exports.id = 'wsmqttpublish';
exports.title = 'WS MQTT publish';
exports.group = 'MQTT';
exports.color = '#888600';
exports.version = '1.0.2';
exports.icon = 'sign-out';
exports.input = 2;
exports.output = 3;
exports.options = { host: 'tb-stage.worksys.io', port: 1883, clientid: "", username: "" };

exports.html = `<div class="padding">
  <div class="row">
    <div class="col-md-6">
      <div data-jc="textbox" data-jc-path="host" data-jc-config="placeholder:test.mosquitto.org;required:false" class="m">Hostname or IP address (if not empty - setting will override db setting)</div>
    </div>
    <div class="col-md-6">
      <div data-jc="textbox" data-jc-path="port" data-jc-config="placeholder:1883;required:true" class="m">Port</div>
    </div>
  </div>
  <div class="row">
    <div class="col-md-6">
      <div data-jc="textbox" data-jc-path="clientid">@(Client id)</div>
    </div>
    <div class="col-md-6">
      <div data-jc="textbox" data-jc-path="username" class="m">@(Username)</div>    
    </div>
  </div>
</div>`;


exports.readme = `
# WS MQTT Publish

Version 1.0.3.

Added:
- database collections,
- rpc response
`;

const { promisifyBuilder } = require('./helper/db_helper');
const { errLogger, monitor } = require('./helper/logger');
const fs = require('fs');
const mqtt = require('mqtt');

const SEND_TO = {
  debug: 0,
  rpcCall: 1,
  services: 2
}

//CONFIG 
let createTelemetryBackup = true;
let saveTelemetryOnError = true;//backup_on_failure overrides this value
//------------------------

let rollers;
if (createTelemetryBackup) rollers = require('streamroller');

const noSqlFileSizeLimit = 4194304;//use 5MB - 4194304
let insertNoSqlCounter = 0;
let insertBackupNoSqlCounter = 0;
let processingData = false;

let backup_on_failure = false;//== saveTelemetryOnError - create backup client send failure
let restore_from_backup = 0; //how many rows process at once?
let restore_backup_wait = 0;//wait seconds
let lastRestoreTime = 0;

// if there is an error in client connection, flow logs to monitor.txt. Not to log messages every second, we use sendClientError variable
let sendClientError = true;

process.on('uncaughtException', function(err) {

  errLogger.error('uncaughtException:', err.message)
  errLogger.error(err.stack);

  //TODO
  //send to service 

  //process.exit(1);
})

const nosql = NOSQL('tbdata');
const nosqlBackup = NOSQL('/backup/tbdata');


exports.install = function(instance) {

  var client;
  var opts;
  var clientReady = false;

  // wsmqtt status for notification purposes on projects.worksys.io database
  let wsmqttName = null;
  let sendWsStatusVar = null;
  let wsmqtt_status = 'disconnected';

  function getWsmqttName(host) {
    if (host == "tb-demo.worksys.io" || host == '192.168.252.4') return 'wsmqtt_demo';
    else if (host == "tb-qas01.worksys.io" || host == '192.168.252.5') return 'wsmqtt_qas01';
    else if (host == "tb-prod01.worksys.io" || host == '192.168.252.1') return 'wsmqtt_prod01';
  }

  function sendWsStatus() {
    instance.send(SEND_TO.services, { [wsmqttName]: wsmqtt_status });
  }


  function main() {
    if (!FLOW.dbLoaded) return;

    loadSettings();
    clearInterval(sendWsStatus);
    sendWsStatusVar = setInterval(sendWsStatus, 180000);
  }

