import { Injectable } from '@nestjs/common';
import { ConfigService } from '@nestjs/config';
import Stripe from 'stripe';

@Injectable()
export class StripeService {
  private stripe: Stripe;

  constructor(private configService: ConfigService) {
    this.stripe = new Stripe(this.configService.get<string>('STRIPE_SECRET_KEY')!, {
      apiVersion: '2023-10-16',
    });
  }

  getClient(): Stripe {
    return this.stripe;
  }

  async createCustomer(email: string, name?: string): Promise<Stripe.Customer> {
    return this.stripe.customers.create({
      email,
      name: name || undefined,
    });
  }

  async createCheckoutSession(params: {
    customerId: string;
    priceId: string;
    successUrl: string;
    cancelUrl: string;
    metadata?: Record<string, string>;
  }): Promise<Stripe.Checkout.Session> {
    return this.stripe.checkout.sessions.create({
      customer: params.customerId,
      mode: 'subscription',
      line_items: [
        {
          price: params.priceId,
          quantity: 1,
        },
      ],
      success_url: params.successUrl,
      cancel_url: params.cancelUrl,
      metadata: params.metadata,
    });
  }

  async createOneTimeCheckoutSession(params: {
    customerId: string;
    successUrl: string;
    cancelUrl: string;
    metadata?: Record<string, string>;
    currency: string;
    unitAmount: number;
    productName: string;
    productDescription?: string;
  }): Promise<Stripe.Checkout.Session> {
    return this.stripe.checkout.sessions.create({
      customer: params.customerId,
      mode: 'payment',
      line_items: [
        {
          price_data: {
            currency: params.currency.toLowerCase(),
            unit_amount: params.unitAmount,
            product_data: {
              name: params.productName,
              description: params.productDescription,
            },
          },
          quantity: 1,
        },
      ],
      success_url: params.successUrl,
      cancel_url: params.cancelUrl,
      metadata: params.metadata,
    });
  }

  async createPortalSession(customerId: string, returnUrl: string): Promise<Stripe.BillingPortal.Session> {
    return this.stripe.billingPortal.sessions.create({
      customer: customerId,
      return_url: returnUrl,
    });
  }

  async getSubscription(subscriptionId: string): Promise<Stripe.Subscription> {
    return this.stripe.subscriptions.retrieve(subscriptionId);
  }

  async cancelSubscription(subscriptionId: string): Promise<Stripe.Subscription> {
    return this.stripe.subscriptions.update(subscriptionId, {
      cancel_at_period_end: true,
    });
  }

  constructWebhookEvent(payload: Buffer, signature: string): Stripe.Event {
    const webhookSecret = this.configService.get<string>('STRIPE_WEBHOOK_SECRET')!;
    return this.stripe.webhooks.constructEvent(payload, signature, webhookSecret);
  }
}