Add DRF serializers, viewsets, what-can-i-cook endpoint, log-cook with pantry deduction

2 files changed, 530 insertions, 2 deletions

diff --git a/kitchen/serializers.py b/kitchen/serializers.py
new file mode 100644
index 0000000..43eb9a7
--- /dev/null
+++ b/kitchen/serializers.py
@@ -0,0 +1,114 @@
+from rest_framework import serializers
+from .models import (
+    Tag,
+    Ingredient,
+    PantryItem,
+    MetaRecipe,
+    Slot,
+    SlotOption,
+    MetaRecipeBase,
+    Recipe,
+    RecipeIngredient,
+    CookLog,
+    ShoppingListItem,
+)
+
+
+class TagSerializer(serializers.ModelSerializer):
+    class Meta:
+        model = Tag
+        fields = "__all__"
+
+
+class IngredientSerializer(serializers.ModelSerializer):
+    tags = TagSerializer(many=True, read_only=True)
+    tag_ids = serializers.PrimaryKeyRelatedField(
+        queryset=Tag.objects.all(), many=True, write_only=True, source="tags", required=False
+    )
+
+    class Meta:
+        model = Ingredient
+        fields = "__all__"
+
+
+class PantryItemSerializer(serializers.ModelSerializer):
+    ingredient_name = serializers.CharField(source="ingredient.name", read_only=True)
+
+    class Meta:
+        model = PantryItem
+        fields = "__all__"
+
+
+# --- Meta-Recipe nested serializers ---
+
+
+class SlotOptionSerializer(serializers.ModelSerializer):
+    ingredient_name = serializers.CharField(source="ingredient.name", read_only=True)
+
+    class Meta:
+        model = SlotOption
+        fields = "__all__"
+
+
+class SlotSerializer(serializers.ModelSerializer):
+    options = SlotOptionSerializer(many=True, read_only=True)
+
+    class Meta:
+        model = Slot
+        fields = "__all__"
+
+
+class MetaRecipeBaseSerializer(serializers.ModelSerializer):
+    ingredient_name = serializers.CharField(source="ingredient.name", read_only=True)
+
+    class Meta:
+        model = MetaRecipeBase
+        fields = "__all__"
+
+
+class MetaRecipeSerializer(serializers.ModelSerializer):
+    slots = SlotSerializer(many=True, read_only=True)
+    base_ingredients = MetaRecipeBaseSerializer(many=True, read_only=True)
+
+    class Meta:
+        model = MetaRecipe
+        fields = "__all__"
+
+
+# --- Fixed Recipe nested serializers ---
+
+
+class RecipeIngredientSerializer(serializers.ModelSerializer):
+    ingredient_name = serializers.CharField(source="ingredient.name", read_only=True)
+
+    class Meta:
+        model = RecipeIngredient
+        fields = "__all__"
+
+
+class RecipeSerializer(serializers.ModelSerializer):
+    ingredients = RecipeIngredientSerializer(many=True, read_only=True)
+
+    class Meta:
+        model = Recipe
+        fields = "__all__"
+
+
+# --- Cook Log & Shopping ---
+
+
+class CookLogSerializer(serializers.ModelSerializer):
+    meta_recipe_name = serializers.CharField(source="meta_recipe.name", read_only=True, default=None)
+    recipe_name = serializers.CharField(source="recipe.name", read_only=True, default=None)
+
+    class Meta:
+        model = CookLog
+        fields = "__all__"
+
+
+class ShoppingListItemSerializer(serializers.ModelSerializer):
+    ingredient_name = serializers.CharField(source="ingredient.name", read_only=True, default=None)
+
+    class Meta:
+        model = ShoppingListItem
+        fields = "__all__"
diff --git a/kitchen/views.py b/kitchen/views.py
index 91ea44a..7521e50 100644
--- a/kitchen/views.py
+++ b/kitchen/views.py
@@ -1,3 +1,417 @@
-from django.shortcuts import render
+from decimal import Decimal
+from datetime import date
 
-# Create your views here.
