var linebot = require('linebot');

var express = require('express');

var SerialPort = require('serialport');

var bot = linebot({

  channelId: '這裡改成自己Line的channelId',

  channelSecret: '這裡改成自己Line的channelSecret',

  channelAccessToken: '這裡改成自己Line的channelAccessToken'

});

//以下的com5請自行修改成自己的micro:bit和電腦連接時的com port名稱

//但是baudRate，115200的值，請勿修改

var mySerial = new SerialPort('com5', {baudRate: 115200});

var myId;

const Delimiter = SerialPort.parsers.Delimiter;

const parser = mySerial.pipe(new Delimiter({ delimiter: Buffer.from('\n') }));

//這一段的程式是專門處理當有人傳送文字訊息給LineBot時，我們的處理回應

bot.on('message', function(event) {

  if (event.message.type = 'text') {

    myId=event.source.userId;

    var msg = event.message.text;

    console.log(msg);

    sendToMicrobit(msg);

  }

});

function sendToMicrobit(msgFromLine){

  var myMsg='';

  if (msgFromLine=='溫度')

     myMsg='temperature\n';

  else if (msgFromLine=='光線')

     myMsg='light\n';

  else if (msgFromLine=='清除'){

     myMsg='clear\n';

     bot.push(myId,'micro:bit的LED畫面已清除！')    

  } else if (msgFromLine.startsWith('聲音')){

     myMsg=msgFromLine.replace('聲音','tn')+'\n';

     bot.push(myId,'micro:bit發出聲音：'+msgFromLine.replace('聲音',''));

  } else if (!isNaN(msgFromLine)){

     bot.push(myId,'已傳送編號'+msgFromLine+'的圖案到micro:bit');

     myMsg=msgFromLine+'\n';

  } else{

     bot.push(myId,'您好，目前可以用的指令有\n溫度(會回報溫度)\n光線(會回報光值)\n0~39(microbit的LED會顯示編號圖案)\n清除(清掉LED畫面)\n聲音加上簡譜數字(例如聲音123)');

     myMsg='\n';

  }

  mySerial.write(myMsg, function(err) {

    if (err) {

      return console.log('Error on write: ', err.message);

    }

    console.log('訊息已傳送至micro:bit:'+myMsg);

  });

}

parser.on('data', function (data) {

  var myString=data.toString();

  console.log('Data:',myString);

  if (myString.startsWith('temperature')){

     myString=myString.replace('temperature','溫度');

  } else if (myString.startsWith('light')){

     myString=myString.replace('light','光線');

  }  else if (myString==='A\r' || myString==='B\r'){

     myString=myString.replace('\r','')+'鍵已被按下！';

  }

  bot.push(myId,myString);

});

mySerial.on('error', function(err) {

  console.log('Error: ', err.message);

})

const app = express();

const linebotParser = bot.parser();

app.post('/', linebotParser);

var server = app.listen(process.env.PORT || 8080, function() {

  var port = server.address().port;

  console.log('目前的port是', port);

});