdin: false, invocationKind: "helper" };
    }
    return { remoteCommand: null, requiresStdin: true, invocationKind: "helper" };
  }
  if (operation === "apply-patch-v1") {
    throw new Error(`ssh ${route.raw} apply-patch-v1 is not supported for Windows routes; use apply-patch v2`);
  }
  if (operation === "patch" || operation === "patch-v1" || operation === "v2") {
    throw new Error("remote patch entrypoints are `apply-patch` for the default v2 engine and `apply-patch-v1` for the legacy helper");
  }
  if (operation === "skills" || operation === "skill-discover" || operation === "discover-skills") {
    return {
      remoteCommand: buildWindowsPowerShellInvocation(buildWindowsSkillsDiscoveryScript(args.slice(1))),
      requiresStdin: false,
      invocationKind: "helper",
    };
  }
  if (operation === "ps" || operation === "powershell" || operation === "powershell.exe") {
    const commandArgs = args[1] === "--" ? args.slice(2) : args.slice(1);
    if (commandArgs.length >= 2 && (commandArgs[0] === "-File" || commandArgs[0] === "-file")) {
      const fileArgs = commandArgs.slice(1).map((a: string) => a.replace(/\\/g, "/")).join(" ");
      return {
        remoteCommand: buildWindowsPowerShellInvocation(buildWindowsPowerShellInlineLauncherScript("& " + fileArgs, route.workspace)),
        requiresStdin: false,
        invocationKind: "helper",
      };
    }
    if (commandArgs.length === 0) {
      return {
        remoteCommand: buildWindowsPowerShellInvocation(buildWindowsPowerShellStdinLauncherScript(route.workspace)),
        requiresStdin: true,
        invocationKind: "helper",
      };
    }
    return {
      remoteCommand: buildWindowsPowerShellInvocation(buildWindowsPowerShellInlineLauncherScript(commandArgs.join(" "), route.workspace)),
      requiresStdin: false,
      invocationKind: "helper",
    };
  }
  if (operation !== "cmd" && operation !== "cmd.exe") {
    throw new Error(`unsupported ssh win operation: ${operation}; use ssh ${route.providerId}:win ps, ssh ${route.providerId}:win cmd <command-line>, ssh ${route.providerId}:win apply-patch, or ssh ${route.providerId}:win skills`);
  }
  const commandArgs = args[1] === "--" ? args.slice(2) : args.slice(1);
  if (commandArgs.length === 0) {
    return {
      remoteCommand: buildWindowsPowerShellInvocation(buildWindowsCmdStdinLauncherScript(route.workspace)),
      requiresStdin: true,
      invocationKind: "helper",
    };
  }
  return {
    remoteCommand: buildWindowsPowerShellInvocation(buildWindowsCmdLauncherScript(buildWindowsCmdLine(commandArgs.join(" "), route.workspace))),
    requiresStdin: false,
    invocationKind: "argv",
  };
}

function buildWindowsCmdLine(userCommand: string, cwd: string | null): string {
  const parts = [
    "chcp 65001>nul",
    'set "PYTHONUTF8=1"',
    'set "PYTHONIOENCODING=utf-8"',
  ];
  if (cwd !== null) parts.push(`cd /d ${windowsCmdQuote(cwd)}`);
  parts.push(userCommand);
  return parts.join(" && ");
}

function windowsCmdQuote(value: string): string {
  if (/[\r\n"]/u.test(value)) throw new Error("ssh win workspace path must not contain quotes or newlines");
  return `"${value}"`;
}

function parseWindowsSkillsOptions(args: string[]): { limit: number; scopes: Array<"agents" | "codex"> } {
  let limit = 100;
  let scope: "agents" | "codex" | "all" = "agents";
  for (let index = 0; index < args.length; index += 1) {
    const arg = args[index] ?? "";
    if (arg === "--limit") {
      const value = args[index + 1];
      if (value === undefined) throw new Error("ssh win skills --limit requires a value");
      limit = positiveInt(value, "ssh win skills --limit");
      index += 1;
      continue;
    }
    if (arg === "--scope") {
      const value = args[index + 1];
      if (value === undefined) throw new Error("ssh win skills --scope requires a value");
      if (value !== "agents" && value !== "codex" && value !== "all") throw new Error("ssh win skills --scope must be one of: agents, codex, all");
      scope = value;
      index += 1;
      continue;
    }
    if (arg === "--all") {
      scope = "all";
      continue;
    }
    throw new Error(`unsupported ssh win skills option: ${arg}`);
  }
  return { limit, scopes: scope === "all" ? ["agents", "codex"] : [scope] };
}

function buildWindowsSkillsDiscoveryScript(args: string[]): string {
  const options = parseWindowsSkillsOptions(args);
  const rootEntries = options.scopes.map((scope) => {
    const relative = scope === "agents" ? ".agents\\skills" : ".codex\\skills";
    return `@{ Scope = ${powerShellSingleQuote(scope)}; Path = (Join-Path $env:USERPROFILE ${powerShellSingleQuote(relative)}) }`;
  }).join(", ");
  return [
    "$ErrorActionPreference = 'Stop';",
    "$ProgressPreference = 'SilentlyContinue';",
    "[Console]::InputEncoding = [System.Text.UTF8Encoding]::new();",
    "[Console]::OutputEncoding = [System.Text.UTF8Encoding]::new();",
    "$OutputEncoding = [System.Text.UTF8Encoding]::new();",
    `$limit = ${options.limit};`,
    `$roots = @(${rootEntries});`,
    "$rootRecords = @();",
    "$skills = @();",
    "foreach ($root in $roots) {",
    "  $exists = Test-Path -LiteralPath $root.Path -PathType Container;",
    "  $rootRecords += [pscustomobject]@{ scope = $root.Scope; path = $root.Path; exists = $exists };",
    "  if (-not $exists) { continue };",
    "  foreach ($dir in @(Get-ChildItem -LiteralPath $root.Path -Directory -Force | Sort-Object Name)) {",
    "    if ($skills.Count -ge $limit) { break };",
    "    $skillFile = Join-Path $dir.FullName 'SKILL.md';",
    "    $hasSkillMd = Test-Path -LiteralPath $skillFile -PathType Leaf;",
    "    if (-not $hasSkillMd) { continue };",
    "    $name = $dir.Name;",
    "    $description = '';",
    "    if ($hasSkillMd) {",
    "      foreach ($line in @(Get-Content -LiteralPath $skillFile -Encoding UTF8 -TotalCount 80)) {",
    "        if ($line -match '^name:\\s*(.+)$') { $name = $Matches[1].Trim(); continue };",
    "        if ($line -match '^description:\\s*(.+)$') { $description = $Matches[1].Trim(); continue };",
    "      }",
    "    }",
    "    $skills += [pscustomobject]@{ scope = $root.Scope; name = $name; directoryName = $dir.Name; path = $dir.FullName; skillFile = $skillFile; hasSkillMd = $hasSkillMd; description = $description };",
    "  }",
    "}",
    "$payload = [pscustomobject]@{ ok = $true; command = 'unidesk ssh win skills'; generatedAt = (Get-Date).ToUniversalTime().ToString('o'); user = $env:USERNAME; userProfile = $env:USERPROFILE; counts = [pscustomobject]@{ roots = $rootRecords.Count; skills = $skills.Count; limit = $limit }; roots = $rootRecords; skills = @($skills) };",
    "$payload | ConvertTo-Json -Depth 6;",
  ].join(" ");
}

function powerShellSingleQuote(value: string): string {
  return `'${value.replace(/'/g, "''")}'`;
}

function buildWindowsCmdLauncherScript(cmdLine: string): string {
  return [
    "$ErrorActionPreference = 'Stop';",
    "[Console]::InputEncoding = [System.Text.UTF8Encoding]::new();",
    "[Console]::OutputEncoding = [System.Text.UTF8Encoding]::new();",
    "$OutputEncoding = [System.Text.UTF8Encoding]::new();",
    "$env:PYTHONUTF8 = '1';",
    "$env:PYTHONIOENCODING = 'utf-8';",
    `& ${powerShellSingleQuote(windowsCmdExeNativePath)} /d /s /c ${powerShellSingleQuote(cmdLine)};`,
    "exit $LASTEXITCODE;",
  ].join(" ");
}

function buildWindowsCmdStdinLauncherScript(cwd: string | null): string {
  const prefixLines = [
    "@echo off",
    "chcp 65001>nul",
    'set "PYTHONUTF8=1"',
    'set "PYTHONIOENCODING=utf-8"',
    ...(cwd === null ? [] : [`cd /d ${windowsCmdQuote(cwd)}`]),
  ];
  return [
    "$ErrorActionPreference = 'Stop';",
    "$ProgressPreference = 'SilentlyContinue';",
    "[Console]::InputEncoding = [System.Text.UTF8Encoding]::new();",
    "[Console]::OutputEncoding = [System.Text.UTF8Encoding]::new();",
    "$OutputEncoding = [System.Text.UTF8Encoding]::new();",
    "$env:PYTHONUTF8 = '1';",
    "$env:PYTHONIOENCODING = 'utf-8';",
    "$script = [Console]::In.ReadToEnd();",
    "$script = $script -replace \"`r`n\", \"`n\";",
    "$script = $script -replace \"`r\", \"`n\";",
    "$script = $script -replace \"`n\", \"`r`n\";",
    "if (-not $script.EndsWith(\"`r`n\")) { $script += \"`r`n\" }",
    "if ([string]::IsNullOrWhiteSpace($script)) { [Console]::Error.WriteLine('ssh win cmd requires a command line or stdin batch script'); exit 2 }",
    `$prefix = ${powerShellSingleQuote(`${prefixLines.join("\r\n")}\r\n`)};`,
    "$temp = [System.IO.Path]::Combine([System.IO.Path]::GetTempPath(), ('unidesk-win-cmd-' + [guid]::NewGuid().ToString('N') + '.cmd'));",
    "try {",
    "  [System.IO.File]::WriteAllText($temp, $prefix + $script, [System.Text.UTF8Encoding]::new($false));",
    "  $cmdArg = '\"' + $temp + '\"';",
    `  & ${powerShellSingleQuote(windowsCmdExeNativePath)} /d /s /c $cmdArg;`,
    "  $code = $LASTEXITCODE;",
    "} finally {",
    "  Remove-Item -LiteralPath $temp -Force -ErrorAction SilentlyContinue;",
    "}",
    "exit $code;",
  ].join(" ");
}

const windowsPowerShellJsonSafetyPreludeLines = [
  "function ConvertTo-UniDeskPlainJsonValue {",
  "  param([object]$Value, [int]$Depth = 6, [int]$Level = 0)",
  "  if ($null -eq $Value) { return $null }",
  "  if ($Value -is [string]) { return [string]$Value }",
  "  if ($Value -is [char]) { return [string]$Value }",
  "  if ($Value -is [bool] -or $Value -is [byte] -or $Value -is [sbyte] -or $Value -is [int16] -or $Value -is [uint16] -or $Value -is [int] -or $Value -is [uint32] -or $Value -is [long] -or $Value -is [uint64] -or $Value -is [single] -or $Value -is [double] -or $Value -is [decimal]) { return $Value }",
  "  if ($Value -is [datetime]) { return $Value.ToUniversalTime().ToString('o') }",
  "  if ($Level -ge $Depth) { return [string]$Value }",
  "  if ($Value -is [System.Collections.IDictionary]) {",
  "    $map = [ordered]@{}",
  "    foreach ($key in $Value.Keys) { $map[[string]$key] = ConvertTo-UniDeskPlainJsonValue -Value $Value[$key] -Depth $Depth -Level ($Level + 1) }",
  "    return $map",
  "  }",
  "  if ($Value -is [System.Collections.IEnumerable] -and -not ($Value -is [string])) {",
  "    $items = New-Object System.Collections.ArrayList",
  "    foreach ($item in $Value) { [void]$items.Add((ConvertTo-UniDeskPlainJsonValue -Value $item -Depth $Depth -Level ($Level + 1))) }",
  "    return $items.ToArray()",
  "  }",
  "  $skip = @('PSPath','PSParentPath','PSChildName','PSDrive','PSProvider','ReadCount')",
  "  $props = @($Value.PSObject.Properties | Where-Object { @('NoteProperty','Property','AliasProperty') -contains $_.MemberType.ToString() -and -not ($skip -contains $_.Name) })",
  "  if ($props.Count -eq 0) { return [string]$Value }",
  "  $out = [ordered]@{}",
  "  foreach ($prop in $props) {",
  "    try { $out[$prop.Name] = ConvertTo-UniDeskPlainJsonValue -Value $prop.Value -Depth $Depth -Level ($Level + 1) }",
  "    catch { $out[$prop.Name] = '<unreadable>' }",
  "  }",
  "  return $out",
  "}",
  "function ConvertTo-Json {",
  "  [CmdletBinding()]",
  "  param(",
  "    [Parameter(ValueFromPipeline=$true)] [object]$InputObject,",
  "    [int]$Depth = 2,",
  "    [switch]$Compress,",
  "    [switch]$EnumsAsStrings",
  "  )",
  "  begin { $items = New-Object System.Collections.ArrayList }",
  "  process { [void]$items.Add($InputObject) }",
  "  end {",
  "    if ($items.Count -eq 0) { $value = $null } elseif ($items.Count -eq 1) { $value = $items[0] } else { $value = $items.ToArray() }",
  "    $plain = ConvertTo-UniDeskPlainJsonValue -Value $value -Depth $Depth -Level 0",
  "    if ($Compress) {",
  "      Microsoft.PowerShell.Utility\\ConvertTo-Json -InputObject $plain -Depth $Depth -Compress",
  "    } else {",
  "      Microsoft.PowerShell.Utility\\ConvertTo-Json -InputObject $plain -Depth $Depth",
  "    }",
  "  }",
  "}",
];

export function windowsPowerShellScriptPrelude(cwd: string | null): string {
  return [
    "$ErrorActionPreference = 'Stop'",
    "$ProgressPreference = 'SilentlyContinue'",
    "[Console]::InputEncoding = [System.Text.UTF8Encoding]::new()",
    "[Console]::OutputEncoding = [System.Text.UTF8Encoding]::new()",
    "$OutputEncoding = [System.Text.UTF8Encoding]::new()",
    "$env:PYTHONUTF8 = '1'",
    "$env:PYTHONIOENCODING = 'utf-8'",
    ...windowsPowerShellJsonSafetyPreludeLines,
    ...(cwd === null ? [] : [`Set-Location -LiteralPath ${powerShellSingleQuote(cwd)}`]),
  ].join("\r\n") + "\r\n";
}