+from rest_framework import viewsets, status
+from rest_framework.decorators import api_view, permission_classes, action
+from rest_framework.permissions import IsAuthenticated
+from rest_framework.response import Response
+
+from .models import (
+    Tag,
+    Ingredient,
+    PantryItem,
+    MetaRecipe,
+    Slot,
+    SlotOption,
+    MetaRecipeBase,
+    Recipe,
+    RecipeIngredient,
+    CookLog,
+    ShoppingListItem,
+)
+from .serializers import (
+    TagSerializer,
+    IngredientSerializer,
+    PantryItemSerializer,
+    MetaRecipeSerializer,
+    SlotSerializer,
+    SlotOptionSerializer,
+    MetaRecipeBaseSerializer,
+    RecipeSerializer,
+    RecipeIngredientSerializer,
+    CookLogSerializer,
+    ShoppingListItemSerializer,
+)
+
+
+# --- Standard CRUD ViewSets ---
+
+
+class TagViewSet(viewsets.ModelViewSet):
+    queryset = Tag.objects.all()
+    serializer_class = TagSerializer
+    permission_classes = [IsAuthenticated]
+
+
+class IngredientViewSet(viewsets.ModelViewSet):
+    queryset = Ingredient.objects.all()
+    serializer_class = IngredientSerializer
+    permission_classes = [IsAuthenticated]
+    search_fields = ["name", "aliases"]
+
+
+class PantryItemViewSet(viewsets.ModelViewSet):
+    queryset = PantryItem.objects.select_related("ingredient").all()
+    serializer_class = PantryItemSerializer
+    permission_classes = [IsAuthenticated]
+    filterset_fields = ["location", "is_staple"]
+
+    @action(detail=False, methods=["get"])
+    def expiring(self, request):
+        """Items expiring within 3 days."""
+        from datetime import timedelta
+
+        cutoff = date.today() + timedelta(days=3)
+        items = self.queryset.filter(
+            expiry_date__isnull=False,
+            expiry_date__lte=cutoff,
+            quantity__gt=0,
+        )
+        serializer = self.get_serializer(items, many=True)
+        return Response(serializer.data)
+
+    @action(detail=False, methods=["get"])
+    def restock(self, request):
+        """Staple items that need restocking (quantity = 0)."""
+        items = self.queryset.filter(is_staple=True, quantity=0)
+        serializer = self.get_serializer(items, many=True)
+        return Response(serializer.data)
+
+
+class MetaRecipeViewSet(viewsets.ModelViewSet):
+    queryset = MetaRecipe.objects.prefetch_related(
+        "slots__options__ingredient", "base_ingredients__ingredient"
+    ).all()
+    serializer_class = MetaRecipeSerializer
+    permission_classes = [IsAuthenticated]
+
+
+class SlotViewSet(viewsets.ModelViewSet):
+    queryset = Slot.objects.prefetch_related("options__ingredient").all()
+    serializer_class = SlotSerializer
+    permission_classes = [IsAuthenticated]
+
+
+class SlotOptionViewSet(viewsets.ModelViewSet):
+    queryset = SlotOption.objects.select_related("ingredient").all()
+    serializer_class = SlotOptionSerializer
+    permission_classes = [IsAuthenticated]
+
+
+class MetaRecipeBaseViewSet(viewsets.ModelViewSet):
+    queryset = MetaRecipeBase.objects.select_related("ingredient").all()
+    serializer_class = MetaRecipeBaseSerializer
+    permission_classes = [IsAuthenticated]
+
+
+class RecipeViewSet(viewsets.ModelViewSet):
+    queryset = Recipe.objects.prefetch_related("ingredients__ingredient").all()
+    serializer_class = RecipeSerializer
+    permission_classes = [IsAuthenticated]
+
+
+class RecipeIngredientViewSet(viewsets.ModelViewSet):
+    queryset = RecipeIngredient.objects.select_related("ingredient").all()
+    serializer_class = RecipeIngredientSerializer
+    permission_classes = [IsAuthenticated]
+
+
+class CookLogViewSet(viewsets.ModelViewSet):
+    queryset = CookLog.objects.select_related("meta_recipe", "recipe").all()
+    serializer_class = CookLogSerializer
+    permission_classes = [IsAuthenticated]
+
+
+class ShoppingListItemViewSet(viewsets.ModelViewSet):
+    queryset = ShoppingListItem.objects.select_related("ingredient").all()
+    serializer_class = ShoppingListItemSerializer
+    permission_classes = [IsAuthenticated]
+    filterset_fields = ["checked"]
+
+
+# --- What Can I Cook? ---
+
+
+@api_view(["GET"])
+@permission_classes([IsAuthenticated])
+def what_can_i_cook(request):
+    """
+    Match pantry contents against meta-recipes and fixed recipes.
+    
+    Returns recipes sorted by feasibility:
+    - ✅ All required slots can be filled from pantry
+    - ⚠️ Most slots filled, some missing (with details)
+    - ❌ Not enough ingredients
+    
+    Also checks expiry warnings on matched ingredients.
