library gnss;

import 'dart:developer';
import 'dart:io';
import 'dart:typed_data';
import 'dart:async';
import "package:libserialport/libserialport.dart";
import "nmea/sentence.dart";
import 'nmea/gga.dart';
import 'nmea/rmc.dart';
import 'nmea/vtg.dart';
import 'nmea/gsa.dart';
import 'nmea/gsv.dart';
import 'nmea/heading.dart';
import 'nmea/bestpos.dart';
import "rtk_base.dart";

class LocationData {
  double latitude = 0; //纬度
  double longitude = 0; //经度
  double speed = 0; //速度
  double baseLength = 0; //基线长度(两天线距离)
  double heading = 0; //
  double pitch = 0; //俯仰角
  double altitude = 0; //海拔
  double adop = 0; //高程定位精度
  double hdop = 0; //水平定位精度
  double vdop = 0; //垂直定位精度
  double course = 0; //航向
  double diffAge = 0; //差分数据年龄
  int numberSv = 0; //可见卫星数
  int numberSa = 0; //使用卫星数
  String fixQuality = ""; //定位质量(字符串)
  int quality = 0; //定位质量(数字)
  @override
  String toString() {
    return "LocationData{latitude=$latitude,longitude=$longitude,speed=$speed,baseLength=$baseLength,heading=$heading,pitch=$pitch,altitude=$altitude,adop=$adop,hdop=$hdop,vdop=$vdop,course=$course,diffAge=$diffAge,numberSv=$numberSv,numberSa=$numberSa,fixQuality=$fixQuality,quality=$quality}";
  }
}

const um982Init = [
  "version\r\n",
  "UNLOGALL\r\n",
  "GPRMC 1\r\n", //0.2
  "GPGGA 1\r\n",
  "GPVTG 1\r\n",
  "LOG HEADINGA ONTIME 0.2\r\n",
  "LOG BESTPOSA ONTIME 0.2\r\n",
  "GPGSV 1\r\n",
  "GPGSA 1\r\n",
  "SAVECONFIG\r\n"
];

class SignalGPS {
  int prn;
  double elevation;
  double azimuth;
  int snrL1;
  int snrL2;
  int snrL5;
  SignalGPS(
      {required this.prn,
      required this.elevation,
      required this.azimuth,
      required this.snrL1,
      required this.snrL2,
      required this.snrL5});
}

class SignalBDS {
  int prn;
  double elevation;
  double azimuth;
  int snrB1I;
  int snrB2I;
  int snrB1C;
  int snrB2a;
  int snrB3I;
  SignalBDS(
      {required this.prn,
      required this.elevation,
      required this.azimuth,
      required this.snrB1I,
      required this.snrB2I,
      required this.snrB1C,
      required this.snrB2a,
      required this.snrB3I});
}

class SignalGLO {
  int prn;
  double elevation;
  double azimuth;
  int snrR1;
  int snrR2;
  SignalGLO(
      {required this.prn,
      required this.elevation,
      required this.azimuth,
      required this.snrR1,
      required this.snrR2});
}

class SignalGAL {
  int prn;
  double elevation;
  double azimuth;
  int snrE1;
  int snrE5a;
  int snrE5b;
  SignalGAL(
      {required this.prn,
      required this.elevation,
      required this.azimuth,
      required this.snrE1,
      required this.snrE5a,
      required this.snrE5b});
}

class SignalData {
  List<SignalGPS> signalsGPS = [];
  List<SignalBDS> signalsBDS = [];
  List<SignalGLO> signalsGLO = [];
  List<SignalGAL> signalsALS = [];
}

class Gnss {
  SerialPort? _serialPort;
  SerialPortReader? _serialPortReader;
  Socket? _socket; // tcp
  RtkBase? rtkBase;
  LineSplitter lineSplitter = LineSplitter();
  SentenceParser sentence = SentenceParser({}, null, null, null);
  var locationStreamController = StreamController<LocationData>.broadcast();
  var signalStreamController = StreamController<SignalData>.broadcast();
  Stream<LocationData> get locationStream => locationStreamController.stream;
  Stream<SignalData> get signalStream => signalStreamController.stream;
  final LocationData _locationData = LocationData();
  final SignalData _signalData = SignalData();
  SignalData get signalData => _signalData;
  bool locationUpdate = false;
  bool signalUpdate = false;
  bool _isTCP = false;

  String _port = "";
  int _baudrate = 0;
  String _host = "";
  int _portTcp = 0;

  Gnss({port = "", baudrate = 115200, host = "", portTCP = 0, isTCP = false}) {
    _port = port;
    _baudrate = baudrate;
    _host = host;
    _portTcp = portTCP;
    _isTCP = isTCP;
  }

  start() {
    if (_isTCP) {
      _connectTcp();
    } else {
      _connectSerialPort();
    }

    rtkBase ??= RtkBase();
    rtkBase!.connect();
    rtkBase!.rtcmStream.listen((rtcmData) {
      if (_serialPort != null) {
        _serialPort!.write(Uint8List.fromList(rtcmData));
      }
    });
  }

  void dispose() {
    if (_isTCP) {
      if (_socket != null) {
        _socket!.close();
        _socket = null;
      }
    } else {
      if (_serialPort != null) {
        _serialPortReader?.close();
        _serialPort!.close();
        _serialPort = null;
      }
    }
  }

