const app = require('./app');
const env = require('./config/env');
const { query } = require('./config/db');
const { startReminderPushWorker } = require('./workers/reminderPushWorker');

function wait(ms) {
  return new Promise((resolve) => {
    setTimeout(resolve, ms);
  });
}

async function startServer() {
  let isDatabaseConnected = false;

  const attempts = env.dbRequiredOnStartup ? env.dbConnectRetries + 1 : 1;
  let lastDbError = null;

  for (let attempt = 1; attempt <= attempts; attempt += 1) {
    try {
      await query('SELECT 1 AS db_ok');
      isDatabaseConnected = true;
      console.log('Database connection established.');
      break;
    } catch (error) {
      lastDbError = error;

      if (attempt >= attempts) {
        break;
      }

      console.warn(
        `Database not ready (attempt ${attempt}/${attempts}). Retrying in ${env.dbConnectRetryDelayMs}ms...`,
      );
      await wait(env.dbConnectRetryDelayMs);
    }
  }

  if (!isDatabaseConnected) {
    if (env.dbRequiredOnStartup) {
      throw lastDbError;
    }

    console.error('Database unavailable at startup; continuing in degraded mode.');
    console.error(lastDbError?.message || lastDbError || 'Unknown DB error');
  }

  app.listen(env.port, () => {
    console.log(
      `Care People backend listening on http://localhost:${env.port}`,
    );

    if (isDatabaseConnected) {
      startReminderPushWorker();
    } else {
      console.log('[push-worker] Skipped startup because database is unavailable.');
    }
  });
}

startServer().catch((error) => {
  console.error('Failed to start the backend server.');
  console.error(error);
  process.exit(1);
});