import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import '../bloc/book_bloc.dart';
import '../bloc/navigation_bloc.dart';
import '../models/models.dart';
import '../widgets/book_card.dart';
import '../theme/app_spacing.dart';

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

  @override
  State<LibraryScreen> createState() => _LibraryScreenState();
}

class _LibraryScreenState extends State<LibraryScreen> {
  String _search = '';
  int _tabIndex = 0;

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

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

        return 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) => setState(() => _search = 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('Все книги', 0),
                    const SizedBox(width: AppSpacing.sm),
                    _tab('Категории', 1),
                  ],
                ),
              ),
              const SizedBox(height: AppSpacing.md),
              // Grid
              Expanded(
                child: _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: () {
                            context.read<NavigationBloc>().add(
                              NavigateTo(
                                AppScreen.details,
                                selectedBook: 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,
                                    ),
                                  ),
                                ),
                              ),
                            ),
                        ],
                      ),
              ),
            ],
          ),
        );
      },
    );
  }

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

    return GestureDetector(
      onTap: () => setState(() => _tabIndex = 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),
          ),
        ),
      ),
    );
  }
}