/**
 * R1 + R2 — the backup/restore data contract belongs to the code.
 *
 * Two templates used to own it in prose, and each half made the other's failure
 * silent:
 *
 *   R1 `commands/rollback.md` drove the restore itself. Its "Implementation"
 *   section showed an ESM `import` block a command template cannot execute and
 *   offered ad-hoc `cp` as the runnable alternative, then pre-rendered
 *   "`(checksum verified)`" in the success output. `cp` verifies nothing, so the
 *   claim was a property of the template, not of the run.
 *
 *   R2 `commands/implement.md` Step 3 hand-built the backup: `mkdir`, `cp`, a
 *   `date +%Y%m%d_%H%M%S` id, and a manifest typed out in the template. The
 *   parser on the other side (`parseManifest`) knew ONE frozen sample of that
 *   format, pinned by a HAND-WRITTEN fixture rather than by the template's own
 *   text — the #63 shape on the data side. Rename a key in the template and
 *   `parseManifest` returns zero files while `rollback` reports success.
 *
 * The fix is one chunk because half of it does not hold: a CLI over a prose
 * format still parses prose, and a clean format with no runnable entry still
 * cannot restore. What this file asserts is that neither half came back.
 *
 * The last test is the one that replaces "(checksum verified)": every field the
 * template renders is checked against a payload produced by RUNNING the CLI, so
 * the output prose can only claim what the code actually reports.
 */

import { test } from 'node:test';
import { strict as assert } from 'node:assert';
import { spawn } from 'node:child_process';
import { readFile, writeFile, mkdtemp, mkdir, rm } from 'node:fs/promises';
import { resolve, dirname, join } from 'node:path';
import { tmpdir } from 'node:os';
import { fileURLToPath } from 'node:url';

const __dirname = dirname(fileURLToPath(import.meta.url));
const ROOT = resolve(__dirname, '..', '..');
const COMMANDS_DIR = join(ROOT, 'commands');
const CLI = join(ROOT, 'scanners', 'rollback-cli.mjs');

const read = (name) => readFile(join(COMMANDS_DIR, name), 'utf-8');

/** Fenced blocks as `[{ lang, body }]`. */
function fences(content) {
  return [...content.matchAll(/```(\w*)\n([\s\S]*?)```/g)].map((m) => ({ lang: m[1], body: m[2] }));
}

test('rollback.md drives the engine through the CLI, like every other command', async () => {
  const content = await read('rollback.md');

  assert.match(
    content,
    /node \$\{CLAUDE_PLUGIN_ROOT\}\/scanners\/rollback-cli\.mjs/,
    'rollback.md must call the rollback CLI at an anchored path. A relative path resolves\n' +
      "against the user's working directory, not the plugin ([[plugin-root-is-the-cache]]).",
  );
  assert.match(
    content,
    /rollback-cli\.mjs[^\n]*--output-file[^\n]*2>\/dev\/null/,
    'The CLI must be invoked as `--output-file <path> 2>/dev/null` (ux-rules rule 2). A payload\n' +
      'the command has to act on cannot ride on stdout or stderr.',
  );
});

test('rollback.md no longer pre-renders a verification it did not perform', async () => {
  const content = await read('rollback.md');

  assert.doesNotMatch(
    content,
    /\(checksum verified\)/,
    'The success block hard-codes "(checksum verified)" for every file. The runnable path in\n' +
      'this template (`cp`) establishes no checksum at all, so the words came from the template\n' +
      'rather than from the run. Render the per-file `status` the CLI returns instead.',
  );
});

test('rollback.md offers no hand-rolled restore beside the engine', async () => {
  const content = await read('rollback.md');

  for (const { lang, body } of fences(content)) {
    if (lang !== 'bash') continue;
    assert.doesNotMatch(
      body,
      /^\s*cp\s+/m,
      'A `cp` restore skips the checksum verification before and after each write that the\n' +
        'engine performs. Two restore paths means the safe one is optional.',
    );
  }

  assert.doesNotMatch(
    content,
    /import\s*\{[^}]*\}\s*from\s*['"][^'"]*rollback-engine\.mjs['"]/,
    'A command template is not an ES module; an `import` block here is instructions the\n' +
      'runtime never executes, which is what left `cp` as the only runnable path.',
  );
});

test('implement.md Step 3 creates its backup through the code, not by hand', async () => {
  const content = await read('implement.md');

