/**
 * Batch user creation script.
 *
 * Usage:
 *   node create_users.js user1 pass1 [user2 pass2 ...]
 *   node create_users.js --file users.json
 *   node create_users.js --interactive
 *
 * JSON format (users.json):
 * [
 *   { "username": "user1", "password": "pass1", "role": "user", "expires_at": null },
 *   { "username": "user2", "password": "pass2", "role": "user", "expires_at": "2026-12-31" }
 * ]
 */
require('dotenv').config({ path: require('path').join(__dirname, '.env') });

const fs = require('fs');
const readline = require('readline');
const db = require('./db');
const auth = require('./auth');

db.initDB();

async function createOne(username, password, role = 'user', expiresAt = null) {
  const existing = db.getUserByUsername(username);
  if (existing) {
    console.log(`  [SKIP] '${username}' already exists`);
    return false;
  }
  const hash = await auth.hashPassword(password);
  db.createUser(username, hash, role, expiresAt || null);
  console.log(`  [OK] '${username}' created (role: ${role}${expiresAt ? ', expires: ' + expiresAt : ''})`);
  return true;
}

async function main() {
  const args = process.argv.slice(2);
  let created = 0;

  if (args.length === 0 || args.includes('--interactive') || args.includes('-i')) {
    // ── Interactive mode ──
    console.log('=== Interactive User Creation ===');
    const rl = readline.createInterface({ input: process.stdin, output: process.stdout });

    while (true) {
      const username = await new Promise(resolve => rl.question('\nUsername (empty to finish): ', resolve));
      if (!username) break;

      const password = await new Promise(resolve => rl.question('Password: ', resolve));
      if (!password) { console.log('  Password required, skipping.'); continue; }

      const role = await new Promise(resolve => rl.question('Role [user/admin] (default: user): ', resolve));
      const expires = await new Promise(resolve => rl.question('Expiry YYYY-MM-DD (default: never): ', resolve));

      if (await createOne(username, password, role || 'user', expires || null)) created++;
    }
    rl.close();

  } else if (args.includes('--file') || args.includes('-f')) {
    // ── JSON file mode ──
    const fileIdx = args.indexOf('--file');
    const fIdx = args.indexOf('-f');
    const filePath = args[fileIdx !== -1 ? fileIdx + 1 : fIdx + 1];

    if (!filePath || !fs.existsSync(filePath)) {
      console.error('File not found:', filePath);
      process.exit(1);
    }

    const users = JSON.parse(fs.readFileSync(filePath, 'utf8'));
    if (!Array.isArray(users)) {
      console.error('JSON must be an array of user objects.');
      process.exit(1);
    }

    console.log(`Creating ${users.length} users from ${filePath}...\n`);
    for (const u of users) {
      if (await createOne(u.username, u.password, u.role || 'user', u.expires_at || null)) created++;
    }

  } else {
    // ── CLI args mode: pairs of username password ──
    if (args.length % 2 !== 0) {
      console.error('Arguments must be in pairs: username password [username password ...]');
      process.exit(1);
    }

    console.log(`Creating ${args.length / 2} users...\n`);
    for (let i = 0; i < args.length; i += 2) {
      if (await createOne(args[i], args[i + 1])) created++;
    }
  }

  console.log(`\nDone. ${created} user(s) created.`);
  process.exit(0);
}

main().catch(err => { console.error('Error:', err); process.exit(1); });