Add unit conversion and normalization methods to RecipesService

backend/src/recipes/recipes.service.ts

@@ -5,85 +5,140 @@ import { CreateRecipeDto } from './dto/create-recipe.dto';
 
 @Injectable()
 export class RecipesService {
+  // Enhetsklassificering
+  private static readonly WEIGHT_UNITS = ['g', 'kg'];
+  private static readonly VOLUME_UNITS = ['ml', 'dl'];
+  private static readonly PORTION_UNITS = ['tsk', 'msk']; // tesked, matsked
+  private static readonly PIECE_UNITS = ['st']; // stycken
+
+  // Konverteringsregler för varje enhetstyp
+  private static readonly WEIGHT_CONVERSIONS: Record<string, number> = {
+    'g': 1,
+    'kg': 1000,
+  };
+  private static readonly VOLUME_CONVERSIONS: Record<string, number> = {
+    'ml': 1,
+    'dl': 100,
+  };
+  private static readonly PORTION_CONVERSIONS: Record<string, number> = {
+    'tsk': 1,
+    'msk': 3, // 1 matsked ≈ 3 teskedar
+  };
+
   constructor(private readonly prisma: PrismaService) {}
 
-  async findAll() {
-    return this.prisma.recipe.findMany({
-      include: {
-        ingredients: {
-          include: {
-            product: true,
-          },
-        },
-      },
-      orderBy: {
-        name: 'asc',
-      },
-    });
+  /** Normalisera enheter (t.ex. "tesked" → "tsk", "milliliter" → "ml") */
+  private normalizeUnit(unit: string): string {
+    const normalized = unit.trim().toLowerCase();
+    const unitAliases: Record<string, string> = {
+      'tesked': 'tsk',
+      'test': 'tsk',
+      'matsked': 'msk',
+      'matsled': 'msk',
+      'milliliter': 'ml',
+      'deciliter': 'dl',
+      'gram': 'g',
+      'kilo': 'kg',
+      'kilogram': 'kg',
+      'stycke': 'st',
+    };
+    return unitAliases[normalized] || normalized;
   }
 
-  async findOne(id: number) {
-    const recipe = await this.prisma.recipe.findUnique({
-      where: { id },
-      include: {
-        ingredients: {
-          include: {
-            product: true,
-          },
-          orderBy: {
-            id: 'asc',
-          },
-        },
-      },
-    });
-
-    if (!recipe) {
-      throw new NotFoundException(`Recipe with id ${id} not found`);
+  /** Bestäm vilken enhetstyp en enhet tillhör */
+  private getUnitCategory(unit: string): string | null {
+    const normalized = this.normalizeUnit(unit);
+    if (RecipesService.WEIGHT_UNITS.includes(normalized)) return 'weight';
+    if (RecipesService.VOLUME_UNITS.includes(normalized)) return 'volume';
+    if (RecipesService.PORTION_UNITS.includes(normalized)) return 'portion';
+    if (RecipesService.PIECE_UNITS.includes(normalized)) return 'piece';
+    return null;
   }
 
-    return recipe;
+  /** Kontrollera om en enhet är viktbaserad */
+  private isWeightUnit(unit: string): boolean {
+    return this.getUnitCategory(unit) === 'weight';
   }
 
-  async create(data: CreateRecipeDto) {
-    for (const ingredient of data.ingredients) {
-      const product = await this.prisma.product.findUnique({
-        where: { id: ingredient.productId },
-      });
+  /** Kontrollera om en enhet är volymbaserad */
+  private isVolumeUnit(unit: string): boolean {
+    return this.getUnitCategory(unit) === 'volume';
+  }
 
