import 'dart:convert';
import 'dart:io' show Platform;

import 'package:cupertino_http/cupertino_http.dart';
import 'package:flutter/foundation.dart' show kIsWeb;
import 'package:http/http.dart' as http;

import '../auth/session_store.dart';
import '../config/app_config.dart';

/// 标注众包 API 客户端（契约见 server/README.md「标注众包」）。
/// 异常语义同 OrderApi：失败抛 AnnotateApiException，登录失效抛 SessionExpired。
class AnnotateApiException implements Exception {
  final String message;
  const AnnotateApiException(this.message);

  @override
  String toString() => message;
}

class SessionExpiredException extends AnnotateApiException {
  const SessionExpiredException() : super('登录已失效，请重新登录');
}

/// 众包任务条目
class AnnotateTaskInfo {
  final int id;
  final String name;
  final String datasetName;
  final String species;
  final int poolRemain;

  const AnnotateTaskInfo({
    required this.id,
    required this.name,
    required this.datasetName,
    required this.species,
    required this.poolRemain,
  });

  factory AnnotateTaskInfo.fromJson(Map<String, dynamic> j) => AnnotateTaskInfo(
        id: (j['id'] as num).toInt(),
        name: (j['name'] as String?) ?? '',
        datasetName: (j['datasetName'] as String?) ?? '',
        species: (j['species'] as String?) ?? '',
        poolRemain: (j['poolRemain'] as num?)?.toInt() ?? 0,
      );
}

/// 我的标注统计（进度/奖励/冻结）
class AnnotateStats {
  final int submittedTotal;
  final int approved;
  final int rejected;
  final double approveRatio;
  final int progressDone;
  final int rewardPerImages;
  final int rewardMinutes;
  final int totalEarnedMinutes;
  final int todayEarnedMinutes;
  final int dailyCapMinutes;
  final DateTime? frozenUntil;
  final DateTime? expiresAt;

  const AnnotateStats({
    required this.submittedTotal,
    required this.approved,
    required this.rejected,
    required this.approveRatio,
    required this.progressDone,
    required this.rewardPerImages,
    required this.rewardMinutes,
    required this.totalEarnedMinutes,
    required this.todayEarnedMinutes,
    required this.dailyCapMinutes,
    required this.frozenUntil,
    required this.expiresAt,
  });

  bool get frozen => frozenUntil != null && frozenUntil!.isAfter(DateTime.now());

  factory AnnotateStats.fromJson(Map<String, dynamic> j) => AnnotateStats(
        submittedTotal: (j['submittedTotal'] as num?)?.toInt() ?? 0,
        approved: (j['approved'] as num?)?.toInt() ?? 0,
        rejected: (j['rejected'] as num?)?.toInt() ?? 0,
        approveRatio: (j['approveRatio'] as num?)?.toDouble() ?? 1,
        progressDone: (j['progressDone'] as num?)?.toInt() ?? 0,
        rewardPerImages: (j['rewardPerImages'] as num?)?.toInt() ?? 10,
        rewardMinutes: (j['rewardMinutes'] as num?)?.toInt() ?? 30,
        totalEarnedMinutes: (j['totalEarnedMinutes'] as num?)?.toInt() ?? 0,
        todayEarnedMinutes: (j['todayEarnedMinutes'] as num?)?.toInt() ?? 0,
        dailyCapMinutes: (j['dailyCapMinutes'] as num?)?.toInt() ?? 120,
        frozenUntil: j['frozenUntil'] == null
            ? null
            : DateTime.tryParse(j['frozenUntil'] as String),
        expiresAt: j['expiresAt'] == null
            ? null
            : DateTime.tryParse(j['expiresAt'] as String),
      );
}

/// 领取到的单张图
class AnnotateClaimImage {
  final int imageId;
  final String url; // 相对路径，需拼 baseUrl；访问需 Bearer 头
  final int width;
  final int height;

  const AnnotateClaimImage({
    required this.imageId,
    required this.url,
    required this.width,
    required this.height,
  });

  factory AnnotateClaimImage.fromJson(Map<String, dynamic> j) =>
      AnnotateClaimImage(
        imageId: (j['imageId'] as num).toInt(),
        url: (j['url'] as String?) ?? '',
        width: (j['width'] as num?)?.toInt() ?? 0,
        height: (j['height'] as num?)?.toInt() ?? 0,
      );
}