function buildWindowsPowerShellInlineLauncherScript(command: string, cwd: string | null): string {
  if (command.trim().length === 0) throw new Error("ssh win ps requires a command or stdin PowerShell script");
  return buildWindowsPowerShellScriptRunner(powerShellSingleQuote(command), cwd);
}

function buildWindowsPowerShellStdinLauncherScript(cwd: string | null): string {
  return buildWindowsPowerShellScriptRunner("[Console]::In.ReadToEnd()", cwd);
}

function buildWindowsPowerShellScriptRunner(scriptExpression: string, cwd: string | null): string {
  return [
    "$ErrorActionPreference = 'Stop';",
    "$ProgressPreference = 'SilentlyContinue';",
    "[Console]::InputEncoding = [System.Text.UTF8Encoding]::new();",
    "[Console]::OutputEncoding = [System.Text.UTF8Encoding]::new();",
    "$OutputEncoding = [System.Text.UTF8Encoding]::new();",
    `$script = ${scriptExpression};`,
    "$script = $script -replace \"`r`n\", \"`n\";",
    "$script = $script -replace \"`r\", \"`n\";",
    "$script = $script -replace \"`n\", \"`r`n\";",
    "if (-not $script.EndsWith(\"`r`n\")) { $script += \"`r`n\" }",
    "if ([string]::IsNullOrWhiteSpace($script)) { [Console]::Error.WriteLine('ssh win ps requires a command or stdin PowerShell script'); exit 2 }",
    "$script += \"`r`nif (`$global:LASTEXITCODE -is [int] -and `$global:LASTEXITCODE -ne 0) { exit `$global:LASTEXITCODE }`r`n\";",
    `$prefix = ${powerShellSingleQuote(windowsPowerShellScriptPrelude(cwd))};`,
    "$temp = [System.IO.Path]::Combine([System.IO.Path]::GetTempPath(), ('unidesk-win-ps-' + [guid]::NewGuid().ToString('N') + '.ps1'));",
    "try {",
    "  [System.IO.File]::WriteAllText($temp, $prefix + $script, [System.Text.UTF8Encoding]::new($true));",
    "  & (Join-Path $PSHOME 'powershell.exe') -NoProfile -ExecutionPolicy Bypass -File $temp;",
    "  $code = $LASTEXITCODE;",
    "  if ($null -eq $code) { $code = 0 }",
    "} finally {",
    "  Remove-Item -LiteralPath $temp -Force -ErrorAction SilentlyContinue;",
    "}",
    "exit $code;",
  ].join(" ");
}

export function buildWindowsPowerShellInvocation(script: string): string {
  return shellArgv([
    windowsPowerShellExePath,
    "-NoProfile",
    "-ExecutionPolicy",
    "Bypass",
    "-EncodedCommand",
    Buffer.from(script, "utf16le").toString("base64"),
  ]);
}

export function sshRoutePayloadCwd(route: ParsedSshRoute): string | undefined {
  if (route.plane === "host") return route.workspace ?? undefined;
  if (route.plane === "win") return windowsBridgeCwd;
  return undefined;
}

function routeSegmentHead(segment: string): string {
  return segment.split("/")[0] ?? segment;
}

function parseK3sRouteTargetSegments(rawResource: string | null, rawContainer: string | null): { resource: string | null; container: string | null; workspace: string | null } {
  const resourceParts = splitK3sResourceWorkspace(rawResource);
  const containerParts = splitK3sContainerWorkspace(rawContainer);
  return {
    resource: resourceParts.resource,
    container: containerParts.container,
    workspace: combineK3sRouteWorkspace(resourceParts.workspace, containerParts.workspace),
  };
}

function normalizeK3sRouteRestSegments(rest: string[]): string[] {
  const normalized: string[] = [];
  for (let index = 0; index < rest.length; index += 1) {
    const current = rest[index] ?? "";
    const podPrefix = k3sPodRoutePrefixes.find((prefix) => current === prefix.slice(0, -1) || current.startsWith(prefix));
    if (podPrefix === undefined) {
      normalized.push(current);
      continue;
    }
    if (current === podPrefix.slice(0, -1)) {
      const next = rest[index + 1];
      if (next === undefined || next.length === 0) throw new Error("ssh k3s pod: route requires a pod name after pod:");
      normalized.push(`pod/${next}`);
      index += 1;
      continue;
    }
    const podName = current.slice(podPrefix.length);
    if (podName.length === 0) throw new Error("ssh k3s pod: route requires a pod name after pod:");
    normalized.push(`pod/${podName}`);
  }
  return normalized;
}

function splitK3sResourceWorkspace(value: string | null): { resource: string | null; workspace: string | null } {
  if (value === null || value.length === 0) return { resource: null, workspace: null };
  const parts = value.split("/");
  if (parts.length <= 1) return { resource: value, workspace: null };
  if (isK3sResourceKindAlias(parts[0] ?? "") && (parts[1] ?? "").length > 0) {
    const workspaceParts = parts.slice(2);
    return {
      resource: `${parts[0]}/${parts[1]}`,
      workspace: workspaceParts.length > 0 ? `/${workspaceParts.join("/")}` : null,
    };
  }
  return {
    resource: parts[0] ?? value,
    workspace: parts.length > 1 ? `/${parts.slice(1).join("/")}` : null,
  };
}

function splitK3sContainerWorkspace(value: string | null): { container: string | null; workspace: string | null } {
  if (value === null || value.length === 0) return { container: null, workspace: null };
  const parts = value.split("/");
  if (parts.length <= 1) return { container: value, workspace: null };
  return { container: parts[0] ?? value, workspace: `/${parts.slice(1).join("/")}` };
}

function combineK3sRouteWorkspace(first: string | null, second: string | null): string | null {
  if (first !== null && second !== null && first !== second) throw new Error("ssh k3s route workspace can be specified once, either after the workload or after the container");
  return first ?? second;
}

function isK3sResourceKindAlias(value: string): boolean {
  return k3sResourceKindAliases.has(value);
}

function k3sOperationInRouteMessage(target: string, operation: string): string {
  const providerId = target.split(":")[0] || "<provider>";
  if (operation === "v2" || operation === "patch" || operation === "patch-v1") {
    return `ssh k3s route must locate a target only; remote patch entrypoints are "apply-patch" for the default v2 engine and "apply-patch-v1" for the legacy helper instead of "${target}"`;
  }
  const operationExample = operation === "guard" ? "guard" : `${operation} ...`;
  return `ssh k3s route must locate a target only; put operation "${operation}" after the route, for example "ssh ${providerId}:k3s ${operationExample}" or "ssh ${providerId}:k3s:<namespace>:<workload> ${operationExample}" instead of "${target}"`;
}

export function shellArgv(args: string[]): string {
  return args.map(shellQuote).join(" ");
}

export function shellQuote(value: string): string {
  return `'${value.replace(/'/g, `'\\''`)}'`;
}

function positiveInt(value: string, option: string): number {
  const parsed = Number(value);
  if (!Number.isInteger(parsed) || parsed <= 0) throw new Error(`${option} must be a positive integer`);
  return parsed;
}

function optionalPositiveInt(value: string, option: string): string {
  return String(positiveInt(value, option));
}

function findOptionValue(args: string[], index: number, option: string): string {
  const value = args[index + 1];
  if (value === undefined || value.length === 0) throw new Error(`ssh find ${option} requires a value`);
  return value;
}

function buildFindCommand(args: string[]): string {
  const paths: string[] = [];
  const predicates: string[] = [];
  const patternPredicates: Array<[string, string]> = [];
  let limit: number | null = null;
  let sortOutput = false;

  for (let index = 0; index < args.length; index += 1) {
    const arg = args[index] ?? "";
    if (arg === "--limit") {
      const value = findOptionValue(args, index, arg);
      limit = positiveInt(value, "ssh find --limit");
      index += 1;
      continue;
    }
    if (arg === "--sort") {
      sortOutput = true;
      continue;
    }
    if (arg === "--max-depth" || arg === "-maxdepth" || arg === "--min-depth" || arg === "-mindepth") {
      const value = findOptionValue(args, index, arg);
      const findArg = arg === "--max-depth" ? "-maxdepth" : arg === "--min-depth" ? "-mindepth" : arg;
      predicates.push(findArg, String(positiveInt(value, `ssh find ${arg}`)));
      index += 1;
      continue;
    }
    if (arg === "--type" || arg === "-type") {
      const value = findOptionValue(args, index, arg);
      if (!/^[bcdpfls]$/u.test(value)) throw new Error("ssh find --type must be one of: b c d p f l s");
      predicates.push("-type", value);
      index += 1;
      continue;
    }
    if (arg === "--name" || arg === "-name" || arg === "--iname" || arg === "-iname" || arg === "--path" || arg === "-path" || arg === "--ipath" || arg === "-ipath") {
      const value = findOptionValue(args, index, arg);
      const findArg = arg.startsWith("--") ? `-${arg.slice(2)}` : arg;
      patternPredicates.push([findArg, value]);
      index += 1;
      continue;
    }
    if (arg === "--contains" || arg === "--icontains") {
      const value = findOptionValue(args, index, arg);
      const findArg = arg === "--contains" ? "-name" : "-iname";
      patternPredicates.push([findArg, `*${value}*`]);
      index += 1;
      continue;
    }
    if (arg === "--mtime" || arg === "-mtime" || arg === "--mmin" || arg === "-mmin" || arg === "--size" || arg === "-size") {
      const value = findOptionValue(args, index, arg);
      const findArg = arg.startsWith("--") ? `-${arg.slice(2)}` : arg;
      predicates.push(findArg, value);
      index += 1;
      continue;
    }
    if (arg.startsWith("-")) {
      throw new Error(`unsupported ssh find option: ${arg}`);
    }
    paths.push(arg);
  }

  const findArgs = ["find", ...(paths.length > 0 ? paths : ["."]), ...predicates];
  if (patternPredicates.length === 1) {
    const [kind, pattern] = patternPredicates[0]!;
    findArgs.push(kind, pattern);
  } else if (patternPredicates.length > 1) {
    findArgs.push("(");
    patternPredicates.forEach(([kind, pattern], index) => {
      if (index > 0) findArgs.push("-o");
      findArgs.push(kind, pattern);
    });
    findArgs.push(")");
  }
  findArgs.push("-print");

  let command = shellArgv(findArgs);
  if (sortOutput) command = `${command} | sort`;
  if (limit !== null) command = `${command} | head -n ${limit}`;
  return command;
}

function parseK3sRouteArgs(route: ParsedSshRoute, args: string[]): ParsedSshArgs {
  if (route.entry === null && route.namespace === null && route.resource === null) {
    return parseK3sControlPlaneOperation(route, args);
  }
  if (route.namespace === null || route.resource === null) {
    throw new Error("ssh k3s target route requires provider:k3s:<namespace>:<deployment|pod:pod-name|pod/resource>");
  }
  return parseK3sTargetOperation(route, args);
}

function parseK3sControlPlaneOperation(route: ParsedSshRoute, args: string[]): ParsedSshArgs {
  const operation = args[0] ?? "guard";
  if (operation === "upload" || operation === "download") {
    throw new Error(`ssh ${route.providerId}:k3s ${operation} requires a workload route: ssh ${route.providerId}:k3s:<namespace>:<workload> ${operation} ...`);
  }
  if (operation === "apply-patch" || operation === "apply-patch-v1") {
    throw new Error(`ssh ${route.providerId}:k3s apply-patch requires a workload route: ssh ${route.providerId}:k3s:<namespace>:<workload> apply-patch`);
  }
  if (operation === "patch" || operation === "patch-v1" || operation === "v2") {
    throw new Error("remote patch entrypoints are `apply-patch` for the default v2 engine and `apply-patch-v1` for the legacy helper");
  }
  if (operation === "script" || operation === "sh") {
    return buildK3sScriptOperation(args.slice(1));
  }
  if (operation === "shell") {
    const parsed = parseShellStringOperationArgs(args.slice(1), `ssh ${route.providerId}:k3s shell`);
    return { remoteCommand: shellArgv(["env", `KUBECONFIG=${nativeK3sKubeconfig}`, parsed.shell, "-c", shellScriptWithCompatibility(parsed.command)]), requiresStdin: false, invocationKind: "helper" };
  }
  if (operation === "guard") {
    if (args.length > 1) throw new Error(`ssh ${route.providerId}:k3s guard does not accept extra arguments`);
    return { remoteCommand: buildK3sGuardCommand(route.providerId), requiresStdin: false, invocationKind: "helper" };
  }
  return { remoteCommand: buildK3sCommand(route.providerId, args), requiresStdin: false, invocationKind: "helper" };
}

function parseK3sTargetOperation(route: ParsedSshRoute, args: string[]): ParsedSshArgs {
  const targetArgs = k3sRouteTargetArgs(route);
  if (args.length === 0) {
    return {
      remoteCommand: buildK3sTargetObjectCommand("get", route, ["-o", "wide"]),
      requiresStdin: false,
      invocationKind: "helper",
    };
  }
  const operation = args[0] ?? "";
  const operationArgs = args.slice(1);
  if (operation === "upload" || operation === "download") {
    return { remoteCommand: null, requiresStdin: false, invocationKind: "helper" };
  }
  if (operation === "apply-patch") {
    if (isApplyPatchV2HelpArgs(operationArgs)) {
      return { remoteCommand: null, requiresStdin: false, invocationKind: "helper" };
    }
    return { remoteCommand: null, requiresStdin: true, invocationKind: "helper" };
  }
  if (operation === "apply-patch-v1") return buildK3sApplyPatchCommand([...targetArgs, ...operationArgs]);
  if (operation === "patch" || operation === "patch-v1" || operation === "v2") {
    throw new Error("remote patch entrypoints are `apply-patch` for the default v2 engine and `apply-patch-v1` for the legacy helper");
  }
  if (operation === "script") return buildK3sScriptOperation([...targetArgs, ...operationArgs]);
  if (operation === "shell") {
    const parsed = parseShellStringOperationArgs(operationArgs, `ssh ${route.raw} shell`);
    return { remoteCommand: buildK3sExecCommand([...targetArgs, "--", parsed.shell, "-c", shellScriptWithCompatibility(parsed.command)]), requiresStdin: false, invocationKind: "helper" };
  }
  if (operation === "logs") return { remoteCommand: buildK3sLogsCommand([...targetArgs, ...operationArgs]), requiresStdin: false, invocationKind: "helper" };
  if (operation === "argv") {
    validateDirectArgvCommand(operation, operationArgs);
    return { remoteCommand: buildK3sExecCommand([...targetArgs, ...k3sRouteCommandArgs(operationArgs)]), requiresStdin: false, invocationKind: "argv" };
  }
  if (operation === "get" || operation === "describe") {
    return { remoteCommand: buildK3sTargetObjectCommand(operation, route, operationArgs), requiresStdin: false, invocationKind: "helper" };
  }
  if (operation === "kubectl") throw new Error(`ssh k3s kubectl is a control-plane operation; use ssh ${route.providerId}:k3s kubectl ...`);
  if (operation === "exec") {
    const execArgs = k3sRouteExecOperationArgs(operationArgs);
    return {
      remoteCommand: buildK3sExecCommand([...targetArgs, ...execArgs]),
      requiresStdin: execArgs.includes("--stdin") || execArgs.includes("-i"),
      invocationKind: "helper",
    };
  }
  return { remoteCommand: buildK3sExecCommand([...targetArgs, ...k3sRouteCommandArgs(args)]), requiresStdin: false, invocationKind: "helper" };
}

