feat(backend): Abfuellungen und Produkte (Modul 23)

ProductsModule (GET/POST /products, GET/PATCH /products/:id) und
BottlingModule (GET/POST /bottling-batches) mit transaktionaler
Reduzierung der HoneyBatch-Restmenge beim Abfuellen; Ablehnung bei
Abfuellmenge > verfuegbarer Menge. Neue Prisma-Modelle Product und
BottlingBatch (Migration bottling_products).

ApiCore-Backend/src/bottling/bottling.service.ts

@@ -0,0 +1,108 @@
+import {
+  BadRequestException,
+  Injectable,
+  NotFoundException,
+} from '@nestjs/common';
+import { PrismaService } from '../prisma/prisma.service';
+import { AuditLogService } from '../audit/audit-log.service';
+import { BottlingBatch } from '../../generated/prisma';
+import { CreateBottlingBatchDto } from './dto/create-bottling-batch.dto';
+
+const bottlingBatchInclude = {
+  honeyBatch: true,
+  product: true,
+} as const;
+
+export interface BottlingBatchFilter {
+  honeyBatchId?: string;
+}
+
+@Injectable()
+export class BottlingService {
+  constructor(
+    private readonly prisma: PrismaService,
+    private readonly auditLog: AuditLogService,
+  ) {}
+
+  async findAll(filter: BottlingBatchFilter = {}) {
+    return this.prisma.bottlingBatch.findMany({
+      where: { honeyBatchId: filter.honeyBatchId },
+      include: bottlingBatchInclude,
+      orderBy: { date: 'desc' },
+    });
+  }
+
+  async findById(id: string) {
+    const bottlingBatch = await this.prisma.bottlingBatch.findUnique({
+      where: { id },
+      include: bottlingBatchInclude,
+    });
+    if (!bottlingBatch) {
+      throw new NotFoundException('Bottling batch not found');
+    }
+    return bottlingBatch;
+  }
+
+  async create(dto: CreateBottlingBatchDto, actingUserId: string) {
+    const honeyBatch = await this.prisma.honeyBatch.findUnique({
+      where: { id: dto.honeyBatchId },
+    });
+    if (!honeyBatch) {
+      throw new NotFoundException('Honey batch not found');
+    }
+    if (dto.productId) {
+      const product = await this.prisma.product.findUnique({
+        where: { id: dto.productId },
+      });
+      if (!product) {
+        throw new NotFoundException('Product not found');
+      }
+    }
+
+    const totalAmount = (dto.jarSize * dto.jarCount) / 1000;
+    if (honeyBatch.amount !== null && totalAmount > honeyBatch.amount) {
+      throw new BadRequestException(
+        'Abfüllmenge übersteigt die verfügbare Menge der Honigcharge',
+      );
+    }
+
+    const bottlingBatch: BottlingBatch = await this.prisma.$transaction(
+      async (tx) => {
+        const created = await tx.bottlingBatch.create({
+          data: {
+            honeyBatchId: dto.honeyBatchId,
+            productId: dto.productId,
+            date: new Date(dto.date),
+            jarSize: dto.jarSize,
+            jarCount: dto.jarCount,
+            totalAmount,
+            bestBeforeDate: new Date(dto.bestBeforeDate),
+            lotNumber: dto.lotNumber,
+            userId: actingUserId,
+          },
+        });
+        await tx.honeyBatch.update({
+          where: { id: dto.honeyBatchId },
+          data: {
+            amount:
+              honeyBatch.amount !== null
+                ? honeyBatch.amount - totalAmount
+                : null,
+            status: 'BOTTLED',
+          },
+        });
+        return created;
+      },
+    );
+
+    await this.auditLog.record({
+      entityType: 'BottlingBatch',
+      entityId: bottlingBatch.id,
+      action: 'CREATE',
+      userId: actingUserId,
+      afterData: bottlingBatch,
+    });
+
+    return this.findById(bottlingBatch.id);
+  }
+}