import { spawnSync } from "node:child_process";
import { mkdtempSync, readFileSync, rmSync, writeFileSync } from "node:fs";
import os from "node:os";
import path from "node:path";
import { sshHelp } from "./src/help";
import { providerTriageRecommendedCrossChecks } from "./src/provider-triage";
import { formatSshFailureHint, parseSshArgs, parseSshInvocation, remoteApplyPatchSource, sshFailureHint } from "./src/ssh";

type JsonRecord = Record<string, unknown>;

function assertCondition(condition: unknown, message: string, detail: unknown = {}): void {
  if (!condition) throw new Error(`${message}: ${JSON.stringify(detail)}`);
}

function assertThrows(fn: () => unknown, pattern: RegExp, message: string): void {
  try {
    fn();
  } catch (error) {
    const text = error instanceof Error ? error.message : String(error);
    assertCondition(pattern.test(text), message, { error: text });
    return;
  }
  throw new Error(`${message}: expected throw`);
}

function applyPatchFixture(args: string[], patch: string, files: Record<string, string>): { status: number | null; stdout: string; stderr: string; files: Record<string, string> } {
  const root = mkdtempSync(path.join(os.tmpdir(), "unidesk-apply-patch-contract-"));
  try {
    const helperPath = path.join(root, "apply_patch");
    writeFileSync(helperPath, remoteApplyPatchSource, "utf8");
    for (const [relativePath, content] of Object.entries(files)) {
      const target = path.join(root, relativePath);
      writeFileSync(target, content, "utf8");
    }
    const run = spawnSync("sh", [helperPath, ...args], {
      cwd: root,
      input: patch,
      encoding: "utf8",
    });
    const outputFiles: Record<string, string> = {};
    for (const relativePath of Object.keys(files)) {
      outputFiles[relativePath] = readFileSync(path.join(root, relativePath), "utf8");
    }
    return {
      status: run.status,
      stdout: run.stdout,
      stderr: run.stderr,
      files: outputFiles,
    };
  } finally {
    rmSync(root, { recursive: true, force: true });
  }
}

export function runSshArgvGuidanceContract(): JsonRecord {
  const argv = parseSshArgs(["argv", "true"]);
  assertCondition(argv.invocationKind === "argv", "argv subcommand must be classified as argv", argv);
  assertCondition(argv.remoteCommand === "'true'", "argv command must shell-quote each token", argv);
  assertCondition(argv.requiresStdin === false, "argv command must not require stdin", argv);
  assertCondition(sshFailureHint("D601", argv, 255, "kex_exchange_identification: Connection closed by remote host") === null, "argv failures must not produce ssh-like friction hint", argv);

  const shortcut = parseSshArgs(["pwd"]);
  assertCondition(shortcut.invocationKind === "argv", "safe command shortcuts must use argv quoting", shortcut);
  assertCondition(shortcut.remoteCommand === "'pwd'", "safe command shortcut should be shell-quoted", shortcut);

  const hostWorkspace = parseSshInvocation("D601:/home/ubuntu/workspace/hwlab-dev", ["pwd"]);
  assertCondition(hostWorkspace.route.plane === "host" && hostWorkspace.route.workspace === "/home/ubuntu/workspace/hwlab-dev", "host workspace route must parse provider:/absolute/path", hostWorkspace);
  assertCondition(hostWorkspace.parsed.remoteCommand === "'pwd'", "host workspace route must leave operation argv independent from location", hostWorkspace);

  const hostWorkspaceLongForm = parseSshInvocation("D601:host:/home/ubuntu/workspace/hwlab-dev", ["argv", "git", "status", "--short"]);
  assertCondition(hostWorkspaceLongForm.route.workspace === "/home/ubuntu/workspace/hwlab-dev", "host: workspace route must parse as the same location model", hostWorkspaceLongForm);
  assertCondition(hostWorkspaceLongForm.parsed.remoteCommand === "'git' 'status' '--short'", "host workspace argv operation must stay argv-quoted", hostWorkspaceLongForm);

  const script = parseSshArgs(["script", "--shell", "bash", "--", "alpha beta"]);
  assertCondition(script.invocationKind === "helper", "script stdin helper must be classified as helper", script);
  assertCondition(script.remoteCommand === "'bash' '-s' '--' 'alpha beta'", "script helper must pass stdin to shell directly", script);
  assertCondition(script.requiresStdin === true, "script helper must require stdin", script);

