class DataToTbHandler {

  constructor(index) {
    this.index = index;

    // time, after new value for the given key will be resend to tb (e.g. {status: "OK"})
    this.timeToHoldTbValue = 30*60; //30 minutes

    this.previousValues = {};
    this.debug = false;
    this.messageCounter = 0;

    this.sender = "";
  }

  dump() {
    console.log("----------------------------");
    console.log("previousValues", this.previousValues);
    console.log("----------------------------");
  }

  setSender(sender) {
    this.sender = sender;
  }

  isEmptyObject(obj) {
    for (var name in obj) {
      return false;
    }
    return true;
  }

  sendToTb(dataToTb, instance) {

    let keys = Object.keys(dataToTb);

    if(keys.length == 0)
    {
      if(this.debug) console.log("sendToTb received empty object", dataToTb);
      return;
    }

    let tbname = keys[0];
    let ts;

    let arrayOfValues = dataToTb[tbname];
    let arrayOfValuesToSend = [];

    for(let i = 0; i < arrayOfValues.length; i++)
    {
      ts = arrayOfValues[i].ts;
      let values = this.prepareValuesForTb(tbname, ts, arrayOfValues[i].values);

      if(!this.isEmptyObject(values)) 
      {
        arrayOfValuesToSend.push({ts: ts, values: values});
      }
    }

    if(arrayOfValuesToSend.length == 0)
    {
      //if(this.debug) console.log("data not sent - empty array");
      return;
    }

    this.messageCounter++;

    let dataToTbModified = {
        [tbname]: arrayOfValuesToSend
    }

    //console.log(this.sender + " DATA SEND TO TB ", tbname, this.messageCounter, new Date(ts), dataToTbModified[tbname][0].values, this.instance);
    //if(this.debug) console.log(this.sender + " DATA SEND TO TB ", this.index, tbname, arrayOfValuesToSend);
    instance.send(this.index, dataToTbModified);
  }

  getDiffTimestamp(key) {
    //TODO set different value for given key!!!
    //if(key == "status") this.timeToHoldTbValue = 2*60*60;//2h
    return this.timeToHoldTbValue * 1000;
  }

  prepareValuesForTb(tbname, timestamp, values) {

    let keys = Object.keys(values);
    if(!this.previousValues.hasOwnProperty(tbname))
    {
      this.previousValues[tbname] = {};
    }

    //if(this.debug) console.log("prepareValuesForTb", tbname, timestamp, values);

    for(let i = 0; i < keys.length; i++)
    {
      let key = keys[i];
      let value = values[key];

      if(!this.previousValues[tbname].hasOwnProperty(key)) 
      {
        this.previousValues[tbname][key] = {ts: timestamp, value: value};
        continue;
      }

      if(this.previousValues[tbname][key].value === value)
      {
        let diff = timestamp - this.previousValues[tbname][key].ts;

        let timestampDiffToRemoveKey = this.getDiffTimestamp(key);
        if(diff > timestampDiffToRemoveKey)
        {
          this.previousValues[tbname][key].ts = Date.now();
          //if(this.debug) console.log(this.sender + ": update ts for key", key, "diff is", diff, "messageCounter", this.messageCounter);

        }
        else
        {
          delete values[key];
          //if(this.debug) console.log(this.sender + ": delete key", key, "diff is", diff, "messageCounter", this.messageCounter, timestampDiffToRemoveKey);
        }
      }
      else
      {
        this.previousValues[tbname][key].value = value;
        this.previousValues[tbname][key].ts = timestamp;
      }

    }

    return values;
  }
}

module.exports =  DataToTbHandler;