import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import '../bloc/book/book_bloc.dart';
import '../bloc/book/book_state.dart';
import '../bloc/library/library_bloc.dart';
import '../bloc/library/library_event.dart';
import '../bloc/library/library_state.dart';
import '../widgets/book_card.dart';
import '../theme/app_spacing.dart';
import 'book_details_screen.dart';
import 'add_book_screen.dart';

class LibraryScreen extends StatelessWidget {
  const LibraryScreen({super.key});

  @override
  Widget build(BuildContext context) {
    return BlocProvider(
      create: (context) => LibraryBloc(),
      child: const _LibraryScreenContent(),
    );
  }
}

class _LibraryScreenContent extends StatelessWidget {
  const _LibraryScreenContent();

  @override
  Widget build(BuildContext context) {
    final colorScheme = Theme.of(context).colorScheme;
    final textTheme = Theme.of(context).textTheme;

    return BlocBuilder<LibraryBloc, LibraryState>(
      builder: (context, libraryState) {
        return BlocBuilder<BookBloc, BookState>(
          builder: (context, bookState) {
            final filtered = bookState.books.where((b) {
              final q = libraryState.searchQuery.toLowerCase();
              return b.title.toLowerCase().contains(q) ||
                  b.author.toLowerCase().contains(q);
            }).toList();

            return Stack(
              children: [
                SafeArea(
                  child: Column(
                    children: [
                      // Header
                      Padding(
                        padding: const EdgeInsets.fromLTRB(
                          AppSpacing.lg,
                          AppSpacing.md,
                          AppSpacing.lg,
                          0,
                        ),
                        child: Row(
                          mainAxisAlignment: MainAxisAlignment.spaceBetween,
                          children: [
                            Text(
                              'Книжная полка',
                              style: textTheme.displayMedium,
                            ),
                            IconButton(
                              icon: const Icon(Icons.notifications_outlined),
                              onPressed: () {},
                            ),
                          ],
                        ),
                      ),
                      // Search
                      Padding(
                        padding: const EdgeInsets.fromLTRB(
                          AppSpacing.lg,
                          AppSpacing.md,
                          AppSpacing.lg,
                          0,
                        ),
                        child: TextField(
                          onChanged: (v) {
                            context.read<LibraryBloc>().add(
                              UpdateSearchQuery(v),
                            );
                          },
                          decoration: InputDecoration(
                            hintText: 'Поиск книг...',
                            prefixIcon: Icon(
                              Icons.search,
                              color: colorScheme.primary,
                            ),
                          ),
                        ),
                      ),
                      // Tabs
                      Padding(
                        padding: const EdgeInsets.fromLTRB(
                          AppSpacing.lg,
                          AppSpacing.md,
                          AppSpacing.lg,
                          0,
                        ),
                        child: Row(
                          children: [
                            _tab(
                              context,
                              'Все книги',
                              0,
                              libraryState.tabIndex,
                            ),
                            const SizedBox(width: AppSpacing.sm),
                            _tab(
                              context,
                              'Категории',
                              1,
                              libraryState.tabIndex,
                            ),
                          ],
                        ),
                      ),
                      const SizedBox(height: AppSpacing.md),
                      // Grid
                      Expanded(
                        child: libraryState.tabIndex == 0
                            ? GridView.builder(
                                padding: const EdgeInsets.fromLTRB(
                                  AppSpacing.lg,
                                  0,
                                  AppSpacing.lg,
                                  100,
                                ),
                                gridDelegate:
                                    const SliverGridDelegateWithFixedCrossAxisCount(
                                      crossAxisCount: 2,
                                      childAspectRatio: 0.55,
                                      crossAxisSpacing: AppSpacing.md,
                                      mainAxisSpacing: AppSpacing.md,
                                    ),
                                itemCount: filtered.length,
                                itemBuilder: (context, i) => BookCard(
                                  book: filtered[i],
                                  onTap: () {
                                    Navigator.of(context).push(
                                      MaterialPageRoute(
                                        builder: (_) => BookDetailsScreen(
                                          book: filtered[i],
                                        ),
                                      ),
                                    );
                                  },
                                ),
                              )
                            : ListView(
                                padding: const EdgeInsets.fromLTRB(
                                  AppSpacing.lg,
                                  0,
                                  AppSpacing.lg,
                                  100,
                                ),
                                children: [
                                  for (final genre
                                      in filtered.map((b) => b.genre).toSet())
                                    Container(
                                      margin: const EdgeInsets.only(
                                        bottom: AppSpacing.sm,
                                      ),
                                      decoration: BoxDecoration(
                                        color: colorScheme.surface,
                                        border: Border.all(
                                          color: colorScheme.outline,
                                        ),
                                        borderRadius: BorderRadius.circular(
                                          AppSpacing.radiusMedium,
                                        ),
                                      ),
                                      child: ListTile(
                                        title: Text(
                                          genre,
                                          style: textTheme.titleMedium,
                                        ),
                                        trailing: Text(
                                          '${filtered.where((b) => b.genre == genre).length}',
                                          style: textTheme.bodyMedium?.copyWith(
                                            color: colorScheme.onSurface
                                                .withValues(alpha: 0.6),
                                          ),
                                        ),
                                      ),
                                    ),
                                ],
                              ),
                      ),
                    ],
                  ),
                ),
                Positioned(
                  bottom: 16,
                  right: 20,
                  child: FloatingActionButton(
                    onPressed: () {
                      Navigator.of(context, rootNavigator: true).push(
                        MaterialPageRoute(
                          builder: (_) => const AddBookScreen(),
                        ),
                      );
                    },
                    child: const Icon(Icons.add),
                  ),
                ),
              ],
            );
          },
        );
      },
    );
  }

  Widget _tab(BuildContext context, String label, int index, int currentIndex) {
    final selected = currentIndex == index;
    final colorScheme = Theme.of(context).colorScheme;
    final textTheme = Theme.of(context).textTheme;
    final disableAnimations = MediaQuery.of(context).disableAnimations;

    return GestureDetector(
      onTap: () => context.read<LibraryBloc>().add(ChangeTab(index)),
      child: AnimatedContainer(
        duration: disableAnimations
            ? Duration.zero
            : const Duration(milliseconds: 200),
        padding: const EdgeInsets.symmetric(
          horizontal: AppSpacing.md,
          vertical: AppSpacing.sm,
        ),
        decoration: BoxDecoration(
          color: selected
              ? colorScheme.primary
              : colorScheme.surfaceContainerHighest,
          border: Border.all(
            color: selected ? colorScheme.primary : colorScheme.outline,
          ),
          borderRadius: BorderRadius.circular(AppSpacing.radiusPill),
        ),
        child: Text(
          label,
          style: textTheme.labelMedium?.copyWith(
            color: selected
                ? Colors.white
                : colorScheme.onSurface.withValues(alpha: 0.7),
          ),
        ),
      ),
    );
  }
}