function buildK3sTargetObjectCommand(action: "get" | "describe", route: ParsedSshRoute, args: string[]): string {
  if (route.namespace === null || route.resource === null) throw new Error(`ssh k3s ${action} target requires namespace and workload route`);
  if (args.includes("--follow") || args.includes("-f")) throw new Error(`ssh k3s target ${action} does not support follow mode`);
  return shellArgv(["env", `KUBECONFIG=${nativeK3sKubeconfig}`, "kubectl", action, "-n", route.namespace, normalizeK3sRouteResource(route.resource), ...args]);
}

function buildK3sTargetCommand(route: ParsedSshRoute, command: string[], options: { stdin?: boolean } = {}): string {
  return buildK3sExecCommand([...k3sRouteTargetArgs(route), ...(options.stdin === true ? ["--stdin"] : []), "--", ...command]);
}

function k3sRouteTargetArgs(route: ParsedSshRoute): string[] {
  if (route.namespace === null) throw new Error(`ssh route ${route.raw} requires a namespace segment`);
  if (route.resource === null) throw new Error(`ssh route ${route.raw} requires a workload or pod segment`);
  return [
    "--namespace", route.namespace,
    "--resource", normalizeK3sRouteResource(route.resource),
    ...(route.container === null ? [] : ["--container", route.container]),
    ...(route.workspace === null ? [] : ["--workdir", route.workspace]),
  ];
}

function k3sRouteCommandArgs(args: string[]): string[] {
  if (args.length === 0) throw new Error("ssh k3s target route requires a command to exec");
  return args[0] === "--" ? args : ["--", ...args];
}

function k3sRouteExecOperationArgs(args: string[]): string[] {
  if (args.length === 0) throw new Error("ssh k3s target exec operation requires a command to exec");
  const result: string[] = [];
  for (let index = 0; index < args.length; index += 1) {
    const arg = args[index] ?? "";
    if (arg === "--") {
      if (index === args.length - 1) throw new Error("ssh k3s target exec operation requires a command after --");
      return [...result, ...args.slice(index)];
    }
    if (arg === "--stdin" || arg === "-i" || arg === "--tty" || arg === "-t") {
      result.push(arg);
      continue;
    }
    if (arg === "--container" || arg === "-c" || arg === "--workdir" || arg === "--cwd") {
      const value = args[index + 1];
      if (value === undefined || value.length === 0) throw new Error(`ssh k3s target exec ${arg} requires a value`);
      result.push(arg, value);
      index += 1;
      continue;
    }
    return [...result, "--", ...args.slice(index)];
  }
  throw new Error("ssh k3s target exec operation requires a command to exec");
}

function buildK3sCommand(providerId: string, args: string[]): string {
  const action = args[0] ?? "";
  if (action.length === 0 || action === "--help" || action === "-h" || action === "help") {
    throw new Error("ssh k3s requires a subcommand: guard, kubectl, get, describe, logs or exec");
  }
  if (action === "guard") return buildK3sGuardCommand(providerId);
  if (action === "exec") return buildK3sExecCommand(args.slice(1));
  if (action === "script") {
    const parsed = buildK3sScriptOperation(args.slice(1));
    if (parsed.remoteCommand === null) throw new Error("ssh k3s script resolved to an interactive command unexpectedly");
    return parsed.remoteCommand;
  }
  if (action === "logs") return buildK3sLogsCommand(args.slice(1));
  if (action === "kubectl") {
    const kubectlArgs = args.slice(1);
    if (kubectlArgs.length === 0) throw new Error("ssh k3s kubectl requires kubectl arguments");
    return shellArgv(["env", `KUBECONFIG=${nativeK3sKubeconfig}`, "kubectl", ...kubectlArgs]);
  }
  return shellArgv(["env", `KUBECONFIG=${nativeK3sKubeconfig}`, "kubectl", ...args]);
}

function buildK3sGuardCommand(providerId: string): string {
  const provider = providerId.toUpperCase();
  const providerNodeCheck = provider === "D601"
    ? "printf '%s\\n' \"$nodes\" | grep -Fx d601 >/dev/null || { printf 'native_k3s_guard=blocked provider=%s reason=d601-node-missing\\n' \"$UNIDESK_K3S_PROVIDER_ID\" >&2; exit 1; }"
    : provider === "G14"
      ? "printf '%s\\n' \"$nodes\" | grep -Fx ubuntu-rog-zephyrus-g14-ga401iv-ga401iv >/dev/null || { printf 'native_k3s_guard=blocked provider=%s reason=g14-node-missing\\n' \"$UNIDESK_K3S_PROVIDER_ID\" >&2; exit 1; }"
      : "[ -n \"$nodes\" ] || { printf 'native_k3s_guard=blocked provider=%s reason=node-list-empty\\n' \"$UNIDESK_K3S_PROVIDER_ID\" >&2; exit 1; }";
  const script = [
    "set -euo pipefail",
    `export KUBECONFIG=${shellQuote(nativeK3sKubeconfig)}`,
    `export UNIDESK_K3S_PROVIDER_ID=${shellQuote(providerId)}`,
    "context=$(kubectl config current-context)",
    "server=$(kubectl config view --minify -o jsonpath='{.clusters[0].cluster.server}')",
    "nodes=$(kubectl get nodes -o jsonpath='{range .items[*]}{.metadata.name}{\"\\n\"}{end}')",
    "printf 'kubeconfig=%s\\n' \"$KUBECONFIG\"",
    "printf 'provider=%s\\n' \"$UNIDESK_K3S_PROVIDER_ID\"",
    "printf 'context=%s\\n' \"$context\"",
    "printf 'server=%s\\n' \"$server\"",
    "printf 'nodes=%s\\n' \"$(printf '%s' \"$nodes\" | tr '\\n' ' ')\"",
    providerNodeCheck,
    "case \"$server\" in *127.0.0.1:11700*|*docker-desktop*) printf 'native_k3s_guard=blocked reason=docker-desktop-context server=%s\\n' \"$server\" >&2; exit 1;; esac",
    "printf 'native_k3s_guard=ok provider=%s\\n' \"$UNIDESK_K3S_PROVIDER_ID\"",
  ].join("; ");
  return shellArgv(["bash", "-c", script]);
}

interface K3sTargetOptions {
  namespace: string | null;
  resource: string | null;
  selector: string | null;
  container: string | null;
  workspace: string | null;
  stdin: boolean;
  tty: boolean;
  shell: string | null;
  command: string[];
  kubectlOptions: string[];
}

interface ParseK3sTargetOptionsOptions {
  requireCommand: boolean;
  allowCommand?: boolean;
  allowShell?: boolean;
  allowSelector?: boolean;
}

function buildK3sExecCommand(args: string[]): string {
  const parsed = parseK3sTargetOptions(args, "ssh k3s exec", { requireCommand: true });
  if (parsed.namespace === null) throw new Error("ssh k3s exec requires --namespace <name>");
  if (parsed.selector !== null) throw new Error("ssh k3s exec does not support --selector");
  if (parsed.resource === null) throw new Error("ssh k3s exec requires --deployment <name>, --pod <name> or --resource <type/name>");
  const kubectlArgs = [
    "exec",
    "-n", parsed.namespace,
    parsed.resource,
    ...(parsed.container === null ? [] : ["-c", parsed.container]),
    ...(parsed.stdin ? ["-i"] : []),
    ...(parsed.tty ? ["-t"] : []),
    ...parsed.kubectlOptions,
    "--",
    ...withK3sWorkspace(parsed, parsed.command),
  ];
  return shellArgv(["env", `KUBECONFIG=${nativeK3sKubeconfig}`, "kubectl", ...kubectlArgs]);
}

function buildK3sScriptOperation(args: string[]): ParsedSshArgs {
  const parsed = parseK3sTargetOptions(args, "ssh k3s script", { requireCommand: false, allowCommand: true, allowShell: true });
  if (parsed.shell === null && parsed.command.length > 0) {
    return { remoteCommand: buildK3sInlineScriptCommand(parsed), requiresStdin: false, invocationKind: "helper" };
  }
  return { remoteCommand: buildK3sStdinScriptCommand(parsed), requiresStdin: true, invocationKind: "helper", stdinPrefix: shellScriptStdinPrefix() };
}

function buildK3sStdinScriptCommand(parsed: K3sTargetOptions): string {
  if (parsed.namespace === null && parsed.resource === null) return buildK3sHostScriptCommand(parsed);
  if (parsed.namespace === null) throw new Error("ssh k3s script target requires --namespace <name>");
  if (parsed.selector !== null) throw new Error("ssh k3s script does not support --selector");
  if (parsed.resource === null) throw new Error("ssh k3s script target requires --deployment <name>, --pod <name> or --resource <type/name>");
  if (parsed.tty) throw new Error("ssh k3s script does not support --tty; stdin is reserved for the script body");
  const shell = parsed.shell ?? "sh";
  const kubectlArgs = [
    "exec",
    "-i",
    "-n", parsed.namespace,
    parsed.resource,
    ...(parsed.container === null ? [] : ["-c", parsed.container]),
    ...parsed.kubectlOptions,
    "--",
    ...withK3sWorkspace(parsed, [shell, "-s", "--", ...parsed.command]),
  ];
  return shellArgv(["env", `KUBECONFIG=${nativeK3sKubeconfig}`, "kubectl", ...kubectlArgs]);
}

function buildK3sInlineScriptCommand(parsed: K3sTargetOptions): string {
  if (parsed.command.length === 0) throw new Error("ssh k3s script -- requires a command");
  if (parsed.selector !== null) throw new Error("ssh k3s script -- does not support --selector");
  if (parsed.tty) throw new Error("ssh k3s script does not support --tty; stdin is reserved for the script body");
  if (parsed.stdin) throw new Error("ssh k3s script -- does not accept --stdin");
  const command = parsed.command.length === 1 ? ["sh", "-c", shellScriptWithCompatibility(parsed.command[0] ?? "")] : parsed.command;
  if (parsed.namespace === null && parsed.resource === null) {
    if (parsed.container !== null) throw new Error("ssh k3s script without a workload does not accept --container");
    if (parsed.workspace !== null) throw new Error("ssh k3s script without a workload does not accept --workdir");
    if (parsed.kubectlOptions.length > 0) throw new Error("ssh k3s script without a workload does not accept kubectl log options");
    return shellArgv(["env", `KUBECONFIG=${nativeK3sKubeconfig}`, ...command]);
  }
  if (parsed.namespace === null) throw new Error("ssh k3s script target requires --namespace <name>");
  if (parsed.resource === null) throw new Error("ssh k3s script target requires --deployment <name>, --pod <name> or --resource <type/name>");
  const kubectlArgs = [
    "exec",
    "-n", parsed.namespace,
    parsed.resource,
    ...(parsed.container === null ? [] : ["-c", parsed.container]),
    ...parsed.kubectlOptions,
    "--",
    ...withK3sWorkspace(parsed, command),
  ];
  return shellArgv(["env", `KUBECONFIG=${nativeK3sKubeconfig}`, "kubectl", ...kubectlArgs]);
}

function buildK3sApplyPatchCommand(args: string[]): ParsedSshArgs {
  const parsed = parseK3sTargetOptions(args, "ssh k3s apply-patch", { requireCommand: false, allowCommand: true });
  if (parsed.namespace === null) throw new Error("ssh k3s apply-patch requires --namespace <name>");
  if (parsed.resource === null) throw new Error("ssh k3s apply-patch requires --deployment <name>, --pod <name> or --resource <type/name>");
  if (parsed.tty) throw new Error("ssh k3s apply-patch does not support --tty; stdin is reserved for the patch body");
  if (parsed.stdin) throw new Error("ssh k3s apply-patch does not accept --stdin; stdin is always the patch body");
  if (parsed.shell !== null) throw new Error("ssh k3s apply-patch does not accept --shell");
  if (parsed.kubectlOptions.length > 0) throw new Error("ssh k3s apply-patch does not accept kubectl log options");
  const kubectlArgs = [
    "exec",
    "-i",
    "-n", parsed.namespace,
    parsed.resource,
    ...(parsed.container === null ? [] : ["-c", parsed.container]),
    "--",
    ...withK3sWorkspace(parsed, ["sh", "-s", "--", ...parsed.command]),
  ];
  const wrapper = podApplyPatchStdinWrapper();
  return {
    remoteCommand: shellArgv(["env", `KUBECONFIG=${nativeK3sKubeconfig}`, "kubectl", ...kubectlArgs]),
    requiresStdin: true,
    invocationKind: "helper",
    stdinPrefix: wrapper.prefix,
    stdinSuffix: wrapper.suffix,
  };
}

function buildK3sHostScriptCommand(parsed: K3sTargetOptions): string {
  if (parsed.tty) throw new Error("ssh k3s script does not support --tty; stdin is reserved for the script body");
  if (parsed.stdin) throw new Error("ssh k3s script does not accept --stdin; stdin is always the script body");
  if (parsed.container !== null) throw new Error("ssh k3s script without a workload does not accept --container");
  if (parsed.workspace !== null) throw new Error("ssh k3s script without a workload does not accept --workdir");
  if (parsed.kubectlOptions.length > 0) throw new Error("ssh k3s script without a workload does not accept kubectl log options");
  const shell = parsed.shell ?? "sh";
  return shellArgv(["env", `KUBECONFIG=${nativeK3sKubeconfig}`, shell, "-s", "--", ...parsed.command]);
}

