/// Catalog of products from confirmed receipts.
library;

import 'package:flutter/material.dart';

import 'models/product.dart';
import 'product_detail_screen.dart';
import 'services/app_settings.dart';
import 'services/product_repository.dart';
import 'utils/fuzzy.dart';
import 'utils/money.dart';
import 'widgets/product_image.dart';
import 'widgets/settings_button.dart';
import 'widgets/store_tag.dart';

class ProductsScreen extends StatefulWidget {
  const ProductsScreen({super.key, required this.repository});

  final ProductRepository repository;

  @override
  State<ProductsScreen> createState() => _ProductsScreenState();
}

class _ProductsScreenState extends State<ProductsScreen> {
  ProductSort _sort = ProductSort.preferred;
  bool _favouritesOnly = false;
  bool _searching = false;
  final TextEditingController _search = TextEditingController();
  late Future<List<Product>> _future;

  @override
  void initState() {
    super.initState();
    _future = _load();
    _search.addListener(() => setState(() {}));
  }

  @override
  void dispose() {
    _search.dispose();
    super.dispose();
  }

  Future<List<Product>> _load() {
    return widget.repository.getAll(
      sort: _sort,
      favouritesOnly: _favouritesOnly,
    );
  }

  void _reload() {
    setState(() => _future = _load());
  }

  List<Product> _filter(List<Product> products) {
    final query = _search.text.trim();
    if (query.isEmpty) return products;
    final ranked = <({Product product, int score})>[];
    for (final product in products) {
      final haystack = [
        product.name,
        if (product.supermarket != null) product.supermarket!,
        if (product.category != null) product.category!,
        if (product.notes != null) product.notes!,
      ].join(' ');
      final score = fuzzyScore(query, haystack);
      if (score != null) {
        ranked.add((product: product, score: score));
      }
    }
    ranked.sort((a, b) => b.score.compareTo(a.score));
    return [for (final row in ranked) row.product];
  }

  Future<void> _openProduct(Product product) async {
    await Navigator.of(context).push<void>(
      MaterialPageRoute(
        builder: (_) => ProductDetailScreen(
          repository: widget.repository,
          productId: product.id,
        ),
      ),
    );
    if (mounted) _reload();
  }

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    final stores = SettingsScope.maybeOf(context)?.supermarkets ?? const [];

    return Scaffold(
      appBar: AppBar(
        title: _searching
            ? TextField(
                controller: _search,
                autofocus: true,
                decoration: const InputDecoration(
                  hintText: 'Search products',
                  border: InputBorder.none,
                  enabledBorder: InputBorder.none,
                  focusedBorder: InputBorder.none,
                  filled: false,
                ),
              )
            : const Text('Products'),
        actions: [
          IconButton(
            tooltip: _searching ? 'Close search' : 'Search',
            onPressed: () {
              setState(() {
                _searching = !_searching;
                if (!_searching) _search.clear();
              });
            },
            icon: Icon(_searching ? Icons.close : Icons.search),
          ),
          const SettingsButton(),
        ],
      ),
      body: Column(
        children: [
          Padding(
            padding: const EdgeInsets.fromLTRB(16, 4, 16, 4),
            child: Row(
              children: [
                Expanded(
                  child: SegmentedButton<ProductSort>(
                    segments: const [
                      ButtonSegment(
                        value: ProductSort.preferred,
                        label: Text('Preferred'),
                      ),
                      ButtonSegment(
                        value: ProductSort.name,
                        label: Text('A–Z'),
                      ),
                    ],
                    selected: {_sort},
                    onSelectionChanged: (selected) {
                      setState(() {
                        _sort = selected.first;
                        _future = _load();
                      });
                    },
                  ),
                ),
                const SizedBox(width: 8),
                IconButton.filledTonal(
                  tooltip: 'Favourites',
                  isSelected: _favouritesOnly,
                  onPressed: () {
                    setState(() {
                      _favouritesOnly = !_favouritesOnly;
                      _future = _load();
                    });
                  },
                  icon: Icon(
                    _favouritesOnly ? Icons.star : Icons.star_outline,
                  ),
                ),
              ],
            ),
          ),
          Expanded(
            child: FutureBuilder<List<Product>>(
              future: _future,
              builder: (context, snapshot) {
                if (snapshot.hasError) {
                  return Center(
                    child: Text(
                      'Could not load products.',
                      style: theme.textTheme.bodyLarge,
                    ),
                  );
                }
                if (!snapshot.hasData) {
                  return const Center(child: CircularProgressIndicator());
                }

                final products = _filter(snapshot.data!);
                if (snapshot.data!.isEmpty) {
                  return Center(
                    child: Text(
                      _favouritesOnly
                          ? 'Star products to keep them as favourites.'
                          : 'Confirmed receipt items will show up here.',
                      textAlign: TextAlign.center,
                      style: theme.textTheme.bodyLarge,
                    ),
                  );
                }
                if (products.isEmpty) {
                  return Center(
                    child: Text(
                      'No products match this search.',
                      textAlign: TextAlign.center,
                      style: theme.textTheme.bodyLarge,
                    ),
                  );
                }

                return ListView.separated(
                  padding: const EdgeInsets.fromLTRB(8, 0, 8, 16),
                  itemCount: products.length,
                  separatorBuilder: (_, _) => const Divider(height: 1),
                  itemBuilder: (context, index) {
                    final product = products[index];
                    return ListTile(
                      dense: true,
                      visualDensity: VisualDensity.compact,
                      contentPadding: const EdgeInsets.symmetric(
                        horizontal: 8,
                        vertical: 0,
                      ),
                      leading: ProductImage(
                        name: product.name,
                        path: product.imagePath,
                        size: 36,
                      ),
                      title: Text(
                        product.name,
                        maxLines: 1,
                        overflow: TextOverflow.ellipsis,
                      ),
                      subtitle: product.supermarket == null
                          ? null
                          : Padding(
                              padding: const EdgeInsets.only(top: 2),
                              child: Align(
                                alignment: Alignment.centerLeft,
                                child: StoreTag(
                                  name: product.supermarket,
                                  stores: stores,
                                  compact: true,
                                ),
                              ),
                            ),
                      trailing: Text(
                        formatEuro(product.lastPrice),
                        style: theme.textTheme.titleMedium,
                      ),
                      onTap: () => _openProduct(product),
                    );
                  },
                );
              },
            ),
          ),
        ],
      ),
    );
  }
}