/**
 * reset-admin.ts — Break-glass CLI: create or reset a local admin account (D-13).
 *
 * Usage (dev only):
 *   docker exec -it familysync-api node --import=tsx/esm scripts/reset-admin.ts \
 *     --username admin --password '<new-password>'
 *
 * Flags:
 *   --username <name>   Required. Username to create/reset.
 *   --password <pass>   Required. New password (never logged).
 *   --dry-run           Validate args + DB connection without writing.
 *
 * Security (T-19-25, T-19-26, D-13, D-15):
 *   - FIRST statement: dev-only guard — throws when NODE_ENV=production (defense-in-depth).
 *   - This script is also excluded from the production image via .dockerignore apps/api/scripts/ (IMG-02).
 *   - The password value is NEVER logged or printed.
 *   - hashPassword is inlined (scrypt PHC) — cannot import compiled TS from a plain script (Pitfall 11).
 *
 * DB:
 *   Reads DB_HOST/DB_PORT/DB_USER/DB_PASSWORD/DB_NAME env (same defaults as global-setup.ts).
 *   Upserts users row (is_admin=true, claimed=true) then upserts local_credentials row.
 *   Idempotent: safe to run multiple times with the same username.
 */

// ── DEV-ONLY GUARD — must be the FIRST executable statement (T-19-25 / D-15) ────────────
if (process.env.NODE_ENV === 'production') {
  throw new Error(
    'reset-admin refused: NODE_ENV=production. ' +
      'This CLI creates/resets local admin credentials and must NEVER run in production. ' +
      'The script is also excluded from the production image via .dockerignore apps/api/scripts/ (IMG-02).',
  );
}

import { createConnection } from 'mysql2/promise';
import { scryptSync, randomBytes } from 'node:crypto';

// ── Inline hashPassword (PHC-style scrypt) ───────────────────────────────────────────────
// Cannot import compiled TS from a plain Node.js script at runtime (Pitfall 11).
// Copy of the 5-line implementation from apps/api/src/auth/localCredentials.ts.
const SCRYPT_N = 16384;
const SCRYPT_R = 8;
const SCRYPT_P = 1;
const KEY_LEN = 32;

function hashPassword(password: string): string {
  const salt = randomBytes(16);
  const hash = scryptSync(password, salt, KEY_LEN, { N: SCRYPT_N, r: SCRYPT_R, p: SCRYPT_P });
  return ['scrypt', SCRYPT_N, SCRYPT_R, SCRYPT_P, salt.toString('base64url'), hash.toString('base64url')].join(
    '$',
  );
}

// ── CLI arg parsing (no new deps — process.argv only) ───────────────────────────────────
// WR-01: support both `--key=value` and `--key value`, and parse values EXPLICITLY rather
// than inferring an empty string whenever the next token starts with '--'. The old heuristic
// coerced `--password --foo` (and a legitimately `--`-prefixed or empty password) silently to
// ''. Here, known value-taking flags (--username, --password) always consume the next token
// verbatim as their value; the only boolean flag (--dry-run) takes no value. This keeps a
// password that begins with '--', or an intentionally empty password, intact.
const VALUE_FLAGS = new Set(['username', 'password']);
const BOOLEAN_FLAGS = new Set(['dry-run']);

function parseArgs(argv: string[]): Record<string, string | undefined> {
  const result: Record<string, string | undefined> = {};
  for (let i = 0; i < argv.length; i++) {
    const arg = argv[i];
    if (!arg.startsWith('--')) continue;

    const eq = arg.indexOf('=');
    if (eq !== -1) {
      // `--key=value` form — value is everything after the first '=', taken verbatim
      // (so `--password=--weird` and `--password=` both work correctly).
      result[arg.slice(2, eq)] = arg.slice(eq + 1);
      continue;
    }

    const key = arg.slice(2);
    if (BOOLEAN_FLAGS.has(key)) {
      result[key] = ''; // presence-only flag; detected via hasOwnProperty
      continue;
    }
    if (VALUE_FLAGS.has(key)) {
      // Consume the NEXT token verbatim as the value — even if it starts with '--' or is
      // empty. If there is no next token, record undefined (genuinely absent, not '').
      result[key] = argv[i + 1];
      if (i + 1 < argv.length) i++; // skip the consumed value token
      continue;
    }
    // Unknown flag — record presence with no value (forward-compatible, no crash).
    result[key] = '';
  }
  return result;
}

const args = parseArgs(process.argv.slice(2));

