import axios from 'axios';

import { Logger } from '../../common/util/logger.class';
import { Database } from './database.class';
import { Timer } from './timer.class';

export class ServerConnector {
  private subscriptions: Array<{ id: number; interval: number; server: Server }> = [];

  constructor(private db: Database) {
    (async () => {
      try {
        const serverList = await db.getAllServerConfigs();

        serverList.forEach(server => {
          const interval = Number(server.config['syncInterval'] ?? '300');
          Logger.info('[INFO] Starting Server Sync Connector for', server.title, 'with interval', interval, 'seconds ...');
          const id = Timer.instance.subscribe(interval, () => this.timerTick(server));
          this.subscriptions.push({ id, interval, server });

          process.nextTick(async () => {
            Logger.info('[INFO] Initial Sync for', server.title, '...');
            await this.timerTick(server);
            Logger.info('[SUCCESS] Initial Sync for', server.title, 'succeeded.');
          });
        });
      } catch (err) {
        Logger.error('[FATAL] Initializing ServerConnector failed:', err);
        Logger.error('[EXITING]');
        process.exit(1);
      }
    })();
  }

  private async timerTick(server: Server) {
    Logger.debug('[DEBUG] TICK', new Date(), JSON.stringify(server));

    let trxHdl: number | undefined = undefined;
    try {
      // Start Transaction, receiving Data and a Transaction Handle
      let response = await axios.get(`http://${server.fqdn}:8890/`, { responseType: 'json' });
      trxHdl = response.data.hdl;

      if (!trxHdl) return; // No data

      const data: ReducedData[] = response.data.data.map((entry: any) => ({ ...entry, time: new Date(entry.time) }));

      // Process data in DB
      await this.db.insertServerData(server.id, data);

      // Commit Transaction
      await axios.patch(`http://${server.fqdn}:8890/${trxHdl}`, null, { responseType: 'json' });
    } catch (err) {
      Logger.error('[ERROR] Server data sync failed:', err);

      if (!!trxHdl) {
        Logger.error(`[WARN] Rolling back transaction #${trxHdl} ... `);
        const response = await axios.delete(`http://${server.fqdn}:8890/${trxHdl}`, { responseType: 'json' });
        if (response.data.ok) {
          Logger.error(`[WARN] Rollback succeeded.`);
        }
      }
    }
  }
}