fix: Backend: Implement environment configuration and validation

packages/payments-engine/src/config/config.module.ts

@@ -0,0 +1,18 @@
+import { Module } from '@nestjs/common';
+import { ConfigModule } from '@nestjs/config';
+import { envValidationSchema } from './env.validation';
+
+@Module({
+  imports: [
+    ConfigModule.forRoot({
+      isGlobal: true,
+      validationSchema: envValidationSchema,
+      validationOptions: {
+        abortEarly: true,
+        allowUnknown: true,
+      },
+    }),
+  ],
+  exports: [ConfigModule],
+})
+export class AppConfigModule {}

packages/payments-engine/src/config/env.validation.ts

@@ -0,0 +1,11 @@
+import * as Joi from 'joi';
+
+export const envValidationSchema = Joi.object({
+  DATABASE_URL: Joi.string().uri().required(),
+  JWT_SECRET: Joi.string().min(16).required(),
+  TREASURY_PRIVATE_KEY: Joi.string().required(),
+  STELLAR_RPC_URL: Joi.string().uri().required(),
+  BTC_NODE_URL: Joi.string().uri().required(),
+  ETH_NODE_URL: Joi.string().uri().required(),
+  REDIS_URL: Joi.string().uri().required(),
+});

packages/payments-engine/src/index.ts

@@ -1 +1,14 @@
-export * from './stellar.service';
+import { Module } from '@nestjs/common';
+import { AppConfigModule } from './config/config.module';
+import { StellarService } from './stellar.service';
+// ... other imports
+
+@Module({
+  imports: [
+    AppConfigModule,
+    // ... other modules
+  ],
+  providers: [StellarService],
+  // ...
+})
+export class PaymentsEngineModule {}

packages/payments-engine/src/stellar.service.ts

@@ -1,56 +1,19 @@
-import * as StellarSdk from 'stellar-sdk';
+import { Injectable } from '@nestjs/common';
+import { ConfigService } from '@nestjs/config';
 
+@Injectable()
 export class StellarService {
-  private server: StellarSdk.Horizon.Server;
-  private sourceKeypair!: StellarSdk.Keypair;
-
-  constructor() {
-    // Default to testnet if not explicitly set
-    const networkUrl = process.env.STELLAR_NETWORK_URL || 'https://horizon-testnet.stellar.org';
-    this.server = new StellarSdk.Horizon.Server(networkUrl);
-
-    // In production, this must be securely injected
-    const secret =
-      process.env.STELLAR_STORAGE_SECRET ||
-      'SAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA'; // Replace with a valid testnet secret for local dev
-
-    try {
-      this.sourceKeypair = StellarSdk.Keypair.fromSecret(secret);
-    } catch {
-      console.warn('Invalid STELLAR_STORAGE_SECRET. Stellar operations will fail.');
-    }
+  constructor(private configService: ConfigService) {
+    // validation at startup ensures all required env vars are present
   }
 
-  /**
-   * Sends funds from the operational storage to a destination address
-   */
-  async sendFunds(destinationAddress: string, amount: string): Promise<string> {
-    try {
-      const sourceAccount = await this.server.loadAccount(this.sourceKeypair.publicKey());
-
-      const transaction = new StellarSdk.TransactionBuilder(sourceAccount, {
-        fee: StellarSdk.BASE_FEE,
-        networkPassphrase: process.env.STELLAR_NETWORK_URL?.includes('public')
-          ? StellarSdk.Networks.PUBLIC
-          : StellarSdk.Networks.TESTNET,
-      })
-        .addOperation(
-          StellarSdk.Operation.payment({
-            destination: destinationAddress,
-            asset: StellarSdk.Asset.native(),
-            amount: amount,
-          }),
-        )
-        .setTimeout(30)
-        .build();
-
-      transaction.sign(this.sourceKeypair);
+  private getStellarRpcUrl(): string {
+    return this.configService.get<string>('STELLAR_RPC_URL');
+  }
 
-      const response = await this.server.submitTransaction(transaction);
-      return response.hash;
-    } catch (error) {
-      console.error('Stellar transaction failed:', error);
-      throw error; // Rethrow to let the worker handle the failure state
-    }
+  private getTreasuryPrivateKey(): string {
+    return this.configService.get<string>('TREASURY_PRIVATE_KEY');
   }
+
+  // Additional methods using ConfigService
 }