import 'dart:convert';
import 'dart:math';

import 'package:dio/dio.dart';
import 'package:shared_preferences/shared_preferences.dart';

import '../models/marquee_message.dart';
import '../models/store_info.dart';
import 'api_client.dart';
import 'marquee_web_source.dart';
import 'org_service.dart';

/// 滚动字幕管理服务。
///
/// 列表/新增/编辑/删除均优先对接 Web 后台 `/theme/scrollingText/*` 接口，
/// 同时保留本地 `SharedPreferences` 缓存作为离线兜底。
class MarqueeService {
  MarqueeService({
    Dio? dio,
    OrgService? orgService,
    MarqueeWebSource? webSource,
  })  : _dio = dio ?? ApiClient.instance.dio,
        _orgService = orgService ?? OrgService(),
        _webSource = webSource ?? MarqueeWebSource(dio: ApiClient.instance.dio);

  final Dio _dio;
  final OrgService _orgService;
  final MarqueeWebSource _webSource;

  static const _storageKey = 'cloudhome_ops_marquee_messages';

  Future<SharedPreferences> get _prefs => SharedPreferences.getInstance();

  /// 获取滚动字幕列表。
  ///
  /// 优先从 Web 端 `/theme/scrollingText/list` 获取；若失败则回退本地缓存。
  Future<List<MarqueeMessage>> getMarqueeList({
    String? storeId,
    String? keyword,
    String method = 'GET',
    String path = MarqueeWebSource.defaultPath,
    Map<String, dynamic>? queryParameters,
    Map<String, dynamic>? body,
  }) async {
    final webResult = await _webSource.fetchMarquees(
      method: method,
      path: path,
      queryParameters: queryParameters,
      body: body,
      storeId: storeId,
      keyword: keyword,
    );

    if (webResult.isSuccess) {
      await _saveAll(webResult.data);
      return _applyFiltersAndSort(webResult.data, storeId: storeId, keyword: keyword);
    }

    final localList = await _loadAll();
    return _applyFiltersAndSort(localList, storeId: storeId, keyword: keyword);
  }

  List<MarqueeMessage> _applyFiltersAndSort(
    List<MarqueeMessage> list, {
    String? storeId,
    String? keyword,
  }) {
    var result = list;
    if (storeId != null && storeId.isNotEmpty) {
      result = result.where((m) => m.storeId == storeId).toList();
    }
    if (keyword != null && keyword.isNotEmpty) {
      final lower = keyword.toLowerCase();
      result = result.where((m) {
        return m.content.toLowerCase().contains(lower) ||
            m.storeName.toLowerCase().contains(lower);
      }).toList();
    }
    result.sort((a, b) {
      // 启用的排在前面，其次按更新时间倒序。
      final statusCompare = b.status.compareTo(a.status);
      if (statusCompare != 0) return statusCompare;
      final bTime = b.updateTime;
      final aTime = a.updateTime;
      if (bTime == null || aTime == null) return 0;
      return bTime.compareTo(aTime);
    });
    return result;
  }

  /// 新增或修改滚动字幕。
  ///
  /// 编辑（data 含 id）调用 `/theme/scrollingText/update`，
  /// 新增调用 `/theme/scrollingText/save`。
  /// 成功后刷新本地缓存。
  Future<void> saveMarquee(Map<String, dynamic> data) async {
    final id = data['id']?.toString();
    final payload = _buildWebPayload(data);

    try {
      if (id != null && id.isNotEmpty) {
        await _dio.post<dynamic>('/theme/scrollingText/update', data: payload);
      } else {
        await _dio.post<dynamic>('/theme/scrollingText/save', data: payload);
      }
    } on DioException {
      // 写操作失败时仅更新本地缓存，保证移动端仍可展示。
    }

    final list = await _loadAll();
    final now = DateTime.now();
    final message = MarqueeMessage(
      id: id ?? _generateId(),
      storeId: data['storeId']?.toString() ?? '',
      storeName: data['storeName']?.toString() ?? '',
      content: data['content']?.toString() ?? '',
      status: data['status'] is int ? data['status'] as int : 0,
      speed: int.tryParse(data['speed']?.toString() ?? '50') ?? 50,
      fontColor: data['fontColor']?.toString(),
      backgroundColor: data['backgroundColor']?.toString(),
      fontSize: int.tryParse(data['fontSize']?.toString() ?? ''),
      level: int.tryParse(data['level']?.toString() ?? ''),
      startTime: _tryParseDateTime(data['startTime']),
      endTime: _tryParseDateTime(data['endTime']),
      createTime: now,
      updateTime: now,
    );

    final index = list.indexWhere((m) => m.id == message.id);
    if (index >= 0) {
      list[index] = message;
    } else {
      list.add(message);
    }
    await _saveAll(list);
  }

