import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import '../bloc/book/book_bloc.dart';
import '../bloc/book/book_event.dart';
import '../bloc/add_book/add_book_bloc.dart';
import '../bloc/add_book/add_book_event.dart';
import '../bloc/add_book/add_book_state.dart';
import '../config/api_config.dart';
import '../models/models.dart';
import '../theme/app_spacing.dart';
import 'scanner_screen.dart';

class AddBookScreen extends StatelessWidget {
  final Book? editBook;
  final Book? prefilledData;

  const AddBookScreen({super.key, this.editBook, this.prefilledData});

  @override
  Widget build(BuildContext context) {
    return BlocProvider(
      create: (context) => AddBookBloc(
        onAddBook: (book) => context.read<BookBloc>().add(AddBook(book)),
        onUpdateBook: (book) => context.read<BookBloc>().add(UpdateBook(book)),
      )..add(InitializeForm(editBook: editBook, prefilledData: prefilledData)),
      child: const _AddBookScreenContent(),
    );
  }
}

class _AddBookScreenContent extends StatefulWidget {
  const _AddBookScreenContent();

  @override
  State<_AddBookScreenContent> createState() => _AddBookScreenContentState();
}

class _AddBookScreenContentState extends State<_AddBookScreenContent> {
  final _titleController = TextEditingController();
  final _authorController = TextEditingController();
  final _annotationController = TextEditingController();

  @override
  void dispose() {
    _titleController.dispose();
    _authorController.dispose();
    _annotationController.dispose();
    super.dispose();
  }

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

    return BlocListener<AddBookBloc, AddBookState>(
      listener: (context, state) {
        // Update controllers when state changes (e.g., from scanned book)
        if (_titleController.text != state.title) {
          _titleController.text = state.title;
        }
        if (_authorController.text != state.author) {
          _authorController.text = state.author;
        }
        if (_annotationController.text != state.annotation) {
          _annotationController.text = state.annotation;
        }

        // Navigate back when saved
        if (state.isSaved) {
          Navigator.pop(context);
        }
      },
      child: BlocBuilder<AddBookBloc, AddBookState>(
        builder: (context, state) {
          final title = state.isEditing ? 'Редактировать' : 'Добавить книгу';