  const k3sGuard = parseSshInvocation("D601:k3s", ["guard"]).parsed;
  assertCondition(k3sGuard.invocationKind === "helper", "k3s guard must be classified as helper", k3sGuard);
  assertCondition(k3sGuard.remoteCommand?.includes("KUBECONFIG") && k3sGuard.remoteCommand.includes("/etc/rancher/k3s/k3s.yaml"), "k3s guard must force native k3s kubeconfig", k3sGuard);

  const k3sExec = parseSshInvocation("D601:k3s", ["exec", "--namespace", "hwlab-dev", "--deployment", "hwlab-cloud-api", "--", "node", "-e", "console.log(process.version)"]).parsed;
  assertCondition(k3sExec.invocationKind === "helper", "k3s exec must be classified as helper", k3sExec);
  assertCondition(k3sExec.remoteCommand === "'env' 'KUBECONFIG=/etc/rancher/k3s/k3s.yaml' 'kubectl' 'exec' '-n' 'hwlab-dev' 'deployment/hwlab-cloud-api' '--' 'node' '-e' 'console.log(process.version)'", "k3s exec must assemble kubectl argv without nested shell quoting", k3sExec);

  const routeKubectl = parseSshInvocation("D601:k3s", ["kubectl", "get", "pods", "-n", "hwlab-dev"]);
  assertCondition(routeKubectl.providerId === "D601", "route must preserve provider id", routeKubectl);
  assertCondition(routeKubectl.route.plane === "k3s" && routeKubectl.route.entry === null, "route must keep kubectl as an operation, not as a route entry", routeKubectl);
  assertCondition(routeKubectl.parsed.remoteCommand === "'env' 'KUBECONFIG=/etc/rancher/k3s/k3s.yaml' 'kubectl' 'get' 'pods' '-n' 'hwlab-dev'", "D601:k3s kubectl must map to kubectl argv", routeKubectl);

  const g14Guard = parseSshInvocation("G14:k3s", []);
  assertCondition(g14Guard.providerId === "G14" && g14Guard.route.plane === "k3s", "G14:k3s must parse as a native k3s route", g14Guard);
  assertCondition(g14Guard.parsed.remoteCommand?.includes("UNIDESK_K3S_PROVIDER_ID") && g14Guard.parsed.remoteCommand.includes("ubuntu-rog-zephyrus-g14-ga401iv-ga401iv"), "G14:k3s guard must use the G14 node profile", g14Guard);

  assertThrows(
    () => parseSshInvocation("G14", ["k3s", "kubectl", "get", "nodes"]),
    /unsupported.*ssh G14:k3s/u,
    "k3s must be a route plane, not a post-provider shorthand",
  );

  const routeTarget = parseSshInvocation("D601:k3s:hwlab-dev:hwlab-cloud-api", ["node", "-e", "console.log(process.version)"]);
  assertCondition(routeTarget.route.namespace === "hwlab-dev" && routeTarget.route.resource === "hwlab-cloud-api", "route target must parse namespace and workload", routeTarget);
  assertCondition(routeTarget.parsed.remoteCommand === "'env' 'KUBECONFIG=/etc/rancher/k3s/k3s.yaml' 'kubectl' 'exec' '-n' 'hwlab-dev' 'deployment/hwlab-cloud-api' '--' 'node' '-e' 'console.log(process.version)'", "D601:k3s:<namespace>:<workload> must default to deployment exec", routeTarget);

  const routeScript = parseSshInvocation("D601:k3s:hwlab-dev:hwlab-cloud-api", ["script", "--shell", "bash", "--", "arg"]);
  assertCondition(routeScript.parsed.requiresStdin === true, "k3s script operation must stream local stdin", routeScript);
  assertCondition(routeScript.parsed.remoteCommand === "'env' 'KUBECONFIG=/etc/rancher/k3s/k3s.yaml' 'kubectl' 'exec' '-i' '-n' 'hwlab-dev' 'deployment/hwlab-cloud-api' '--' 'bash' '-s' '--' 'arg'", "D601:k3s:<namespace>:<workload> script must map stdin to shell -s", routeScript);

  const routeControlScript = parseSshInvocation("D601:k3s", ["script", "--shell", "bash", "--", "arg"]);
  assertCondition(routeControlScript.parsed.requiresStdin === true, "k3s control-plane script operation must stream local stdin", routeControlScript);
  assertCondition(routeControlScript.parsed.remoteCommand === "'env' 'KUBECONFIG=/etc/rancher/k3s/k3s.yaml' 'bash' '-s' '--' 'arg'", "D601:k3s script must inject native kubeconfig without manual export", routeControlScript);