// ── Validate required args ────────────────────────────────────────────────────────────────
const username = args['username'];
const password = args['password'];
const dryRun = Object.prototype.hasOwnProperty.call(args, 'dry-run');

if (!username || username.trim() === '') {
  console.error('reset-admin: --username is required');
  process.exit(1);
}
if (!dryRun && (!password || password.trim() === '')) {
  console.error('reset-admin: --password is required (use --dry-run to test without writing)');
  process.exit(1);
}
if (dryRun && !password) {
  // In dry-run mode a placeholder password is acceptable — skip real validation
  console.log('[dry-run] Args validated: --username present, --dry-run active (no write will occur)');
}

// ── DB connection ─────────────────────────────────────────────────────────────────────────
const conn = await createConnection({
  host: process.env.DB_HOST ?? '127.0.0.1',
  port: Number(process.env.DB_PORT ?? 3306),
  user: process.env.DB_USER ?? 'familysync',
  password: process.env.DB_PASSWORD ?? '',
  database: process.env.DB_NAME ?? 'familysync',
});

try {
  // Verify DB connectivity (used by --dry-run to confirm connection works)
  await conn.query('SELECT 1');
  console.log('[reset-admin] DB connection OK');

  if (dryRun) {
    console.log('[dry-run] Connection verified. Exiting without writing.');
    await conn.end();
    process.exit(0);
  }

  // ── Upsert users row ─────────────────────────────────────────────────────────────────
  // Find existing user by username (via local_credentials join) or create a new one.
  // is_admin=true + claimed=true for break-glass recovery (D-13).
  // Never logs the password value (T-19-26).
  const [lcRows] = await conn.execute<{ user_id: number }[]>(
    'SELECT user_id FROM local_credentials WHERE username = ? LIMIT 1',
    [username],
  );

  let userId: number;

  if (lcRows.length > 0) {
    // Existing local_credentials row — update password and ensure is_admin
    userId = lcRows[0].user_id;
    await conn.execute('UPDATE users SET is_admin = true, claimed = true WHERE id = ?', [userId]);
    // WR-01: do not echo the username — log only the resolved user id (no credential data).
    console.log(`[reset-admin] Found existing user id=${userId}`);
  } else {
    // No existing row — insert a new user
    const displayName = username;
    const [insertResult] = await conn.execute<{ insertId: number }>(
      `INSERT INTO users (oidc_iss, oidc_sub, display_name, color, is_admin, claimed)
       VALUES (NULL, NULL, ?, '#4A90D9', true, true)`,
      [displayName],
    );
    userId = (insertResult as unknown as { insertId: number }).insertId;
    // WR-01: do not echo the username — log only the resolved user id.
    console.log(`[reset-admin] Created new user id=${userId}`);
  }

  // ── Upsert local_credentials row ─────────────────────────────────────────────────────
  const passwordHash = hashPassword(password!);
  await conn.execute(
    `INSERT INTO local_credentials (user_id, username, password_hash)
     VALUES (?, ?, ?)
     ON DUPLICATE KEY UPDATE password_hash = VALUES(password_hash), username = VALUES(username)`,
    [userId, username, passwordHash],
  );

  console.log(`[reset-admin] Local credential upserted for user id=${userId}`);
  console.log(`[reset-admin] Done. User id=${userId} is now a local admin.`);
} finally {
  await conn.end();
}