function shellStringFromArgs(args: string[], commandName = "ssh shell"): string {
  if (args.length === 0) throw new Error(`${commandName} requires a command string`);
  return args.join(" ");
}

function parseShellStringOperationArgs(args: string[], commandName: string): { shell: string; command: string } {
  let shell = "sh";
  const commandArgs: string[] = [];
  for (let index = 0; index < args.length; index += 1) {
    const arg = args[index] ?? "";
    if (arg === "--shell") {
      shell = k3sScriptShell(k3sOptionValue(args, index, `${commandName} --shell`), `${commandName} --shell`);
      index += 1;
      continue;
    }
    commandArgs.push(arg);
  }
  return { shell, command: shellStringFromArgs(commandArgs, commandName) };
}

function buildK3sLogsCommand(args: string[]): string {
  const parsed = parseK3sTargetOptions(args, "ssh k3s logs", { requireCommand: false, allowSelector: true });
  if (parsed.namespace === null) throw new Error("ssh k3s logs requires --namespace <name>");
  if (parsed.resource === null && parsed.selector === null) throw new Error("ssh k3s logs requires --deployment <name>, --pod <name>, --resource <type/name> or --selector <label-selector>");
  if (parsed.resource !== null && parsed.selector !== null) throw new Error("ssh k3s logs accepts either a resource or --selector, not both");
  if (parsed.stdin || parsed.tty) throw new Error("ssh k3s logs does not support --stdin or --tty");
  if (parsed.workspace !== null) throw new Error("ssh k3s logs does not accept --workdir");
  const kubectlArgs = [
    "logs",
    "-n", parsed.namespace,
    ...(parsed.selector === null ? [parsed.resource ?? ""] : ["-l", parsed.selector]),
    ...(parsed.container === null ? [] : ["-c", parsed.container]),
    ...parsed.kubectlOptions,
  ];
  return shellArgv(["env", `KUBECONFIG=${nativeK3sKubeconfig}`, "kubectl", ...kubectlArgs]);
}

function parseK3sTargetOptions(args: string[], commandName: string, options: ParseK3sTargetOptionsOptions): K3sTargetOptions {
  let namespace: string | null = null;
  let resource: string | null = null;
  let selector: string | null = null;
  let container: string | null = null;
  let workspace: string | null = null;
  let stdin = false;
  let tty = false;
  let shell: string | null = null;
  const kubectlOptions: string[] = [];
  const command: string[] = [];
  let afterDoubleDash = false;

  for (let index = 0; index < args.length; index += 1) {
    const arg = args[index] ?? "";
    if (afterDoubleDash) {
      command.push(arg);
      continue;
    }
    if (arg === "--") {
      afterDoubleDash = true;
      continue;
    }
    if (arg === "--namespace" || arg === "-n") {
      namespace = k3sOptionValue(args, index, `${commandName} ${arg}`);
      index += 1;
      continue;
    }
    const namespaceValue = k3sEqualsOptionValue(arg, "--namespace", commandName);
    if (namespaceValue !== null) {
      namespace = namespaceValue;
      continue;
    }
    if (arg === "--deployment" || arg === "--deploy") {
      resource = `deployment/${k3sOptionValue(args, index, `${commandName} ${arg}`)}`;
      index += 1;
      continue;
    }
    const deploymentValue = k3sEqualsOptionValue(arg, "--deployment", commandName) ?? k3sEqualsOptionValue(arg, "--deploy", commandName);
    if (deploymentValue !== null) {
      resource = `deployment/${deploymentValue}`;
      continue;
    }
    if (arg === "--pod") {
      resource = `pod/${k3sOptionValue(args, index, `${commandName} ${arg}`)}`;
      index += 1;
      continue;
    }
    const podValue = k3sEqualsOptionValue(arg, "--pod", commandName);
    if (podValue !== null) {
      resource = `pod/${podValue}`;
      continue;
    }
    if (arg === "--resource") {
      resource = normalizeK3sResource(k3sOptionValue(args, index, `${commandName} ${arg}`));
      index += 1;
      continue;
    }
    const resourceValue = k3sEqualsOptionValue(arg, "--resource", commandName);
    if (resourceValue !== null) {
      resource = normalizeK3sResource(resourceValue);
      continue;
    }
    if (arg === "--selector" || arg === "-l") {
      if (options.allowSelector !== true) throw new Error(`${commandName} does not support ${arg}`);
      selector = k3sOptionValue(args, index, `${commandName} ${arg}`);
      index += 1;
      continue;
    }
    const selectorValue = k3sEqualsOptionValue(arg, "--selector", commandName) ?? k3sEqualsOptionValue(arg, "-l", commandName);
    if (selectorValue !== null) {
      if (options.allowSelector !== true) throw new Error(`${commandName} does not support ${arg.split("=", 1)[0]}`);
      selector = selectorValue;
      continue;
    }
    if (arg === "--container" || arg === "-c") {
      container = k3sOptionValue(args, index, `${commandName} ${arg}`);
      index += 1;
      continue;
    }
    const containerValue = k3sEqualsOptionValue(arg, "--container", commandName);
    if (containerValue !== null) {
      container = containerValue;
      continue;
    }
    if (arg === "--workdir" || arg === "--cwd") {
      workspace = k3sWorkspaceValue(k3sOptionValue(args, index, `${commandName} ${arg}`), `${commandName} ${arg}`);
      index += 1;
      continue;
    }
    const workdirValue = k3sEqualsOptionValue(arg, "--workdir", commandName) ?? k3sEqualsOptionValue(arg, "--cwd", commandName);
    if (workdirValue !== null) {
      workspace = k3sWorkspaceValue(workdirValue, `${commandName} ${arg.split("=", 1)[0]}`);
      continue;
    }
    if (arg === "--shell") {
      if (!options.allowShell) throw new Error(`${commandName} does not support --shell`);
      shell = k3sScriptShell(k3sOptionValue(args, index, `${commandName} ${arg}`), `${commandName} ${arg}`);
      index += 1;
      continue;
    }
    const shellValue = k3sEqualsOptionValue(arg, "--shell", commandName);
    if (shellValue !== null) {
      if (!options.allowShell) throw new Error(`${commandName} does not support --shell`);
      shell = k3sScriptShell(shellValue, `${commandName} --shell`);
      continue;
    }
    if (arg === "--stdin" || arg === "-i") {
      stdin = true;
      continue;
    }
    if (arg === "--tty" || arg === "-t") {
      tty = true;
      continue;
    }
    if (arg === "--tail") {
      kubectlOptions.push("--tail", optionalPositiveInt(k3sOptionValue(args, index, `${commandName} ${arg}`), `${commandName} --tail`));
      index += 1;
      continue;
    }
    const tailValue = k3sEqualsOptionValue(arg, "--tail", commandName);
    if (tailValue !== null) {
      kubectlOptions.push("--tail", optionalPositiveInt(tailValue, `${commandName} --tail`));
      continue;
    }
    if (arg === "--since" || arg === "--since-time" || arg === "--limit-bytes") {
      kubectlOptions.push(arg, k3sOptionValue(args, index, `${commandName} ${arg}`));
      index += 1;
      continue;
    }
    const sinceValue = k3sEqualsOptionValue(arg, "--since", commandName);
    const sinceTimeValue = k3sEqualsOptionValue(arg, "--since-time", commandName);
    const limitBytesValue = k3sEqualsOptionValue(arg, "--limit-bytes", commandName);
    if (sinceValue !== null || sinceTimeValue !== null || limitBytesValue !== null) {
      const optionName = sinceValue !== null ? "--since" : sinceTimeValue !== null ? "--since-time" : "--limit-bytes";
      const optionValue = sinceValue ?? sinceTimeValue ?? limitBytesValue;
      kubectlOptions.push(optionName, optionValue ?? "");
      continue;
    }
    if (arg === "--previous" || arg === "--timestamps" || arg === "--all-containers" || arg === "--prefix") {
      kubectlOptions.push(arg);
      continue;
    }
    if (arg === "--follow" || arg === "-f") {
      throw new Error(`${commandName} does not support ${arg}; use a bounded logs command and poll again`);
    }
    if (arg.startsWith("-")) throw new Error(`unsupported ${commandName} option: ${arg}`);
    if (resource === null) {
      resource = normalizeK3sResource(arg);
      continue;
    }
    throw new Error(`unexpected ${commandName} argument before --: ${arg}`);
  }

  if (options.requireCommand && command.length === 0) throw new Error(`${commandName} requires -- <command> [args...]`);
  if (!options.requireCommand && options.allowCommand !== true && command.length > 0) throw new Error(`${commandName} does not accept a command after --`);
  return { namespace, resource, selector, container, workspace, stdin, tty, shell, command, kubectlOptions };
}

function k3sEqualsOptionValue(arg: string, option: string, commandName: string): string | null {
  const prefix = `${option}=`;
  if (!arg.startsWith(prefix)) return null;
  const value = arg.slice(prefix.length);
  if (value.length === 0) throw new Error(`${commandName} ${option} requires a value`);
  return value;
}

function k3sOptionValue(args: string[], index: number, option: string): string {
  const value = args[index + 1];
  if (value === undefined || value.length === 0) throw new Error(`${option} requires a value`);
  return value;
}

function k3sWorkspaceValue(value: string, option: string): string {
  if (!value.startsWith("/")) throw new Error(`${option} must be an absolute pod workspace path`);
  return value;
}

function withK3sWorkspace(parsed: K3sTargetOptions, command: string[]): string[] {
  if (parsed.workspace === null) return command;
  if (command.length === 0) throw new Error("ssh k3s workspace route requires a command to execute");
  return ["sh", "-c", 'cd "$1" || exit; shift; exec "$@"', "unidesk-cwd", parsed.workspace, ...command];
}

function normalizeK3sResource(value: string): string {
  if (value.includes("/")) return value;
  return `pod/${value}`;
}

function normalizeK3sRouteResource(value: string): string {
  if (value.startsWith("deploy/")) return `deployment/${value.slice("deploy/".length)}`;
  if (value.startsWith("po/")) return `pod/${value.slice("po/".length)}`;
  if (value.startsWith("pod:")) return `pod/${value.slice("pod:".length)}`;
  if (value.startsWith("po:")) return `pod/${value.slice("po:".length)}`;
  if (value.startsWith("pods:")) return `pod/${value.slice("pods:".length)}`;
  if (value.includes("/")) return value;
  return `deployment/${value}`;
}

function k3sScriptShell(value: string, option: string): string {
  if (!/^[A-Za-z0-9_./-]+$/u.test(value)) throw new Error(`${option} must be a shell executable name or path without whitespace`);
  return value;
}

function shellScriptPrelude(): string {
  return `${sshUserToolPathPrelude}\n${sshShellCompatibilityPrelude}`;
}

function shellScriptWithCompatibility(command: string): string {
  return `${shellScriptPrelude()}\n${command}`;
}

function shellScriptStdinPrefix(): string {
  return `${shellScriptPrelude()}\n`;
}

function buildShellCommand(args: string[]): ParsedSshArgs {
  let shell = "sh";
  const scriptArgs: string[] = [];
  let afterDoubleDash = false;
  let directArgvMode = false;
  let shellOptionSeen = false;
  for (let index = 0; index < args.length; index += 1) {
    const arg = args[index] ?? "";
    if (afterDoubleDash) {
      scriptArgs.push(arg);
      continue;
    }
    if (arg === "--") {
      if (!shellOptionSeen && scriptArgs.length === 0) {
        directArgvMode = true;
        scriptArgs.push(...args.slice(index + 1));
        break;
      }
      afterDoubleDash = true;
      continue;
    }
    if (arg === "--shell") {
      shell = k3sScriptShell(k3sOptionValue(args, index, "ssh script --shell"), "ssh script --shell");
      shellOptionSeen = true;
      index += 1;
      continue;
    }
    if (arg.startsWith("-")) throw new Error(`unsupported ssh script option: ${arg}`);
    scriptArgs.push(arg);
  }
  if (directArgvMode) {
    if (scriptArgs.length === 0) throw new Error("ssh script -- requires a command");
    if (scriptArgs.length === 1) return { remoteCommand: shellArgv([shell, "-c", shellScriptWithCompatibility(scriptArgs[0] ?? "")]), requiresStdin: false, invocationKind: "helper" };
    return { remoteCommand: shellArgv(scriptArgs), requiresStdin: false, invocationKind: "argv" };
  }
  return { remoteCommand: shellArgv([shell, "-s", "--", ...scriptArgs]), requiresStdin: true, invocationKind: "helper", stdinPrefix: shellScriptStdinPrefix() };
}

function buildShellStringCommand(args: string[]): ParsedSshArgs {
  const parsed = parseShellStringOperationArgs(args, "ssh shell");
  return { remoteCommand: shellArgv([parsed.shell, "-c", shellScriptWithCompatibility(parsed.command)]), requiresStdin: false, invocationKind: "helper" };
}

function podApplyPatchStdinWrapper(): { prefix: string; suffix: string } {
  const toolMarker = "__UNIDESK_APPLY_PATCH_TOOL__";
  const patchMarker = "__UNIDESK_APPLY_PATCH_PAYLOAD__";
  if (remoteApplyPatchSource.includes(toolMarker)) throw new Error("remote apply_patch source contains reserved heredoc marker");
  return {
    prefix: [
      "set -eu",
      'UNIDESK_SSH_TOOL_DIR="${UNIDESK_SSH_TOOL_DIR:-/tmp/unidesk-ssh-tools}"',
      'mkdir -p "$UNIDESK_SSH_TOOL_DIR"',
      `cat > "$UNIDESK_SSH_TOOL_DIR/apply_patch" <<'${toolMarker}'`,
      remoteApplyPatchSource.trimEnd(),
      toolMarker,
      'chmod 700 "$UNIDESK_SSH_TOOL_DIR/apply_patch"',
      `"$UNIDESK_SSH_TOOL_DIR/apply_patch" "$@" <<'${patchMarker}'`,
    ].join("\n") + "\n",
    suffix: `\n${patchMarker}\n`,
  };
}

