const { ipcMain } = require('electron')
const SerialPort  = require('serialport')
const InterByteTimeout = require('@serialport/parser-inter-byte-timeout')
const config      = require('./config')

const NMEAHandler = require('./api/NMEAHandler')

const DEFAULT_BAUDRATE = 9600
const getSerialPortConstructorArguments = (ports) => {
  let serialport = config.get('serialport')
  const path     = ( serialport && serialport.path )     ? serialport.path     : ports[0].path
  const baudRate = ( serialport && serialport.baudRate ) ? serialport.baudRate : DEFAULT_BAUDRATE
  return { path, baudRate }
}

const senders = []
ipcMain.on("APP_MOUNTED", (event) => {
  const { sender } = event
  senders.push(sender)

  sender.once('destroyed', () => {
    const index = senders.indexOf(sender)
    if (index >= 0) senders.splice(index, 1)
  })
})

const sendMsg = (channel, msg) => {
  if (senders.length <= 0) return
  
  try {
    senders.forEach((sender) => {
      sender.send(channel, msg)
    })
  } catch (error) {
    console.error(error)
  }
}

SerialPort.list().then((ports, err) => {
  if (err) {
    console.log(err)
    return
  }

  // console.log(ports, '=====================')

  // 过滤掉COM1口，很多电脑自带COM1接口
  ports.filter((port) => port.path != 'COM1')
  if (ports.length == 0) {
    console.error('设备为连接')
    return
  }
  
  try {
    const { path, baudRate } = getSerialPortConstructorArguments(ports)
    const serialPort = new SerialPort(path, { baudRate })

    const parser     = serialPort.pipe(new InterByteTimeout({interval: 30}))

    NMEAHandler.on('handled' , (nmeaObj) => {
      sendMsg('nmea', JSON.stringify(nmeaObj))
    })

    parser.on('data', (data) => NMEAHandler.handle(data.toString()))
  } catch (error) {
    console.error(error);
  }
})