import 'dart:convert';
import 'package:flutter/material.dart';
import 'package:flutter_map/flutter_map.dart';
import 'package:latlong2/latlong.dart';
import 'package:flutter/services.dart' show rootBundle;

// 🔥 1. 定义场站模型（核心）
class DJIStation {
  /// 场站标识（对应瓦片目录名：assets/tiles/[name]）
  final String name;

  /// 场站显示名称（用于UI展示，如"一号场站"）
  final String displayName;

  const DJIStation({required this.name, required this.displayName});
}

/// 大疆高清瓦片图层组件（适配 flutter_map v6.x）
class DJITileLayer extends StatefulWidget {
  /// 场站名称（对应 tiles/[stationName] 目录）
  final String stationName;

  /// 地图控制器（用于加载中心点后移动地图）
  final MapController mapController;

  const DJITileLayer({super.key, required this.stationName, required this.mapController});

  @override
  State<DJITileLayer> createState() => _DJITileLayerState();
}

class _DJITileLayerState extends State<DJITileLayer> {
  /// 场站中心点（从 parm/center.json 读取）
  LatLng? _stationCenter;

  /// 瓦片缩放级别范围
  final double _minZoom = 16;
  final double _maxZoom = 23;

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

  @override
  void didUpdateWidget(covariant DJITileLayer oldWidget) {
    super.didUpdateWidget(oldWidget);
    if (oldWidget.stationName != widget.stationName) {
      _loadStationCenter();
    }
  }

  /// 从 assets/tiles/[stationName]/parm/center.json 读取中心点
  Future<void> _loadStationCenter() async {
    try {
      debugPrint("xsdscdvc");

      final String configPath = 'assets/tiles/${widget.stationName}/parm/center.json';
      debugPrint(configPath);
      final jsonString = await rootBundle.loadString('assets/tiles/liaoning/parm/center.json');
      debugPrint("$jsonString,jsonString");
      final Map<String, dynamic> centerJson = json.decode(jsonString);
      debugPrint("$centerJson,centerJson");

      final double lng = centerJson['lng'] ?? centerJson['lon'];
      final double lat = centerJson['lat'];
      final LatLng newCenter = LatLng(lat, lng);

      setState(() => _stationCenter = newCenter);
      widget.mapController.move(newCenter, 19);
    } catch (e) {
      debugPrint('加载${widget.stationName}中心点失败：$e');
      setState(() => _stationCenter = const LatLng(32.040644, 120.805718));
    }
  }

  @override
  Widget build(BuildContext context) {
    final String tileUrlTemplate = 'assets/tiles/${widget.stationName}/{z}/{x}/{y}.png';

    return TileLayer(
      urlTemplate: tileUrlTemplate,
      tileProvider: AssetTileProvider(), // 修复：直接使用类实例
      tms: true,
      minZoom: _minZoom,
      maxZoom: _maxZoom,
    );
  }
}

/// 修复：适配 v6.x 的 AssetTileProvider（移除过时的 TileLayerOptions）
class AssetTileProvider extends TileProvider {
  @override
  ImageProvider<Object> getImage(TileCoordinates coords, TileLayer options) {
    // 修复：v6.x 中使用 TileCoordinates 替代 Coords，TileLayer 替代 TileLayerOptions
    final String path = options.urlTemplate!
        .replaceAll('{z}', coords.z.toString())
        .replaceAll('{x}', coords.x.toString())
        .replaceAll('{y}', coords.y.toString());
    debugPrint('加载大疆瓦片：$path');
    return AssetImage(path);
  }
}