added provider for recipe wizard

lib/models/ingredient.dart

@@ -13,4 +13,12 @@ class Ingredient {
     this.possibleUnits = const [],
     this.preferredBrands = const [],
   });
+
+  @override
+  bool operator ==(Object other) =>
+      identical(this, other) ||
+      other is Ingredient && other.title == title && other.type == type;
+
+  @override
+  int get hashCode => Object.hash(title, type);
 }

lib/models/ingredient_list_entry.dart

@@ -8,4 +8,14 @@ class IngredientListEntry {
   final bool optional;
 
   IngredientListEntry(this.ingredient, this.amount, this.unit, this.optional);
+
+  @override
+  bool operator ==(Object other) =>
+      identical(this, other) ||
+      other is IngredientListEntry &&
+          ingredient == other.ingredient &&
+          amount == other.amount;
+
+  @override
+  int get hashCode => Object.hash(ingredient.hashCode, amount.hashCode);
 }

lib/models/recipe.dart

@@ -6,26 +6,67 @@ class Recipe {
   final String title;
   final String description;
   final Difficulty difficulty;
-  final List<IngredientListEntry> ingredients = [];
-  final List<String> steps = [];
+  final List<IngredientListEntry> ingredients;
+  final List<String> steps;
   final DateTime datePublished;
   final Duration prepTime;
   final Duration cookTime;
   final Duration totalTime;
-  final List<String> keywords = [];
+  final List<String> keywords;
   final MealCategory mealCategory;
   final Cuisine cuisine;
 
   Recipe({
-    required this.id,
-    required this.title,
-    required this.description,
-    required this.difficulty,
+    this.id = -1,
+    this.title = '',
+    this.description = '',
+    this.difficulty = Difficulty.notSelected,
     required this.datePublished,
-    required this.prepTime,
-    required this.cookTime,
-    required this.totalTime,
-    required this.mealCategory,
-    required this.cuisine,
+    this.prepTime = const Duration(),
+    this.cookTime = const Duration(),
+    this.totalTime = const Duration(),
+    this.mealCategory = MealCategory.notSelected,
+    this.cuisine = Cuisine.notSelected,
+    this.ingredients = const [],
+    this.keywords = const [],
+    this.steps = const [],
   });
+
+  Recipe copyWith({
+    int? id,
+    String? title,
+    String? description,
+    Difficulty? difficulty,
+    List<IngredientListEntry>? ingredients,
+    List<String>? steps,
+    DateTime? datePublished,
+    Duration? prepTime,
+    Duration? cookTime,
+    Duration? totalTime,
+    List<String>? keywords,
+    MealCategory? mealCategory,
+    Cuisine? cuisine,
+  }) {
+    return Recipe(
+      id: id ?? this.id,
+      title: title ?? this.title,
+      description: description ?? this.description,
+      difficulty: difficulty ?? this.difficulty,
+      ingredients: ingredients != null
+          ? List<IngredientListEntry>.from(ingredients)
+          : List<IngredientListEntry>.from(this.ingredients),
+      steps: steps != null
+          ? List<String>.from(steps)
+          : List<String>.from(this.steps),
+      datePublished: datePublished ?? this.datePublished,
+      prepTime: prepTime ?? this.prepTime,
+      cookTime: cookTime ?? this.cookTime,
+      totalTime: totalTime ?? this.totalTime,
+      keywords: keywords != null
+          ? List<String>.from(keywords)
+          : List<String>.from(this.keywords),
+      mealCategory: mealCategory ?? this.mealCategory,
+      cuisine: cuisine ?? this.cuisine,
+    );
+  }
 }

