didvan-app/lib/views/home/studio/studio_details/studio_details_state.dart

import 'dart:async';
import 'dart:math';

import 'package:didvan/models/enums.dart';
import 'package:didvan/models/overview_data.dart';
import 'package:didvan/models/requests/studio.dart';
import 'package:didvan/models/studio_details_data.dart';
import 'package:didvan/providers/core_provider.dart';
import 'package:didvan/services/media/media.dart';
import 'package:didvan/services/network/request.dart';
import 'package:didvan/services/network/request_helper.dart';

class StudioDetailsState extends CoreProvier {
  final List<StudioDetailsData?> studios = [];
  late int initialIndex;
  late StudioRequestArgs args;
  int _selectedDetailsIndex = 0;
  bool isFetchingNewItem = false;
  final List<int> relatedQueue = [];
  bool currentTypeIsVideo = true;

  int _currentIndex = 0;
  int get currentIndex => _currentIndex;

  int get selectedDetailsIndex => _selectedDetailsIndex;
  set selectedDetailsIndex(int value) {
    _selectedDetailsIndex = value;
    if (value == 2) {
      getRelatedContents();
    }
    notifyListeners();
  }

  StudioDetailsData get currentStudio {
    try {
      return studios[_currentIndex]!;
    } catch (e) {
      return studios[_currentIndex + 1]!;
    }
  }

  Future<void> getStudioDetails(
    int id, {
    bool? isForward,
    StudioRequestArgs? args,
  }) async {
    if (args != null) {
      this.args = args;
    }
    if (isForward == null) {
      _selectedDetailsIndex = 0;
      appState = AppState.busy;
    } else {
      isFetchingNewItem = true;
      notifyListeners();
    }
    final service = RequestService(RequestHelper.studioDetails(id, this.args));
    await service.httpGet();
    if (service.isSuccess) {
      studios.clear();
      final result = service.result;
      final studio = StudioDetailsData.fromJson(result['studio']);
      await _handlePodcastPlayback(studio);
      if (this.args.page == 0) {
        studios.add(studio);
        initialIndex = 0;
        appState = AppState.idle;
        return;
      }

      StudioDetailsData? prevStudio;
      if (result['prevStudio'].isNotEmpty) {
        prevStudio = StudioDetailsData.fromJson(result['prevStudio']);
      }

      StudioDetailsData? nextStudio;
      if (result['nextStudio'].isNotEmpty) {
        nextStudio = StudioDetailsData.fromJson(result['nextStudio']);
      }

      if (isForward == null) {
        studios
            .addAll(List.generate(max(studio.order - 2, 0), (index) => null));
        if (prevStudio != null) {
          studios.add(prevStudio);
        }
        studios.add(studio);
        if (nextStudio != null) {
          studios.add(nextStudio);
        }
        _currentIndex = initialIndex = studio.order - 1;
      } else if (isForward) {
        if (!exists(nextStudio) && nextStudio != null) {
          studios.add(nextStudio);
        }
        _currentIndex++;
      } else if (!isForward) {
        if (!exists(prevStudio) && prevStudio != null) {
          studios[_currentIndex - 2] = prevStudio;
        }
        _currentIndex--;
      }
      isFetchingNewItem = false;
      appState = AppState.idle;
      return;
    }
    //why? total page state shouldn't die!
    if (isForward == null) {
      appState = AppState.failed;
    }
  }

  Future<void> _handlePodcastPlayback(StudioDetailsData studio) async {
    if (args.type == 'podcast') {
      MediaService.currentPodcast = studio;
      MediaService.podcastPlaylistArgs = args;
      await MediaService.handleAudioPlayback(
        audioSource: studio.media,
        isVoiceMessage: false,
      );
    }
  }

  Future<void> getRelatedContents() async {
    if (currentStudio.relatedContents.isNotEmpty) return;
    relatedQueue.add(currentStudio.id);
    final service = RequestService(RequestHelper.tag(
      ids: currentStudio.tags.map((tag) => tag.id).toList(),
      itemId: currentStudio.id,
      type: currentStudio.media.contains('iframe') ? 'video' : 'podcast',
    ));
    await service.httpGet();
    if (service.isSuccess) {
      final relateds = service.result['contents'];
      for (var i = 0; i < relateds.length; i++) {
        studios
            .where((element) => element != null)
            .firstWhere((element) => element!.id == currentStudio.id)!
            .relatedContents
            .add(OverviewData.fromJson(relateds[i]));
      }
      notifyListeners();
    }
  }

  bool exists(StudioDetailsData? studio) =>
      studios.any((r) => studio != null && r != null && r.id == studio.id);

  void onCommentsChanged(int count) {
    studios.firstWhere((studio) => studio?.id == currentStudio.id)!.comments =
        count;
    notifyListeners();
  }
}