  _connectSerialPort() {
    _serialPort = SerialPort(_port);
    if (!_serialPort!.openReadWrite()) {
      throw Exception(SerialPort.lastError);
    }
    var config = _serialPort!.config;
    config.baudRate = _baudrate;
    config.bits = 8;
    config.parity = 0;
    config.stopBits = 1;
    config.setFlowControl(0);
    _serialPort!.config = config;
    _serialPortReader = SerialPortReader(_serialPort!);
    _serialPortReader!.stream.listen(_onData);
    if (_serialPort != null) {
      int i = 0;
      _serialPort!.write(Uint8List.fromList(um982Init[i].codeUnits));
      Timer.periodic(const Duration(milliseconds: 100), (timer) {
        if (_serialPort != null) {
          _serialPort!.write(Uint8List.fromList(um982Init[i].codeUnits));
        }
        i++;
        if (i == um982Init.length - 1) {
          timer.cancel();
        }
      });
    }
  }

  void _connectTcp() {
    if (_host == "" || _portTcp == 0) {
      return;
    }
    log("尝试连接$_host:$_port");
    Socket.connect(_host, _portTcp).then((socket) {
      _socket = socket;
      log("连接成功");
      socket.listen(_onData);
      socket.handleError((error) {
        log("error=$error");
      });
      socket.timeout(const Duration(seconds: 15), onTimeout: (sink) {
        log("timeout");
        socket.destroy();
        _reconnect();
      });
    }).onError((error, stackTrace) {
      log("error=$error");
      _socket = null;
      _reconnect();
    });
  }

  void _reconnect() {
    log("尝试重新连接...");
    Future.delayed(const Duration(seconds: 5), () {
      _connectTcp();
    });
  }

  _onData(Uint8List data) {
    var lines = lineSplitter.pushData(data);
    for (int i = 0; i < lines.length; i++) {
      try {
        var s = sentence.parse(lines[i]);
        switch (s.type) {
          case TypeBESTPOSA:
            var bestpos = BESTPOSA.newBESTPOSA(s);
            // log("bestposa=${bestposa.lat},${bestposa.lon}");
            _locationData.latitude = bestpos.lat;
            _locationData.longitude = bestpos.lon;
            _locationData.altitude = bestpos.hgt;
            _locationData.adop = bestpos.adop;
            _locationData.hdop = bestpos.hdop;
            _locationData.vdop = bestpos.vdop;
            _locationData.diffAge = bestpos.diffAge;
            _locationData.fixQuality = bestpos.fixQuality;
            // _locationData.pdop = bestpos.pdop;
            break;
          case TypeHEADINGA:
            var h = HEADINGA.newHEADINGA(s);
            // log("heading=${h.heading}");
            _locationData.baseLength = h.length;
            _locationData.heading = h.heading;
            _locationData.pitch = h.pitch;
            _locationData.numberSv = h.numberSv;
            _locationData.numberSa = h.numberSa;
            locationUpdate = true;
            break;

          case TypeRMC:
            var rmc = RMC.newRMC(s);
            _locationData.course = rmc.course;
            // log("rmc=${rmc.latitude},${rmc.longitude},${rmc.speed}");
            break;

          case TypeGGA:
            var gga = GGA.newGGA(s);
            if (rtkBase != null) {
              rtkBase!.sendGGA(s.raw);
            }
            // log("gga=${gga.latitude},${gga.longitude}");
            _locationData.quality = gga.quality;
            break;

          case TypeVTG:
            // 速度
            var vtg = VTG.newVTG(s);
            // log("vtg=${vtg.groundSpeedKnots}");
            _locationData.speed = vtg.groundSpeedKnots;
            break;

          case TypeGSA:
            // 已使用
            var gsa = GSA.newGSA(s);
            // log("gsa=${gsa.pdop}");
            // SV 可用
            break;
          case TypeGSV:
            // 可见
            var gsv = GSV.newGSV(s);
            // log("gsv=${gsv.numberSVsInView}");
            signalUpdate = true;
            break;
          default:
            log('Unhandled sentence type: ${s.type}');
        }
      } catch (e) {
        log("error=$e");
      }
    }
    if (locationUpdate) {
      locationStreamController.add(_locationData);
      locationUpdate = false;
    }
    if (signalUpdate) {
      signalStreamController.add(_signalData);
      signalUpdate = false;
    }
  }
}

class LineSplitter {
  pushData(Uint8List data) {
    List<String> sentences = [];
    if (endIndex + data.length > dataBuf.length) {
      endIndex = 0;
      sentenceStart = -1;
    }
    dataBuf.setAll(endIndex, data);
    endIndex = endIndex += data.length;
    int index = 0;
    while (index < endIndex) {
      if (sentenceStart < 0) {
        if (startDelimiter.contains(dataBuf[index]) == false) {
          index++;
        } else {
          sentenceStart = index;
          seekIndex = index + 1;
        }
      } else {
        for (; seekIndex < endIndex; seekIndex++) {
          if (dataBuf[seekIndex] == 0x0a) {
            sentences
                .add(String.fromCharCodes(dataBuf, sentenceStart, seekIndex));
            sentenceStart = -1;
            index = seekIndex + 1;
            break;
          }
        }
        if (seekIndex == endIndex) {
          break;
        }
      }
    }
    // log("index=$index,endIndex=$endIndex, data.length=${data.length}");
    if (index == endIndex) {
      endIndex = 0;
    } else if (index > 0) {
      dataBuf.setAll(0, dataBuf.sublist(index, endIndex));
      sentenceStart = -1;
      endIndex -= index;
    }
    return sentences;
  }

  int endIndex = 0;
  int seekIndex = 0;
  int sentenceStart = -1;
  Uint8List dataBuf = Uint8List(4096);
  static const startDelimiter = [0x24, 0x23]; //$23 #23
}