const MODULE_NAME = 'CALLBACK';
  
  const express = require('express');
  const uniqid = require('uniqid');
  
  const config = require('komodo-sdk/config');

  const logger = require('tektrans-logger');

  
  const morgan = require('morgan');
  const moment = require('moment');
  const rfs = require('rotating-file-stream');
  
  const dumper = require('./dumper');
  const apikeyChecker = require('./apikey-checker');
  const handlerPrepaid = require('./handler-prepaid');

  const handlerPostpaid = require('./handler-postpaid');

  
  const baseFileName = 'logs/callback_access_log';
  
  const app = express();
  
  const listenPort = config.partner.callback && config.partner.callback.port;
  
  if (!listenPort) {
      logger.warn(`${MODULE_NAME} BC903CB7: Unknown listen port. Please specified on config.partner.callback.port`);
      process.exit(1);
  }

  if (config.partner && config.partner.callback && config.partner.callback.trust_proxy) {
      logger.verbose(`${MODULE_NAME} 9774C2DB: Trusting proxy`, {
          trusted: config.partner.callback.trust_proxy,
      });
  
      app.set('trust proxy', config.partner.callback.trust_proxy);
  }

  app.use((req, res, next) => {
      res.locals.xid = uniqid();
      next();
  });
  
  morgan.token('xid', (req, res) => (res.locals.xid));
  
  const accessLogFilenameGenerator = (time, index) => {
      if (!time) return baseFileName;
  
      return [
          baseFileName,
          moment(time).format('YYYY-MM-DD'),
          index || null,
      ].filter((item) => item)
          .join('.');
  };
  
  const accessLogStream = rfs.createStream(accessLogFilenameGenerator, {
      interval: '1d',
  });
  
  app.use(
      morgan(
          ':remote-addr - :remote-user [:date[clf]] ":method :url HTTP/:http-version" :status :res[content-length] ":referrer" ":user-agent" :xid',
          {
              stream: accessLogStream,
          },
      ),
  );
  
  app.use((req, res, next) => {
      const { xid } = res.locals;
  
      logger.info(`${MODULE_NAME} 78F5DD49: Got a request on callback listener`, {
          xid,
          ip: req.ip,
          method: req.method,
          url: req.url,
      });
  
      next();
  });
  
  app.use('/apikey/:apikey', apikeyChecker);
  app.use('/apikey/:apikey', express.urlencoded({ extended: true }));
  app.use('/apikey/:apikey', express.json());
  
  app.use('/apikey/:apikey', dumper);
  app.use('/apikey/:apikey/prepaid', handlerPrepaid);

  app.use('/apikey/:apikey/TOPUP', handlerPrepaid);
  app.use('/apikey/:apikey/:hitType', handlerPostpaid);

  app.use('/', (req, res) => {
      const { xid } = res.locals;
  
      res.json({
          status: 'OK',
          error: null,
          ts: new Date(),
          message: 'Have you RTFM?',
          xid,
      });
  });

  app
      .listen(listenPort, () => {
          logger.info(`${MODULE_NAME} F702D60D: Callback listener ready to get request`, {
              listenPort,
          });
      })
      .on('error', (e) => {
          logger.warn(`${MODULE_NAME} B299BD82: Exception on EXPRESS SERVER`, {
              eCode: e.code,
              eMessage: e.message,
          });
  
          process.exit(1);
      });