  // `--create(?![a-z])`, not `--create`: the same line carries `--created`, so a
  // prefix match is satisfied by the very flag whose presence proves nothing
  // about whether a backup is being MADE. Measured by mutating `--create` away
  // and watching this assertion stay green.
  assert.match(
    content,
    /node \$\{CLAUDE_PLUGIN_ROOT\}\/scanners\/rollback-cli\.mjs[^\n]*--create(?![a-z])/,
    'Step 3 must call `rollback-cli.mjs --create`. Backing up through the same code path the\n' +
      'fix pipeline uses is what deletes the second copy of the backup policy.',
  );
  assert.match(
    content,
    /--created\b/,
    'Files this run will CREATE have no backup and must be recorded so rollback can say what\n' +
      'it is leaving behind. The list moved from hand-written YAML to a flag; it must still exist.',
  );
});

test('implement.md hand-builds no manifest and invents no backup id', async () => {
  const content = await read('implement.md');

  for (const { body } of fences(content)) {
    assert.doesNotMatch(
      body,
      /^\s*sha256:/m,
      'Step 3 types out a manifest whose only reader is `parseManifest`. Every key here is a\n' +
        'contract with code, maintained by hand on one side — the seam that already failed once\n' +
        '(M-BUG-25) and whose fixture was hand-written rather than derived from this template.',
    );
    assert.doesNotMatch(
      body,
      /mkdir\s+-p\s+~\/\.claude\/config-audit\/backups/,
      'The template builds the backup directory layout itself. The layout is `createBackup`\'s\n' +
        'to define; a second definition in prose drifts away from it silently.',
    );
    assert.doesNotMatch(
      body,
      /BACKUP_ID=\$\(date/,
      'A backup id derived by the template is a second id generator. `createBackup` returns the\n' +
        'id it actually used; anything else can name a directory that does not exist.',
    );
  }
});

test('every field rollback.md renders is a field the CLI really emits', async () => {
  // The replacement for "(checksum verified)": the output prose is checked
  // against a payload produced by RUNNING the CLI. A renamed payload key turns
  // the template's claim into a violation here rather than into a confident
  // sentence in front of a user who is already in trouble.
  //
  // `K` is the only derived reference — a count the model computes from the
  // classified targets, not a field any scanner emits.
  const DERIVED = new Set(['K']);

  const root = await mkdtemp(join(tmpdir(), 'ca-rbrender-'));
  try {
    const home = join(root, 'home');
    const work = join(root, 'work');
    const cwd = join(root, 'cwd');
    await mkdir(join(home, '.claude'), { recursive: true });
    await mkdir(work, { recursive: true });
    await mkdir(cwd, { recursive: true });
    const backupRoot = join(home, '.claude', 'config-audit', 'backups');
    const env = {
      ...process.env,
      HOME: home,
      USERPROFILE: home,
      CONFIG_AUDIT_BACKUP_ROOT: backupRoot,
      CONFIG_AUDIT_LEGACY_BACKUP_ROOT: join(home, '.config-audit', 'backups'),
    };
    const runCli = (argv) => new Promise((res) => {
      const child = spawn(process.execPath, [CLI, ...argv], { cwd, env });
      child.stdout.on('data', () => {});
      child.stderr.on('data', () => {});
      child.on('close', (code) => res(code));
    });

    const target = join(work, 'CLAUDE.md');
    await writeFile(target, '# original\n');
    const createOut = join(root, 'create.json');
    await runCli([
      '--create', '--target', target,
      '--created', join(work, 'made-by-implement.md'),
      '--repo', work, '--output-file', createOut,
    ]);
    const created = JSON.parse(await readFile(createOut, 'utf-8'));

    const listOut = join(root, 'list.json');
    await runCli(['--list', '--output-file', listOut]);
    const listed = JSON.parse(await readFile(listOut, 'utf-8'));

    const restoreOut = join(root, 'restore.json');
    await runCli([
      '--restore', created.backupId, '--repo', work, '--dry-run', '--output-file', restoreOut,
    ]);
    const restored = JSON.parse(await readFile(restoreOut, 'utf-8'));

    const keys = new Set();
    const walk = (node) => {
      if (Array.isArray(node)) node.slice(0, 5).forEach(walk);
      else if (node && typeof node === 'object') {
        for (const k of Object.keys(node)) { keys.add(k); walk(node[k]); }
      }
    };
    [created, listed, restored].forEach(walk);

    const content = await read('rollback.md');
    // Render fences only. A `bash` fence is a command, not a render contract,
    // and `${CLAUDE_PLUGIN_ROOT}` would otherwise read as a payload field.
    const refs = new Set();
    for (const { lang, body } of fences(content)) {
      if (lang === 'bash') continue;
      for (const m of body.matchAll(/\{([a-zA-Z][a-zA-Z0-9_.]*)\}/g)) refs.add(m[1]);
    }
    assert.ok(refs.size > 0, 'no render reference found in rollback.md — the sweep certifies nothing');

    const missing = [...refs].filter((r) => !DERIVED.has(r) && !keys.has(r.split('.').pop()));
    assert.deepEqual(
      missing,
      [],
      'rollback.md renders fields rollback-cli.mjs never emits:\n  ' + missing.join('\n  '),
    );
  } finally {
    await rm(root, { recursive: true, force: true });
  }
});