  const routeApplyPatch = parseSshInvocation("D601:k3s:hwlab-dev:hwlab-cloud-api", ["apply-patch"]);
  assertCondition(routeApplyPatch.parsed.requiresStdin === true, "k3s apply-patch operation must stream local patch stdin", routeApplyPatch);
  assertCondition(routeApplyPatch.parsed.remoteCommand === "'env' 'KUBECONFIG=/etc/rancher/k3s/k3s.yaml' 'kubectl' 'exec' '-i' '-n' 'hwlab-dev' 'deployment/hwlab-cloud-api' '--' 'sh' '-s' '--'", "D601:k3s:<namespace>:<workload> apply-patch must enter pod with stdin", routeApplyPatch);
  assertCondition(routeApplyPatch.parsed.stdinPrefix?.includes("apply_patch") && routeApplyPatch.parsed.stdinPrefix.includes("__UNIDESK_APPLY_PATCH_PAYLOAD__"), "k3s apply-patch operation must inject pod helper before patch stdin", routeApplyPatch);
  assertCondition(routeApplyPatch.parsed.stdinPrefix?.includes("#!/bin/sh"), "k3s apply-patch operation must inject the same sh helper used by host apply-patch", routeApplyPatch);
  assertCondition(!routeApplyPatch.parsed.stdinPrefix?.includes("python3") && !routeApplyPatch.parsed.stdinPrefix?.includes("node "), "k3s apply-patch operation must use the sh-only pod helper", routeApplyPatch);
  assertCondition(routeApplyPatch.parsed.stdinSuffix === "\n__UNIDESK_APPLY_PATCH_PAYLOAD__\n", "k3s apply-patch operation must terminate patch heredoc", routeApplyPatch);

  const hostApplyPatchLoose = parseSshArgs(["apply-patch", "--allow-loose"]);
  assertCondition(hostApplyPatchLoose.remoteCommand === "'apply_patch' '--allow-loose'", "host apply-patch must pass --allow-loose as an explicit helper argument", hostApplyPatchLoose);

  const safePatch = applyPatchFixture([], [
    "*** Begin Patch",
    "*** Update File: sample.txt",
    "@@",
    " function alpha() {",
    "   return 1;",
    " }",
    "+function inserted() {",
    "+  return 3;",
    "+}",
    " function beta() {",
    "   return 2;",
    " }",
    "*** End Patch",
    "",
  ].join("\n"), {
    "sample.txt": [
      "function alpha() {",
      "  return 1;",
      "}",
      "function beta() {",
      "  return 2;",
      "}",
      "",
    ].join("\n"),
  });
  assertCondition(safePatch.status === 0, "apply_patch sh helper should accept anchored insertions", safePatch);
  assertCondition(safePatch.stderr.includes("apply_patch: hunk 1 matched sample.txt:1"), "apply_patch sh helper must report matched file:line", safePatch);
  assertCondition(safePatch.files["sample.txt"]?.includes("function inserted()"), "apply_patch sh helper should apply anchored insertion", safePatch);

  const lowContextPatch = applyPatchFixture([], [
    "*** Begin Patch",
    "*** Update File: sample.txt",
    "@@",
    " function alpha() {",
    "   return 1;",
    " }",
    "+function misplaced() {",
    "+  return 9;",
    "+}",
    "*** End Patch",
    "",
  ].join("\n"), {
    "sample.txt": [
      "function alpha() {",
      "  return 1;",
      "}",
      "function beta() {",
      "  return 2;",
      "}",
      "",
    ].join("\n"),
  });
  assertCondition(lowContextPatch.status !== 0, "apply_patch sh helper should reject insert-only hunks without trailing context", lowContextPatch);
  assertCondition(lowContextPatch.stderr.includes("insert-only without both leading and trailing context"), "low-context rejection must explain the risk", lowContextPatch);

  const duplicateContextPatch = applyPatchFixture([], [
    "*** Begin Patch",
    "*** Update File: sample.txt",
    "@@",
    " marker",
    "+inserted",
    " x",
    "*** End Patch",
    "",
  ].join("\n"), {
    "sample.txt": "marker\nx\nmarker\nx\n",
  });
  assertCondition(duplicateContextPatch.status !== 0, "apply_patch sh helper should reject hunks whose context matches multiple locations", duplicateContextPatch);
  assertCondition(duplicateContextPatch.stderr.includes("matched multiple locations"), "duplicate context rejection must explain the risk", duplicateContextPatch);