+    """
+    servings = int(request.query_params.get("servings", 2))
+
+    # Build pantry lookup: ingredient_id -> list of {quantity, unit, location, expiry}
+    pantry = {}
+    for item in PantryItem.objects.select_related("ingredient").filter(quantity__gt=0):
+        if item.ingredient_id not in pantry:
+            pantry[item.ingredient_id] = []
+        pantry[item.ingredient_id].append({
+            "quantity": item.quantity,
+            "unit": item.unit,
+            "location": item.location,
+            "expiry_date": item.expiry_date,
+            "is_expired": item.expiry_date and item.expiry_date < date.today(),
+            "expiring_soon": (
+                item.expiry_date
+                and not (item.expiry_date < date.today())
+                and (item.expiry_date - date.today()).days <= 2
+            ),
+        })
+
+    def get_pantry_total(ingredient_id):
+        """Total quantity available across all locations."""
+        if ingredient_id not in pantry:
+            return Decimal("0")
+        return sum(p["quantity"] for p in pantry[ingredient_id])
+
+    def get_pantry_warnings(ingredient_id):
+        """Get expiry warnings for an ingredient."""
+        warnings = []
+        if ingredient_id in pantry:
+            for p in pantry[ingredient_id]:
+                if p["is_expired"]:
+                    warnings.append(f"EXPIRED in {p['location']} (exp {p['expiry_date']})")
+                elif p["expiring_soon"]:
+                    warnings.append(f"expiring soon in {p['location']} (exp {p['expiry_date']})")
+        return warnings
+
+    results = []
+
+    # Check meta-recipes
+    for meta in MetaRecipe.objects.prefetch_related(
+        "slots__options__ingredient", "base_ingredients__ingredient"
+    ).all():
+        recipe_result = {
+            "type": "meta_recipe",
+            "id": meta.id,
+            "name": meta.name,
+            "slots": [],
+            "base_missing": [],
+            "warnings": [],
+            "feasible": True,
+        }
+
+        # Check base ingredients
+        for base in meta.base_ingredients.all():
+            needed = base.quantity_per_serving * servings
+            available = get_pantry_total(base.ingredient_id)
+            warnings = get_pantry_warnings(base.ingredient_id)
+
+            if available < needed:
+                if base.ingredient.is_staple_ingredient:
+                    # Staples like oil/salt — assume always available even if tracking says 0
+                    pass
+                else:
+                    recipe_result["base_missing"].append({
+                        "ingredient": base.ingredient.name,
+                        "needed": f"{needed} {base.unit}",
+                        "have": f"{available} {base.unit}" if available > 0 else "none",
+                    })
+            if warnings:
+                recipe_result["warnings"].extend(
+                    [f"{base.ingredient.name}: {w}" for w in warnings]
+                )
+
+        # Check each slot
+        for slot in meta.slots.all():
+            slot_result = {
+                "name": slot.name,
+                "required": slot.required,
+                "max_choices": slot.max_choices,
+                "available_options": [],
+                "missing_options": [],
+            }
+
+            for option in slot.options.all():
+                needed = option.quantity_per_serving * servings
+                available = get_pantry_total(option.ingredient_id)
+                warnings = get_pantry_warnings(option.ingredient_id)
+
+                option_info = {
+                    "ingredient": option.ingredient.name,
+                    "needed": f"{needed} {option.unit}",
+                    "have": f"{available} {option.unit}",
+                    "notes": option.notes,
+                }
+
+                if warnings:
+                    option_info["warnings"] = warnings
+
+                if available >= needed:
+                    slot_result["available_options"].append(option_info)
+                else:
+                    slot_result["missing_options"].append(option_info)
+
+            # Is this slot satisfied?
+            if slot.required and not slot_result["available_options"]:
+                recipe_result["feasible"] = False
+
+            recipe_result["slots"].append(slot_result)
+
+        # Determine status
+        if recipe_result["feasible"] and not recipe_result["base_missing"]:
+            recipe_result["status"] = "ready"
+            recipe_result["emoji"] = "✅"
+        elif recipe_result["feasible"]:
+            recipe_result["status"] = "partial"
+            recipe_result["emoji"] = "⚠️"
+        else:
+            recipe_result["status"] = "missing"
+            recipe_result["emoji"] = "❌"
+
+        results.append(recipe_result)
+
+    # Check fixed recipes
+    for recipe in Recipe.objects.prefetch_related("ingredients__ingredient").all():
+        recipe_result = {
+            "type": "recipe",
+            "id": recipe.id,
+            "name": recipe.name,
+            "missing": [],
+            "warnings": [],
+            "feasible": True,
+        }
+
+        for ri in recipe.ingredients.all():
+            needed = ri.quantity * (servings / recipe.servings)
+            available = get_pantry_total(ri.ingredient_id)
+            warnings = get_pantry_warnings(ri.ingredient_id)
+
+            if available < needed and not ri.optional:
+                recipe_result["feasible"] = False
+                recipe_result["missing"].append({
+                    "ingredient": ri.ingredient.name,
+                    "needed": f"{needed} {ri.unit}",
+                    "have": f"{available} {ri.unit}" if available > 0 else "none",
+                })
+
+            if warnings:
+                recipe_result["warnings"].extend(
+                    [f"{ri.ingredient.name}: {w}" for w in warnings]
+                )
+
+        recipe_result["status"] = "ready" if recipe_result["feasible"] else "missing"
+        recipe_result["emoji"] = "✅" if recipe_result["feasible"] else "❌"
+        results.append(recipe_result)
+
+    # Sort: ready first, then partial, then missing
+    order = {"ready": 0, "partial": 1, "missing": 2}
+    results.sort(key=lambda r: order.get(r["status"], 3))
+
+    return Response({
+        "servings": servings,
+        "pantry_items": PantryItem.objects.filter(quantity__gt=0).count(),
+        "results": results,
+    })
+
+
+@api_view(["POST"])
+@permission_classes([IsAuthenticated])
+def log_cook(request):
+    """
+    Log a meal that was cooked. Optionally deducts ingredients from pantry.