  //set opts according to db settings
  function loadSettings() {

    if (instance.options.host !== "") {
      //override settings from database
      var o = instance.options;
      opts = {
        host: o.host,
        port: o.port,
        clientId: o.clientid,
        username: o.username,
        rejectUnauthorized: false,
        resubscribe: false
      };

      wsmqttName = getWsmqttName(o.host);

      console.log("wsmqttpublich -> loadSettings from instance.options", instance.options);
    }
    else {

      const SETTINGS = FLOW.GLOBALS.settings;
      backup_on_failure = SETTINGS.backup_on_failure;
      saveTelemetryOnError = backup_on_failure;

      restore_from_backup = SETTINGS.restore_from_backup;
      restore_backup_wait = SETTINGS.restore_backup_wait;

      let mqtt_host = SETTINGS.mqtt_host;
      let mqtt_clientid = SETTINGS.mqtt_clientid;
      let mqtt_username = SETTINGS.mqtt_username;
      let mqtt_port = SETTINGS.mqtt_port;

      opts = {
        host: mqtt_host,
        port: mqtt_port,
        keepalive: 10,
        clientId: mqtt_clientid,
        username: mqtt_username,
        rejectUnauthorized: false,
        resubscribe: false
      };

      wsmqttName = getWsmqttName(mqtt_host);
    }

    connectToTbServer();
  }

  function connectToTbServer() {
    var url = "mqtt://" + opts.host + ":" + opts.port;
    console.log("MQTT URL: ", url);

    client = mqtt.connect(url, opts);

    client.on('connect', function() {
      instance.status("Connected", "green");
      //monitor.info("MQTT client connected");

      sendClientError = true;
      clientReady = true;
      wsmqtt_status = 'connected';
    });

    client.on('reconnect', function() {
      instance.status("Reconnecting", "yellow");
      clientReady = false;
    });

    client.on('message', function(topic, message) {
      // message is type of buffer
      message = message.toString();
      if (message[0] === '{') {
        TRY(function() {

          message = JSON.parse(message);
          if (message.hasOwnProperty("device") && message.hasOwnProperty("data") && message.data.hasOwnProperty("id")) {
            client.publish(topic, `{"device": ${message.device}, "id": ${message.data.id}, "data": {"success": true}}`, { qos: 1 });
            instance.send(SEND_TO.rpcCall, { "device": message.device, "id": message.data.id, "RPC response": { "success": true } });
          }

        }, () => instance.debug('MQTT: Error parsing data', message));
      }

      instance.send(SEND_TO.rpcCall, { "topic": topic, "content": message });
    });

    client.on('close', function() {
      clientReady = false;
      wsmqtt_status = 'disconnected';

      instance.status("Disconnected", "red");
      instance.send(SEND_TO.debug, { "message": "Client CLOSE signal received !" });
    });

    client.on('error', function(err) {
      instance.status("Err: " + err.code, "red");
      instance.send(SEND_TO.debug, { "message": "Client ERROR signal received !", "error": err, "opt": opts });
      if (sendClientError) {
        monitor.info('MQTT client error', err);
        sendClientError = false;
      }
      clientReady = false;
      wsmqtt_status = 'disconnected';
    });

  }


  instance.on("0", _ => {
    main();
  })


  instance.on('1', function(data) {

    if (clientReady) {
      //do we have some data in backup file? if any, process data from database
      if (saveTelemetryOnError) {
        //read telemetry data and send back to server
        if (!processingData) processDataFromDatabase();
      }

      let stringifiedJson = JSON.stringify(data.data);
      client.publish("v1/gateway/telemetry", stringifiedJson, { qos: 1 });

      //backup telemetry
      if (createTelemetryBackup) {
        data.data.id = UID();
        nosqlBackup.insert(data.data);

        insertBackupNoSqlCounter++;
        if (insertBackupNoSqlCounter > 150) {
          let options = { compress: true };
          let path = __dirname + "/../databases/backup/tbdata.nosql";
          var stream = new rollers.RollingFileStream(path, noSqlFileSizeLimit, 150, options);
          stream.write("");
          stream.end();

          insertBackupNoSqlCounter = 0;
        }
      }

    }
    else {
      //logger.debug("Client unavailable. Data not sent !", JSON.stringify(data.data));
      instance.send(SEND_TO.debug, { "message": "Client unavailable. Data not sent !", "data": data.data });

      if (saveTelemetryOnError) {
        //create new file from tbdata.nosql, if file size exceeds given limit, and clear tbdata.nosql
        makeBackupFromDbFile();