          return Material(
            child: SafeArea(
              child: Column(
                children: [
                  // Header
                  Padding(
                    padding: const EdgeInsets.fromLTRB(
                      AppSpacing.sm,
                      AppSpacing.sm,
                      AppSpacing.sm,
                      0,
                    ),
                    child: Row(
                      children: [
                        IconButton(
                          icon: const Icon(Icons.arrow_back),
                          onPressed: () => Navigator.pop(context),
                        ),
                        Text(title, style: textTheme.headlineMedium),
                      ],
                    ),
                  ),
                  Expanded(
                    child: ListView(
                      padding: const EdgeInsets.all(AppSpacing.lg),
                      children: [
                        // Cover placeholder / scanner trigger
                        GestureDetector(
                          onTap: () => _openScanner(context),
                          child: Container(
                            height: 160,
                            decoration: BoxDecoration(
                              border: Border.all(color: colorScheme.outline),
                              borderRadius: BorderRadius.circular(
                                AppSpacing.radiusMedium,
                              ),
                              color: colorScheme.surfaceContainerHighest,
                            ),
                            child: Center(
                              child: Column(
                                mainAxisAlignment: MainAxisAlignment.center,
                                children: [
                                  Icon(
                                    Icons.camera_alt,
                                    size: 40,
                                    color: colorScheme.primary,
                                  ),
                                  const SizedBox(height: AppSpacing.sm),
                                  Text(
                                    'Загрузить или отсканировать',
                                    style: textTheme.bodyMedium?.copyWith(
                                      color: colorScheme.onSurface.withValues(
                                        alpha: 0.6,
                                      ),
                                    ),
                                  ),
                                ],
                              ),
                            ),
                          ),
                        ),
                        const SizedBox(height: AppSpacing.lg),
                        _field(
                          context,
                          'Название',
                          _titleController,
                          textTheme,
                          (value) =>
                              context.read<AddBookBloc>().add(UpdateTitle(value)),
                        ),
                        const SizedBox(height: AppSpacing.md),
                        _field(
                          context,
                          'Автор',
                          _authorController,
                          textTheme,
                          (value) => context.read<AddBookBloc>().add(
                            UpdateAuthor(value),
                          ),
                        ),
                        const SizedBox(height: AppSpacing.md),
                        // Genre dropdown
                        Text('Жанр', style: textTheme.labelMedium),
                        const SizedBox(height: AppSpacing.xs),
                        DropdownButtonFormField<String>(
                          value: state.genre,
                          dropdownColor: colorScheme.surface,
                          decoration: const InputDecoration(),
                          items: const [
                            DropdownMenuItem(
                              value: 'fiction',
                              child: Text('Фантастика'),
                            ),
                            DropdownMenuItem(
                              value: 'fantasy',
                              child: Text('Фэнтези'),
                            ),
                            DropdownMenuItem(
                              value: 'science',
                              child: Text('Научпоп'),
                            ),
                            DropdownMenuItem(
                              value: 'biography',
                              child: Text('Биография'),
                            ),
                            DropdownMenuItem(
                              value: 'detective',
                              child: Text('Детектив'),
                            ),
                            DropdownMenuItem(
                              value: 'other',
                              child: Text('Другое'),
                            ),
                          ],
                          onChanged: (v) {
                            if (v != null) {
                              context.read<AddBookBloc>().add(UpdateGenre(v));
                            }
                          },
                        ),
                        const SizedBox(height: AppSpacing.md),
                        Text('Аннотация', style: textTheme.labelMedium),
                        const SizedBox(height: AppSpacing.xs),
                        TextField(
                          controller: _annotationController,
                          maxLines: 4,
                          onChanged: (value) => context.read<AddBookBloc>().add(
                            UpdateAnnotation(value),
                          ),
                        ),
                        const SizedBox(height: 100),
                      ],
                    ),
                  ),
                  // Bottom actions
                  Container(
                    padding: const EdgeInsets.symmetric(
                      horizontal: AppSpacing.screenPadding,
                      vertical: AppSpacing.md,
                    ),
                    decoration: BoxDecoration(
                      color: colorScheme.surface,
                      border: Border(
                        top: BorderSide(color: colorScheme.outlineVariant),
                      ),
                      boxShadow: [
                        BoxShadow(
                          color: colorScheme.shadow,
                          blurRadius: 8,
                          offset: const Offset(0, -2),
                        ),
                      ],
                    ),
                    child: Row(
                      children: [
                        Expanded(
                          child: OutlinedButton(
                            onPressed: () => Navigator.pop(context),
                            child: const Text('Отмена'),
                          ),
                        ),
                        const SizedBox(width: AppSpacing.md),
                        Expanded(
                          flex: 2,
                          child: ElevatedButton(
                            onPressed: () =>
                                context.read<AddBookBloc>().add(SaveBook()),
                            child: const Text('Сохранить'),
                          ),
                        ),
                      ],
                    ),
                  ),
                ],
              ),
            ),
          );
        },
      ),
    );
  }

  Widget _field(
    BuildContext context,
    String label,
    TextEditingController controller,
    TextTheme textTheme,
    void Function(String) onChanged,
  ) {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Text(label, style: textTheme.labelMedium),
        const SizedBox(height: AppSpacing.xs),
        TextField(controller: controller, onChanged: onChanged),
      ],
    );
  }

  Future<void> _openScanner(BuildContext context) async {
    if (!context.mounted) return;

    final scannedBook = await Navigator.of(context, rootNavigator: true)
        .push<Book>(
          MaterialPageRoute(
            builder: (_) => ScannerScreen(
              geminiApiKey: ApiConfig.geminiApiKey,
              openaiApiKey: ApiConfig.openaiApiKey,
              openaiBaseUrl: ApiConfig.openaiBaseUrl,
            ),
          ),
        );

    if (scannedBook != null && context.mounted) {
      context.read<AddBookBloc>().add(ApplyScannedBook(scannedBook));
    }
  }
}