import 'dotenv/config';
import { Pool } from 'pg';
import { scrapeAll } from './scraper';
import { syncToDatabase } from './db';

function log(msg: string) {
  console.log(`[sync] ${new Date().toISOString()} ${msg}`);
}

function requireEnv(name: string): string {
  const val = process.env[name];
  if (!val) throw new Error(`Missing required environment variable: ${name}`);
  return val;
}

/** Returns milliseconds until the next midnight (00:00:00) in local time. */
function msUntilMidnight(): number {
  const now = new Date();
  const midnight = new Date(now);
  midnight.setDate(now.getDate() + 1);
  midnight.setHours(0, 0, 0, 0);
  return midnight.getTime() - now.getTime();
}

async function runSync(): Promise<void> {
  const username = requireEnv('FDISK_USERNAME');
  const password = requireEnv('FDISK_PASSWORD');

  const pool = new Pool({
    host:     requireEnv('DB_HOST'),
    port:     parseInt(process.env.DB_PORT ?? '5432'),
    database: requireEnv('DB_NAME'),
    user:     requireEnv('DB_USER'),
    password: requireEnv('DB_PASSWORD'),
  });

  try {
    log('Starting FDISK sync');
    const { members, ausbildungen } = await scrapeAll(username, password);
    await syncToDatabase(pool, members, ausbildungen);
    log(`Sync complete — ${members.length} members, ${ausbildungen.length} Ausbildungen`);
  } finally {
    await pool.end();
  }
}

async function main(): Promise<void> {
  log('FDISK sync service started');

  // Run once immediately on startup so the first sync doesn't wait until midnight
  await runSync().catch(err => log(`ERROR during initial sync: ${err.message}`));

  // Then schedule at midnight every day
  while (true) {
    const delay = msUntilMidnight();
    const nextRun = new Date(Date.now() + delay);
    log(`Next sync scheduled at ${nextRun.toLocaleString()} (in ${Math.round(delay / 60000)} min)`);
    await new Promise(r => setTimeout(r, delay));
    await runSync().catch(err => log(`ERROR during scheduled sync: ${err.message}`));
  }
}

main().catch(err => {
  console.error(`[sync] Fatal error: ${err.message}`);
  process.exit(1);
});