        //write to tb
        data.data.id = UID();
        nosql.insert(data.data);
      }
    }
  });


  instance.close = function(done) {
    if (clientReady) {
      client.end();
      clearInterval(sendWsStatusVar);
    }
  };


  function getDbBackupFileCounter(type) {
    var files = fs.readdirSync(__dirname + "/../databases");

    let counter = 0;
    for (var i = 0; i < files.length; i++) {

      if (files[i] == "tbdata.nosql") continue;

      if (files[i].endsWith(".nosql")) {

        let pos = files[i].indexOf(".");
        if (pos > -1) {

          let fileCounter = counter;
          let firstDigit = files[i].slice(0, pos);

          fileCounter = parseInt(firstDigit);
          if (isNaN(fileCounter)) fileCounter = 0;
          //console.log("getDbBackupFileCounter digit:", files[i], firstDigit, fileCounter, isNaN(fileCounter), type);

          if (type == "max") {
            if (fileCounter > counter) {
              counter = fileCounter;
            }
          }
          else if (type == "min") {
            if (counter == 0) counter = fileCounter;

            if (fileCounter < counter) {
              counter = fileCounter;
            }
          }
        }
      }

    }

    if (type == "max") counter++;

    return counter;
  }

  const makeBackupFromDbFile = async () => {

    if (!saveTelemetryOnError) return;

    //to avoid large file: tbdata.nosql

    //init value is 0!
    if (insertNoSqlCounter > 0) {
      --insertNoSqlCounter;
      return;
    }

    insertNoSqlCounter = 100;

    let source = __dirname + "/../databases/tbdata.nosql";

    var stats = fs.statSync(source);
    var fileSizeInBytes = stats.size;

    if (fileSizeInBytes > noSqlFileSizeLimit) {

      let counter = 1;
      counter = getDbBackupFileCounter("max");

      let destination = __dirname + "/../databases/" + counter + "." + "tbdata.nosql";

      //make backup file
      fs.copyFileSync(source, destination);
      //fs.renameSync(p, p + "." + counter);

      //clear tbdata.nosql
      fs.writeFileSync(source, "");
      fs.truncateSync(source, 0);

    }
  }

  const processDataFromDatabase = async () => {

    if (restore_from_backup <= 0) return;

    //calculate diff
    const now = new Date();
    let currentTime = now.getTime();
    let diff = currentTime - lastRestoreTime;

    if ((diff / 1000) < restore_backup_wait) {
      //console.log("*********restore_backup_wait", diff, restore_backup_wait);
      return;
    }

    processingData = true;

    //get filename to process
    let counter = getDbBackupFileCounter("min");

    //we have some backup files
    let dataBase = 'tbdata';

    var nosql;
    if (counter == 0) dataBase = 'tbdata';
    else dataBase = counter + "." + 'tbdata';

    nosql = NOSQL(dataBase);

    //select all data - use limit restore_from_backup
    let records = await promisifyBuilder(nosql.find().take(restore_from_backup));

    for (let i = 0; i < records.length; i++) {
      if (clientReady) {

        let item = records[i];
        let id = item.id;

        if (id !== undefined) {
          //console.log("------------processDataFromDatabase - remove", id, dataBase, i);

          try {

            let message = JSON.parse(JSON.stringify(item));
            delete message.id;

            client.publish("v1/gateway/telemetry", JSON.stringify(message), { qos: 1 });

            //remove from database
            await promisifyBuilder(nosql.remove().where("id", id));

          } catch (error) {
            //process error
            console.log("processDataFromDatabase", error);
          }

        }

      }
      else {
        processingData = false;
        return;
      }
    }

    if (records.length > 0) {
      //clean backup file
      if (counter > 0) nosql.clean();
    }

    //no data in db, remove
    if (records.length == 0) {
      if (counter > 0) nosql.drop();
    }

    const d = new Date();
    lastRestoreTime = d.getTime();

    processingData = false;

  }

  instance.on('options', main);
  //instance.reconfigure();
};