/// Named shopping lists of things to buy.
library;

import 'package:flutter/material.dart';

import 'models/shopping_list.dart';
import 'services/product_repository.dart';
import 'shopping_list_detail_screen.dart';
import 'widgets/confirm_dialog.dart';
import 'widgets/name_dialog.dart';
import 'widgets/settings_button.dart';

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

  final ProductRepository repository;

  @override
  State<ShoppingListsScreen> createState() => _ShoppingListsScreenState();
}

class _ShoppingListsScreenState extends State<ShoppingListsScreen> {
  late Future<List<ShoppingList>> _future;
  bool _editing = false;

  @override
  void initState() {
    super.initState();
    _future = widget.repository.getShoppingLists();
  }

  void _reload() {
    setState(() => _future = widget.repository.getShoppingLists());
  }

  Future<void> _create() async {
    final name = await showNameDialog(
      context,
      title: 'New shopping list',
      label: 'List name',
      confirmLabel: 'Create',
    );
    if (name == null || !mounted) return;
    final id = await widget.repository.createShoppingList(name);
    if (!mounted) return;
    await _openList(id);
  }

  Future<void> _openList(int id) async {
    await Navigator.of(context).push<void>(
      MaterialPageRoute(
        builder: (_) =>
            ShoppingListDetailScreen(repository: widget.repository, listId: id),
      ),
    );
    if (mounted) _reload();
  }

  Future<void> _removeList(ShoppingList list) async {
    final confirmed = await confirmAction(
      context,
      title: 'Delete shopping list?',
      message: '"${list.name}" and its items will be deleted.',
    );
    if (!confirmed || !mounted) return;
    await widget.repository.deleteShoppingList(list.id);
    if (mounted) _reload();
  }

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

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

          final lists = snapshot.data!;
          if (lists.isEmpty) {
            return Center(
              child: Text(
                'Create a list for your next shop.',
                textAlign: TextAlign.center,
                style: theme.textTheme.bodyLarge,
              ),
            );
          }

          return ListView.separated(
            padding: const EdgeInsets.fromLTRB(8, 8, 8, 88),
            itemCount: lists.length,
            separatorBuilder: (_, _) => const SizedBox(height: 4),
            itemBuilder: (context, index) {
              final list = lists[index];
              final remaining = list.itemCount - list.checkedCount;
              return ListTile(
                leading: CircleAvatar(child: Text('${list.itemCount}')),
                title: Text(list.name),
                subtitle: Text(
                  list.itemCount == 0
                      ? 'Empty'
                      : remaining == 0
                      ? 'All done'
                      : remaining == 1
                      ? '1 item left'
                      : '$remaining items left',
                ),
                trailing: _editing
                    ? IconButton(
                        tooltip: 'Delete',
                        onPressed: () => _removeList(list),
                        icon: const Icon(Icons.delete_outline),
                      )
                    : const Icon(Icons.chevron_right),
                onTap: _editing ? null : () => _openList(list.id),
              );
            },
          );
        },
      ),
    );
  }
}