function buildPythonStdinCommand(args: string[]): string {
  const pythonArgs = args.map(shellQuote).join(" ");
  const execArgs = pythonArgs.length > 0 ? ` "$UNIDESK_SSH_PY_FILE" ${pythonArgs}` : ' "$UNIDESK_SSH_PY_FILE"';
  return [
    'UNIDESK_SSH_PY_FILE="$(mktemp /tmp/unidesk-ssh-py.XXXXXX.py)" || exit 1',
    `trap 'rm -f "$UNIDESK_SSH_PY_FILE"' EXIT`,
    'cat > "$UNIDESK_SSH_PY_FILE"',
    `python3 -u${execArgs}`,
  ].join("; ");
}

const remoteToolSources: Record<SshHelperName, string> = {
  apply_patch: remoteApplyPatchSource,
  glob: remoteGlobSource,
  "skill-discover": remoteSkillDiscoverSource,
};

function remoteToolBootstrapCommand(helpers: readonly SshHelperName[] = []): string {
  const uniqueHelpers = [...new Set(helpers)];
  if (uniqueHelpers.length === 0) return "";
  const commands = [
    "UNIDESK_SSH_TOOL_DIR=/tmp/unidesk-ssh-tools",
    'mkdir -p "$UNIDESK_SSH_TOOL_DIR"',
  ];
  for (const helper of uniqueHelpers) {
    const source = remoteToolSources[helper];
    const encoded = Buffer.from(source, "utf8").toString("base64");
    commands.push(`printf %s ${shellQuote(encoded)} | base64 -d > "$UNIDESK_SSH_TOOL_DIR/${helper}"`);
    commands.push(`chmod 700 "$UNIDESK_SSH_TOOL_DIR/${helper}"`);
  }
  commands.push('export PATH="$UNIDESK_SSH_TOOL_DIR:$PATH"');
  return commands.join("; ");
}

export function wrapSshRemoteCommand(command: string | null, helpers: readonly SshHelperName[] = []): string {
  const bootstrap = remoteToolBootstrapCommand(helpers);
  const prelude = [sshUserToolPathPrelude, bootstrap].filter((part) => part.length > 0).join("; ");
  const prefix = prelude.length > 0 ? `${prelude}; ` : "";
  if (command === null) return `${prefix}exec "\${SHELL:-/bin/bash}" -l`;
  return `${prefix}stty -echo 2>/dev/null || true; ${command}`;
}

function safeProviderId(providerId: string): string {
  return /^[A-Za-z0-9_.-]{1,64}$/u.test(providerId) ? providerId : "<provider>";
}

function classifySshLikeFailure(exitCode: number, stderrText: string): SshFailureHint["trigger"] | null {
  const normalized = stderrText.toLowerCase();
  if (
    normalized.includes("kex_exchange_identification")
    || normalized.includes("ssh_exchange_identification")
    || normalized.includes("connection closed by remote host")
    || normalized.includes("connection reset by peer")
    || normalized.includes("connection timed out")
    || normalized.includes("operation timed out")
    || normalized.includes("timed out waiting for provider session")
    || normalized.includes("the operation was aborted")
  ) {
    return "timeout-or-kex";
  }
  return exitCode === 255 ? "exit-255" : null;
}

export function sshFailureHint(providerId: string, parsed: ParsedSshArgs, exitCode: number, stderrText: string): SshFailureHint | null {
  if (parsed.invocationKind !== "ssh-like") return null;
  const trigger = classifySshLikeFailure(exitCode, stderrText);
  if (trigger === null) return null;
  const shownProviderId = safeProviderId(providerId);
  return {
    code: "ssh-like-command-friction",
    providerId: shownProviderId,
    trigger,
    exitCode,
    message: "ssh-like remote command failed before proving Host SSH is globally unavailable; prefer structured argv or stdin script passthrough for non-interactive commands.",
    try: `trans ${shownProviderId} script <<'SCRIPT'`,
    triage: `bun scripts/cli.ts provider triage ${shownProviderId} --observed-scope ssh --observed-error '<ssh-like timeout or kex failure>'`,
    note: "This hint intentionally does not echo the original remote command.",
  };
}

export function formatSshFailureHint(hint: SshFailureHint): string {
  return `UNIDESK_SSH_HINT ${JSON.stringify(hint)}\n`;
}

export function sshSlowWarningThresholdMs(env: NodeJS.ProcessEnv = process.env): number {
  const raw = env.UNIDESK_SSH_SLOW_WARNING_MS;
  const parsed = raw === undefined ? NaN : Number(raw);
  if (!Number.isFinite(parsed) || parsed <= 0) return defaultSshSlowWarningMs;
  return Math.max(1000, Math.trunc(parsed));
}

export function sshRuntimeTimingHint(options: {
  invocation: ParsedSshInvocation;
  transport: SshRuntimeTimingHint["transport"];
  exitCode: number;
  startedAtMs: number;
  finishedAtMs?: number;
  thresholdMs?: number;
}): SshRuntimeTimingHint {
  const finishedAtMs = options.finishedAtMs ?? Date.now();
  const thresholdMs = options.thresholdMs ?? sshSlowWarningThresholdMs();
  const elapsedMs = Math.max(0, Math.round(finishedAtMs - options.startedAtMs));
  const elapsedSeconds = Number((elapsedMs / 1000).toFixed(3));
  const slow = elapsedMs > thresholdMs;
  const thresholdSeconds = Number((thresholdMs / 1000).toFixed(3));
  return {
    code: "ssh-runtime-timing",
    level: slow ? "warning" : "info",
    providerId: safeProviderId(options.invocation.providerId),
    route: options.invocation.route.raw,
    transport: options.transport,
    invocationKind: options.invocation.parsed.invocationKind,
    exitCode: options.exitCode,
    elapsedMs,
    elapsedSeconds,
    thresholdMs,
    slow,
    message: slow
      ? `ssh operation took ${elapsedSeconds}s, above the ${thresholdSeconds}s warning threshold; consider checking provider/session latency, remote command cost, helper bootstrap, or tran/apply-patch optimization before repeating high-frequency operations.`
      : `ssh operation completed in ${elapsedSeconds}s.`,
    note: "Timing hint is written to stderr and intentionally does not echo the original remote command.",
  };
}

export function formatSshRuntimeTimingHint(hint: SshRuntimeTimingHint): string {
  if (!hint.slow) return "";
  return `UNIDESK_SSH_TIMING ${JSON.stringify(hint)}\n`;
}

export function sshRuntimeTimeoutMs(env: NodeJS.ProcessEnv = process.env): number {
  const raw = env.UNIDESK_SSH_RUNTIME_TIMEOUT_MS ?? env.UNIDESK_TRAN_RUNTIME_TIMEOUT_MS;
  const parsed = raw === undefined ? NaN : Number(raw);
  if (!Number.isFinite(parsed) || parsed <= 0) return defaultSshRuntimeTimeoutMs;
  return Math.min(maxSshRuntimeTimeoutMs, Math.max(1000, Math.trunc(parsed)));
}

export function sshRuntimeTimeoutHint(options: {
  invocation: ParsedSshInvocation;
  transport: SshRuntimeTimeoutHint["transport"];
  timeoutMs: number;
}): SshRuntimeTimeoutHint {
  const timeoutSeconds = Number((options.timeoutMs / 1000).toFixed(3));
  return {
    code: "ssh-runtime-timeout",
    level: "warning",
    providerId: safeProviderId(options.invocation.providerId),
    route: options.invocation.route.raw,
    transport: options.transport,
    invocationKind: options.invocation.parsed.invocationKind,
    timeoutMs: options.timeoutMs,
    timeoutSeconds,
    message: `ssh/tran operation exceeded the ${timeoutSeconds}s top-level runtime limit and was disconnected.`,
    action: "Use short query plus poll semantics; do not keep tran open waiting for long CI/CD, trace, logs, or build progress.",
    note: "Timeout hint is written to stderr and intentionally does not echo the original remote command.",
  };
}

export function formatSshRuntimeTimeoutHint(hint: SshRuntimeTimeoutHint): string {
  return `UNIDESK_SSH_RUNTIME_TIMEOUT ${JSON.stringify(hint)}\n`;
}

export function sshStdoutStreamMaxBytes(env: NodeJS.ProcessEnv = process.env): number {
  const raw = env.UNIDESK_SSH_STDOUT_STREAM_MAX_BYTES ?? env.UNIDESK_TRAN_STDOUT_STREAM_MAX_BYTES;
  const parsed = raw === undefined ? NaN : Number(raw);
  if (!Number.isFinite(parsed) || parsed <= 0) return defaultSshStdoutStreamMaxBytes;
  return Math.min(maxSshStdoutStreamMaxBytes, Math.max(minSshStdoutStreamMaxBytes, Math.trunc(parsed)));
}

export function sshStdoutTruncationHint(options: {
  invocation: ParsedSshInvocation;
  transport: SshStdoutTruncationHint["transport"];
  thresholdBytes: number;
  observedBytesAtTruncation: number;
  dumpPath: string | null;
  dumpError?: string | null;
}): SshStdoutTruncationHint {
  return {
    code: "ssh-stdout-truncated",
    level: "warning",
    providerId: safeProviderId(options.invocation.providerId),
    route: options.invocation.route.raw,
    transport: options.transport,
    invocationKind: options.invocation.parsed.invocationKind,
    thresholdBytes: options.thresholdBytes,
    observedBytesAtTruncation: options.observedBytesAtTruncation,
    dumpPath: options.dumpPath,
    dumpError: options.dumpError ?? null,
    message: `ssh stdout exceeded ${options.thresholdBytes} bytes; stdout is bounded and the complete stream is written to a local dump when possible.`,
    action: "Inspect the dump path, or rerun a narrower remote command with tail/paging instead of emitting full logs or huge JSON.",
    note: "This hint is written to stderr and intentionally does not echo the original remote command.",
  };
}

export function formatSshStdoutTruncationHint(hint: SshStdoutTruncationHint): string {
  return `UNIDESK_SSH_STDOUT_TRUNCATED ${JSON.stringify(hint)}\n`;
}

function sshStdoutDumpPath(invocation: ParsedSshInvocation): string {
  mkdirSync(sshStdoutDumpDir, { recursive: true, mode: 0o700 });
  const timestamp = new Date().toISOString().replace(/[:.]/gu, "-");
  const suffix = randomBytes(4).toString("hex");
  const slug = `${invocation.providerId}-${invocation.route.raw}-${invocation.route.plane}`
    .replace(/[^A-Za-z0-9._-]+/gu, "-")
    .replace(/^-+|-+$/gu, "")
    .slice(0, 80) || "ssh";
  return join(sshStdoutDumpDir, `${timestamp}-${process.pid}-${suffix}-${slug}.stdout.bin`);
}

export function createSshStdoutForwarder(options: {
  invocation: ParsedSshInvocation;
  transport: SshStdoutTruncationHint["transport"];
  maxBytes?: number;
  stdout?: NodeJS.WritableStream;
}): { write: (chunk: Buffer) => string | null } {
  const stdout = options.stdout ?? process.stdout;
  const maxBytes = options.maxBytes ?? sshStdoutStreamMaxBytes();
  let observedBytes = 0;
  let forwardedBytes = 0;
  let truncated = false;
  let dumpPath: string | null = null;
  let dumpError: string | null = null;
  const bufferedChunks: Buffer[] = [];

  const appendDump = (chunk: Buffer): void => {
    if (dumpError !== null) return;
    try {
      if (dumpPath === null) {
        dumpPath = sshStdoutDumpPath(options.invocation);
        writeFileSync(dumpPath, Buffer.alloc(0), { mode: 0o600 });
        for (const buffered of bufferedChunks) appendFileSync(dumpPath, buffered);
        bufferedChunks.length = 0;
      }
      appendFileSync(dumpPath, chunk);
    } catch (error) {
      dumpError = error instanceof Error ? error.message : String(error);
      dumpPath = null;
    }
  };

  return {
    write(chunk: Buffer): string | null {
      observedBytes += chunk.length;
      if (!truncated && observedBytes <= maxBytes) {
        bufferedChunks.push(Buffer.from(chunk));
        stdout.write(chunk);
        forwardedBytes += chunk.length;
        return null;
      }

      if (!truncated) {
        truncated = true;
        const remaining = Math.max(0, maxBytes - forwardedBytes);
        if (remaining > 0) {
          stdout.write(chunk.subarray(0, remaining));
          forwardedBytes += remaining;
        }
        appendDump(chunk);
        return formatSshStdoutTruncationHint(sshStdoutTruncationHint({
          invocation: options.invocation,
          transport: options.transport,
          thresholdBytes: maxBytes,
          observedBytesAtTruncation: observedBytes,
          dumpPath,
          dumpError,
        }));
      }

      appendDump(chunk);
      return null;
    },
  };
}

function brokerSource(): string {
  return String.raw`
const open = JSON.parse(process.argv[2] || process.argv[1] || "{}");
const token = process.env.PROVIDER_TOKEN || process.env.UNIDESK_PROVIDER_TOKEN || "";
const baseUrl = process.env.UNIDESK_SSH_BROKER_URL || "ws://backend-core:8080/ws/ssh";
const url = baseUrl + "?token=" + encodeURIComponent(token);
const ws = new WebSocket(url);
let exitCode = 255;
let canSend = false;
let sessionReady = false;
let opened = false;
const pending = [];
const pendingInput = [];
const openTimer = setTimeout(() => {
  if (opened) return;
  process.stderr.write("unidesk ssh bridge timed out waiting for provider session\n");
  try { ws.close(); } catch {}
  process.exit(255);
}, Number(open.openTimeoutMs || 15000));
const runtimeTimeoutMs = Number(open.runtimeTimeoutMs || 60000);
const runtimeTimeoutMode = open.runtimeTimeoutMode === "inactivity" ? "inactivity" : "wall-clock";
let runtimeTimer = null;
function armRuntimeTimer() {
  if (runtimeTimer !== null) clearTimeout(runtimeTimer);
  runtimeTimer = setTimeout(() => {
    const noun = runtimeTimeoutMode === "inactivity" ? "inactivity timeout" : "runtime timeout";
    process.stderr.write("unidesk ssh bridge " + noun + "; use short query plus poll semantics for long non-streaming work\n");
    exitCode = 124;
    try { ws.close(); } catch {}
    setTimeout(() => process.exit(124), 250).unref?.();
  }, runtimeTimeoutMs);
}
function clearRuntimeTimer() {
  if (runtimeTimer !== null) clearTimeout(runtimeTimer);
  runtimeTimer = null;
}
armRuntimeTimer();

