import { Meteor } from 'meteor/meteor';
import { WebAppInternals } from 'meteor/webapp';
import Langmap from 'langmap';
import fs from 'fs';
import Users from '/imports/api/users';
import './settings';
import { check } from 'meteor/check';
import Logger from './logger';

import setMinBrowserVersions from './minBrowserVersion';
import { PrometheusAgent, METRIC_NAMES } from './prom-metrics/index.js'

let guestWaitHtml = '';

const DEFAULT_LANGUAGE = Meteor.settings.public.app.defaultSettings.application.fallbackLocale;
const FALLBACK_ON_EMPTY_STRING = Meteor.settings.public.app.fallbackOnEmptyLocaleString;

const env = Meteor.isDevelopment ? 'development' : 'production';

const meteorRoot = fs.realpathSync(`${process.cwd()}/../`);

const applicationRoot = (env === 'development')
  ? fs.realpathSync(`${meteorRoot}'/../../../../public/locales/`)
  : fs.realpathSync(`${meteorRoot}/../programs/web.browser/app/locales/`);

const AVAILABLE_LOCALES = fs.readdirSync(`${applicationRoot}`);
const FALLBACK_LOCALES = JSON.parse(Assets.getText('config/fallbackLocales.json'));

process.on('uncaughtException', (err) => {
  Logger.error(`uncaughtException: ${err}`);
  process.exit(1);
});

const formatMemoryUsage = (data) => `${Math.round(data / 1024 / 1024 * 100) / 100} MB`

const serverHealth = () => {
  const memoryData = process.memoryUsage();
  const memoryUsage = {
    rss: formatMemoryUsage(memoryData.rss),
    heapTotal: formatMemoryUsage(memoryData.heapTotal),
    heapUsed: formatMemoryUsage(memoryData.heapUsed),
    external: formatMemoryUsage(memoryData.external),
  }

  const cpuData = process.cpuUsage();
  const cpuUsage = {
    system: formatMemoryUsage(cpuData.system),
    user: formatMemoryUsage(cpuData.user),
  }

  Logger.info('Server health', {memoryUsage, cpuUsage});
};

Meteor.startup(() => {
  const APP_CONFIG = Meteor.settings.public.app;
  const CDN_URL = APP_CONFIG.cdn;
  const instanceId = parseInt(process.env.INSTANCE_ID, 10) || 1;

  Logger.warn(`Started bbb-html5 process with instanceId=${instanceId}`);

  const LOG_CONFIG = Meteor.settings.private.serverLog;
  const { healthChecker } = LOG_CONFIG;
  const { enable: enableHealthCheck, intervalMs: healthCheckInterval } = healthChecker;

  if (enableHealthCheck) {
    Meteor.setInterval(() => {
      serverHealth();
    }, healthCheckInterval);
  }

  const { customHeartbeat, customHeartbeatUseDataFrames } = APP_CONFIG;

  if (customHeartbeat) {
    Logger.warn('Custom heartbeat functions are enabled');
    // https://github.com/sockjs/sockjs-node/blob/1ef08901f045aae7b4df0f91ef598d7a11e82897/lib/transport/websocket.js#L74-L82
    const heartbeatFactory = function ({ heartbeatTimeoutCallback }) {
      return function () {
        const currentTime = new Date().getTime();

        if (customHeartbeatUseDataFrames) {
          // Skipping heartbeat, because websocket is sending data
          if (currentTime - this.ws.lastSentFrameTimestamp < 10000) {
            try {
              Logger.debug('Skipping heartbeat, because websocket is sending data', {
                currentTime,
                lastSentFrameTimestamp: this.ws.lastSentFrameTimestamp,
                userId: this.session?.connection?._meteorSession?.userId,
              });
              return;
            } catch (err) {
              Logger.error(`Skipping heartbeat error: ${err}`);
            }
          }
        }

        const supportsHeartbeats = this.ws.ping(null, () => {
          clearTimeout(this.hto_ref);
        });

        if (supportsHeartbeats) {
          this.hto_ref = setTimeout(() => {
            try {
              Logger.warn('Heartbeat timeout', { userId: this.session?.connection?._meteorSession?.userId, sentAt: currentTime, now: new Date().getTime() });
            } catch (err) {
              Logger.error(`Heartbeat timeout error: ${err}`);
            } finally {
              if (typeof heartbeatTimeoutCallback === 'function') {
                heartbeatTimeoutCallback();
              }
            }
          }, Meteor.server.options.heartbeatTimeout);
        } else {
          Logger.error('Unexpected error supportsHeartbeats=false');
        }
      };
    };

