// src/modules/payments/payment.service.tsimport Stripe from 'stripe'; const stripe = new Stripe(process.env.STRIPE_SECRET_KEY!); export class PaymentService {  async createCheckout(orderId: string, userId: string) {    const order = await prisma.order.findFirst({      where: { id: orderId, userId, status: 'PENDING' },      include: { items: true },    });     if (!order) throw new AppError('Order not found', 404);     const session = await stripe.checkout.sessions.create({      payment_method_types: ['card'],      mode: 'payment',      client_reference_id: order.id,      line_items: order.items.map(item => ({        price_data: {          currency: 'usd',          product_data: { name: item.name },          unit_amount: Math.round(Number(item.price) * 100),        },        quantity: item.quantity,      })),      success_url: `${process.env.FRONTEND_URL}/orders/${order.id}?success=true`,      cancel_url: `${process.env.FRONTEND_URL}/orders/${order.id}?canceled=true`,    });     return { url: session.url };  }   async handleWebhook(payload: Buffer, signature: string) {    const event = stripe.webhooks.constructEvent(      payload, signature, process.env.STRIPE_WEBHOOK_SECRET!    );     if (event.type === 'checkout.session.completed') {      const session = event.data.object;      await prisma.order.update({        where: { id: session.client_reference_id },        data: { status: 'PAID' },      });    }  }}

export class ReviewService {  async create(data: CreateReviewDTO) {    const hasPurchased = await prisma.orderItem.findFirst({      where: {        productId: data.productId,        order: { userId: data.userId, status: { in: ['PAID', 'DELIVERED'] } },      },    });     if (!hasPurchased) {      throw new AppError('You must purchase to review', 403);    }     return prisma.review.create({ data });  }}

export class AdminService {  async getDashboard() {    const [users, products, orders, revenue] = await Promise.all([      prisma.user.count(),      prisma.product.count({ where: { active: true } }),      prisma.order.count(),      prisma.order.aggregate({        where: { status: { in: ['PAID', 'DELIVERED'] } },        _sum: { total: true },      }),    ]);     return {      stats: { users, products, orders, revenue: revenue._sum.total || 0 },    };  }}