feat(db): add database repositories

src/database/customer.database.repository.ts

@@ -0,0 +1,36 @@
+import { Injectable } from '@nestjs/common';
+import { PrismaService } from '../../prisma/prisma.service';
+import { Customer } from '../../prisma/generated/client';
+import { CustomerCreateInput } from '../../prisma/generated/models/Customer';
+
+/** Database access to customers. Rows are matched with Hiboutik by `hiboutikId`. */
+@Injectable()
+export class CustomerDatabaseRepository {
+  constructor(private readonly prisma: PrismaService) {}
+
+  async getAll(): Promise<Customer[]> {
+    return this.prisma.customer.findMany({
+      orderBy: { hiboutikId: 'asc' },
+    });
+  }
+
+  /** Creates or updates the customer with the same `hiboutikId`. */
+  async upsert(customer: CustomerCreateInput): Promise<Customer> {
+    return this.prisma.customer.upsert({
+      where: { hiboutikId: customer.hiboutikId },
+      create: customer,
+      update: customer,
+    });
+  }
+
+  /**
+   * Deletes the customers that no longer exist in Hiboutik.
+   * Their addresses are deleted (onDelete: Cascade), their orders are kept with no customer (onDelete: SetNull).
+   */
+  async deleteMissing(keptHiboutikIds: number[]): Promise<number> {
+    const result = await this.prisma.customer.deleteMany({
+      where: { hiboutikId: { notIn: keptHiboutikIds } },
+    });
+    return result.count;
+  }
+}