function send(value) {
  const text = JSON.stringify(value);
  if (!canSend || ws.readyState !== WebSocket.OPEN) {
    pending.push(text);
    return;
  }
  ws.send(text);
}

function flush() {
  while (pending.length > 0 && ws.readyState === WebSocket.OPEN) {
    ws.send(pending.shift());
  }
}

function sendInput(value) {
  const text = JSON.stringify(value);
  if (!sessionReady || ws.readyState !== WebSocket.OPEN) {
    pendingInput.push(text);
    return;
  }
  ws.send(text);
}

function flushInput() {
  if (!sessionReady || ws.readyState !== WebSocket.OPEN) return;
  while (pendingInput.length > 0) {
    ws.send(pendingInput.shift());
  }
}

function decodeData(data) {
  return typeof data === "string" ? data : Buffer.from(data).toString("utf8");
}

ws.addEventListener("open", () => {
  canSend = true;
  send({
    type: "ssh.open",
    providerId: open.providerId,
    command: open.command || undefined,
    cwd: open.cwd || undefined,
    tty: open.tty === true,
    cols: open.cols || 100,
    rows: open.rows || 30,
  });
  flush();
});

ws.addEventListener("message", (event) => {
  const message = JSON.parse(decodeData(event.data));
  if (runtimeTimeoutMode === "inactivity") armRuntimeTimer();
  if (message.type === "ssh.data") {
    opened = true;
    const chunk = Buffer.from(message.data || "", "base64");
    if (message.stream === "stderr") process.stderr.write(chunk);
    else process.stdout.write(chunk);
    return;
  }
  if (message.type === "ssh.opened") {
    opened = true;
    sessionReady = true;
    clearTimeout(openTimer);
    if (open.stdinEotOnEnd === true) setTimeout(flushInput, 200);
    else flushInput();
    return;
  }
  if (message.type === "ssh.dispatched") {
    return;
  }
  if (message.type === "ssh.error") {
    clearTimeout(openTimer);
    clearRuntimeTimer();
    process.stderr.write(String(message.message || "ssh bridge error") + "\n");
    exitCode = 255;
    ws.close();
    return;
  }
  if (message.type === "ssh.exit") {
    clearTimeout(openTimer);
    clearRuntimeTimer();
    exitCode = Number.isInteger(message.exitCode) ? message.exitCode : 255;
    ws.close();
  }
});

ws.addEventListener("close", () => {
  clearTimeout(openTimer);
  clearRuntimeTimer();
  process.exit(exitCode);
});

ws.addEventListener("error", () => {
  process.stderr.write("unidesk ssh bridge websocket error\n");
  process.exit(255);
});

process.stdin.on("data", (chunk) => {
  sendInput({ type: "ssh.input", data: Buffer.from(chunk).toString("base64"), encoding: "base64" });
});
process.stdin.on("end", () => {
  if (open.stdinEotOnEnd === true) {
    sendInput({ type: "ssh.input", data: Buffer.from([4]).toString("base64"), encoding: "base64" });
  }
  sendInput({ type: "ssh.eof" });
});
`;
}

function terminalSize(): { cols: number; rows: number } {
  return {
    cols: Number(process.stdout.columns) > 0 ? Number(process.stdout.columns) : 100,
    rows: Number(process.stdout.rows) > 0 ? Number(process.stdout.rows) : 30,
  };
}

export function remoteCommandForRoute(route: ParsedSshRoute, command: string[], options: { stdin?: boolean } = {}): string {
  if (route.plane === "k3s") return buildK3sTargetCommand(route, command, options);
  if (route.plane === "win") throw new Error(`ssh apply-patch does not support win routes yet: ${route.raw}`);
  return shellArgv(command);
}

type WindowsApplyPatchFsOperation =
  | "stat"
  | "read-b64-block"
  | "read-bulk-b64"
  | "apply-replacements-bulk-stdin"
  | "write-b64-stdin"
  | "write-b64-begin"
  | "write-b64-append-stdin"
  | "write-b64-commit"
  | "delete";

const windowsApplyPatchWriteB64ChunkChars = 12_000;

function createWindowsApplyPatchFileSystem(config: UniDeskConfig, invocation: ParsedSshInvocation): ApplyPatchV2FileSystem {
  async function checked(operation: WindowsApplyPatchFsOperation, args: string[], input?: string): Promise<SshCaptureResult> {
    const command = buildWindowsPowerShellInvocation(windowsApplyPatchFsScript(invocation.route.workspace, operation, args));
    const result = await runSshCaptureRemoteCommand(config, invocation, command, input);
    if (result.exitCode === 0) return result;
    throw new Error(`windows apply-patch fs operation failed: ${operation} ${JSON.stringify({
      route: invocation.route.raw,
      args: args.slice(0, 4),
      exitCode: result.exitCode,
      stdout: result.stdout.slice(-2000),
      stderr: result.stderr.slice(-4000),
    })}`);
  }

  return {
    async stat(filePath) {
      const result = await checked("stat", [filePath]);
      const [bytesText, sha256] = result.stdout.trim().split(/\s+/u);
      const bytes = Number(bytesText);
      if (!Number.isSafeInteger(bytes) || bytes < 0 || !/^[0-9a-f]{64}$/u.test(sha256 ?? "")) {
        throw new Error(`windows apply-patch fs stat returned invalid metadata: ${JSON.stringify({ filePath, stdout: result.stdout.slice(0, 500) })}`);
      }
      return { bytes, sha256: sha256! };
    },
    async readBlock(filePath, blockIndex, blockBytes) {
      const result = await checked("read-b64-block", [filePath, String(blockIndex), String(blockBytes)]);
      const encoded = result.stdout.replace(/\s+/gu, "");
      return encoded.length === 0 ? Buffer.alloc(0) : Buffer.from(encoded, "base64");
    },
    async writeFile(filePath, content) {
      const encoded = content.toString("base64");
      const expectedBytes = String(content.length);
      const expectedSha256 = createHash("sha256").update(content).digest("hex");
      try {
        await checked("write-b64-stdin", [filePath, expectedBytes, expectedSha256], encoded);
        return;
      } catch {
        const token = `${process.pid}-${Date.now()}-${randomBytes(4).toString("hex")}-${expectedSha256.slice(0, 12)}`;
        await checked("write-b64-begin", [filePath, token]);
        for (const chunk of chunkString(encoded, windowsApplyPatchWriteB64ChunkChars)) {
          await checked("write-b64-append-stdin", [filePath, token], chunk);
        }
        await checked("write-b64-commit", [filePath, token, expectedBytes, expectedSha256]);
      }
    },
    async deleteFile(filePath) {
      await checked("delete", [filePath]);
    },
    async readFiles(filePaths) {
      const result = await checked("read-bulk-b64", [String(filePaths.length)], `${filePaths.join("\n")}\n`);
      return decodeApplyPatchV2BulkRead(result.stdout, filePaths);
    },
    async applyReplacementsBulk(filePaths, plans: Map<string, ApplyPatchV2BulkReplacementWritePlan>) {
      const { targets, payload } = formatApplyPatchV2BulkReplacementPayload(filePaths, plans);
      if (targets.length === 0) return;
      await checked("apply-replacements-bulk-stdin", [String(targets.length)], payload);
    },
  };
}

function windowsApplyPatchFsScript(basePath: string | null, operation: WindowsApplyPatchFsOperation, args: string[]): string {
  const target = args[0] ?? "";
  const arg1 = args[1] ?? "";
  const arg2 = args[2] ?? "";
  const arg3 = args[3] ?? "";
  return [
    "$ErrorActionPreference = 'Stop';",
    "$ProgressPreference = 'SilentlyContinue';",
    "[Console]::InputEncoding = [System.Text.UTF8Encoding]::new();",
    "[Console]::OutputEncoding = [System.Text.UTF8Encoding]::new();",
    "$OutputEncoding = [System.Text.UTF8Encoding]::new();",
    `$basePath = ${powerShellSingleQuote(basePath ?? "")};`,
    `$operation = ${powerShellSingleQuote(operation)};`,
    `$targetArg = ${powerShellSingleQuote(target)};`,
    `$arg1 = ${powerShellSingleQuote(arg1)};`,
    `$arg2 = ${powerShellSingleQuote(arg2)};`,
    `$arg3 = ${powerShellSingleQuote(arg3)};`,
    "function Fail([string]$Message, [int]$Code) { [Console]::Error.WriteLine($Message); exit $Code }",
    "function Resolve-UnideskPath([string]$Raw) { if ([string]::IsNullOrWhiteSpace($Raw)) { Fail 'empty apply-patch path' 2 }; if ([System.IO.Path]::IsPathRooted($Raw)) { return [System.IO.Path]::GetFullPath($Raw) }; if (-not [string]::IsNullOrWhiteSpace($basePath)) { return [System.IO.Path]::GetFullPath([System.IO.Path]::Combine($basePath, $Raw)) }; return [System.IO.Path]::GetFullPath($Raw) }",
    "function Ensure-Parent([string]$Target) { $parent = [System.IO.Path]::GetDirectoryName($Target); if (-not [string]::IsNullOrWhiteSpace($parent)) { [System.IO.Directory]::CreateDirectory($parent) | Out-Null } }",
    "function Get-Sha256([string]$Path) { return (Get-FileHash -LiteralPath $Path -Algorithm SHA256).Hash.ToLowerInvariant() }",
    "function Get-Sha256Bytes([byte[]]$Bytes) { $sha = [System.Security.Cryptography.SHA256]::Create(); try { return ([System.BitConverter]::ToString($sha.ComputeHash($Bytes))).Replace('-', '').ToLowerInvariant() } finally { $sha.Dispose() } }",
    "function Decode-Utf8([string]$Encoded) { return [System.Text.Encoding]::UTF8.GetString([System.Convert]::FromBase64String($Encoded)) }",
    "function Encode-Utf8([string]$Value) { return [System.Convert]::ToBase64String([System.Text.Encoding]::UTF8.GetBytes($Value)) }",
    "function Set-TmpPaths([string]$Target, [string]$Token) { if ($Token -notmatch '^[A-Za-z0-9_.-]+$') { Fail 'invalid apply-patch temp token' 2 }; $dir = [System.IO.Path]::GetDirectoryName($Target); if ([string]::IsNullOrWhiteSpace($dir)) { $dir = (Get-Location).ProviderPath }; $base = [System.IO.Path]::GetFileName($Target); $script:tmp = [System.IO.Path]::Combine($dir, '.' + $base + '.unidesk-v2-' + $Token + '.tmp'); $script:tmpB64 = $script:tmp + '.b64' }",
    "function Verify-Temp([string]$Target, [string]$Tmp, [Int64]$ExpectedBytes, [string]$ExpectedSha256) { $actualBytes = ([System.IO.FileInfo]$Tmp).Length; if ($actualBytes -ne $ExpectedBytes) { Remove-Item -LiteralPath $Tmp -Force -ErrorAction SilentlyContinue; Fail ('apply-patch byte count mismatch for ' + $Target + ': expected=' + $ExpectedBytes + ' actual=' + $actualBytes) 23 }; $actualSha256 = Get-Sha256 $Tmp; if ($actualSha256 -ne $ExpectedSha256) { Remove-Item -LiteralPath $Tmp -Force -ErrorAction SilentlyContinue; Fail ('apply-patch sha256 mismatch for ' + $Target + ': expected=' + $ExpectedSha256 + ' actual=' + $actualSha256) 24 } }",
    "function Decode-ToTarget([string]$Target, [string]$Encoded, [Int64]$ExpectedBytes, [string]$ExpectedSha256) { Ensure-Parent $Target; Set-TmpPaths $Target ([guid]::NewGuid().ToString('N')); try { $bytes = [Convert]::FromBase64String(($Encoded -replace '\\s','')) } catch { Fail ('apply-patch base64 decode failed for ' + $Target + ': ' + $_.Exception.Message) 22 }; [System.IO.File]::WriteAllBytes($script:tmp, $bytes); Verify-Temp $Target $script:tmp $ExpectedBytes $ExpectedSha256; Move-Item -LiteralPath $script:tmp -Destination $Target -Force; $actualSha256 = Get-Sha256 $Target; if ($actualSha256 -ne $ExpectedSha256) { Fail ('apply-patch final sha256 mismatch for ' + $Target) 25 } }",
    "$target = Resolve-UnideskPath $targetArg;",
    "switch ($operation) {",
    "  'stat' { if (-not (Test-Path -LiteralPath $target -PathType Leaf)) { Fail ('file not found: ' + $target) 1 }; $bytes = ([System.IO.FileInfo]$target).Length; $digest = Get-Sha256 $target; [Console]::Out.WriteLine(([string]$bytes) + ' ' + $digest); break }",
    "  'read-b64-block' { $blockIndex = [Int64]$arg1; $blockSize = [Int32]$arg2; if ($blockIndex -lt 0 -or $blockSize -le 0) { Fail 'invalid read block args' 2 }; $fs = [System.IO.File]::Open($target, [System.IO.FileMode]::Open, [System.IO.FileAccess]::Read, [System.IO.FileShare]::ReadWrite); try { [void]$fs.Seek($blockIndex * $blockSize, [System.IO.SeekOrigin]::Begin); $buffer = New-Object byte[] $blockSize; $read = $fs.Read($buffer, 0, $blockSize); if ($read -gt 0) { [Console]::Out.Write([Convert]::ToBase64String($buffer, 0, $read)) } } finally { $fs.Dispose() }; break }",
    "  'read-bulk-b64' { $expectedCount = [Int32]$targetArg; $items = @([Console]::In.ReadToEnd() -split \"`r?`n\" | Where-Object { -not [string]::IsNullOrWhiteSpace($_) }); if ($items.Count -ne $expectedCount) { Fail ('bulk read record count mismatch: expected=' + $expectedCount + ' actual=' + $items.Count) 23 }; [Console]::Out.WriteLine('UNIDESK_APPLY_PATCH_V2_BULK_READ ' + $items.Count); foreach ($item in $items) { $path = Resolve-UnideskPath $item; if (-not (Test-Path -LiteralPath $path -PathType Leaf)) { Fail ('file not found: ' + $path) 1 }; $bytes = [System.IO.File]::ReadAllBytes($path); $pathB64 = Encode-Utf8 $item; $digest = Get-Sha256Bytes $bytes; [Console]::Out.Write($pathB64 + ' ' + $bytes.Length + ' ' + $digest + ' '); [Console]::Out.Write([System.Convert]::ToBase64String($bytes)); [Console]::Out.WriteLine() }; break }",
    "  'apply-replacements-bulk-stdin' { $expectedCount = [Int32]$targetArg; $records = @([Console]::In.ReadToEnd() -split \"`r?`n\" | Where-Object { -not [string]::IsNullOrWhiteSpace($_) }); if ($records.Count -ne $expectedCount) { Fail ('bulk replacement record count mismatch: expected=' + $expectedCount + ' actual=' + $records.Count) 23 }; $utf8 = [System.Text.UTF8Encoding]::new($false); $plans = New-Object System.Collections.Generic.List[object]; $index = 0; foreach ($record in $records) { $index += 1; $fields = $record -split '\\s+'; if ($fields.Count -ne 6) { Fail 'bulk replacement malformed record' 23 }; $targetRelative = Decode-Utf8 $fields[0]; $resolved = Resolve-UnideskPath $targetRelative; $originalBytes = [Int64]$fields[1]; $originalSha256 = $fields[2]; $finalBytes = [Int64]$fields[3]; $finalSha256 = $fields[4]; $replacementsText = $fields[5]; if (-not (Test-Path -LiteralPath $resolved -PathType Leaf)) { Fail ('file not found: ' + $resolved) 1 }; $source = [System.IO.File]::ReadAllBytes($resolved); if ($source.Length -ne $originalBytes -or (Get-Sha256Bytes $source) -ne $originalSha256) { Fail ('bulk replacement original integrity mismatch for ' + $resolved) 23 }; $lines = New-Object System.Collections.Generic.List[string]; $sourceText = [System.Text.Encoding]::UTF8.GetString($source); foreach ($line in ($sourceText -split \"`n\", -1)) { $lines.Add($line) | Out-Null }; if ($lines.Count -gt 0 -and $lines[$lines.Count - 1] -eq '') { $lines.RemoveAt($lines.Count - 1) }; $replacements = New-Object System.Collections.Generic.List[object]; if (-not [string]::IsNullOrEmpty($replacementsText)) { foreach ($item in ($replacementsText -split ';')) { if ([string]::IsNullOrWhiteSpace($item)) { continue }; $parts = $item -split ',', 3; if ($parts.Count -ne 3) { Fail 'bulk replacement malformed replacement' 23 }; $newText = Decode-Utf8 $parts[2]; $newLines = New-Object System.Collections.Generic.List[string]; foreach ($line in ($newText -split \"`n\", -1)) { $newLines.Add($line) | Out-Null }; if ($newLines.Count -gt 0 -and $newLines[$newLines.Count - 1] -eq '') { $newLines.RemoveAt($newLines.Count - 1) }; $replacements.Add([pscustomobject]@{ start = [Int32]$parts[0]; oldLength = [Int32]$parts[1]; newLines = [string[]]$newLines }) | Out-Null } }; foreach ($replacement in @($replacements | Sort-Object -Property start -Descending)) { if ($replacement.start -lt 0 -or $replacement.oldLength -lt 0 -or ($replacement.start + $replacement.oldLength) -gt $lines.Count) { Fail ('bulk replacement out of bounds for ' + $resolved) 23 }; $removeCount = $replacement.oldLength; if ($removeCount -gt 0) { $lines.RemoveRange($replacement.start, $removeCount) }; if ($replacement.newLines.Count -gt 0) { $lines.InsertRange($replacement.start, [string[]]$replacement.newLines) } }; $outputText = if ($lines.Count -eq 0) { '' } else { ([string]::Join(\"`n\", [string[]]$lines) + \"`n\") }; $outputBytes = [System.Text.Encoding]::UTF8.GetBytes($outputText); if ($outputBytes.Length -ne $finalBytes -or (Get-Sha256Bytes $outputBytes) -ne $finalSha256) { Fail ('bulk replacement final integrity mismatch for ' + $resolved) 23 }; $tmp = [System.IO.Path]::Combine([System.IO.Path]::GetDirectoryName($resolved), ('.' + [System.IO.Path]::GetFileName($resolved) + '.unidesk-v2-bulk-' + [guid]::NewGuid().ToString('N') + '.tmp')); [System.IO.File]::WriteAllText($tmp, $outputText, $utf8); $plans.Add([pscustomobject]@{ target = $resolved; tmp = $tmp; sha256 = $finalSha256 }) | Out-Null }; foreach ($plan in $plans) { Ensure-Parent $plan.target; Move-Item -LiteralPath $plan.tmp -Destination $plan.target -Force; if ((Get-Sha256 $plan.target) -ne $plan.sha256) { Fail ('bulk replacement final sha256 mismatch for ' + $plan.target) 25 } }; break }",
    "  'write-b64-stdin' { Decode-ToTarget $target ([Console]::In.ReadToEnd()) ([Int64]$arg1) $arg2; break }",
    "  'write-b64-begin' { Ensure-Parent $target; Set-TmpPaths $target $arg1; [System.IO.File]::WriteAllText($script:tmpB64, '', [System.Text.Encoding]::ASCII); break }",
    "  'write-b64-append-stdin' { Set-TmpPaths $target $arg1; $chunk = ([Console]::In.ReadToEnd()) -replace '\\s',''; [System.IO.File]::AppendAllText($script:tmpB64, $chunk, [System.Text.Encoding]::ASCII); break }",
    "  'write-b64-commit' { Set-TmpPaths $target $arg1; $encoded = [System.IO.File]::ReadAllText($script:tmpB64, [System.Text.Encoding]::ASCII); Remove-Item -LiteralPath $script:tmpB64 -Force -ErrorAction SilentlyContinue; Decode-ToTarget $target $encoded ([Int64]$arg2) $arg3; break }",
    "  'delete' { Remove-Item -LiteralPath $target -Force -ErrorAction SilentlyContinue; break }",
    "  default { Fail ('unsupported apply-patch fs op: ' + $operation) 2 }",
    "}",
  ].join(" ");
}

