// 远程日记仓库 — 通过 API 客户端连接后端

import 'dart:async';

import '../models/journal_element.dart';
import '../models/journal_entry.dart';
import '../remote/api_client.dart';
import 'journal_repository.dart';

/// 远程日记仓库 — 通过 HTTP API 操作后端数据
///
/// 所有操作需要网络连接。离线场景由 SyncEngine 协调 Isar 本地仓库处理。
class RemoteJournalRepository implements JournalRepository {
  final ApiClient _api;

  /// 变更通知流控制器 — 写操作成功后通知 UI 刷新
  final StreamController<void> _changeController =
      StreamController<void>.broadcast();

  RemoteJournalRepository({required ApiClient api}) : _api = api;

  @override
  Future<List<JournalEntry>> getJournals({
    DateTime? dateFrom,
    DateTime? dateTo,
    int? page,
    int? pageSize,
    String? mood,
    String? tag,
    String? classId,
  }) async {
    final queryParams = <String, dynamic>{};
    // 后端 NaiveDateTime 格式: "2026-06-01T00:00:00"（不带毫秒）
    if (dateFrom != null) {
      queryParams['date_from'] = dateFrom.toIso8601String().replaceFirst(RegExp(r'\.\d+'), '');
    }
    if (dateTo != null) {
      queryParams['date_to'] = dateTo.toIso8601String().replaceFirst(RegExp(r'\.\d+'), '');
    }
    if (page != null) queryParams['page'] = page;
    if (pageSize != null) queryParams['page_size'] = pageSize;
    if (mood != null) queryParams['mood'] = mood;
    if (tag != null) queryParams['tag'] = tag;
    if (classId != null) queryParams['class_id'] = classId;

    final response = await _api.get('/diary/journals', queryParams: queryParams);
    final body = response.data as Map<String, dynamic>;
    // 后端信封格式: { success, data: { data: [...], total, page, ... }, message }
    final envelope = body['data'] as Map<String, dynamic>? ?? {};
    final items = envelope['data'] as List? ?? [];
    return items
        .map((json) => JournalEntry.fromJson(json as Map<String, dynamic>))
        .toList();
  }

  @override
  Future<int> getJournalCount() async {
    final response = await _api.get('/diary/journals', queryParams: {
      'page': 1,
      'page_size': 1,
    });
    final body = response.data as Map<String, dynamic>;
    // 后端信封格式: { success, data: { data: [...], total, ... }, message }
    final envelope = body['data'] as Map<String, dynamic>? ?? {};
    return (envelope['total'] as int?) ?? 0;
  }

  @override
  Future<JournalEntry?> getJournal(String id) async {
    try {
      final response = await _api.get('/diary/journals/$id');
      final body = response.data as Map<String, dynamic>;
      return JournalEntry.fromJson(body['data'] as Map<String, dynamic>);
    } on ApiException catch (e) {
      if (e.statusCode == 404) return null;
      rethrow;
    }
  }

  @override
  Future<JournalEntry> createJournal(JournalEntry entry) async {
    // 后端 CreateJournalReq.date 是 NaiveDate（只有日期），需转换格式
    final json = entry.toJson();
    json['date'] = entry.date.toIso8601String().substring(0, 10);
    final response = await _api.post('/diary/journals', data: json);
    final body = response.data as Map<String, dynamic>;
    final created = JournalEntry.fromJson(body['data'] as Map<String, dynamic>);
    _changeController.add(null); // 通知 UI 刷新列表
    return created;
  }

  @override
  Future<JournalEntry> updateJournal(JournalEntry entry) async {
    final response = await _api.put(
      '/diary/journals/${entry.id}',
      data: {
        'title': entry.title,
        'mood': entry.mood.value,
        'weather': entry.weather.value,
        'tags': entry.tags,
        'is_private': entry.isPrivate,
        'shared_to_class': entry.sharedToClass,
        'version': entry.version,
      },
    );
    final body = response.data as Map<String, dynamic>;
    _changeController.add(null); // 通知 UI 刷新列表
    return JournalEntry.fromJson(body['data'] as Map<String, dynamic>);
  }

  @override
  Future<void> deleteJournal(String id) async {
    await _api.delete('/diary/journals/$id');
    _changeController.add(null); // 通知 UI 刷新列表
  }

  @override
  Future<List<JournalElement>> getElements(String journalId) async {
    final response = await _api.get('/diary/journals/$journalId/elements');
    final body = response.data as Map<String, dynamic>;
    final items = body['data'] as List? ?? [];
    return items
        .map((json) => JournalElement.fromJson(json as Map<String, dynamic>))
        .toList();
  }

  @override
  Future<JournalElement> addElement(JournalElement element) async {
    final response = await _api.post(
      '/diary/journals/${element.journalId}/elements',
      data: element.toJson(),
    );
    final body = response.data as Map<String, dynamic>;
    return JournalElement.fromJson(body['data'] as Map<String, dynamic>);
  }

  @override
  Future<JournalElement> updateElement(JournalElement element) async {
    final response = await _api.put(
      '/diary/journals/${element.journalId}/elements/${element.id}',
      data: element.toJson(),
    );
    final body = response.data as Map<String, dynamic>;
    return JournalElement.fromJson(body['data'] as Map<String, dynamic>);
  }

  @override
  Future<void> removeElement(String elementId) async {
    await _api.delete('/diary/elements/$elementId');
  }

  /// 变更通知流 — 写操作后广播，供 HomeBloc 自动刷新
  @override
  Stream<void> get onJournalChanged => _changeController.stream;
}

/// API 异常封装 — 后端返回非 2xx 状态码时抛出
class ApiException implements Exception {
  final String message;
  final int statusCode;
  final dynamic responseBody;

  const ApiException({
    required this.message,
    required this.statusCode,
    this.responseBody,
  });

  @override
  String toString() => 'ApiException($statusCode): $message';
}