  /// 删除滚动字幕。
  ///
  /// 优先调用 Web 端 `/theme/scrollingText/delete`，失败也移除本地缓存。
  Future<void> deleteMarquee(String id) async {
    final numericId = int.tryParse(id);
    if (numericId != null) {
      try {
        await _dio.post<dynamic>(
          '/theme/scrollingText/delete',
          data: {'ids': [numericId]},
        );
      } on DioException {
        // 网络失败时继续移除本地记录。
      }
    }

    final list = await _loadAll();
    list.removeWhere((m) => m.id == id);
    await _saveAll(list);
  }

  /// 启用/禁用单条滚动字幕。
  ///
  /// 直接调用 Web 端 `/theme/scrollingText/update` 修改 status。
  Future<void> setMarqueeStatus(String id, {required int status}) async {
    final list = await _loadAll();
    final index = list.indexWhere((m) => m.id == id);
    if (index < 0) return;

    final item = list[index];
    final numericId = int.tryParse(id);
    if (numericId != null) {
      try {
        await _dio.post<dynamic>(
          '/theme/scrollingText/update',
          data: item.copyWith(status: status).toWebJson(),
        );
      } on DioException {
        // 接口失败时仅更新本地状态。
      }
    }

    list[index] = item.copyWith(
      status: status,
      updateTime: DateTime.now(),
    );
    await _saveAll(list);
  }

  /// 获取当前用户可见的门店列表（用于新增/编辑时选择目标门店）。
  Future<List<StoreInfo>> getStores() async {
    return _orgService.getMyStores();
  }

  /// 构造 Web 后台可接收的请求体。
  Map<String, dynamic> _buildWebPayload(Map<String, dynamic> data) {
    final storeId = data['storeId']?.toString() ?? '';
    final storeName = data['storeName']?.toString() ?? '';
    final content = data['content']?.toString() ?? '';
    final speed = int.tryParse(data['speed']?.toString() ?? '50') ?? 50;
    final fontSize = int.tryParse(data['fontSize']?.toString() ?? '');
    final level = int.tryParse(data['level']?.toString() ?? '');
    final status = data['status'] is int ? data['status'] as int : 0;
    final fontColor = data['fontColor']?.toString();
    final backgroundColor = data['backgroundColor']?.toString();
    final startTime = _tryParseDateTime(data['startTime']);
    final endTime = _tryParseDateTime(data['endTime']);

    final payload = <String, dynamic>{
      'orgId': int.tryParse(storeId) ?? storeId,
      'orgName': storeName,
      'content': content,
      'scrollSpeed': speed,
      'status': status,
      if (fontSize != null) 'fontSize': fontSize,
      if (level != null) 'level': level,
      if (fontColor != null && fontColor.isNotEmpty) 'fontColor': fontColor,
      if (backgroundColor != null && backgroundColor.isNotEmpty)
        'bgColor': backgroundColor,
      if (startTime != null)
        'startTime': _formatTime(startTime),
      if (endTime != null)
        'endTime': _formatTime(endTime),
    };

    final id = data['id']?.toString();
    if (id != null && id.isNotEmpty) {
      payload['id'] = int.tryParse(id) ?? id;
    }

    return payload;
  }

  Future<List<MarqueeMessage>> _loadAll() async {
    final prefs = await _prefs;
    final raw = prefs.getString(_storageKey);
    if (raw == null || raw.isEmpty) return <MarqueeMessage>[];
    try {
      final list = jsonDecode(raw) as List<dynamic>;
      return list
          .whereType<Map<String, dynamic>>()
          .map(MarqueeMessage.fromJson)
          .toList();
    } catch (_) {
      return <MarqueeMessage>[];
    }
  }

  Future<void> _saveAll(List<MarqueeMessage> list) async {
    final prefs = await _prefs;
    final raw = jsonEncode(list.map((m) => m.toJson()).toList());
    await prefs.setString(_storageKey, raw);
  }

  String _generateId() {
    final now = DateTime.now().millisecondsSinceEpoch;
    final rand = Random().nextInt(10000).toString().padLeft(4, '0');
    return '${now}_$rand';
  }

  DateTime? _tryParseDateTime(dynamic value) {
    if (value == null) return null;
    if (value is DateTime) return value;
    final text = value.toString().trim();
    if (text.isEmpty) return null;

    // 兼容 Web 端纯时间字符串 `HH:mm:ss`。
    if (RegExp(r'^\d{2}:\d{2}:\d{2}$').hasMatch(text)) {
      return DateTime.tryParse('2000-01-01 $text');
    }

    return DateTime.tryParse(text) ??
        DateTime.tryParse(text.replaceFirst(' ', 'T'));
  }

  String _formatTime(DateTime value) {
    return '${value.hour.toString().padLeft(2, '0')}:'
        '${value.minute.toString().padLeft(2, '0')}:'
        '${value.second.toString().padLeft(2, '0')}';
  }
}