import { spawn } from "node:child_process";
import { type UniDeskConfig, repoRoot } from "./config";

export interface ParsedSshArgs {
  remoteCommand: string | null;
  requiresStdin: boolean;
  invocationKind: SshInvocationKind;
}

export type SshInvocationKind = "interactive" | "argv" | "helper" | "ssh-like";

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;
}

const argvQuotedSshSubcommands = new Set(["rg", "grep", "sed", "nl", "stat", "du", "ls", "cat", "head", "tail", "wc", "pwd"]);

const remoteApplyPatchSource = String.raw`#!/usr/bin/env python3
import sys
from pathlib import Path


def die(message):
    print(f"apply_patch: {message}", file=sys.stderr)
    sys.exit(1)


def write_file(path, text):
    target = Path(path)
    target.parent.mkdir(parents=True, exist_ok=True)
    target.write_text(text)


def move_file(source, destination):
    source_path = Path(source)
    destination_path = Path(destination)
    if not source_path.exists():
        die(f"file not found: {source}")
    if destination_path.exists():
        die(f"target file already exists: {destination}")
    destination_path.parent.mkdir(parents=True, exist_ok=True)
    source_path.rename(destination_path)


def read_file(path):
    try:
        return Path(path).read_text()
    except FileNotFoundError:
        die(f"file not found: {path}")


def apply_update(path, body):
    old = read_file(path)
    output = []
    search_from = 0
    index = 0
    while index < len(body):
        if body[index].startswith("*** End of File"):
            index += 1
            continue
        if not body[index].startswith("@@"):
            die(f"expected hunk header in {path}")
        index += 1
        sequence = []
        while index < len(body) and not body[index].startswith("@@"):
            line = body[index]
            index += 1
            if line.startswith("*** End of File"):
                continue
            if line.startswith(" "):
                sequence.append((" ", line[1:]))
            elif line.startswith("-"):
                sequence.append(("-", line[1:]))
            elif line.startswith("+"):
                sequence.append(("+", line[1:]))
            elif line.rstrip("\n") == r"\ No newline at end of file":
                continue
            else:
                die(f"bad hunk line in {path}: {line[:80].rstrip()}")
        search = "".join(text for kind, text in sequence if kind in (" ", "-"))
        replacement = "".join(text for kind, text in sequence if kind in (" ", "+"))
        offset = old.find(search, search_from)
        if offset < 0:
            offset = old.find(search)
        if offset < 0:
            die(f"hunk context not found in {path}")
        output.append(old[search_from:offset])
        output.append(replacement)
        search_from = offset + len(search)
    output.append(old[search_from:])
    write_file(path, "".join(output))


def main():
    if len(sys.argv) > 1 and sys.argv[1] in ("-h", "--help"):
        print("apply_patch: read *** Begin Patch format from stdin; supports add/update/delete/move")
        return
    lines = sys.stdin.read().splitlines(keepends=True)
    if not lines or lines[0].strip() != "*** Begin Patch":
        die("patch must start with *** Begin Patch")
    index = 1
    while index < len(lines):
        line = lines[index].rstrip("\n")
        if line == "*** End Patch":
            print("Done!")
            return
        if line.startswith("*** Add File: "):
            path = line[len("*** Add File: "):].strip()
            index += 1
            content = []
            while index < len(lines) and not lines[index].startswith("*** "):
                if not lines[index].startswith("+"):
                    die(f"add file lines must start with + for {path}")
                content.append(lines[index][1:])
                index += 1
            if Path(path).exists():
                die(f"file already exists: {path}")
            write_file(path, "".join(content))
            continue
        if line.startswith("*** Delete File: "):
            path = line[len("*** Delete File: "):].strip()
            try:
                Path(path).unlink()
            except FileNotFoundError:
                die(f"file not found: {path}")
            index += 1
            continue
        if line.startswith("*** Update File: "):
            path = line[len("*** Update File: "):].strip()
            index += 1
            move_to = None
            if index < len(lines) and lines[index].startswith("*** Move to: "):
                move_to = lines[index][len("*** Move to: "):].strip()
                index += 1
            body = []
            while index < len(lines) and not (
                lines[index].startswith("*** Add File: ")
                or lines[index].startswith("*** Update File: ")
                or lines[index].startswith("*** Delete File: ")
                or lines[index].startswith("*** End Patch")
            ):
                if lines[index].startswith("*** Move to: "):
                    die("move marker must appear before update hunks")
                body.append(lines[index])
                index += 1
            if body:
                apply_update(path, body)
            elif move_to is None and not Path(path).exists():
                die(f"file not found: {path}")
            if move_to is not None:
                move_file(path, move_to)
            continue
        die(f"unexpected patch line: {line}")
    die("missing *** End Patch")


if __name__ == "__main__":
    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 (isSshSkillDiscoveryArgs(args)) {
    const toolArgs = subcommand === "skill" ? ["skill-discover", ...args.slice(2)] : ["skill-discover", ...args.slice(1)];
    return { remoteCommand: shellArgv(toolArgs), requiresStdin: false, invocationKind: "helper" };
  }
  if (subcommand === "apply-patch" || subcommand === "patch") {
    const toolArgs = ["apply_patch", ...args.slice(1)];
    return { remoteCommand: shellArgv(toolArgs), requiresStdin: true, invocationKind: "helper" };
  }
  if (subcommand === "py") {
    return { remoteCommand: buildPythonStdinCommand(args.slice(1)), requiresStdin: true, invocationKind: "helper" };
  }
  if (subcommand === "argv" || subcommand === "exec") {
    const toolArgs = args.slice(1);
    if (toolArgs.length === 0) throw new Error(`ssh ${subcommand} requires a command`);
    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" };
  }
  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",
  };
}