+    
+    Body:
+    {
+        "meta_recipe_id": 1,          // or "recipe_id": 1
+        "slot_choices": {"protein": "pork mince", "carb": "egg noodles"},
+        "servings": 2,
+        "notes": "added extra garlic",
+        "deduct": true                // auto-deduct from pantry
+    }
+    """
+    meta_recipe_id = request.data.get("meta_recipe_id")
+    recipe_id = request.data.get("recipe_id")
+    slot_choices = request.data.get("slot_choices", {})
+    servings = int(request.data.get("servings", 2))
+    notes = request.data.get("notes", "")
+    deduct = request.data.get("deduct", False)
+
+    if not meta_recipe_id and not recipe_id:
+        return Response(
+            {"error": "Must provide meta_recipe_id or recipe_id"},
+            status=status.HTTP_400_BAD_REQUEST,
+        )
+
+    # Create cook log
+    log = CookLog.objects.create(
+        meta_recipe_id=meta_recipe_id,
+        recipe_id=recipe_id,
+        slot_choices=slot_choices,
+        servings=servings,
+        notes=notes,
+    )
+
+    deducted = []
+
+    if deduct and meta_recipe_id:
+        meta = MetaRecipe.objects.prefetch_related(
+            "slots__options__ingredient", "base_ingredients__ingredient"
+        ).get(id=meta_recipe_id)
+
+        # Deduct base ingredients
+        for base in meta.base_ingredients.all():
+            amount = base.quantity_per_serving * servings
+            deducted += _deduct_ingredient(base.ingredient, amount, base.unit)
+
+        # Deduct slot choices
+        for slot_name, ingredient_name in slot_choices.items():
+            try:
+                slot = meta.slots.get(name=slot_name)
+                option = slot.options.get(ingredient__name=ingredient_name)
+                amount = option.quantity_per_serving * servings
+                deducted += _deduct_ingredient(option.ingredient, amount, option.unit)
+            except (Slot.DoesNotExist, SlotOption.DoesNotExist):
+                pass
+
+    elif deduct and recipe_id:
+        recipe = Recipe.objects.prefetch_related("ingredients__ingredient").get(id=recipe_id)
+        for ri in recipe.ingredients.all():
+            amount = ri.quantity * (servings / recipe.servings)
+            deducted += _deduct_ingredient(ri.ingredient, amount, ri.unit)
+
+    return Response({
+        "cook_log_id": log.id,
+        "deducted": deducted,
+    }, status=status.HTTP_201_CREATED)
+
+
+def _deduct_ingredient(ingredient, amount, unit):
+    """Deduct an amount from pantry, preferring fridge items first (use oldest first)."""
+    remaining = Decimal(str(amount))
+    deducted = []
+
+    # Prefer fridge (expires first), then cupboard, then freezer
+    items = PantryItem.objects.filter(
+        ingredient=ingredient, quantity__gt=0
+    ).order_by(
+        # Fridge first, then cupboard, then freezer
+        # Within same location, earliest expiry first
+        "expiry_date",
+    )
+
+    for item in items:
+        if remaining <= 0:
+            break
+
+        take = min(item.quantity, remaining)
+        item.quantity -= take
+        item.save(update_fields=["quantity"])
+        remaining -= take
+
+        deducted.append({
+            "ingredient": ingredient.name,
+            "amount": str(take),
+            "unit": unit,
+            "from": item.location,
+            "remaining_in_pantry": str(item.quantity),
+        })
+
+    return deducted