const { runner } = require('node-pg-migrate');
const { Client } = require('pg');
const path = require('path');

const direction = process.argv[2] || 'up';

const dbConfig = {
  host: process.env.PGHOST || 'localhost',
  port: parseInt(process.env.PGPORT || '5432', 10),
  user: process.env.PGUSER,
  password: process.env.PGPASSWORD,
  database: process.env.PGDATABASE
};

// This now runs at container start, ahead of the app, so it can come up before
// Postgres is accepting connections — on the NAS the database container is
// routinely slower to be ready than the app container. Without a wait the
// migration would fail, take the app down with it, and look like a broken
// deploy rather than a startup race.
const WAIT_ATTEMPTS = 30;
const WAIT_INTERVAL_MS = 2000;

async function waitForDb() {
  for (let attempt = 1; attempt <= WAIT_ATTEMPTS; attempt++) {
    const client = new Client(dbConfig);
    try {
      await client.connect();
      await client.end();
      return;
    } catch (err) {
      await client.end().catch(() => {});
      if (attempt === WAIT_ATTEMPTS) {
        throw new Error(`Database unreachable after ${WAIT_ATTEMPTS} attempts: ${err.message}`);
      }
      console.log(`Waiting for database (attempt ${attempt}/${WAIT_ATTEMPTS})...`);
      await new Promise((resolve) => setTimeout(resolve, WAIT_INTERVAL_MS));
    }
  }
}

waitForDb()
  .then(() =>
    runner({
      databaseUrl: dbConfig,
      dir: path.resolve(__dirname, 'migrations'),
      direction,
      migrationsTable: 'pgmigrations',
      count: direction === 'down' ? 1 : Infinity,
      log: (msg) => console.log(msg)
    })
  )
  .then((applied) => {
    console.log(`Migration complete — ${applied.length} migration(s) ${direction === 'down' ? 'reverted' : 'applied'}.`);
    process.exit(0);
  })
  .catch((err) => {
    console.error('Migration failed:', err.message);
    process.exit(1);
  });