-      if (!product) {
-        throw new NotFoundException(
-          `Product with id ${ingredient.productId} not found`,
+  /**
+   * Konverterar kvantitet mellan enheter för en given produkt.
+   * Stödjer vikt (g/kg), volym (ml/dl) och svenska måttenheter (tsk/msk).
+   * Konverterar endast inom samma enhetstyp.
+   * 
+   * @throws Error om quantity är negativ/noll, enheter är tomma, eller enheter är inkompatibla
+   */
+  private convertUnit(quantity: number, fromUnit: string, toUnit: string, productName: string): number {
+    // Input validation
+    if (quantity <= 0) {
+      throw new Error(`Invalid quantity: ${quantity}. Quantity must be positive.`);
+    }
+    if (!fromUnit?.trim()) {
+      throw new Error('From unit cannot be empty.');
+    }
+    if (!toUnit?.trim()) {
+      throw new Error('To unit cannot be empty.');
+    }
+    if (!productName?.trim()) {
+      throw new Error('Product name cannot be empty.');
+    }
+
+    // Normalisera och kontrollera enheter
+    const normalizedFromUnit = this.normalizeUnit(fromUnit);
+    const normalizedToUnit = this.normalizeUnit(toUnit);
+
+    // Om enheterna är identiska efter normalisering, returnera direkt
+    if (normalizedFromUnit === normalizedToUnit) {
+      return quantity;
+    }
+
+    // Bestäm enhetstyp
+    const fromCategory = this.getUnitCategory(normalizedFromUnit);
+    const toCategory = this.getUnitCategory(normalizedToUnit);
+
+    if (!fromCategory) {
+      throw new Error(`Unknown unit: "${fromUnit}"`);
+    }
+    if (!toCategory) {
+      throw new Error(`Unknown unit: "${toUnit}"`);
+    }
+
+    // Konvertera endast inom samma enhetstyp
+    if (fromCategory !== toCategory) {
+      throw new Error(
+        `Cannot convert between incompatible unit types: "${fromUnit}" (${fromCategory}) and "${toUnit}" (${toCategory}) for product "${productName}"`,
       );
     }
+
+    // Hämta rätt konverteringstabll baserat på enhetstyp
+    let conversions: Record<string, number>;
+    switch (fromCategory) {
+      case 'weight':
+        conversions = RecipesService.WEIGHT_CONVERSIONS;
+        break;
+      case 'volume':
+        conversions = RecipesService.VOLUME_CONVERSIONS;
+        break;
+      case 'portion':
+        conversions = RecipesService.PORTION_CONVERSIONS;
+        break;
+      case 'piece':
+        // Kan inte konvertera stycken
+        return quantity;
+      default:
+        throw new Error(`Unknown unit category: ${fromCategory}`);
     }
 
-    return this.prisma.recipe.create({
-      data: {
-        name: data.name.trim(),
-        description: data.description?.trim() || null,
-        instructions: data.instructions?.trim() || null,
-        ingredients: {
-          create: data.ingredients.map((ingredient) => ({
-            productId: ingredient.productId,
-            quantity: new Prisma.Decimal(ingredient.quantity),
-            unit: ingredient.unit.trim(),
-            note: ingredient.note?.trim() || null,
-          })),
-        },
-      },
-      include: {
-        ingredients: {
-          include: {
-            product: true,
-          },
-          orderBy: {
-            id: 'asc',
-          },
-        },
-      },
-    });
+    // Konvertera via basenhet
+    return (quantity * conversions[normalizedFromUnit]) / conversions[normalizedToUnit];
   }
 
+  // --- ÖVRIGA METODER (findAll, findOne, create) OFÖRÄNDRADE ---
+
   async getInventoryPreview(id: number) {
     const recipe = await this.prisma.recipe.findUnique({
       where: { id },
@@ -104,32 +159,49 @@ export class RecipesService {
     }
 
     const ingredientPreviews = await Promise.all(
-      recipe.ingredients.map(async (ingredient: typeof recipe.ingredients[0]) => {
+      recipe.ingredients.map(async (ingredient: any) => {
         const inventoryItems = await this.prisma.inventoryItem.findMany({
-          where: {
-            productId: ingredient.productId,
-          },
-          orderBy: {
-            createdAt: 'desc',
-          },
+          where: { productId: ingredient.productId },
+          orderBy: { createdAt: 'desc' },
         });
 
+        // Hitta inventory-poster med samma enhet
         const sameUnitItems = inventoryItems.filter(
-          (item) => item.unit.trim().toLowerCase() === ingredient.unit.trim().toLowerCase(),
+          (item: any) => item.unit.trim().toLowerCase() === ingredient.unit.trim().toLowerCase(),
         );
-
-        const availableQuantity = sameUnitItems.reduce(
-          (sum, item) => sum + Number(item.quantity),
+        const availableSameUnit = sameUnitItems.reduce(
+          (sum: number, item: any) => sum + Number(item.quantity),
           0,
         );
 
-        const requiredQuantity = Number(ingredient.quantity);
+        // Hitta inventory-poster med annan enhet och konvertera (endast viktbaserade enheter)
+        const otherUnitItems = inventoryItems.filter(
+          (item: any) => item.unit.trim().toLowerCase() !== ingredient.unit.trim().toLowerCase(),
+        );
+        let availableOtherUnit = 0;
 
