bookshelf/bookshelf_flutter/lib/bloc/app_bloc.dart

import 'package:flutter_bloc/flutter_bloc.dart';
import '../models/models.dart';
import 'app_event.dart';
import 'app_state.dart';

class AppBloc extends Bloc<AppEvent, AppState> {
  AppBloc() : super(AppState(books: _initialBooks)) {
    on<ScreenChanged>(_onScreenChanged);
    on<BookClicked>(_onBookClicked);
    on<AddBookClicked>(_onAddBookClicked);
    on<BookSaved>(_onBookSaved);
    on<BookDeleted>(_onBookDeleted);
    on<BookDetected>(_onBookDetected);
    on<SearchChanged>(_onSearchChanged);
  }

  static List<Book> get _initialBooks => [
        createBook(
          id: '1',
          title: 'Великий Гэтсби',
          author: 'Ф. Скотт Фицджеральд',
          genre: 'Classic',
          annotation:
              'История о несбывшейся любви и трагедии американской мечты на фоне бурных двадцатых годов.',
          coverUrl: 'https://picsum.photos/seed/gatsby/400/600',
          pages: 208,
          language: 'English',
          publishedYear: 1925,
          rating: 4.8,
          status: BookStatus.reading,
          progress: 45,
          isFavorite: true,
        ),
        createBook(
          id: '2',
          title: '1984',
          author: 'Джордж Оруэлл',
          genre: 'Dystopian',
          annotation:
              'Антиутопия о тоталитарном государстве, где мысли контролируются, а правда переменчива.',
          coverUrl: 'https://picsum.photos/seed/1984/400/600',
          pages: 328,
          language: 'English',
          publishedYear: 1949,
          rating: 4.9,
          status: BookStatus.wantToRead,
          isFavorite: true,
        ),
        createBook(
          id: '3',
          title: 'Дюна',
          author: 'Фрэнк Герберт',
          genre: 'Sci-Fi',
          annotation:
              'Эпическая сага о борьбе за власть над самой важной планетой во Вселенной.',
          coverUrl: 'https://picsum.photos/seed/dune/400/600',
          pages: 896,
          language: 'English',
          publishedYear: 1965,
          rating: 4.7,
          status: BookStatus.reading,
          progress: 12,
          isFavorite: false,
        ),
        createBook(
          id: '4',
          title: 'Хоббит',
          author: 'Дж. Р. Р. Толкин',
          genre: 'Fantasy',
          annotation:
              'Путешествие Бильбо Бэггинса туда и обратно в поисках сокровищ гномов.',
          coverUrl: 'https://picsum.photos/seed/hobbit/400/600',
          pages: 310,
          language: 'English',
          publishedYear: 1937,
          rating: 4.9,
          status: BookStatus.done,
          isFavorite: false,
        ),
      ];

  void _onScreenChanged(ScreenChanged event, Emitter<AppState> emit) {
    emit(state.copyWith(currentScreen: event.screen));
  }

  void _onBookClicked(BookClicked event, Emitter<AppState> emit) {
    emit(state.copyWith(
      selectedBook: event.book,
      currentScreen: AppScreen.details,
    ));
  }

  void _onAddBookClicked(AddBookClicked event, Emitter<AppState> emit) {
    emit(state.copyWith(
      prefilledData: null,
      selectedBook: null,
      currentScreen: AppScreen.addBook,
    ));
  }

  void _onBookSaved(BookSaved event, Emitter<AppState> emit) {
    final bookData = event.bookData;
    
    if (state.selectedBook != null) {
      // Edit existing book
      final updatedBooks = state.books.map((book) {
        if (book.id == state.selectedBook!.id) {
          return book.copyWith(
            title: bookData['title'] as String? ?? book.title,
            author: bookData['author'] as String? ?? book.author,
            genre: bookData['genre'] as String? ?? book.genre,
            annotation: bookData['annotation'] as String? ?? book.annotation,
            coverUrl: bookData['coverUrl'] as String?,
            pages: bookData['pages'] as int?,
            language: bookData['language'] as String?,
            publishedYear: bookData['publishedYear'] as int?,
            rating: bookData['rating'] as double?,
            status: bookData['status'] as BookStatus? ?? book.status,
            progress: bookData['progress'] as int?,
            isFavorite: bookData['isFavorite'] as bool? ?? book.isFavorite,
          );
        }
        return book;
      }).toList();
      
      emit(state.copyWith(
        books: updatedBooks,
        currentScreen: AppScreen.library,
        selectedBook: null,
        prefilledData: null,
      ));
    } else {
      // Add new book
      final newBook = createBook(
        id: DateTime.now().millisecondsSinceEpoch.toString(),
        title: bookData['title'] as String? ?? 'Unknown',
        author: bookData['author'] as String? ?? 'Unknown',
        genre: bookData['genre'] as String? ?? 'Unknown',
        annotation: bookData['annotation'] as String? ?? '',
        coverUrl: bookData['coverUrl'] as String? ??
            'https://picsum.photos/seed/${DateTime.now().millisecondsSinceEpoch}/400/600',
        pages: bookData['pages'] as int?,
        language: bookData['language'] as String?,
        publishedYear: bookData['publishedYear'] as int?,
        rating: bookData['rating'] as double?,
        status: bookData['status'] as BookStatus? ?? BookStatus.wantToRead,
        progress: bookData['progress'] as int?,
        isFavorite: bookData['isFavorite'] as bool? ?? false,
      );
      
      emit(state.copyWith(
        books: [...state.books, newBook],
        currentScreen: AppScreen.library,
        selectedBook: null,
        prefilledData: null,
      ));
    }
  }

  void _onBookDeleted(BookDeleted event, Emitter<AppState> emit) {
    final updatedBooks = state.books.where((book) => book.id != event.id).toList();
    emit(state.copyWith(
      books: updatedBooks,
      currentScreen: AppScreen.library,
      selectedBook: null,
    ));
  }

  void _onBookDetected(BookDetected event, Emitter<AppState> emit) {
    emit(state.copyWith(
      prefilledData: event.bookData,
      currentScreen: AppScreen.addBook,
    ));
  }

  void _onSearchChanged(SearchChanged event, Emitter<AppState> emit) {
    emit(state.copyWith(searchQuery: event.query));
  }
}