    // https://github.com/davhani/hagty/blob/6a5c78e9ae5a5e4ade03e747fb4cc8ea2df4be0c/faye-websocket/lib/faye/websocket/api.js#L84-L88
    const newSend = function send(data) {
      try {
        this.lastSentFrameTimestamp = new Date().getTime();

        if (this.meteorHeartbeat) {
          // Call https://github.com/meteor/meteor/blob/1e7e56eec8414093cd0c1c70750b894069fc972a/packages/ddp-common/heartbeat.js#L80-L88
          this.meteorHeartbeat._seenPacket = true;
          if (this.meteorHeartbeat._heartbeatTimeoutHandle) {
            this.meteorHeartbeat._clearHeartbeatTimeoutTimer();
          }
        }

        if (this.readyState > 1/* API.OPEN = 1 */) return false;
        if (!(data instanceof Buffer)) data = String(data);
        return this._driver.messages.write(data);
      } catch (err) {
        console.error('Error on send data', err);
        return false;
      }
    };

    Meteor.setInterval(() => {
      for (const session of Meteor.server.sessions.values()) {
        const { socket } = session;
        const recv = socket._session.recv;

        if (session.bbbFixApplied || !recv || !recv.ws) {
          continue;
        }

        recv.ws.meteorHeartbeat = session.heartbeat;
        recv.heartbeat = heartbeatFactory({
          heartbeatTimeoutCallback: recv.heartbeat_cb
        });
        recv.ws.send = newSend;
        session.bbbFixApplied = true;
      }
    }, 5000);
  }
  if (CDN_URL.trim()) {
    // Add CDN
    BrowserPolicy.content.disallowEval();
    BrowserPolicy.content.allowInlineScripts();
    BrowserPolicy.content.allowInlineStyles();
    BrowserPolicy.content.allowImageDataUrl(CDN_URL);
    BrowserPolicy.content.allowFontDataUrl(CDN_URL);
    BrowserPolicy.content.allowOriginForAll(CDN_URL);
    WebAppInternals.setBundledJsCssPrefix(CDN_URL + APP_CONFIG.basename + Meteor.settings.public.app.instanceId);

    const fontRegExp = /\.(eot|ttf|otf|woff|woff2)$/;

    WebApp.rawConnectHandlers.use('/', (req, res, next) => {
      if (fontRegExp.test(req._parsedUrl.pathname)) {
        res.setHeader('Access-Control-Allow-Origin', '*');
        res.setHeader('Vary', 'Origin');
        res.setHeader('Pragma', 'public');
        res.setHeader('Cache-Control', '"public"');
      }
      return next();
    });
  }

  setMinBrowserVersions();

  Meteor.onMessage(event => {
    const { method } = event;
    if (method) {
      const methodName = method.includes('stream-cursor') ? 'stream-cursor' : method;
      PrometheusAgent.increment(METRIC_NAMES.METEOR_METHODS, { methodName });
    }
  });

  Logger.warn(`SERVER STARTED.
  ENV=${env}
  nodejs version=${process.version}
  BBB_HTML5_ROLE=${process.env.BBB_HTML5_ROLE}
  INSTANCE_ID=${instanceId}
  PORT=${process.env.PORT}
  CDN=${CDN_URL}\n`, APP_CONFIG);
});

const generateLocaleOptions = () => {
  try {
    Logger.warn('Calculating aggregateLocales (heavy)');

    // remove duplicated locales (always remove more generic if same name)
    const tempAggregateLocales = AVAILABLE_LOCALES
      .map(file => file.replace('.json', ''))
      .map(file => file.replace('_', '-'))
      .map((locale) => {
        const localeName = (Langmap[locale] || {}).nativeName
          || (FALLBACK_LOCALES[locale] || {}).nativeName
          || locale;
        return {
          locale,
          name: localeName,
        };
      }).reverse()
      .filter((item, index, self) => index === self.findIndex(i => (
        i.name === item.name
      )))
      .reverse();

    Logger.warn(`Total locales: ${tempAggregateLocales.length}`, tempAggregateLocales);

    const filePath = `${applicationRoot}/index.json`;
    const jsContent = JSON.stringify(AVAILABLE_LOCALES, null, 2);

