import 'package:flutter/cupertino.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:wow_english/common/request/dao/lesson_dao.dart';
import 'package:wow_english/common/request/exception.dart';
import 'package:wow_english/common/request/dao/listen_dao.dart';
import 'package:wow_english/models/course_process_entity.dart';
import 'package:wow_english/utils/loading.dart';
import 'package:wow_english/utils/toast_util.dart';

import '../../../models/course_section_entity.dart';
import '../../../models/course_unit_entity.dart';
import '../../../utils/list_ext.dart';

part 'section_event.dart';
part 'section_state.dart';

class SectionBloc extends Bloc<SectionEvent, SectionState> {

  PageController _pageController;

  PageController get pageController => _pageController;

  ///当前页索引
  int _currentPage = 0;

  int get currentPage => _currentPage;

  ScrollController _listController;

  ScrollController get listController => _listController;

  CourseUnitEntity _courseUnitEntity;

  CourseUnitEntity get courseUnitEntity => _courseUnitEntity;

  CourseUnitDetail _courseUnitDetail;

  CourseUnitDetail get courseUnitDetail => _courseUnitDetail;

  List<CourseSectionEntity>? _courseSectionDatas;

  List<CourseSectionEntity>? get courseSectionDatas => _courseSectionDatas;

  CourseProcessEntity? _processEntity;

  CourseProcessEntity? get processEntity => _processEntity;

  SectionBloc(this._courseUnitEntity, this._courseUnitDetail, this._pageController, this._listController) : super(LessonInitial()) {
    on<RequestDataEvent>(_requestData);
    on<RequestExitClassEvent>(_requestExitClass);
    on<RequestEndClassEvent>(_requestEndClass);
    on<RequestEnterClassEvent>(_requestEnterClass);
    on<RequestVideoLessonEvent>(_requestVideoLesson);
    on<CurrentUnitIndexChangeEvent>(_pageControllerChange);
  }

  void _requestData(RequestDataEvent event, Emitter<SectionState> emitter) async {
    try {
      await loading(() async {
        _courseSectionDatas = await LessonDao.courseSection(courseUnitId: _courseUnitDetail.id!);
        emitter(LessonDataLoadState());
      });
    } catch (e) {
      if (e is ApiException) {
        showToast(e.message.toString());
      }
    }
  }

  void _requestVideoLesson(RequestVideoLessonEvent event, Emitter<SectionState> emitter) async {
    try {
      await loading(() async {
        _processEntity = await ListenDao.process(event.courseLessonId);
        emitter(RequestVideoLessonState(event.courseLessonId,event.courseType));
      });
    } catch (e) {
      if (e is ApiException) {
        showToast(e.message??'请求失败,请检查网络连接');
      }
    }
  }


  void _requestEnterClass(RequestEnterClassEvent event,Emitter<SectionState> emitter) async {
    try {
      await loading(() async {
         await ListenDao.enterClass(event.courseLessonId);
         emitter(RequestEnterClassState(event.courseLessonId,event.courseType));
      });
    } catch (e) {
      if (e is ApiException) {
        showToast(e.message??'请求失败,请检查网络连接');
      }
    }
  }

  void _requestExitClass(RequestExitClassEvent event,Emitter<SectionState> emitter) async {
    await ListenDao.exitClass(event.courseLessonId,event.currentStep);
  }

  void _requestEndClass(RequestEndClassEvent event,Emitter<SectionState> emitter) async {
    final obj = await ListenDao.endClass(event.courseLessonId,event.currentStep);
    if (event.autoNextSection) {
      final nextCourseSection = getNextCourseSectionBySort(int.parse(event.courseLessonId));
      ///进入课堂
      add(RequestEnterClassEvent(nextCourseSection!.id.toString() ?? '', nextCourseSection.courseType));
    }
  }

  void _pageControllerChange(CurrentUnitIndexChangeEvent event,
      Emitter<SectionState> emitter) async {
    _currentPage = event.unitIndex;
    emitter(CurrentPageIndexState());
  }

  // 未锁定的页数
  int unlockPageCount() {
    return _courseUnitEntity.courseUnitVOList?.indexWhereOrNull((element) => element.lock == true) ?? 1;
  }

  CourseSectionEntity? getNextCourseSectionBySort(int courseLessonId) {
    final curCourseSectionEntity = _courseSectionDatas?.firstWhere((element) => element.id == courseLessonId);
    final curSort = curCourseSectionEntity?.sortOrder ?? 0;
    CourseSectionEntity? nextCourseSectionEntity = _courseSectionDatas?.firstWhere((element) => element.sortOrder == curSort + 1);
    if (nextCourseSectionEntity != null) {
      return nextCourseSectionEntity;
    } else {
      ///跨unit选lesson
      final curCourseUnitDetail = _courseUnitEntity.courseUnitVOList?.firstWhere((element) => element.id == curCourseSectionEntity?.courseUnitId);
      if (curCourseUnitDetail != null) {
        final nextCourseUnitDetail = _courseUnitEntity.courseUnitVOList?.firstWhere((element) => element.sortOrder == 0);
        if (nextCourseUnitDetail != null) {
          ///pageView翻页了，可能需要预加载 todo
          return null;
        } else {
          ///最后一个unit了
          return null;
        }
      } else {
        ///找不到对应的unitDetail，理论上不可能
        return null;
      }
    }
  }
}