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

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 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 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("; ");
}

function remoteToolBootstrapCommand(): string {
  const encodedApplyPatch = Buffer.from(remoteApplyPatchSource, "utf8").toString("base64");
  const encodedGlob = Buffer.from(remoteGlobSource, "utf8").toString("base64");
  const encodedSkillDiscover = Buffer.from(remoteSkillDiscoverSource, "utf8").toString("base64");
  return [
    "UNIDESK_SSH_TOOL_DIR=/tmp/unidesk-ssh-tools",
    'mkdir -p "$UNIDESK_SSH_TOOL_DIR"',
    `printf %s ${shellQuote(encodedApplyPatch)} | base64 -d > "$UNIDESK_SSH_TOOL_DIR/apply_patch"`,
    `printf %s ${shellQuote(encodedGlob)} | base64 -d > "$UNIDESK_SSH_TOOL_DIR/glob"`,
    `printf %s ${shellQuote(encodedSkillDiscover)} | base64 -d > "$UNIDESK_SSH_TOOL_DIR/skill-discover"`,
    'chmod 700 "$UNIDESK_SSH_TOOL_DIR/apply_patch"',
    'chmod 700 "$UNIDESK_SSH_TOOL_DIR/glob"',
    'chmod 700 "$UNIDESK_SSH_TOOL_DIR/skill-discover"',
    'export PATH="$UNIDESK_SSH_TOOL_DIR:$PATH"',
  ].join("; ");
}

export function wrapSshRemoteCommand(command: string | null): string {
  const bootstrap = remoteToolBootstrapCommand();
  if (command === null) return `${bootstrap}; exec "\${SHELL:-/bin/bash}" -l`;
  return `${bootstrap}; 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 argv form for non-interactive commands.",
    try: `bun scripts/cli.ts ssh ${shownProviderId} argv bash -lc '<command>'`,
    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`;
}

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));

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 (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);
    process.stderr.write(String(message.message || "ssh bridge error") + "\n");
    exitCode = 255;
    ws.close();
    return;
  }
  if (message.type === "ssh.exit") {
    clearTimeout(openTimer);
    exitCode = Number.isInteger(message.exitCode) ? message.exitCode : 255;
    ws.close();
  }
});

ws.addEventListener("close", () => {
  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 async function runSsh(config: UniDeskConfig, providerId: string, args: string[]): Promise<number> {
  if (!providerId) throw new Error("ssh requires provider id, for example: bun scripts/cli.ts ssh D518");
  const parsed = parseSshArgs(args);
  const size = terminalSize();
  const openTimeoutMs = Math.max(15000, Number(process.env.UNIDESK_SSH_OPEN_TIMEOUT_MS || 60000));
  const payload = {
    providerId,
    command: wrapSshRemoteCommand(parsed.remoteCommand),
    tty: parsed.remoteCommand === null,
    stdinEotOnEnd: parsed.remoteCommand !== null,
    openTimeoutMs,
    cols: size.cols,
    rows: size.rows,
  };
  const payloadJson = JSON.stringify(payload);
  const encodedBrokerSource = Buffer.from(brokerSource(), "utf8").toString("base64");
  const script = [
    "set -euo pipefail",
    `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")}`,
    `printf %s ${shellQuote(encodedBrokerSource)} | base64 -d >/tmp/unidesk-ssh-broker.js`,
    "exec bun /tmp/unidesk-ssh-broker.js \"$payload\"",
  ].join("\n");
  const child = spawn("docker", [
    "exec",
    "-i",
    "unidesk-backend-core",
    "sh",
    "-lc",
    script,
  ], {
    cwd: repoRoot,
    stdio: ["pipe", "pipe", "pipe"],
  });

  const rawMode = parsed.remoteCommand === null && process.stdin.isTTY;
  if (rawMode) process.stdin.setRawMode(true);
  process.stdin.resume();
  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);
  };
  child.stdout.pipe(process.stdout);
  child.stderr.on("data", (chunk: Buffer) => {
    appendStderrTail(chunk);
    process.stderr.write(chunk);
  });

  return await new Promise<number>((resolve) => {
    const restore = (): void => {
      process.stdin.unpipe(child.stdin);
      if (rawMode) process.stdin.setRawMode(false);
    };
    child.on("error", (error) => {
      restore();
      const message = `unidesk ssh failed to start broker: ${error.message}\n`;
      appendStderrTail(message);
      process.stderr.write(message);
      const hint = sshFailureHint(providerId, parsed, 255, stderrTail);
      if (hint !== null) process.stderr.write(formatSshFailureHint(hint));
      resolve(255);
    });
    child.on("close", (code) => {
      restore();
      const exitCode = code ?? 255;
      const hint = sshFailureHint(providerId, parsed, exitCode, stderrTail);
      if (hint !== null) process.stderr.write(formatSshFailureHint(hint));
      resolve(exitCode);
    });
  });
}