feat: add Binance Pay webhook handler and implement payment order creation in billing service

apps/api/src/billing/providers/binance.provider.ts

@@ -1,33 +1,115 @@
-import { Injectable, Logger } from '@nestjs/common';
+import { Injectable, Logger, InternalServerErrorException } from '@nestjs/common';
 import { ConfigService } from '@nestjs/config';
+import axios from 'axios';
+import * as crypto from 'crypto';
 
 @Injectable()
 export class BinanceProvider {
   private readonly logger = new Logger(BinanceProvider.name);
+  private readonly apiUrl = 'https://bpay.binanceapi.com/binancepay/openapi/v2/order';
 
   constructor(private configService: ConfigService) {}
 
-  /**
-   * Mock Binance Pay Order Creation
-   * Will lead to a success/fail redirect for testing
-   */
-  async createOrder(tenantId: string, amount: number, plan: string) {
-    this.logger.log(`[Mock] Creating Binance Pay order for ${tenantId} - ${plan}`);
-    
-    // In production, this calls https://bpay.binanceapi.com/binancepay/openapi/v2/order
-    // and returns a checkoutUrl.
-    
-    return {
-      checkoutUrl: `https://map-dashbord.intaleqapp.com/api/billing/mock-binance-success?tenantId=${tenantId}&plan=${plan}`,
-      prepayId: `mock_${Date.now()}`
-    };
+  private get apiKey(): string {
+    return this.configService.get<string>('BINANCE_PAY_API_KEY');
+  }
+
+  private get secretKey(): string {
+    return this.configService.get<string>('BINANCE_PAY_SECRET_KEY');
   }
 
   /**
-   * Mock Webhook Signature Verification
+   * Create the Binance Pay Signature
    */
-  verifySignature(payload: any, signature: string): boolean {
-    // In production, uses HMAC-SHA512 with Binance Secret Key
-    return true; 
+  private generateSignature(timestamp: string, nonce: string, body: any): string {
+    const payload = timestamp + '\n' + nonce + '\n' + JSON.stringify(body) + '\n';
+    return crypto
+      .createHmac('sha512', this.secretKey)
+      .update(payload)
+      .digest('hex')
+      .toUpperCase();
+  }
+
+  /**
+   * Create a Binance Pay Order
+   */
+  async createOrder(tenantId: string, amount: number, plan: string) {
+    this.logger.log(`Creating Binance Pay order for ${tenantId} - ${plan}`);
+
+    if (!this.apiKey || !this.secretKey) {
+      this.logger.error('Binance Pay API keys are not configured');
+      throw new InternalServerErrorException('Payment provider is not configured properly');
+    }
+
+    const nonce = crypto.randomBytes(16).toString('hex');
+    const timestamp = Date.now().toString();
+    const merchantTradeNo = `txn_${Date.now()}_${Math.floor(Math.random() * 10000)}`;
+
+    const body = {
+      env: {
+        terminalType: 'WEB',
+      },
+      merchantTradeNo: merchantTradeNo,
+      orderAmount: amount,
+      currency: 'USDT',
+      goods: {
+        goodsType: '01',
+        goodsCategory: 'Z000',
+        referenceGoodsId: plan,
+        goodsName: `${plan} Plan Subscription`,
+        goodsDetail: `Subscription to ${plan} plan for Maps SaaS`,
+      },
+      passThroughInfo: JSON.stringify({ tenantId, plan }),
+      returnUrl: `https://map-dashboard.intaleqapp.com/dashboard.html#billing`,
+    };
+
+    const signature = this.generateSignature(timestamp, nonce, body);
+
+    try {
+      const response = await axios.post(this.apiUrl, body, {
+        headers: {
+          'Content-Type': 'application/json',
+          'BinancePay-Timestamp': timestamp,
+          'BinancePay-Nonce': nonce,
+          'BinancePay-Certificate-SN': this.apiKey,
+          'BinancePay-Signature': signature,
+        },
+      });
+
+      if (response.data && response.data.status === 'SUCCESS') {
+        return {
+          checkoutUrl: response.data.data.checkoutUrl,
+          orderId: merchantTradeNo,
+          prepayId: response.data.data.prepayId,
+        };
+      } else {
+        this.logger.error(`Binance API Error: ${JSON.stringify(response.data)}`);
+        throw new InternalServerErrorException('Failed to create Binance order');
+      }
+    } catch (error: any) {
+      this.logger.error(`Error communicating with Binance API: ${error.message}`);
+      throw new InternalServerErrorException('Failed to communicate with payment provider');
+    }
+  }
+
+  /**
+   * Verify Webhook Signature
+   */
+  verifySignature(timestamp: string, nonce: string, signature: string, payloadBody: any): boolean {
+    const payload = timestamp + '\n' + nonce + '\n' + JSON.stringify(payloadBody) + '\n';
+    const expectedSignature = crypto
+      .createHmac('sha512', this.secretKey)
+      .update(payload)
+      .digest('hex')
+      .toUpperCase();
+
+    try {
+        return crypto.timingSafeEqual(
+            Buffer.from(signature || ''), 
+            Buffer.from(expectedSignature)
+        );
+    } catch (e) {
+        return false;
+    }
   }
 }