function chunkString(value: string, chunkSize: number): string[] {
  const chunks: string[] = [];
  for (let index = 0; index < value.length; index += chunkSize) {
    chunks.push(value.slice(index, index + chunkSize));
  }
  return chunks.length > 0 ? chunks : [""];
}

async function runSshCaptureCommand(config: UniDeskConfig, invocation: ParsedSshInvocation, command: string[], input?: string): Promise<SshCaptureResult> {
  const remoteCommand = remoteCommandForRoute(invocation.route, command, { stdin: input !== undefined });
  return await runSshCaptureRemoteCommand(config, invocation, remoteCommand, input);
}

async function runSshCaptureRemoteCommand(config: UniDeskConfig, invocation: ParsedSshInvocation, remoteCommand: string, input?: string): Promise<SshCaptureResult> {
  const startedAtMs = Date.now();
  const size = terminalSize();
  const runtimeTimeoutMs = sshRuntimeTimeoutMs();
  const payload = {
    providerId: invocation.providerId,
    command: wrapSshRemoteCommand(remoteCommand),
    cwd: sshRoutePayloadCwd(invocation.route),
    tty: false,
    stdinEotOnEnd: false,
    openTimeoutMs: Math.max(15000, Number(process.env.UNIDESK_SSH_OPEN_TIMEOUT_MS || 60000)),
    runtimeTimeoutMs,
    cols: size.cols,
    rows: size.rows,
  };
  const payloadJson = JSON.stringify(payload);
  const encodedBrokerSource = Buffer.from(brokerSource(), "utf8").toString("base64");
  const script = [
    "set -eu",
    `payload=${shellQuote(payloadJson)}`,
    "if command -v backend-core >/dev/null 2>&1; then",
    '  exec backend-core --ssh-broker "$payload"',
    "fi",
    `export UNIDESK_SSH_BROKER_URL=${shellQuote("ws://127.0.0.1:8080/ws/ssh")}`,
    'broker_js="$(mktemp "${TMPDIR:-/tmp}/unidesk-ssh-broker.XXXXXX")"',
    'trap \'rm -f "$broker_js"\' EXIT',
    `printf %s ${shellQuote(encodedBrokerSource)} | base64 -d >"$broker_js"`,
    'bun "$broker_js" "$payload"',
  ].join("\n");
  const child = spawn("docker", ["exec", "-i", "unidesk-backend-core", "sh", "-c", script], {
    cwd: repoRoot,
    stdio: ["pipe", "pipe", "pipe"],
  });
  if (input !== undefined) {
    writeChunkedStdin(child.stdin, input);
  } else {
    child.stdin.end();
  }
  let stdout = "";
  let stderr = "";
  child.stdout.on("data", (chunk: Buffer) => {
    stdout += chunk.toString("utf8");
  });
  child.stderr.on("data", (chunk: Buffer) => {
    stderr += chunk.toString("utf8");
  });
  return await new Promise<SshCaptureResult>((resolve) => {
    let settled = false;
    let killTimer: NodeJS.Timeout | null = null;
    const finish = (exitCode: number): void => {
      if (settled) return;
      settled = true;
      clearTimeout(runtimeTimer);
      if (killTimer !== null) clearTimeout(killTimer);
      const timingHint = formatSshRuntimeTimingHint(sshRuntimeTimingHint({
        invocation,
        transport: "backend-core-broker",
        exitCode,
        startedAtMs,
      }));
      if (timingHint) stderr += timingHint;
      resolve({ exitCode, stdout, stderr });
    };
    const runtimeTimer = setTimeout(() => {
      const hint = formatSshRuntimeTimeoutHint(sshRuntimeTimeoutHint({
        invocation,
        transport: "backend-core-broker",
        timeoutMs: runtimeTimeoutMs,
      }));
      stderr += hint;
      try {
        child.kill("SIGTERM");
      } catch {
        // Ignore.
      }
      killTimer = setTimeout(() => {
        try {
          child.kill("SIGKILL");
        } catch {
          // Ignore.
        }
      }, 2000);
      finish(124);
    }, runtimeTimeoutMs);
    child.on("error", (error) => {
      stderr += `unidesk ssh failed to start broker: ${error.message}\n`;
      finish(255);
    });
    child.on("close", (code) => finish(code ?? 255));
  });
}

async function runSshStreamRemoteCommand(
  config: UniDeskConfig,
  invocation: ParsedSshInvocation,
  remoteCommand: string,
  handlers: SshRemoteCommandStreamHandlers,
  input?: string,
  options: { inactivityTimeoutMs?: number } = {},
): Promise<SshCaptureResult> {
  const streamInvocation = {
    ...invocation,
    parsed: { ...invocation.parsed, remoteCommand, requiresStdin: input !== undefined, invocationKind: "helper" as const },
  };
  const startedAtMs = Date.now();
  const size = terminalSize();
  const inactivityTimeoutMs = options.inactivityTimeoutMs ?? sshRuntimeTimeoutMs();
  const runtimeTimeoutMs = options.inactivityTimeoutMs === undefined ? inactivityTimeoutMs : Math.max(inactivityTimeoutMs * 4, 60 * 60_000);
  const payload = {
    providerId: invocation.providerId,
    command: wrapSshRemoteCommand(remoteCommand),
    cwd: sshRoutePayloadCwd(invocation.route),
    tty: false,
    stdinEotOnEnd: false,
    openTimeoutMs: Math.max(15000, Number(process.env.UNIDESK_SSH_OPEN_TIMEOUT_MS || 60000)),
    runtimeTimeoutMs,
    runtimeTimeoutMode: options.inactivityTimeoutMs === undefined ? "wall-clock" : "inactivity",
    cols: size.cols,
    rows: size.rows,
  };
  const payloadJson = JSON.stringify(payload);
  const encodedBrokerSource = Buffer.from(brokerSource(), "utf8").toString("base64");
  const script = [
    "set -eu",
    `payload=${shellQuote(payloadJson)}`,
    "if command -v backend-core >/dev/null 2>&1; then",
    '  exec backend-core --ssh-broker "$payload"',
    "fi",
    `export UNIDESK_SSH_BROKER_URL=${shellQuote("ws://127.0.0.1:8080/ws/ssh")}`,
    'broker_js="$(mktemp "${TMPDIR:-/tmp}/unidesk-ssh-broker.XXXXXX")"',
    'trap \'rm -f "$broker_js"\' EXIT',
    `printf %s ${shellQuote(encodedBrokerSource)} | base64 -d >"$broker_js"`,
    'bun "$broker_js" "$payload"',
  ].join("\n");
  const child = spawn("docker", ["exec", "-i", "unidesk-backend-core", "sh", "-c", script], {
    cwd: repoRoot,
    stdio: ["pipe", "pipe", "pipe"],
  });
  if (input !== undefined) {
    writeChunkedStdin(child.stdin, input);
  } else {
    child.stdin.end();
  }
  let stdout = "";
  let stderr = "";
  let streamError: unknown = null;
  let streamWrites = Promise.resolve();
  const queueStreamWrite = (chunk: Buffer, stream: "stdout" | "stderr"): void => {
    streamWrites = streamWrites.then(async () => {
      if (stream === "stdout") await handlers.onStdout(chunk);
      else if (handlers.onStderr !== undefined) await handlers.onStderr(chunk);
    }).catch((error) => {
      streamError = error;
      stderr += `unidesk ssh stream sink failed: ${error instanceof Error ? error.message : String(error)}\n`;
      try {
        child.kill("SIGTERM");
      } catch {
        // Ignore kill failures after a local stream sink error.
      }
    });
  };
  child.stdout.on("data", (chunk: Buffer) => {
    queueStreamWrite(chunk, "stdout");
  });
  child.stderr.on("data", (chunk: Buffer) => {
    stderr += chunk.toString("utf8");
    queueStreamWrite(chunk, "stderr");
  });
  return await new Promise<SshCaptureResult>((resolve) => {
    let settled = false;
    let killTimer: NodeJS.Timeout | null = null;
    let inactivityTimer: NodeJS.Timeout | null = null;
    const refreshActivityTimer = (): void => {
      if (settled || options.inactivityTimeoutMs === undefined) return;
      if (inactivityTimer !== null) clearTimeout(inactivityTimer);
      inactivityTimer = setTimeout(() => {
        const hint = formatSshRuntimeTimeoutHint(sshRuntimeTimeoutHint({
          invocation: streamInvocation,
          transport: "backend-core-broker",
          timeoutMs: inactivityTimeoutMs,
        }));
        stderr += hint;
        try {
          child.kill("SIGTERM");
        } catch {
          // Ignore.
        }
        killTimer = setTimeout(() => {
          try {
            child.kill("SIGKILL");
          } catch {
            // Ignore.
          }
        }, 2000);
        finish(124);
      }, inactivityTimeoutMs);
    };
    const finish = (exitCode: number): void => {
      if (settled) return;
      settled = true;
      clearTimeout(runtimeTimer);
      if (inactivityTimer !== null) clearTimeout(inactivityTimer);
      if (killTimer !== null) clearTimeout(killTimer);
      void streamWrites.then(() => {
        const finalCode = streamError === null ? exitCode : 255;
        const timingHint = formatSshRuntimeTimingHint(sshRuntimeTimingHint({
          invocation: streamInvocation,
          transport: "backend-core-broker",
          exitCode: finalCode,
          startedAtMs,
        }));
        if (timingHint) stderr += timingHint;
        resolve({ exitCode: finalCode, stdout, stderr });
      });
    };
    const runtimeTimer = setTimeout(() => {
      const hint = formatSshRuntimeTimeoutHint(sshRuntimeTimeoutHint({
        invocation: streamInvocation,
        transport: "backend-core-broker",
        timeoutMs: runtimeTimeoutMs,
      }));
      stderr += hint;
      try {
        child.kill("SIGTERM");
      } catch {
        // Ignore.
      }
      killTimer = setTimeout(() => {
        try {
          child.kill("SIGKILL");
        } catch {
          // Ignore.
        }
      }, 2000);
      finish(124);
    }, runtimeTimeoutMs);
    refreshActivityTimer();
    child.on("error", (error) => {
      stderr += `unidesk ssh failed to start broker: ${error.message}\n`;
      finish(255);
    });
    child.on("close", (code) => finish(code ?? 255));
    child.stdout.on("data", refreshActivityTimer);
    child.stderr.on("data", refreshActivityTimer);
  });
}