  const reviewedLoosePatch = applyPatchFixture(["--allow-loose"], [
    "*** Begin Patch",
    "*** Update File: sample.txt",
    "@@",
    " marker",
    "+reviewed",
    " x",
    "*** End Patch",
    "",
  ].join("\n"), {
    "sample.txt": "marker\nx\nmarker\nx\n",
  });
  assertCondition(reviewedLoosePatch.status === 0, "--allow-loose should allow an explicitly reviewed ambiguous hunk", reviewedLoosePatch);
  assertCondition(reviewedLoosePatch.files["sample.txt"] === "marker\nreviewed\nx\nmarker\nx\n", "--allow-loose should still apply only one hunk", reviewedLoosePatch);

  assertThrows(
    () => parseSshInvocation("D601:k3s:kubectl", ["get", "pods"]),
    /route must locate a target only.*ssh D601:k3s kubectl/u,
    "operation names must not be accepted as k3s route segments",
  );
  assertThrows(
    () => parseSshInvocation("D601:k3s:hwlab-ci:kubectl", ["get", "pods"]),
    /route must locate a target only.*operation "kubectl" after the route/u,
    "operation names must not be accepted as nested k3s route segments",
  );
  assertThrows(
    () => parseSshInvocation("D601:k3s:hwlab-dev:hwlab-cloud-api:logs", []),
    /route must locate a target only.*operation "logs" after the route/u,
    "operation names must not be accepted as k3s container route segments",
  );
  assertThrows(
    () => parseSshInvocation("D601:k3s:apply-patch:hwlab-dev:hwlab-cloud-api", []),
    /route must locate a target only.*apply-patch/u,
    "pod apply-patch must be an operation after the route",
  );

  const routePodTarget = parseSshInvocation("D601:k3s:hwlab-dev:pod/hwlab-cloud-api-abc:api", ["printenv", "HOSTNAME"]);
  assertCondition(routePodTarget.parsed.remoteCommand === "'env' 'KUBECONFIG=/etc/rancher/k3s/k3s.yaml' 'kubectl' 'exec' '-n' 'hwlab-dev' 'pod/hwlab-cloud-api-abc' '-c' 'api' '--' 'printenv' 'HOSTNAME'", "pod route with container must preserve explicit pod kind", routePodTarget);

  const routePodWorkspace = parseSshInvocation("D601:k3s:hwlab-dev:pod/hwlab-cloud-api-abc/workspace/app:api", ["pwd"]);
  assertCondition(routePodWorkspace.route.resource === "pod/hwlab-cloud-api-abc" && routePodWorkspace.route.container === "api" && routePodWorkspace.route.workspace === "/workspace/app", "pod route must support a workspace suffix after the pod id", routePodWorkspace);
  assertCondition(routePodWorkspace.parsed.remoteCommand === "'env' 'KUBECONFIG=/etc/rancher/k3s/k3s.yaml' 'kubectl' 'exec' '-n' 'hwlab-dev' 'pod/hwlab-cloud-api-abc' '-c' 'api' '--' 'sh' '-c' 'cd \"$1\" || exit; shift; exec \"$@\"' 'unidesk-cwd' '/workspace/app' 'pwd'", "pod workspace route must run commands through a fixed cwd wrapper", routePodWorkspace);

  const routeDeploymentWorkspaceScript = parseSshInvocation("D601:k3s:hwlab-dev:hwlab-cloud-api/app", ["script"]);
  assertCondition(routeDeploymentWorkspaceScript.route.resource === "hwlab-cloud-api" && routeDeploymentWorkspaceScript.route.workspace === "/app", "deployment shorthand route must support workspace suffix", routeDeploymentWorkspaceScript);
  assertCondition(routeDeploymentWorkspaceScript.parsed.remoteCommand === "'env' 'KUBECONFIG=/etc/rancher/k3s/k3s.yaml' 'kubectl' 'exec' '-i' '-n' 'hwlab-dev' 'deployment/hwlab-cloud-api' '--' 'sh' '-c' 'cd \"$1\" || exit; shift; exec \"$@\"' 'unidesk-cwd' '/app' 'sh' '-s' '--'", "pod workspace script must set cwd before shell -s consumes stdin", routeDeploymentWorkspaceScript);

  const routeApplyPatchWorkspace = parseSshInvocation("D601:k3s:hwlab-dev:hwlab-cloud-api/app", ["apply-patch"]);
  assertCondition(routeApplyPatchWorkspace.parsed.requiresStdin === true, "pod workspace apply-patch must still stream patch stdin", routeApplyPatchWorkspace);
  assertCondition(routeApplyPatchWorkspace.parsed.remoteCommand === "'env' 'KUBECONFIG=/etc/rancher/k3s/k3s.yaml' 'kubectl' 'exec' '-i' '-n' 'hwlab-dev' 'deployment/hwlab-cloud-api' '--' 'sh' '-c' 'cd \"$1\" || exit; shift; exec \"$@\"' 'unidesk-cwd' '/app' 'sh' '-s' '--'", "pod workspace apply-patch must set cwd before injecting the sh helper", routeApplyPatchWorkspace);