    // Write JSON data to a file
    fs.writeFile(filePath, jsContent, (err) => {
      if (err) {
        Logger.error('Error writing file:', err);
      } else {
        Logger.info(`JSON data has been written to ${filePath}`);
      }
    });

    return tempAggregateLocales;
  } catch (e) {
    Logger.error(`'Could not process locales error: ${e}`);
    return [];
  }
};

let avaibleLocalesNamesJSON = JSON.stringify(generateLocaleOptions());

WebApp.connectHandlers.use('/check', (req, res) => {
  const payload = { html5clientStatus: 'running' };

  res.setHeader('Content-Type', 'application/json');
  res.writeHead(200);
  res.end(JSON.stringify(payload));
});

WebApp.connectHandlers.use('/locale', (req, res) => {
  const APP_CONFIG = Meteor.settings.public.app;
  const fallback = APP_CONFIG.defaultSettings.application.fallbackLocale;
  const override = APP_CONFIG.defaultSettings.application.overrideLocale;
  const browserLocale = override && req.query.init === 'true'
    ? override.split(/[-_]/g) : req.query.locale.split(/[-_]/g);

  let localeFile = fallback;

  const usableLocales = AVAILABLE_LOCALES
    .map(file => file.replace('.json', ''))
    .reduce((locales, locale) => (locale.match(browserLocale[0])
      ? [...locales, locale]
      : locales), []);

  let normalizedLocale;

  const regionDefault = usableLocales.find(locale => browserLocale[0] === locale);

  if (browserLocale.length > 1) {
    // browser asks for specific locale
    normalizedLocale = `${browserLocale[0]}_${browserLocale[1]?.toUpperCase()}`;

    const normDefault = usableLocales.find(locale => normalizedLocale === locale);
    if (normDefault) {
      localeFile = normDefault;
    } else {
      if (regionDefault) {
        localeFile = regionDefault;
      } else {
        const specFallback = usableLocales.find(locale => browserLocale[0] === locale.split("_")[0]);
        if (specFallback) localeFile = specFallback;
      }
    }
  } else {
    // browser asks for region default locale
    if (regionDefault && localeFile === fallback && regionDefault !== localeFile) {
      localeFile = regionDefault;
    } else {
      const normFallback = usableLocales.find(locale => browserLocale[0] === locale.split("_")[0]);
      if (normFallback) localeFile = normFallback;
    }
  }

  res.setHeader('Content-Type', 'application/json');
  res.end(JSON.stringify({
    normalizedLocale: localeFile,
    regionDefaultLocale: (regionDefault && regionDefault !== localeFile) ? regionDefault : '',
    defaultLocale: DEFAULT_LANGUAGE,
    fallbackOnEmptyLocaleString: FALLBACK_ON_EMPTY_STRING,
  }));
});

WebApp.connectHandlers.use('/locale-list', (req, res) => {
  if (!avaibleLocalesNamesJSON) {
    avaibleLocalesNamesJSON = JSON.stringify(generateLocaleOptions());
  }

  res.setHeader('Content-Type', 'application/json');
  res.writeHead(200);
  res.end(avaibleLocalesNamesJSON);
});

WebApp.connectHandlers.use('/feedback', (req, res) => {
  req.on('data', Meteor.bindEnvironment((data) => {
    const body = JSON.parse(data);
    const {
      meetingId,
      userId,
      authToken,
      userName: reqUserName,
      comment,
      rating,
    } = body;

    check(meetingId, String);
    check(userId, String);
    check(authToken, String);
    check(reqUserName, String);
    check(comment, String);
    check(rating, Number);

    const user = Users.findOne({
      meetingId,
      userId,
      authToken,
    });

    if (!user) {
      Logger.warn('Couldn\'t find user for feedback');
    }

    res.setHeader('Content-Type', 'application/json');
    res.writeHead(200);
    res.end(JSON.stringify({ status: 'ok' }));

    body.userName = user ? user.name : `[unconfirmed] ${reqUserName}`;

    const feedback = {
      ...body,
    };
    Logger.info('FEEDBACK LOG:', feedback);
  }));
});

WebApp.connectHandlers.use('/guestWait', (req, res) => {
  if (!guestWaitHtml) {
    try {
      guestWaitHtml = Assets.getText('static/guest-wait/guest-wait.html');
    } catch (e) {
      Logger.warn(`Could not process guest wait html file: ${e}`);
    }
  }

  res.setHeader('Content-Type', 'text/html');
  res.writeHead(200);
  res.end(guestWaitHtml);
});