/// One shopping trip: receipt photo, supermarket, products and costs.
library;

import 'dart:io';

import 'package:flutter/material.dart';

import 'models/line_item.dart';
import 'models/shop.dart';
import 'product_detail_screen.dart';
import 'services/product_repository.dart';
import 'utils/dates.dart';
import 'utils/money.dart';
import 'widgets/confirm_dialog.dart';
import 'widgets/item_edit_sheet.dart';

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

  final ProductRepository repository;
  final int shopId;

  @override
  State<ShopDetailScreen> createState() => _ShopDetailScreenState();
}

class _ShopDetailScreenState extends State<ShopDetailScreen> {
  late Future<({Shop shop, List<ShopItem> items})> _future;
  bool _editing = false;

  @override
  void initState() {
    super.initState();
    _future = _load();
  }

  Future<({Shop shop, List<ShopItem> items})> _load() async {
    final shop = await widget.repository.getShop(widget.shopId);
    if (shop == null) {
      throw StateError('Shop not found');
    }
    final items = await widget.repository.getShopItems(widget.shopId);
    return (shop: shop, items: items);
  }

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

  Future<void> _openReceipt(File file) async {
    await showDialog<void>(
      context: context,
      builder: (context) {
        return Dialog(
          insetPadding: const EdgeInsets.all(16),
          child: InteractiveViewer(
            child: Image.file(file, fit: BoxFit.contain),
          ),
        );
      },
    );
  }

  Future<void> _openProduct(int productId) async {
    await Navigator.of(context).push<void>(
      MaterialPageRoute(
        builder: (_) => ProductDetailScreen(
          repository: widget.repository,
          productId: productId,
        ),
      ),
    );
  }

  Future<void> _editItem(ShopItem item) async {
    final result = await showItemEditSheet(
      context,
      item: LineItem(
        id: '${item.id}',
        name: item.name,
        price: item.price,
        quantity: item.quantity,
        unitPrice: item.unitPrice,
      ),
    );
    if (result == null || !mounted) return;
    await widget.repository.updateShopItem(
      id: item.id,
      name: result.name,
      price: result.price,
      quantity: result.quantity,
      unitPrice: result.unitPrice,
    );
    if (mounted) _reload();
  }

  Future<void> _removeItem(ShopItem item) async {
    final confirmed = await confirmAction(
      context,
      title: 'Remove item?',
      message:
          '"${item.name}" will be removed from this trip. The product stays in your catalog.',
      confirmLabel: 'Remove',
    );
    if (!confirmed || !mounted) return;
    await widget.repository.deleteShopItem(item.id);
    if (mounted) _reload();
  }

  Widget? _itemSubtitle(ShopItem item) {
    final parts = [
      if (item.quantity != null)
        '${item.quantity} × ${formatEuro(item.unitPrice ?? 0)}',
      if (_editing) formatEuro(item.price),
    ];
    if (parts.isEmpty) return null;
    return Text(parts.join(' · '));
  }

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

    return Scaffold(
      appBar: AppBar(
        title: const Text('Shopping trip'),
        actions: [
          IconButton(
            tooltip: _editing ? 'Done' : 'Edit',
            onPressed: () => setState(() => _editing = !_editing),
            icon: Icon(_editing ? Icons.check : Icons.edit_outlined),
          ),
        ],
      ),
      body: FutureBuilder(
        future: _future,
        builder: (context, snapshot) {
          if (snapshot.hasError) {
            return Center(
              child: Text(
                'Could not load this trip.',
                style: theme.textTheme.bodyLarge,
              ),
            );
          }
          if (!snapshot.hasData) {
            return const Center(child: CircularProgressIndicator());
          }

          final shop = snapshot.data!.shop;
          final items = snapshot.data!.items;
          final receipt = shop.receiptImagePath;
          final receiptFile = receipt == null ? null : File(receipt);
          final hasReceipt = receiptFile != null && receiptFile.existsSync();

          return ListView(
            padding: const EdgeInsets.fromLTRB(16, 8, 16, 32),
            children: [
              Text(shop.supermarket, style: theme.textTheme.headlineMedium),
              const SizedBox(height: 4),
              Text(
                formatDate(shop.shoppedAt),
                style: theme.textTheme.bodyLarge,
              ),
              if (hasReceipt) ...[
                const SizedBox(height: 16),
                GestureDetector(
                  onTap: () => _openReceipt(receiptFile),
                  child: ClipRRect(
                    borderRadius: BorderRadius.circular(16),
                    child: Image.file(
                      receiptFile,
                      height: 180,
                      width: double.infinity,
                      fit: BoxFit.cover,
                      cacheWidth: 900,
                    ),
                  ),
                ),
              ],
              const SizedBox(height: 24),
              Text('Products', style: theme.textTheme.titleMedium),
              const SizedBox(height: 8),
              if (items.isEmpty)
                Text(
                  'No items on this trip.',
                  style: theme.textTheme.bodyLarge,
                ),
              for (final item in items)
                ListTile(
                  contentPadding: EdgeInsets.zero,
                  title: Text(item.name),
                  subtitle: _itemSubtitle(item),
                  trailing: _editing
                      ? Row(
                          mainAxisSize: MainAxisSize.min,
                          children: [
                            IconButton(
                              tooltip: 'Edit',
                              visualDensity: VisualDensity.compact,
                              onPressed: () => _editItem(item),
                              icon: const Icon(Icons.edit_outlined),
                            ),
                            IconButton(
                              tooltip: 'Remove',
                              visualDensity: VisualDensity.compact,
                              onPressed: () => _removeItem(item),
                              icon: const Icon(Icons.delete_outline),
                            ),
                          ],
                        )
                      : Text(
                          formatEuro(item.price),
                          style: theme.textTheme.titleMedium,
                        ),
                  onTap: _editing ? null : () => _openProduct(item.productId),
                ),
              const Divider(),
              ListTile(
                contentPadding: EdgeInsets.zero,
                title: Text('Total', style: theme.textTheme.titleMedium),
                trailing: Text(
                  formatEuro(shop.total),
                  style: theme.textTheme.titleLarge,
                ),
              ),
            ],
          );
        },
      ),
    );
  }
}