nj/app/lib/features/parent/bloc/parent_bloc.dart

// 家长中心 BLoC — 管理家长-孩子绑定和数据操作
//
// 状态机: ParentInitial → ParentLoading → ParentChildrenLoaded / ParentJournalsLoaded / ParentDataExported / ParentDataDeleted / ParentError
// API: /diary/parent/* 端点

import 'package:flutter/foundation.dart';
import 'package:flutter_bloc/flutter_bloc.dart';

import '../../../data/remote/api_client.dart';

part 'parent_event.dart';
part 'parent_state.dart';

/// 家长中心 BLoC — 处理孩子绑定、日记查看、数据导出/删除
class ParentBloc extends Bloc<ParentEvent, ParentState> {
  final ApiClient _api;

  ParentBloc({required ApiClient api})
      : _api = api,
        super(const ParentInitial()) {
    on<ParentLoadChildren>(_onLoadChildren);
    on<ParentBindChild>(_onBindChild);
    on<ParentViewJournals>(_onViewJournals);
    on<ParentExportData>(_onExportData);
    on<ParentDeleteData>(_onDeleteData);
    on<ParentUnbindChild>(_onUnbindChild);
  }

  /// 加载已绑定的孩子列表
  Future<void> _onLoadChildren(
    ParentLoadChildren event,
    Emitter<ParentState> emit,
  ) async {
    emit(const ParentLoading());
    try {
      final response = await _api.get('/diary/parent/children');
      final body = response.data as Map<String, dynamic>;
      final items = body['data'] as List? ?? [];
      final children = items
          .map((j) => ChildBinding.fromJson(j as Map<String, dynamic>))
          .toList();
      emit(ParentChildrenLoaded(children));
    } catch (e) {
      debugPrint('ParentBloc._onLoadChildren 失败: $e');
      emit(const ParentError('加载孩子列表失败'));
    }
  }

  /// 绑定孩子（输入孩子 ID）
  Future<void> _onBindChild(
    ParentBindChild event,
    Emitter<ParentState> emit,
  ) async {
    emit(const ParentLoading());
    try {
      await _api.post('/diary/parent/bind', data: {
        'child_id': event.childId,
      });
      // 绑定成功后重新加载列表
      add(const ParentLoadChildren());
    } catch (e) {
      debugPrint('ParentBloc._onBindChild 失败: $e');
      emit(const ParentError('绑定失败，请检查孩子 ID'));
    }
  }

  /// 查看孩子日记（只读）
  Future<void> _onViewJournals(
    ParentViewJournals event,
    Emitter<ParentState> emit,
  ) async {
    emit(const ParentLoading());
    try {
      final response = await _api.get(
        '/diary/parent/journals',
        queryParams: {
          'child_id': event.childId,
          'page': 1,
          'page_size': 50,
        },
      );
      final body = response.data as Map<String, dynamic>;
      final items = body['data'] as List? ?? [];
      emit(ParentJournalsLoaded(
        childId: event.childId,
        journals: items.cast<Map<String, dynamic>>(),
      ));
    } catch (e) {
      debugPrint('ParentBloc._onViewJournals 失败: $e');
      emit(const ParentError('加载日记失败'));
    }
  }

  /// 导出孩子数据（PIPL 合规）
  Future<void> _onExportData(
    ParentExportData event,
    Emitter<ParentState> emit,
  ) async {
    emit(const ParentLoading());
    try {
      final response = await _api.get(
        '/diary/parent/export',
        queryParams: {'child_id': event.childId},
      );
      emit(ParentDataExported(
        childId: event.childId,
        data: response.data as Map<String, dynamic>,
      ));
    } catch (e) {
      debugPrint('ParentBloc._onExportData 失败: $e');
      emit(const ParentError('导出失败'));
    }
  }

  /// 删除孩子数据（PIPL 合规，需二次确认）
  Future<void> _onDeleteData(
    ParentDeleteData event,
    Emitter<ParentState> emit,
  ) async {
    emit(const ParentLoading());
    try {
      await _api.delete('/diary/parent/data', data: {
        'child_id': event.childId,
      });
      emit(ParentDataDeleted(event.childId));
    } catch (e) {
      debugPrint('ParentBloc._onDeleteData 失败: $e');
      emit(const ParentError('删除失败'));
    }
  }

  /// 解绑孩子
  Future<void> _onUnbindChild(
    ParentUnbindChild event,
    Emitter<ParentState> emit,
  ) async {
    try {
      await _api.delete('/diary/parent/bind', data: {
        'child_id': event.childId,
      });
      add(const ParentLoadChildren());
    } catch (e) {
      debugPrint('ParentBloc._onUnbindChild 失败: $e');
      emit(const ParentError('解绑失败'));
    }
  }
}