const resp = require('../util/resp')
const noble = require('noble');

let inRange = {};
let blueDeviceList = []
let blueCharacteristics = []


let connectedCharacteristic = null;
let on_data_callback = null;

noble.on('discover', function (peripheral) {
  if(peripheral.addressType != 'public') {
     return;
  }
  inRange[peripheral.id] = {
    peripheral: peripheral
  };
  var blueDevice = {
    'id': peripheral.id,
    'localName': peripheral.advertisement.localName,
    'serviceUuids': JSON.stringify(peripheral.advertisement.serviceUuids),
    'address': peripheral.address,
    'addressType': peripheral.addressType,
    'connectable': peripheral.connectable,
    'rssi': peripheral.rssi,
  }
  blueDeviceList.push(blueDevice)

});


function onServicesAndCharacteristicsDiscovered(error, services, characteristics) {
    if(connectedCharacteristic ==null) {
        console.log('Discovered services and characteristics');
        const echoCharacteristic = characteristics[0];
        // data callback receives notifications
        echoCharacteristic.on('data', (data, isNotification) => {
            if (on_data_callback) {
                on_data_callback(data)
            }
        });
        // subscribe to be notified whenever the peripheral update the characteristic
        echoCharacteristic.subscribe(error => {
            if (error) {
                console.error('Error subscribing to echoCharacteristic');
            } else {
                console.log('Subscribed for echoCharacteristic notifications');
            }
        });
        connectedCharacteristic = echoCharacteristic
    }
}

module.exports = {
  scan: function (resp_callback) {
    try {
      blueDeviceList = []
      blueCharacteristics = []
      setTimeout(() => {
        noble.stopScanning()
        resp_callback(resp.ok_resp(blueDeviceList))
      }, 3000);
      noble.startScanning()
    } catch (e) {
      resp_callback(resp.fail_resp(e.message))
    }
  },
  // 连接蓝牙设备
  connectDevice:function (args,callBack) {
      let peripheral = inRange[args.id].peripheral
      on_data_callback = args.on_data_cb;
      peripheral.connect(error => {
          if(error == null) {
              callBack(resp.ok_resp('success'))
          } else {
              callBack(resp.fail_resp('error'))
          }
      })
      peripheral.on('disconnect', () => {
            console.log('disconnect')
          // callBack(resp.fail_resp('connectError'))
      });
  },
  // 断开蓝牙设备
  disConnectDevice:function (id,callBack) {
      let peripheral = inRange[id].peripheral
      peripheral.disconnect(error=>{
          if(error == null) {
            callBack(resp.ok_resp('success'))
          } else {
            callBack(resp.fail_resp('error'))
          }
      })
  },
  getCharList:function (id,callBack) {
      let peripheral = inRange[id].peripheral
      peripheral.discoverServices([], function (error, services) {
          for (let serviceIndex = 0; serviceIndex < services.length; serviceIndex++) {
              (function (service) {
                  service.discoverCharacteristics([], function (error, characteristics) {
                      for (let charIndex = 0; charIndex < characteristics.length; charIndex++) {
                          let c = characteristics[charIndex];
                          let info = {
                              id: peripheral.id,
                              uuid: service.uuid,
                              name: service.name,
                              characteristic: {
                                  'uuid': c.uuid,
                                  'properties': c.properties
                              }
                          }
                          callBack(info)
                      }
                  })
              })(services[serviceIndex])
          }
      })
  },
  setUp:function (row) {
      const serviceUUIDs = [row.uuid];
      const characteristicUUIDs = [row.characteristic.uuid];
      let peripheral = inRange[row.id].peripheral
      peripheral.discoverSomeServicesAndCharacteristics(
          serviceUUIDs,
          characteristicUUIDs,
          onServicesAndCharacteristicsDiscovered
      );
  },
  disSetUp:function () {
      if(connectedCharacteristic != null) {
          connectedCharacteristic.unsubscribe(error =>{
              if(error ==null) {
                  console.log('unsubscribe,success!')
                  connectedCharacteristic = null
              }
          })
      }
  },

  write: function (msg, resp_callback) {
    try {
        connectedCharacteristic.write(msg);
    } catch (e) {
      resp_callback(resp.fail_resp(e.message))
    }
  }
}