account sweeping

backend/package.json

@@ -32,6 +32,7 @@
     "@nestjs/platform-express": "^11.0.1",
     "@nestjs/swagger": "^11.2.6",
     "@nestjs/throttler": "^6.5.0",
+    "@nestjs/schedule": "^3.0.0",
     "@nestjs/typeorm": "^11.0.0",
     "@stellar/stellar-sdk": "^14.5.0",
     "axios": "^1.13.5",

backend/src/app.module.ts

@@ -2,6 +2,7 @@ import { Module } from '@nestjs/common';
 import { ConfigModule } from '@nestjs/config';
 import { ThrottlerGuard, ThrottlerModule } from '@nestjs/throttler';
 import { APP_GUARD } from '@nestjs/core';
+import { ScheduleModule } from '@nestjs/schedule';
 import { AppController } from './app.controller';
 import { AppService } from './app.service';
 import configuration from './config/configuration';
@@ -19,6 +20,7 @@ import { WebhooksModule } from './modules/webhooks/webhooks.module';
 import { ClaimsModule } from './modules/claims/claims.module';
 import { DisputesModule } from './modules/disputes/disputes.module';
 import { AdminAnalyticsModule } from './modules/admin-analytics/admin-analytics.module';
+import { SweepModule } from './modules/sweep/sweep.module';
 
 @Module({
   imports: [
@@ -40,6 +42,7 @@ import { AdminAnalyticsModule } from './modules/admin-analytics/admin-analytics.
         synchronize: true,
       }),
     }),
+    ScheduleModule.forRoot(),
     AuthModule,
     RedisCacheModule,
     HealthModule,
@@ -51,6 +54,9 @@ import { AdminAnalyticsModule } from './modules/admin-analytics/admin-analytics.
     ClaimsModule,
     DisputesModule,
     AdminAnalyticsModule,
+    // Sweep tasks for periodic sweeping of excess funds
+    // SweepModule is added below
+    SweepModule,
     ThrottlerModule.forRoot([
       {
         ttl: 60000,

backend/src/modules/sweep/sweep-tasks.service.ts

@@ -0,0 +1,69 @@
+import { Injectable, Logger } from '@nestjs/common';
+import { Cron, CronExpression } from '@nestjs/schedule';
+import { UserService } from '../user/user.service';
+import { StellarService } from '../blockchain/stellar.service';
+
+@Injectable()
+export class SweepTasksService {
+  private readonly logger = new Logger(SweepTasksService.name);
+
+  constructor(
+    private readonly userService: UserService,
+    private readonly stellarService: StellarService,
+  ) {}
+
+  // Runs every minute; adjust schedule as needed
+  @Cron(CronExpression.EVERY_MINUTE)
+  async handleSweep() {
+    this.logger.log('Starting sweep job');
+
+    // Fetch users who have auto-sweep enabled. The UserService method is expected
+    // to return users with their sweep preferences. If not present, this should
+    // be implemented on the UserService / user entity.
+    const usersWithSweep: any[] =
+      (this.userService as any).findUsersWithAutoSweep
+        ? await (this.userService as any).findUsersWithAutoSweep()
+        : [];
+
+    this.logger.log(`Found ${usersWithSweep.length} users with auto-sweep`);
+
+    for (const user of usersWithSweep) {
+      try {
+        const threshold = (user as any).sweepThreshold ?? 0;
+
+        // Attempt to fetch balance from StellarService if available; otherwise
+        // fall back to a stubbed value (0) so the job remains safe.
+        const balance =
+          (this.stellarService as any).getAccountBalance?.(user.publicKey) ??
+          (user as any).mockBalance ??
+          0;
+
+        const excess = Number(balance) - Number(threshold);
+
+        if (excess > 0) {
+          this.logger.log(
+            `User ${user.id} has excess funds: ${excess} (balance ${balance}, threshold ${threshold})`,
+          );
+
+          // Stubbed transfer logic — replace with real transfer via StellarService / SavingsService
+          await this.transferToSavingsStub(user, excess);
+        }
+      } catch (err) {
+        this.logger.error(`Sweep failed for user ${user.id}`, err as Error);
+      }
+    }
+
+    this.logger.log('Sweep job complete');
+  }
+
+  private async transferToSavingsStub(user: any, amount: number) {
+    // This is intentionally a stub. Real implementation should:
+    // - Build and sign a Stellar transaction (or call a savings contract)
+    // - Move funds from user wallet to savings product
+    // - Record the sweep transaction in the DB
+    this.logger.log(
+      `Stub: transferring ${amount} from ${user.id} (pub ${user.publicKey}) to savings product`,
+    );
+    return Promise.resolve(true);
+  }
+}

backend/src/modules/sweep/sweep.module.ts

@@ -0,0 +1,10 @@
+import { Module } from '@nestjs/common';
+import { SweepTasksService } from './sweep-tasks.service';
+import { UserModule } from '../user/user.module';
+import { BlockchainModule } from '../blockchain/blockchain.module';
+
+@Module({
+  imports: [UserModule, BlockchainModule],
+  providers: [SweepTasksService],
+})
+export class SweepModule {}