/// 提交结果（是否触发奖励发放）
class AnnotateSubmitResult {
  final bool granted;
  final int minutes;
  final int todayEarnedMinutes;
  final int progressDone;

  const AnnotateSubmitResult({
    required this.granted,
    required this.minutes,
    required this.todayEarnedMinutes,
    required this.progressDone,
  });

  factory AnnotateSubmitResult.fromJson(Map<String, dynamic> j) =>
      AnnotateSubmitResult(
        granted: j['granted'] == true,
        minutes: (j['minutes'] as num?)?.toInt() ?? 0,
        todayEarnedMinutes: (j['todayEarnedMinutes'] as num?)?.toInt() ?? 0,
        progressDone: (j['progressDone'] as num?)?.toInt() ?? 0,
      );
}

class AnnotateApi {
  final String baseUrl;
  final SessionStore sessionStore;
  final http.Client _client;

  // iOS 本地网络 socket 拦截绕行，同 OrderApi（见其注释）
  AnnotateApi({String? baseUrl, required this.sessionStore, http.Client? client})
      : baseUrl = baseUrl ?? AppConfig.apiBaseUrl,
        _client = client ?? _defaultHttpClient();

  static http.Client _defaultHttpClient() {
    if (!kIsWeb && Platform.isIOS) {
      return CupertinoClient.defaultSessionConfiguration();
    }
    return http.Client();
  }

  /// 可领任务列表 + 我的统计
  Future<(List<AnnotateTaskInfo>, AnnotateStats)> tasks() async {
    final json = await _get('/api/v1/annotate/tasks');
    final list = (json['list'] as List? ?? [])
        .map((e) => AnnotateTaskInfo.fromJson((e as Map).cast<String, dynamic>()))
        .toList();
    final stats = AnnotateStats.fromJson(
        ((json['stats'] as Map?) ?? const {}).cast<String, dynamic>());
    return (list, stats);
  }

  /// 领取一批标注图片
  Future<List<AnnotateClaimImage>> claim(int taskId) async {
    final json = await _post(
        '/api/v1/annotate/claim', jsonEncode({'taskId': taskId}));
    return (json['images'] as List? ?? [])
        .map((e) =>
            AnnotateClaimImage.fromJson((e as Map).cast<String, dynamic>()))
        .toList();
  }

  /// 提交单张标注（boxes 元素：{class,cx,cy,w,h,confidence}，归一化坐标）
  Future<AnnotateSubmitResult> submit(
      int imageId, List<Map<String, dynamic>> boxes) async {
    final json = await _post(
        '/api/v1/annotate/submit', jsonEncode({'imageId': imageId, 'boxes': boxes}));
    return AnnotateSubmitResult.fromJson(json);
  }

  /// 我的统计
  Future<AnnotateStats> me() async {
    final json = await _get('/api/v1/annotate/me');
    return AnnotateStats.fromJson(
        ((json['stats'] as Map?) ?? const {}).cast<String, dynamic>());
  }

  /// 图片完整 URL（Image.network 用，需带 Bearer 头）
  Uri imageUrl(String relative) => Uri.parse('$baseUrl$relative');

  /// 图片请求头（标注器 Image.network 加载用）
  Future<Map<String, String>> imageHeaders() => _authHeaders();

  Future<Map<String, String>> _authHeaders() async {
    final token = await sessionStore.readToken();
    if (token == null || token.isEmpty) {
      throw const SessionExpiredException();
    }
    return {'Authorization': 'Bearer $token'};
  }

  Future<Map<String, dynamic>> _get(String path) async {
    try {
      final res = await _client
          .get(Uri.parse('$baseUrl$path'), headers: await _authHeaders())
          .timeout(const Duration(seconds: 30));
      return _decode(res);
    } catch (e) {
      if (e is AnnotateApiException) rethrow;
      throw AnnotateApiException('网络请求失败: $e');
    }
  }

  Future<Map<String, dynamic>> _post(String path, String body) async {
    try {
      final res = await _client
          .post(Uri.parse('$baseUrl$path'),
              headers: {
                'Content-Type': 'application/json',
                ...await _authHeaders(),
              },
              body: body)
          .timeout(const Duration(seconds: 30));
      return _decode(res);
    } catch (e) {
      if (e is AnnotateApiException) rethrow;
      throw AnnotateApiException('网络请求失败: $e');
    }
  }

  Map<String, dynamic> _decode(http.Response res) {
    final Map<String, dynamic> json;
    try {
      json = jsonDecode(res.body) as Map<String, dynamic>;
    } catch (_) {
      throw AnnotateApiException('服务端响应异常 (${res.statusCode})');
    }
    if (res.statusCode != 200 || json['code'] != 0) {
      final message = json['message'] as String? ?? '服务端错误 (${res.statusCode})';
      if (json['code'] == 61) {
        throw const SessionExpiredException();
      }
      throw AnnotateApiException(message);
    }
    return json['data'] as Map<String, dynamic>;
  }
}