edit_recipe_page.dart

// Copyright 2024 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import 'dart:convert';

import 'package:flutter/material.dart';
import 'package:flutter_ai_toolkit/flutter_ai_toolkit.dart';
import 'package:go_router/go_router.dart';
import 'package:google_generative_ai/google_generative_ai.dart';
import 'package:uuid/uuid.dart';

import '../../gemini_api_key.dart';
import '../data/recipe_data.dart';
import '../data/recipe_repository.dart';
import '../data/settings.dart';

class EditRecipePage extends StatefulWidget {
  const EditRecipePage({super.key, required this.recipe});

  final Recipe recipe;

  @override
  State<EditRecipePage> createState() => _EditRecipePageState();
}

class _EditRecipePageState extends State<EditRecipePage> {
  final _formKey = GlobalKey<FormState>();
  late final TextEditingController _titleController;
  late final TextEditingController _descriptionController;
  late final TextEditingController _ingredientsController;
  late final TextEditingController _instructionsController;

  final _provider = GeminiProvider(
    model: GenerativeModel(
      model: "gemini-1.5-flash",
      apiKey: geminiApiKey,
      generationConfig: GenerationConfig(
        responseMimeType: 'application/json',
        responseSchema: Schema(
          SchemaType.object,
          properties: {
            'modifications': Schema(
              description: 'The modifications to the recipe you made',
              SchemaType.string,
            ),
            'recipe': Schema(
              SchemaType.object,
              properties: {
                'title': Schema(SchemaType.string),
                'description': Schema(SchemaType.string),
                'ingredients': Schema(
                  SchemaType.array,
                  items: Schema(SchemaType.string),
                ),
                'instructions': Schema(
                  SchemaType.array,
                  items: Schema(SchemaType.string),
                ),
              },
            ),
          },
        ),
      ),
      systemInstruction: Content.system('''
You are a helpful assistant that generates recipes based on the ingredients and 
instructions provided:
${Settings.foodPreferences.isEmpty ? 'I don\'t have any food preferences' : Settings.foodPreferences}

When you generate a recipe, you should generate a JSON object.
'''),
    ),
  );

  @override
  void initState() {
    super.initState();

    _titleController = TextEditingController(text: widget.recipe.title);
    _descriptionController = TextEditingController(
      text: widget.recipe.description,
    );
    _ingredientsController = TextEditingController(
      text: widget.recipe.ingredients.join('\n'),
    );
    _instructionsController = TextEditingController(
      text: widget.recipe.instructions.join('\n'),
    );
  }

  @override
  void dispose() {
    _titleController.dispose();
    _descriptionController.dispose();
    _ingredientsController.dispose();
    _instructionsController.dispose();
    super.dispose();
  }

  bool get _isNewRecipe => widget.recipe.id == RecipeRepository.newRecipeID;

  @override
  Widget build(BuildContext context) => Scaffold(
    appBar: AppBar(title: Text('${_isNewRecipe ? "Add" : "Edit"} Recipe')),
    body: Form(
      key: _formKey,
      child: SingleChildScrollView(
        padding: const EdgeInsets.all(16.0),
        child: Column(
          children: [
            TextFormField(
              controller: _titleController,
              decoration: const InputDecoration(
                labelText: 'Title',
                hintText: 'Enter a name for your recipe...',
              ),
              validator:
                  (value) =>
                      (value == null || value.isEmpty)
                          ? 'Recipe title is requires'
                          : null,
            ),
            TextField(
              controller: _descriptionController,
              decoration: const InputDecoration(
                labelText: 'Description',
                hintText: 'In a few words, describe your recipe...',
              ),
              maxLines: null,
            ),
            TextField(
              controller: _ingredientsController,
              decoration: const InputDecoration(
                labelText: 'Ingredients🍎 (one per line)',
                hintText: 'e.g., 2 cups flour\n1 tsp salt\n1 cup sugar',
              ),
              maxLines: null,
            ),
            TextField(
              controller: _instructionsController,
              decoration: const InputDecoration(
                labelText: 'Instructions🥧 (one per line)',
                hintText: 'e.g., Mix ingredients\nBake for 30 minutes',
              ),
              maxLines: null,
            ),
            const SizedBox(height: 16),
            OverflowBar(
              spacing: 16,
              children: [
                ElevatedButton(onPressed: _onMagic, child: const Text('Magic')),
                OutlinedButton(onPressed: _onDone, child: const Text('Done')),
              ],
            ),
          ],
        ),
      ),
    ),
  );

  void _onDone() {
    if (!_formKey.currentState!.validate()) return;

    final recipe = Recipe(
      id: _isNewRecipe ? const Uuid().v4() : widget.recipe.id,
      title: _titleController.text,
      description: _descriptionController.text,
      ingredients: _ingredientsController.text.split('\n'),
      instructions: _instructionsController.text.split('\n'),
    );

    if (_isNewRecipe) {
      RecipeRepository.addNewRecipe(recipe);
    } else {
      RecipeRepository.updateRecipe(recipe);
    }

    if (context.mounted) context.goNamed('home');
  }

  Future<void> _onMagic() async {
    final stream = _provider.sendMessageStream(
      'Generate a modified version of this recipe based on my food preferences: '
      '${_ingredientsController.text}\n\n${_instructionsController.text}',
    );
    var response = await stream.join();
    final json = jsonDecode(response);

    try {
      final modifications = json['modifications'];
      final recipe = Recipe.fromJson(json['recipe']);

      if (!context.mounted) return;
      final accept = await showDialog<bool>(
        // ignore: use_build_context_synchronously
        context: context,
        builder:
            (context) => AlertDialog(
              title: Text(recipe.title),
              content: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                spacing: 16,
                children: [
                  const Text('Modifications:'),
                  Text(_wrapText(modifications)),
                ],
              ),
              actions: [
                TextButton(
                  onPressed: () => context.pop(true),
                  child: const Text('Accept'),
                ),
                TextButton(
                  onPressed: () => context.pop(false),
                  child: const Text('Reject'),
                ),
              ],
            ),
      );

      if (accept == true) {
        setState(() {
          _titleController.text = recipe.title;
          _descriptionController.text = recipe.description;
          _ingredientsController.text = recipe.ingredients.join('\n');
          _instructionsController.text = recipe.instructions.join('\n');
        });
      }
    } catch (ex) {
      if (context.mounted) {
        showDialog(
          // ignore: use_build_context_synchronously
          context: context,
          builder:
              (context) => AlertDialog(
                title: const Text('Error'),
                content: Text(ex.toString()),
                actions: [
                  TextButton(
                    onPressed: () => context.pop(),
                    child: const Text('OK'),
                  ),
                ],
              ),
        );
      }
    }
  }

  String _wrapText(String text, {int lineLength = 80}) {
    final words = text.split(RegExp(r'\s+'));
    final lines = <String>[];

    var currentLine = '';
    for (final word in words) {
      if (currentLine.isEmpty) {
        currentLine = word;
      } else if (('$currentLine $word').length <= lineLength) {
        currentLine += ' $word';
      } else {
        lines.add(currentLine);
        currentLine = word;
      }
    }

    if (currentLine.isNotEmpty) lines.add(currentLine);
    return lines.join('\n');
  }
}