/// Validated form that inserts a new [Item] into [ItemController].
library;

import 'package:flutter/material.dart';
import 'package:provider/provider.dart';

import '../models/item.dart';
import '../providers/item_provider.dart';
import '../widgets/app_text_field.dart';
import '../widgets/responsive_body.dart';

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

  @override
  State<AddItemScreen> createState() => _AddItemScreenState();
}

class _AddItemScreenState extends State<AddItemScreen> {
  final _formKey = GlobalKey<FormState>();
  final _title = TextEditingController();
  final _subtitle = TextEditingController();
  final _description = TextEditingController();
  ItemCategory? _category;
  bool _submitted = false;

  @override
  void dispose() {
    _title.dispose();
    _subtitle.dispose();
    _description.dispose();
    super.dispose();
  }

  String? _requiredLength(String? value, {required int min, String? label}) {
    final text = value?.trim() ?? '';
    if (text.isEmpty) return 'Enter a ${label ?? 'value'}.';
    if (text.length < min) {
      return '${label ?? 'This field'} must be at least $min characters.';
    }
    return null;
  }

  void _submit() {
    setState(() => _submitted = true);
    final form = _formKey.currentState;
    if (form == null || !form.validate() || _category == null) return;

    context.read<ItemController>().addItem(
          title: _title.text,
          subtitle: _subtitle.text,
          description: _description.text,
          category: _category!,
        );

    ScaffoldMessenger.of(context).showSnackBar(
      SnackBar(content: Text('Added “${_title.text.trim()}”')),
    );
    Navigator.of(context).pop();
  }

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

    return Scaffold(
      appBar: AppBar(title: const Text('Add item')),
      body: ResponsiveBody(
        child: Form(
          key: _formKey,
          autovalidateMode: _submitted
              ? AutovalidateMode.onUserInteraction
              : AutovalidateMode.disabled,
          child: ListView(
            children: [
              const SizedBox(height: 8),
              Text(
                'Create a catalog entry. All fields are required.',
                style: theme.textTheme.bodyMedium,
              ),
              const SizedBox(height: 20),
              AppTextField(
                controller: _title,
                label: 'Title',
                hint: 'Give it a short name',
                autofocus: true,
                textInputAction: TextInputAction.next,
                validator: (value) =>
                    _requiredLength(value, min: 3, label: 'Title'),
              ),
              const SizedBox(height: 16),
              AppTextField(
                controller: _subtitle,
                label: 'Summary',
                hint: 'One sentence overview',
                textInputAction: TextInputAction.next,
                validator: (value) =>
                    _requiredLength(value, min: 8, label: 'Summary'),
              ),
              const SizedBox(height: 16),
              DropdownButtonFormField<ItemCategory>(
                initialValue: _category,
                decoration: const InputDecoration(labelText: 'Category'),
                items: [
                  for (final category in ItemCategory.values)
                    DropdownMenuItem(
                      value: category,
                      child: Text(category.label),
                    ),
                ],
                onChanged: (value) => setState(() => _category = value),
                validator: (value) =>
                    value == null ? 'Choose a category.' : null,
              ),
              const SizedBox(height: 16),
              AppTextField(
                controller: _description,
                label: 'Description',
                hint: 'A longer note the detail screen will show',
                maxLines: 5,
                keyboardType: TextInputType.multiline,
                validator: (value) =>
                    _requiredLength(value, min: 16, label: 'Description'),
              ),
              const SizedBox(height: 24),
              FilledButton(
                onPressed: _submit,
                child: const Text('Save item'),
              ),
              const SizedBox(height: 12),
              OutlinedButton(
                onPressed: () => Navigator.of(context).pop(),
                child: const Text('Cancel'),
              ),
              const SizedBox(height: 24),
            ],
          ),
        ),
      ),
    );
  }
}