  const sshLike = parseSshArgs(["echo hello"]);
  const hint = sshFailureHint("D601", sshLike, 255, "kex_exchange_identification: Connection closed by remote host");
  assertCondition(hint !== null, "ssh-like kex failure must produce a hint", sshLike);
  assertCondition(hint?.try === "bun scripts/cli.ts ssh D601 script <<'SCRIPT'", "hint must provide canonical stdin script retry", hint);
  assertCondition(hint?.triage.includes("provider triage D601"), "hint must provide provider triage command", hint);
  const formatted = formatSshFailureHint(hint!);
  assertCondition(formatted.startsWith("UNIDESK_SSH_HINT "), "formatted hint must have structured prefix", formatted);
  assertCondition(!formatted.includes("echo hello"), "formatted hint must not echo the original remote command", formatted);

  const timeoutHint = sshFailureHint("D601", sshLike, 255, "unidesk ssh bridge timed out waiting for provider session");
  assertCondition(timeoutHint?.trigger === "timeout-or-kex", "provider session timeout must map to timeout-or-kex", timeoutHint);

  const helpText = JSON.stringify(sshHelp());
  assertCondition(helpText.includes("ssh <providerId> script [--shell sh|bash] [script-args...] <<'SCRIPT'"), "ssh help must recommend stdin script passthrough for shell scripts", helpText);
  assertCondition(helpText.includes("inherits provider proxy variables"), "ssh help must state default script inherits provider proxy env", helpText);
  assertCondition(helpText.includes("not as a proxy workaround"), "ssh help must reserve --shell bash for bash syntax instead of proxy workarounds", helpText);
  assertCondition(helpText.includes("ssh D601:/home/ubuntu/workspace/hwlab-dev git status --short --branch"), "ssh help must document host workspace routes", helpText);
  assertCondition(helpText.includes("ssh D601:k3s kubectl get pods -n hwlab-dev"), "ssh help must document k3s kubectl operation", helpText);
  assertCondition(helpText.includes("ssh G14:k3s kubectl get pipelineruns -n hwlab-ci"), "ssh help must document G14 k3s route operation", helpText);
  assertCondition(helpText.includes("ssh D601:k3s:hwlab-dev:hwlab-cloud-api/app pwd"), "ssh help must document k3s pod workspace route", helpText);
  assertCondition(helpText.includes("ssh D601:k3s script <<'SCRIPT'"), "ssh help must document k3s control-plane script operation", helpText);
  assertCondition(helpText.includes("ssh D601:k3s:hwlab-dev:hwlab-cloud-api apply-patch <<'PATCH'"), "ssh help must document k3s pod apply-patch operation", helpText);
  assertCondition(helpText.includes("apply-patch [--allow-loose]") && helpText.includes("low-context update hunks"), "ssh help must document apply-patch loose-context guard", helpText);
  assertCondition(helpText.includes("ssh D601:k3s:hwlab-dev:hwlab-cloud-api script <<'SCRIPT'"), "ssh help must document k3s script operation", helpText);
  assertCondition(helpText.includes("UNIDESK_SSH_HINT"), "ssh help must document structured failure hint", helpText);

  const crossChecks = providerTriageRecommendedCrossChecks("D601");
  assertCondition(crossChecks.includes("bun scripts/cli.ts ssh D601 argv true"), "provider triage cross-checks must keep argv true", crossChecks);

  return {
    ok: true,
    checks: [
      "argv form is classified and quoted as the success path for non-interactive commands",
      "stdin script form removes shell-command strings for host and k3s workload scripts",
      "pod apply-patch operation injects helper and forwards patch stdin",
      "apply-patch uses one sh helper for host and pod paths and rejects low-context hunks unless --allow-loose is explicit",
      "legacy operation-in-route forms are rejected in any k3s route segment with canonical route-plus-operation guidance",
      "post-provider k3s shorthand is rejected so location and operation stay separated",
      "k3s route stays location-only while operations fix native kubeconfig and assemble kubectl exec as argv",
      "ssh-like timeout/kex failures emit one structured argv retry hint",
      "help text documents stdin script passthrough and UNIDESK_SSH_HINT",
      "provider triage recommendedCrossChecks keeps ssh D601 argv true",
    ],
  };
}

if (import.meta.main) {
  process.stdout.write(`${JSON.stringify(runSshArgvGuidanceContract(), null, 2)}\n`);
}