flutterApp/lib/features/home/presentation/widgets/map/testmap_pages.dart

import 'dart:async';
import 'dart:math';
import 'package:flutter/material.dart';
import 'package:flutter_map/flutter_map.dart';
import 'package:geolocator/geolocator.dart';
import 'package:latlong2/latlong.dart';

import '../path_list_pages.dart';

class MapPageEnterprise extends StatefulWidget {
  const MapPageEnterprise({Key? key}) : super(key: key);

  @override
  State<MapPageEnterprise> createState() => _MapPageEnterpriseState();
}

class _MapPageEnterpriseState extends State<MapPageEnterprise> {
  final MapController _mapController = MapController();

  LatLng? _currentLatLng;
  StreamSubscription<Position>? _positionSub;
  bool _hasMovedOnce = false;

  @override
  void initState() {
    super.initState();
    _initLocationEnterprise();
  }

  /// ===============================
  /// 企业级定位初始化（已修复坐标系）
  /// ===============================
  Future<void> _initLocationEnterprise() async {
    final serviceEnabled = await Geolocator.isLocationServiceEnabled();
    if (!serviceEnabled) return;

    LocationPermission permission = await Geolocator.checkPermission();
    if (permission == LocationPermission.denied) {
      permission = await Geolocator.requestPermission();
    }
    if (permission != LocationPermission.whileInUse &&
        permission != LocationPermission.always) {
      return;
    }

    // 1️⃣ 首次强制获取定位
    final position = await Geolocator.getCurrentPosition(
      desiredAccuracy: LocationAccuracy.bestForNavigation,
    );

    final gcj = wgs84ToGcj02(position.latitude, position.longitude);
    _updateLocation(gcj, moveMap: true);

    // 2️⃣ 实时监听（不再强制移动地图）
    _positionSub = Geolocator.getPositionStream(
      locationSettings: const LocationSettings(
        accuracy: LocationAccuracy.bestForNavigation,
        distanceFilter: 2,
      ),
    ).listen((pos) {
      final gcj = wgs84ToGcj02(pos.latitude, pos.longitude);
      _updateLocation(gcj, moveMap: false);
    });
  }

  /// ===============================
  /// 更新位置
  /// ===============================
  void _updateLocation(LatLng latLng, {bool moveMap = false}) {
    setState(() {
      _currentLatLng = latLng;
    });

    if (moveMap && !_hasMovedOnce) {
      _hasMovedOnce = true;
      _mapController.move(latLng, 17);
    }
  }

  /// 手动回到当前位置
  void _moveToCurrentLocation() {
    if (_currentLatLng == null) return;
    _mapController.move(_currentLatLng!, 17);
  }

  @override
  void dispose() {
    _positionSub?.cancel();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    final screenHeight = MediaQuery.of(context).size.height;
    final menuHeight = 16 * 6; // 假设 VerticalFloatMenu 有 6 个选项，每个高度为 56
    final maxTop = screenHeight - menuHeight;
    return Scaffold(
      body:
      SafeArea(
        child: Stack(
        children: [
          FlutterMap(
            mapController: _mapController,
            options: MapOptions(
              initialCenter:
              _currentLatLng ?? const LatLng(39.9042, 116.4074),
              initialZoom: 15,
              maxZoom: 18,
            ),
            children: [
              /// 高德瓦片（GCJ-02）
              TileLayer(
                urlTemplate:
                'https://webrd02.is.autonavi.com/appmaptile'
                    '?style=8&x={x}&y={y}&z={z}&lang=zh_cn&size=1&scale=1'
                    '&key=bbb1f0f20eed6bf679eddf2625630aba',
              ),

              /// 当前定位 Marker
              if (_currentLatLng != null)
                MarkerLayer(
                  markers: [
                    Marker(
                      point: _currentLatLng!,
                      width: 40,
                      height: 40,
                      child: const Icon(
                        Icons.my_location,
                        color: Colors.blue,
                        size: 30,
                      ),
                    ),
                  ],
                ),
            ],
          ),

          Positioned(
            height: 336,
            right: 16,
            top: maxTop > 10 ? 11 : maxTop, // 确保不超出屏幕范围
            child: FloatingActionButton(
              onPressed: _moveToCurrentLocation,
              child: new VerticalFloatMenu(),
            ),
          ),
        ],
      ),
    ));
  }
}

/// =======================================================
/// 坐标转换：WGS84 -> GCJ02（国内高德/腾讯通用）
/// =======================================================

const double _pi = 3.14159265358979324;
const double _a = 6378245.0;
const double _ee = 0.00669342162296594323;

LatLng wgs84ToGcj02(double lat, double lon) {
  if (_outOfChina(lat, lon)) {
    return LatLng(lat, lon);
  }
  double dLat = _transformLat(lon - 105.0, lat - 35.0);
  double dLon = _transformLon(lon - 105.0, lat - 35.0);
  double radLat = lat / 180.0 * _pi;
  double magic = sin(radLat);
  magic = 1 - _ee * magic * magic;
  double sqrtMagic = sqrt(magic);
  dLat = (dLat * 180.0) /
      ((_a * (1 - _ee)) / (magic * sqrtMagic) * _pi);
  dLon = (dLon * 180.0) / (_a / sqrtMagic * cos(radLat) * _pi);
  double mgLat = lat + dLat;
  double mgLon = lon + dLon;
  return LatLng(mgLat, mgLon);
}

bool _outOfChina(double lat, double lon) {
  return lon < 72.004 ||
      lon > 137.8347 ||
      lat < 0.8293 ||
      lat > 55.8271;
}

double _transformLat(double x, double y) {
  double ret = -100.0 +
      2.0 * x +
      3.0 * y +
      0.2 * y * y +
      0.1 * x * y +
      0.2 * sqrt(x.abs());
  ret += (20.0 * sin(6.0 * x * _pi) +
      20.0 * sin(2.0 * x * _pi)) *
      2.0 /
      3.0;
  ret += (20.0 * sin(y * _pi) +
      40.0 * sin(y / 3.0 * _pi)) *
      2.0 /
      3.0;
  ret += (160.0 * sin(y / 12.0 * _pi) +
      320 * sin(y * _pi / 30.0)) *
      2.0 /
      3.0;
  return ret;
}

double _transformLon(double x, double y) {
  double ret = 300.0 +
      x +
      2.0 * y +
      0.1 * x * x +
      0.1 * x * y +
      0.1 * sqrt(x.abs());
  ret += (20.0 * sin(6.0 * x * _pi) +
      20.0 * sin(2.0 * x * _pi)) *
      2.0 /
      3.0;
  ret += (20.0 * sin(x * _pi) +
      40.0 * sin(x / 3.0 * _pi)) *
      2.0 /
      3.0;
  ret += (150.0 * sin(x / 12.0 * _pi) +
      300.0 * sin(x / 30.0 * _pi)) *
      2.0 /
      3.0;
  return ret;
}