import fs from 'fs';
import fsp from 'fs/promises';
import path from 'path';
import moment from 'moment';
import { Pool } from 'mysql';

import { Logger, LogLevel } from '../../common/util/logger.class';

import { ControllerPool } from './ctrl/controller-pool.interface';
import { HttpCheckController } from './ctrl/http-check-controller.class';
import { MariaDBDatabase } from './ctrl/mariadb-database.class';
import { MariaDBImporter } from './ctrl/mariadb-importer.class';
import { MariaDBPoolFactory } from './ctrl/mariadb-poolfactory.class';
import { ServerConnector } from './ctrl/server-connector.class';
import { Webserver } from './webserver.class';
import { Timer } from './timer.class';

const LOG_LEVEL: LogLevel = (process.env.LOG_LEVEL as LogLevel) || 'INFO';
Logger.logLevel = LOG_LEVEL;

process.on('SIGABRT', exitGracefully);
process.on('SIGQUIT', exitGracefully);
process.on('SIGTERM', exitGracefully);

let pool: ControllerPool;
let db: MariaDBDatabase;
let mig: MariaDBImporter;
let connectionPool: Pool;
(async () => {
  connectionPool = await MariaDBPoolFactory.createConnectionPool();
  const sqliteDir = path.resolve(process.cwd(), process.env.DATA_DIR || 'data');
  const doneFile = path.resolve(sqliteDir, 'import_done.txt');

  if (fs.existsSync(sqliteDir) && !fs.existsSync(doneFile)) {
    mig = new MariaDBImporter(connectionPool);
    await mig.connect();
    await mig.runImport();
    await fsp.writeFile(doneFile, moment().format('YYYY-MM-DD[T]HH:mm:ss.SSSZZ'), { encoding: 'utf-8' });
  }

  db = new MariaDBDatabase(connectionPool);
  await db.open();

  pool = {
    connectionPool,
    serverConnector: new ServerConnector(connectionPool),
    httpChecks: new HttpCheckController(connectionPool)
  };

  Timer.instance.start();
  new Webserver(Number(process.env.WEB_PORT ?? '80'), pool);
})();

async function exitGracefully(...args: any[]) {
  Logger.info(`[EXITING] Graceful exit, received ${JSON.stringify(args)}`);
  try {
    if (mig) {
      Logger.info(`[EXITING] Tear down MariaDBImporter instance ...`);
      await mig.close();
    }

    Logger.info(`[EXITING] Tear down Main Database Controller ...`);
    if (db) await db.close();

    Logger.info(`[EXITING] Tear down MariaDB Connection Pool ...`);
    if (connectionPool) await MariaDBPoolFactory.end(connectionPool);
  } catch (err) {
    Logger.error(`[ERROR] Tear down sequence failed:`, err);
    process.exit(2);
  }

  Logger.info(`[EXITING] Tear down sequence succeeded. exiting.`);
  process.exit(0);
}