feat: implement meal planning feature with CRUD operations and UI integration

backend/src/meal-plan/meal-plan.service.ts

@@ -0,0 +1,80 @@
+import { Injectable, NotFoundException } from '@nestjs/common';
+import { PrismaService } from '../prisma/prisma.service';
+import { CreateMealPlanEntryDto } from './dto/create-meal-plan-entry.dto';
+
+const recipeSelect = {
+  id: true,
+  name: true,
+  imageUrl: true,
+  ingredients: {
+    select: {
+      quantity: true,
+      unit: true,
+      note: true,
+      product: { select: { id: true, name: true, canonicalName: true } },
+    },
+  },
+};
+
+@Injectable()
+export class MealPlanService {
+  constructor(private readonly prisma: PrismaService) {}
+
+  /** Hämta matplan för ett datumintervall (default: nuvarande vecka) */
+  async findByRange(from: string, to: string) {
+    return this.prisma.mealPlanEntry.findMany({
+      where: {
+        date: { gte: new Date(from), lte: new Date(to) },
+      },
+      include: { recipe: { select: recipeSelect } },
+      orderBy: { date: 'asc' },
+    });
+  }
+
+  /** Sätt recept för ett datum (upsert — ett recept per dag) */
+  async upsert(dto: CreateMealPlanEntryDto) {
+    const date = new Date(dto.date);
+    return this.prisma.mealPlanEntry.upsert({
+      where: { date },
+      create: { date, recipeId: dto.recipeId },
+      update: { recipeId: dto.recipeId },
+      include: { recipe: { select: recipeSelect } },
+    });
+  }
+
+  /** Ta bort matplanspost för ett datum */
+  async removeByDate(date: string) {
+    const entry = await this.prisma.mealPlanEntry.findUnique({
+      where: { date: new Date(date) },
+    });
+    if (!entry) throw new NotFoundException('Ingen matplanspost för detta datum');
+    return this.prisma.mealPlanEntry.delete({ where: { id: entry.id } });
+  }
+
+  /** Samlad ingredienslista för ett datumintervall */
+  async shoppingList(from: string, to: string) {
+    const entries = await this.findByRange(from, to);
+
+    // Summera ingredienser per produkt+enhet
+    const map = new Map<string, { productId: number; name: string; quantity: number; unit: string }>();
+    for (const entry of entries) {
+      for (const ing of entry.recipe.ingredients) {
+        const key = `${ing.product.id}-${ing.unit}`;
+        const existing = map.get(key);
+        const qty = Number(ing.quantity);
+        if (existing) {
+          existing.quantity += qty;
+        } else {
+          map.set(key, {
+            productId: ing.product.id,
+            name: ing.product.canonicalName || ing.product.name,
+            quantity: qty,
+            unit: ing.unit,
+          });
+        }
+      }
+    }
+
+    return Array.from(map.values()).sort((a, b) => a.name.localeCompare(b.name, 'sv'));
+  }
+}