lib/services/providers/recipe_provider.dart

@@ -0,0 +1,151 @@
+import 'package:flutter/material.dart';
+
+import '../../models/ingredient_list_entry.dart';
+import '../../models/recipe.dart';
+import '../../src/enums.dart';
+
+class RecipeProvider extends ChangeNotifier {
+  Recipe _recipe = Recipe(datePublished: DateTime.now());
+
+  Recipe get recipe => _recipe;
+
+  void updateTitle(String title, {bool silent = false}) {
+    _recipe = _recipe.copyWith(title: title);
+    if (!silent) {
+      notifyListeners();
+    }
+  }
+
+  void updateDescription(String description, {bool silent = false}) {
+    _recipe = _recipe.copyWith(description: description);
+    if (!silent) {
+      notifyListeners();
+    }
+  }
+
+  void updateDifficulty(Difficulty difficulty, {bool silent = false}) {
+    _recipe = _recipe.copyWith(difficulty: difficulty);
+    if (!silent) {
+      notifyListeners();
+    }
+  }
+
+  void updateIngredients(List<IngredientListEntry> ingredients,
+      {bool silent = false}) {
+    _recipe = _recipe.copyWith(ingredients: ingredients);
+    if (!silent) {
+      notifyListeners();
+    }
+  }
+
+  void updateSteps(List<String> steps, {bool silent = false}) {
+    _recipe = _recipe.copyWith(steps: steps);
+    if (!silent) {
+      notifyListeners();
+    }
+  }
+
+  void updateDatePublished(DateTime datePublished, {bool silent = false}) {
+    _recipe = _recipe.copyWith(datePublished: datePublished);
+    if (!silent) {
+      notifyListeners();
+    }
+  }
+
+  void updatePrepTime(Duration prepTime, {bool silent = false}) {
+    _recipe = _recipe.copyWith(prepTime: prepTime);
+    if (!silent) {
+      notifyListeners();
+    }
+  }
+
+  void updateCookTime(Duration cookTime, {bool silent = false}) {
+    _recipe = _recipe.copyWith(cookTime: cookTime);
+    if (!silent) {
+      notifyListeners();
+    }
+  }
+
+  void updateTotalTime(Duration totalTime, {bool silent = false}) {
+    _recipe = _recipe.copyWith(totalTime: totalTime);
+    if (!silent) {
+      notifyListeners();
+    }
+  }
+
+  void updateKeywords(List<String> keywords, {bool silent = false}) {
+    _recipe = _recipe.copyWith(keywords: keywords);
+    if (!silent) {
+      notifyListeners();
+    }
+  }
+
+  void updateMealCategory(MealCategory mealCategory, {bool silent = false}) {
+    _recipe = _recipe.copyWith(mealCategory: mealCategory);
+    if (!silent) {
+      notifyListeners();
+    }
+  }
+
+  void updateCuisine(Cuisine cuisine, {bool silent = false}) {
+    _recipe = _recipe.copyWith(cuisine: cuisine);
+    if (!silent) {
+      notifyListeners();
+    }
+  }
+
+// Helper methods for list operations
+  void addIngredient(IngredientListEntry ingredient, {bool silent = false}) {
+    _recipe = _recipe.copyWith(
+      ingredients: [..._recipe.ingredients, ingredient],
+    );
+    if (!silent) {
+      notifyListeners();
+    }
+  }
+
+  void removeIngredient(IngredientListEntry ingredient, {bool silent = false}) {
+    _recipe = _recipe.copyWith(
+      ingredients: _recipe.ingredients.where((i) => i != ingredient).toList(),
+    );
+    if (!silent) {
+      notifyListeners();
+    }
+  }
+
+  void addStep(String step, {bool silent = false}) {
+    _recipe = _recipe.copyWith(
+      steps: [..._recipe.steps, step],
+    );
+    if (!silent) {
+      notifyListeners();
+    }
+  }
+
+  void removeStep(String step, {bool silent = false}) {
+    _recipe = _recipe.copyWith(
+      steps: _recipe.steps.where((s) => s != step).toList(),
+    );
+    if (!silent) {
+      notifyListeners();
+    }
+  }
+
+  void addKeyword(String keyword, {bool silent = false}) {
+    _recipe = _recipe.copyWith(
+      keywords: [..._recipe.keywords, keyword],
+    );
+    if (!silent) {
+      notifyListeners();
+    }
+  }
+
+  void removeKeyword(String keyword, {bool silent = false}) {
+    _recipe = _recipe.copyWith(
+      keywords: _recipe.keywords.where((k) => k != keyword).toList(),
+    );
+    if (!silent) {
+      notifyListeners();
+    }
+  }
+}

lib/src/enums.dart

@@ -16,6 +16,7 @@ enum Difficulty {
 }
 
 enum IngredientType {
+  notSelected,
   vegetable,
   meat,
   fish,
@@ -28,6 +29,7 @@ enum IngredientType {
 }
 
 enum MealCategory {
+  notSelected,
   // Main Meals
   breakfast,
   brunch,
@@ -44,6 +46,7 @@ enum MealCategory {
 }
 
 enum Cuisine {
+  notSelected,
   // Asian Cuisines
   chinese,
   japanese,