#!/usr/bin/env node
const { Client } = require('pg');

const SECOND = 1000;
const DEFAULT_TIMEOUT = Number.parseInt(process.env.DB_WAIT_TIMEOUT_MS || `${60 * SECOND}`, 10);
const RETRY_INTERVAL = Number.parseInt(process.env.DB_WAIT_RETRY_MS || '2000', 10);

function deriveConnectionString() {
  if (process.env.DATABASE_URL) {
    return process.env.DATABASE_URL;
  }

  const {
    POSTGRES_USER = 'merchantsofhope_user',
    POSTGRES_PASSWORD,
    POSTGRES_DB = 'merchantsofhope_supplyanddemandportal',
    POSTGRES_HOST = 'merchantsofhope-supplyanddemandportal-database',
    POSTGRES_PORT = '5432'
  } = process.env;

  if (!POSTGRES_PASSWORD) {
    return null;
  }

  return `postgresql://${POSTGRES_USER}:${POSTGRES_PASSWORD}@${POSTGRES_HOST}:${POSTGRES_PORT}/${POSTGRES_DB}`;
}

const connectionString = deriveConnectionString();

if (!connectionString) {
  console.error('[wait-for-db] DATABASE_URL or POSTGRES_PASSWORD must be provided.');
  process.exit(1);
}

const startTime = Date.now();

async function waitForDatabase() {
  const client = new Client({
    connectionString,
    connectionTimeoutMillis: Math.min(RETRY_INTERVAL, DEFAULT_TIMEOUT)
  });

  try {
    await client.connect();
  } catch (error) {
    const elapsed = Date.now() - startTime;
    if (elapsed >= DEFAULT_TIMEOUT) {
      console.error('[wait-for-db] Timed out waiting for database connection.');
      console.error(error);
      process.exit(1);
    }

    const remaining = DEFAULT_TIMEOUT - elapsed;
    const delay = Math.min(RETRY_INTERVAL, remaining);
    console.info(`[wait-for-db] Database not ready yet. Retrying in ${delay}ms...`);
    await new Promise((resolve) => setTimeout(resolve, delay));
    return waitForDatabase();
  } finally {
    await client.end().catch(() => {});
  }

  console.info('[wait-for-db] Database connection established.');
}

waitForDatabase().then(() => process.exit(0));