flutter_integrated_whb/lib/customWidget/BaiDuMap/Map_page.dart

import 'dart:convert';
import 'package:flutter/material.dart';
import 'package:qhd_prevention/customWidget/BaiDuMap/BaiduMapWebView.dart';
import 'package:qhd_prevention/customWidget/toast_util.dart';
import 'package:qhd_prevention/pages/my_appbar.dart';
import 'package:qhd_prevention/services/location_service.dart';
import 'package:qhd_prevention/tools/coord_convert.dart';
import 'package:qhd_prevention/tools/tools.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'package:webview_flutter/webview_flutter.dart';
import 'package:geolocator/geolocator.dart';

class MapPage extends StatefulWidget {
  final String gson;

  const MapPage({super.key, required this.gson});

  @override
  State<MapPage> createState() => _MapPageState();
}

class _MapPageState extends State<MapPage> {
  late final WebViewController _controller;
  bool _isLoading = true;
  String? _errorMessage;
  double? _longitude;
  double? _latitude;
  List<dynamic> _gsonList = [];
  late Map<String, dynamic> mapData = {};
  @override
  void initState() {
    super.initState();
    _loadWebView();
  }

  /// 获取定位（并初始化 WebView 控制器）
  // Future<void> _initLocation() async {
  //   setState(() {
  //     _isLoading = true;
  //     _errorMessage = null;
  //   });
  //   Map<String, double> prefs = geographicCentroid(_gsonList);
  //   _loadWebView(LocationResult(latitude: prefs['lat'].toString(), longitude: prefs['lon'].toString()));
  //
  // }
  Future<void> _loadWebView() async {
    // 解析 gson
    try {
      final parsed = jsonDecode(widget.gson);
      if (parsed is List) {
        _gsonList = parsed;
      } else {
        _gsonList = [];
      }
    } catch (e) {
      debugPrint('解析 gson 失败: $e');
      _gsonList = [];
    }
    if (!mounted) return;
    Map<String, double> prefs = geographicCentroid(_gsonList);
    // _loadWebView(LocationResult(latitude: prefs['lat'].toString(), longitude: prefs['lon'].toString()));
    setState(() {
      _longitude = prefs['lon'];
      _latitude = prefs['lat'];
    });


    // 初始化 WebViewController 并加载本地页面
    _controller = WebViewController()
      ..setJavaScriptMode(JavaScriptMode.unrestricted)
    // 注册 JS 通道 'JS' —— 对应 HTML 中的 window.JS.postMessage(...)
      ..addJavaScriptChannel('JS', onMessageReceived: (dynamic message) {
        // message 是动态对象，不在签名中引用具体类型以避免 "Undefined class" 问题
        String payload;
        try {
          payload = message.message ?? message.toString();
        } catch (e) {
          payload = message.toString();
        }
        _onJsMessage(payload);
      })
    // 也保留一个备用通道 'Flutter'
      ..addJavaScriptChannel('Flutter', onMessageReceived: (dynamic message) {
        String payload;
        try {
          payload = message.message ?? message.toString();
        } catch (e) {
          payload = message.toString();
        }
        _onJsMessage(payload);
      })
      ..setNavigationDelegate(
        NavigationDelegate(
          onPageFinished: (String url) async {
            debugPrint('网页加载完成: $url');
            await _injectLocationParams();
          },
          onWebResourceError: (err) {
            debugPrint('Web resource error: ${err.description}');
          },
        ),
      );

    // 加载本地 assets 中的 HTML
    // await _controller.loadFlutterAsset('assets/map/index.html');
    await _controller.loadRequest(Uri.parse('http://47.92.102.56:7811/file/fluteightmap/index.html'));

    setState(() {
      _isLoading = false;
    });
  }

  /// 注入参数并调用页面初始化函数 window.initWithData(...)
  Future<void> _injectLocationParams() async {
    if (_longitude == null || _latitude == null) {
      debugPrint('位置尚未准备好，跳过注入');
      return;
    }

    final params = {
      'longitude': _longitude,
      'latitude': _latitude,
      'GSON': _gsonList,
      't': DateTime.now().millisecondsSinceEpoch,
    };
    debugPrint('网页初始化参数: ${jsonEncode(params)}');

    final jsonParams = jsonEncode(params);

    try {
      await _controller.runJavaScript('''
        (function(){
          try {
            if (typeof window.initWithData === 'function') {
              window.initWithData($jsonParams);
            } else if (typeof window.initMap === 'function') {
              window.initMap($jsonParams);
            } else {
              console.error('initWithData / initMap function not found');
            }
          } catch(e) {
            console.error('call initWithData error', e);
          }
        })();
      ''');
      debugPrint('已注入地图初始化参数');
    } catch (e) {
      debugPrint('注入位置参数失败: $e');
    }
  }

  /// 处理来自 Web 的消息（字符串或 JSON）
  void _onJsMessage(String message) {
    debugPrint('收到来自 Web 的消息: $message');
    if (message.isEmpty) return;
    try {
      Map<String,dynamic> data = jsonDecode(message);
      if (FormUtils.hasValue(data, 'ok') && data['ok'] == true) {
      }else{
        if (FormUtils.hasValue(data, 'type') && data['type'] == 'converted') {
          setState(() {
            mapData = data;
          });
        }else{
          ToastUtil.showNormal(context, '当前选择点位不在区域中');
          setState(() {
            mapData = {};
          });
        }
      }
    } catch (_) {
      setState(() {
        mapData = {};
      });
      ToastUtil.showNormal(context, '当前选择点位不在区域中');
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: MyAppbar(title: '地图选择', actions: [
        if (mapData.isNotEmpty)
         TextButton(onPressed: (){
           Navigator.of(context).pop((mapData));
         }, child: Text('确定', style: TextStyle(color: Colors.white, fontSize: 17),))
      ],),
      body: SafeArea(
        child: BaiduMapWebView(
        controller: _isLoading || _errorMessage != null ? null : _controller,
        isLoading: _isLoading,
        errorMessage: _errorMessage,
        onRetry: _loadWebView,
      ),),
    );
  }
}