async function runRemoteSsh(config: UniDeskConfig, host: string, providerId: string, args: string[]): Promise<number> {
  const { runRemoteCli } = await import("./remote");
  return await runRemoteCli({
    host,
    user: "root",
    port: 22,
    projectRoot: repoRoot,
    identityFile: null,
    transport: "frontend",
    args: ["ssh", providerId, ...args],
  }, config);
}

export async function runSshCommandCapture(config: UniDeskConfig, target: string, args: string[], input?: string): Promise<SshCaptureResult> {
  const invocation = parseSshInvocation(target, args);
  const parsed = invocation.parsed;
  if (parsed.remoteCommand === null) throw new Error(`ssh ${target} capture requires a non-interactive operation`);
  const stdin = parsed.stdinPrefix !== undefined || parsed.stdinSuffix !== undefined
    ? `${parsed.stdinPrefix ?? ""}${input ?? ""}${parsed.stdinSuffix ?? ""}`
    : input;
  const plan = sshCaptureBackendPlan(config, process.env);
  if (plan.backend === "remote-frontend-websocket" && plan.remoteHost !== null) {
    return await runRemoteSshCapture(config, plan.remoteHost, target, args, stdin);
  }
  const local = await runSshCaptureRemoteCommand(config, invocation, parsed.remoteCommand, stdin);
  const fallbackHost = sshCaptureRemoteHost(config, process.env);
  if (local.exitCode !== 0 && fallbackHost !== null && isLocalSshCaptureBackendUnavailable(local)) {
    return await runRemoteSshCapture(config, fallbackHost, target, args, stdin);
  }
  return local;
}

async function runRemoteSshCapture(config: UniDeskConfig, host: string, target: string, args: string[], input?: string): Promise<SshCaptureResult> {
  const { runRemoteSshCommandCapture } = await import("./remote");
  return await runRemoteSshCommandCapture(config, host, target, args, input);
}

export function sshCaptureBackendPlan(config: UniDeskConfig, env: NodeJS.ProcessEnv = process.env): SshCaptureBackendPlan {
  const localBackendCore = detectLocalBackendCoreStatus();
  const remoteHost = sshCaptureRemoteHost(config, env);
  const runnerEnv = isRunnerEnvironment(env);
  if (runnerEnv && remoteHost !== null) return { backend: "remote-frontend-websocket", remoteHost, reason: "runner-environment", localBackendCore };
  if (!localBackendCore.backendCoreContainer && remoteHost !== null) return { backend: "remote-frontend-websocket", remoteHost, reason: "local-backend-core-unavailable", localBackendCore };
  return { backend: "local-backend-core-broker", remoteHost: null, reason: "main-server-local-backend-core", localBackendCore };
}

function sshCaptureRemoteHost(config: UniDeskConfig, env: NodeJS.ProcessEnv): string | null {
  return normalizeRemoteHost(env.UNIDESK_MAIN_SERVER_IP)
    ?? normalizeRemoteHost(env.UNIDESK_MAIN_SERVER_HOST)
    ?? normalizeRemoteHost(env.CODE_QUEUE_DEV_CONTAINER_MASTER_HOST)
    ?? normalizeRemoteHost(config.network.publicHost);
}

function normalizeRemoteHost(raw: string | undefined): string | null {
  const value = raw?.trim() ?? "";
  if (value.length === 0 || value === "localhost" || value === "127.0.0.1" || value === "::1") return null;
  return value.replace(/\/+$/u, "");
}

function isRunnerEnvironment(env: NodeJS.ProcessEnv): boolean {
  return Boolean(
    env.AGENTRUN_BOOT_MODE
      || env.AGENTRUN_RUN_ID
      || env.AGENTRUN_K8S_JOB_NAME
      || env.CODE_QUEUE_SERVICE_ROLE
      || env.CODE_QUEUE_INSTANCE_ID
      || env.KUBERNETES_SERVICE_HOST,
  );
}

function detectLocalBackendCoreStatus(): SshCaptureBackendPlan["localBackendCore"] {
  const result = spawnSync("docker", ["ps", "--format", "{{.Names}}"], { encoding: "utf8", timeout: 2000 });
  if (result.error !== undefined) return { dockerExecutable: false, backendCoreContainer: false, error: result.error.message };
  const output = `${result.stdout ?? ""}\n${result.stderr ?? ""}`.trim();
  return {
    dockerExecutable: result.status === 0,
    backendCoreContainer: result.status === 0 && String(result.stdout ?? "").split(/\r?\n/u).includes("unidesk-backend-core"),
    error: result.status === 0 ? null : output || `docker ps exited ${result.status ?? "unknown"}`,
  };
}

function isLocalSshCaptureBackendUnavailable(result: SshCaptureResult): boolean {
  return /No such container: unidesk-backend-core|failed to start broker|Executable not found.*"docker"|docker: not found|Cannot connect to the Docker daemon/iu.test(result.stderr);
}

function writeChunkedStdin(stdin: NodeJS.WritableStream, input: string): void {
  const buffer = Buffer.from(input, "utf8");
  const chunkSize = 32 * 1024;
  for (let offset = 0; offset < buffer.length; offset += chunkSize) {
    stdin.write(buffer.subarray(offset, Math.min(buffer.length, offset + chunkSize)));
  }
  stdin.end();
}

export async function runSsh(config: UniDeskConfig, providerId: string, args: string[]): Promise<number> {
  const normalizedArgs = normalizeSshOperationArgs(args);
  process.stderr.write(sshRouteSeparatorCompatibilityHint(args, normalizedArgs));
  const plan = sshCaptureBackendPlan(config, process.env);
  if (plan.backend === "remote-frontend-websocket" && plan.remoteHost !== null) {
    return await runRemoteSsh(config, plan.remoteHost, providerId, normalizedArgs);
  }
  const invocation = parseSshInvocation(providerId, normalizedArgs);
  const parsed = invocation.parsed;
  const operationName = normalizedArgs[0] ?? "";
  if (isSshFileTransferOperation(normalizedArgs)) {
    const executor: SshRemoteCommandExecutor = {
      runRemoteCommand: (remoteCommand, input) => runSshCaptureRemoteCommand(config, invocation, remoteCommand, input),
      streamRemoteCommand: (remoteCommand, handlers, input, options) => runSshStreamRemoteCommand(config, invocation, remoteCommand, handlers, input, options),
    };
    return await runSshFileTransferOperation(invocation, normalizedArgs, executor, {
      buildRouteCommand: remoteCommandForRoute,
      buildWindowsPowerShellCommand: buildWindowsPowerShellInvocation,
    });
  }
  if (operationName === "apply-patch") {
    const executor: ApplyPatchV2Executor = invocation.route.plane === "win"
      ? { fs: createWindowsApplyPatchFileSystem(config, invocation) }
      : { run: (command, input) => runSshCaptureCommand(config, invocation, command, input) };
    return await runApplyPatchV2({
      executor,
      stdin: process.stdin,
      stdout: process.stdout,
      stderr: process.stderr,
      argv: normalizedArgs.slice(1),
      timing: {
        providerId: invocation.providerId,
        route: invocation.route.raw,
        transport: "backend-core-broker",
      },
    });
  }
  const startedAtMs = Date.now();
  const size = terminalSize();
  const openTimeoutMs = Math.max(15000, Number(process.env.UNIDESK_SSH_OPEN_TIMEOUT_MS || 60000));
  const runtimeTimeoutMs = sshRuntimeTimeoutMs();
  const payload = {
    providerId: invocation.providerId,
    command: wrapSshRemoteCommand(parsed.remoteCommand, parsed.requiredHelpers),
    cwd: sshRoutePayloadCwd(invocation.route),
    tty: parsed.remoteCommand === null,
    stdinEotOnEnd: parsed.remoteCommand !== null && parsed.requiresStdin !== true,
    openTimeoutMs,
    runtimeTimeoutMs,
    cols: size.cols,
    rows: size.rows,
  };
  const payloadJson = JSON.stringify(payload);
  const encodedBrokerSource = Buffer.from(brokerSource(), "utf8").toString("base64");
  const script = [
    "set -eu",
    `payload=${shellQuote(payloadJson)}`,
    "if command -v backend-core >/dev/null 2>&1; then",
    '  exec backend-core --ssh-broker "$payload"',
    "fi",
    `export UNIDESK_SSH_BROKER_URL=${shellQuote("ws://127.0.0.1:8080/ws/ssh")}`,
    'broker_js="$(mktemp "${TMPDIR:-/tmp}/unidesk-ssh-broker.XXXXXX")"',
    'trap \'rm -f "$broker_js"\' EXIT',
    `printf %s ${shellQuote(encodedBrokerSource)} | base64 -d >"$broker_js"`,
    'bun "$broker_js" "$payload"',
  ].join("\n");
  const child = spawn("docker", [
    "exec",
    "-i",
    "unidesk-backend-core",
    "sh",
    "-c",
    script,
  ], {
    cwd: repoRoot,
    stdio: ["pipe", "pipe", "pipe"],
  });

  const rawMode = parsed.remoteCommand === null && process.stdin.isTTY;
  if (rawMode) process.stdin.setRawMode(true);
  process.stdin.resume();
  if (parsed.stdinPrefix !== undefined || parsed.stdinSuffix !== undefined) {
    if (parsed.stdinPrefix) child.stdin.write(parsed.stdinPrefix);
    process.stdin.pipe(child.stdin, { end: false });
    process.stdin.once("end", () => {
      if (parsed.stdinSuffix) child.stdin.write(parsed.stdinSuffix);
      child.stdin.end();
    });
  } else {
    process.stdin.pipe(child.stdin);
  }
  let stderrTail = "";
  const appendStderrTail = (chunk: Buffer | string): void => {
    const text = Buffer.isBuffer(chunk) ? chunk.toString("utf8") : chunk;
    stderrTail = (stderrTail + text).slice(-16_384);
  };
  if (parsed.remoteCommand === null) {
    child.stdout.pipe(process.stdout);
  } else {
    const stdoutForwarder = createSshStdoutForwarder({
      invocation,
      transport: "backend-core-broker",
    });
    child.stdout.on("data", (chunk: Buffer) => {
      const hint = stdoutForwarder.write(chunk);
      if (hint !== null) {
        appendStderrTail(hint);
        process.stderr.write(hint);
      }
    });
  }
  child.stderr.on("data", (chunk: Buffer) => {
    appendStderrTail(chunk);
    process.stderr.write(chunk);
  });

  return await new Promise<number>((resolve) => {
    let settled = false;
    let timedOut = false;
    let killTimer: NodeJS.Timeout | null = null;
    const runtimeTimer = setTimeout(() => {
      if (settled) return;
      timedOut = true;
      const hint = sshRuntimeTimeoutHint({
        invocation,
        transport: "backend-core-broker",
        timeoutMs: runtimeTimeoutMs,
      });
      const formatted = formatSshRuntimeTimeoutHint(hint);
      appendStderrTail(formatted);
      process.stderr.write(formatted);
      try {
        child.stdin.destroy();
      } catch {
        // Ignore stdin teardown failures on the timeout path.
      }
      try {
        child.kill("SIGTERM");
      } catch {
        // Ignore kill failures and fall through to finish.
      }
      killTimer = setTimeout(() => {
        try {
          child.kill("SIGKILL");
        } catch {
          // Process may have already exited.
        }
      }, 2000);
      finish(124);
    }, runtimeTimeoutMs);
    const restore = (): void => {
      clearTimeout(runtimeTimer);
      if (killTimer && !timedOut) clearTimeout(killTimer);
      process.stdin.unpipe(child.stdin);
      if (rawMode) process.stdin.setRawMode(false);
    };
    const finish = (exitCode: number): void => {
      if (settled) return;
      settled = true;
      restore();
      const hint = timedOut ? null : sshFailureHint(invocation.providerId, parsed, exitCode, stderrTail);
      if (hint !== null) process.stderr.write(formatSshFailureHint(hint));
      const timingHint = formatSshRuntimeTimingHint(sshRuntimeTimingHint({
        invocation,
        transport: "backend-core-broker",
        exitCode,
        startedAtMs,
      }));
      if (timingHint) process.stderr.write(timingHint);
      resolve(exitCode);
    };
    child.on("error", (error) => {
      const message = `unidesk ssh failed to start broker: ${error.message}\n`;
      appendStderrTail(message);
      process.stderr.write(message);
      finish(255);
    });
    child.on("close", (code) => {
      finish(code ?? 255);
    });
  });
}