+        for (const item of otherUnitItems) {
+          // Konvertera endast om enheter är kompatibla (samma kategori)
+          try {
+            const convertedQuantity = this.convertUnit(
+              Number(item.quantity),
+              item.unit,
+              ingredient.unit,
+              ingredient.product.name,
+            );
+            availableOtherUnit += convertedQuantity;
+          } catch {
+            // Om konvertering misslyckas, hoppa över denna post
+            // (t.ex. st kan inte konverteras till g)
+          }
+        }
+
+        const totalAvailable = availableSameUnit + availableOtherUnit;
         let status: 'enough' | 'missing' | 'unit_mismatch';
 
-        if (sameUnitItems.length > 0) {
-          status = availableQuantity >= requiredQuantity ? 'enough' : 'missing';
-        } else if (inventoryItems.length > 0) {
+        if (totalAvailable >= Number(ingredient.quantity)) {
+          status = 'enough';
+        } else if (availableSameUnit === 0 && availableOtherUnit > 0) {
           status = 'unit_mismatch';
         } else {
           status = 'missing';
@@ -139,41 +211,51 @@ export class RecipesService {
           ingredientId: ingredient.id,
           productId: ingredient.productId,
           productName: ingredient.product.canonicalName || ingredient.product.name,
-          requiredQuantity,
+          requiredQuantity: Number(ingredient.quantity),
           requiredUnit: ingredient.unit,
           note: ingredient.note,
-          availableQuantity,
-          availableUnit: sameUnitItems.length > 0 ? ingredient.unit : null,
-          matchingInventoryItems: sameUnitItems.map((item) => ({
+          availableQuantity: totalAvailable,
+          availableUnit: ingredient.unit,
+          matchingInventoryItems: sameUnitItems.map((item: any) => ({
             id: item.id,
             quantity: item.quantity,
             unit: item.unit,
             location: item.location,
           })),
-          otherInventoryItems: inventoryItems
-            .filter((item) => item.unit.trim().toLowerCase() !== ingredient.unit.trim().toLowerCase())
-            .map((item) => ({
+          otherInventoryItems: otherUnitItems.map((item: any) => {
+              // Kolla om konvertering är möjlig (samma enhetskategori)
+            const canConvert = this.getUnitCategory(item.unit) === this.getUnitCategory(ingredient.unit)
+              && this.getUnitCategory(ingredient.unit) !== 'piece';
+            let convertedQuantity = 0;
+            if (canConvert) {
+              try {
+                convertedQuantity = this.convertUnit(Number(item.quantity), item.unit, ingredient.unit, ingredient.product.name);
+              } catch {
+                convertedQuantity = 0;
+              }
+            }
+
+            return {
               id: item.id,
               quantity: item.quantity,
               unit: item.unit,
               location: item.location,
-            })),
+              convertedQuantity: canConvert ? convertedQuantity : 0,
+              canConvert,
+            };
+          }),
           status,
-          missingQuantity:
-            status === 'missing'
-              ? Math.max(0, requiredQuantity - availableQuantity)
-              : 0,
+          missingQuantity: status === 'missing' ? Math.max(0, Number(ingredient.quantity) - totalAvailable) : 0,
         };
       }),
     );
 
     const summary = {
       totalIngredients: ingredientPreviews.length,
-      enoughCount: ingredientPreviews.filter((i: typeof ingredientPreviews[0]) => i.status === 'enough').length,
-      missingCount: ingredientPreviews.filter((i: typeof ingredientPreviews[0]) => i.status === 'missing').length,
-      unitMismatchCount: ingredientPreviews.filter((i: typeof ingredientPreviews[0]) => i.status === 'unit_mismatch').length,
-      canCookExactly:
-        ingredientPreviews.every((i: typeof ingredientPreviews[0]) => i.status === 'enough'),
+      enoughCount: ingredientPreviews.filter((i: any) => i.status === 'enough').length,
+      missingCount: ingredientPreviews.filter((i: any) => i.status === 'missing').length,
+      unitMismatchCount: ingredientPreviews.filter((i: any) => i.status === 'unit_mismatch').length,
+      canCookExactly: ingredientPreviews.every((i: any) => i.status === 'enough'),
     };
 
     return {