feat(blockchain): cross-chain bridge integration

src/app.module.ts

@@ -82,11 +82,11 @@ import { InsuranceTransaction } from './protection/entities/insurance-transactio
 import { LiquidationEvent } from './protection/entities/liquidation-event.entity';
 import { ProtectionModule } from './protection/protection.module';
 
-// Blockchain Domain — Stellar & Cross-Chain Bridge (issues #381 & #386)
-import { BlockchainModule } from './blockchain/blockchain.module';
+// Blockchain — Cross-Chain Bridge (issue #386)
+import { CrossChainBridgeModule } from './blockchain/cross-chain-bridge.module';
+import { CrossChainBridge } from './blockchain/entities/cross-chain-bridge.entity';
 import { BlockchainTransaction } from './blockchain/entities/blockchain-transaction.entity';
 import { WalletAddress } from './blockchain/entities/wallet-address.entity';
-import { CrossChainBridge } from './blockchain/entities/cross-chain-bridge.entity';
 
 @Module({
   imports: [
@@ -167,10 +167,10 @@ import { CrossChainBridge } from './blockchain/entities/cross-chain-bridge.entit
           InsuranceFundTier,
           InsuranceTransaction,
           LiquidationEvent,
-          // Blockchain — Stellar & Cross-Chain Bridge (issues #381 & #386)
+          // Blockchain — Cross-Chain Bridge (issue #386)
+          CrossChainBridge,
           BlockchainTransaction,
           WalletAddress,
-          CrossChainBridge,
         ],
         synchronize: configService.get<boolean>('DB_SYNCHRONIZE', true),
         logging: configService.get<boolean>('DB_LOGGING', false),
@@ -192,6 +192,8 @@ import { CrossChainBridge } from './blockchain/entities/cross-chain-bridge.entit
     // ── Protection Domain — Insurance Fund (issue #380) ──
     ProtectionModule,
 
+    // ── Blockchain — Cross-Chain Bridge (issue #386) ──
+    CrossChainBridgeModule,
     // ── Blockchain Domain — Stellar & Cross-Chain Bridge (issues #381 & #386) ──
     BlockchainModule,
 

src/blockchain/blockchain.module.ts

@@ -2,22 +2,11 @@ import { Module } from '@nestjs/common';
 import { TypeOrmModule } from '@nestjs/typeorm';
 import { BlockchainTransaction } from './entities/blockchain-transaction.entity';
 import { WalletAddress } from './entities/wallet-address.entity';
-import { CrossChainBridge } from './entities/cross-chain-bridge.entity';
 import { StellarService } from './services/stellar.service';
-import { EthereumService } from './services/ethereum.service';
-import { CrossChainBridgeService } from './services/cross-chain-bridge.service';
-import { BlockchainController } from './blockchain.controller';
 
 @Module({
-  imports: [
-    TypeOrmModule.forFeature([
-      BlockchainTransaction,
-      WalletAddress,
-      CrossChainBridge,
-    ]),
-  ],
-  controllers: [BlockchainController],
-  providers: [StellarService, EthereumService, CrossChainBridgeService],
-  exports: [StellarService, EthereumService, CrossChainBridgeService],
+  imports: [TypeOrmModule.forFeature([BlockchainTransaction, WalletAddress])],
+  providers: [StellarService],
+  exports: [StellarService],
 })
 export class BlockchainModule {}

src/blockchain/cross-chain-bridge.controller.ts

@@ -0,0 +1,50 @@
+import { Controller, Post, Get, Body, Param, Request, UseGuards } from '@nestjs/common';
+import { ApiTags, ApiOperation, ApiBearerAuth } from '@nestjs/swagger';
+import { JwtAuthGuard } from '../auth/guards/jwt-auth.guard';
+import { CrossChainBridgeService } from './services/cross-chain-bridge.service';
+import { BridgeTransferDto } from './dto/bridge.dto';
+
+@ApiTags('cross-chain-bridge')
+@ApiBearerAuth()
+@UseGuards(JwtAuthGuard)
+@Controller('bridge')
+export class CrossChainBridgeController {
+  constructor(private readonly bridgeService: CrossChainBridgeService) {}
+
+  @Post()
+  @ApiOperation({ summary: 'Initiate a cross-chain bridge transfer' })
+  async initiateBridge(@Request() req, @Body() dto: BridgeTransferDto) {
+    return this.bridgeService.initiateBridge(
+      req.user.id,
+      dto.sourceNetwork,
+      dto.destinationNetwork,
+      dto.sourceAddress,
+      dto.destinationAddress,
+      dto.amount,
+    );
+  }
+
+  @Post(':id/approve')
+  @ApiOperation({ summary: 'Add a multi-sig approval to a bridge operation' })
+  async approveBridge(@Param('id') id: string) {
+    return this.bridgeService.addApproval(id);
+  }
+
+  @Get('health')
+  @ApiOperation({ summary: 'Check bridge fund health and reserve status' })
+  async bridgeHealth() {
+    return this.bridgeService.getBridgeHealth();
+  }
+
+  @Get('history')
+  @ApiOperation({ summary: 'Get cross-chain bridge history for current user' })
+  async bridgeHistory(@Request() req) {
+    return this.bridgeService.getBridgeHistory(req.user.id);
+  }
+
+  @Get(':id')
+  @ApiOperation({ summary: 'Get bridge transfer status by ID' })
+  async getBridge(@Param('id') id: string) {
+    return this.bridgeService.getBridgeById(id);
+  }
+}

src/blockchain/cross-chain-bridge.module.ts

@@ -0,0 +1,14 @@
+import { Module } from '@nestjs/common';
+import { TypeOrmModule } from '@nestjs/typeorm';
+import { CrossChainBridge } from './entities/cross-chain-bridge.entity';
+import { CrossChainBridgeService } from './services/cross-chain-bridge.service';
+import { CrossChainBridgeController } from './cross-chain-bridge.controller';
+import { BlockchainModule } from './blockchain.module';
+
+@Module({
+  imports: [TypeOrmModule.forFeature([CrossChainBridge]), BlockchainModule],
+  controllers: [CrossChainBridgeController],
+  providers: [CrossChainBridgeService],
+  exports: [CrossChainBridgeService],
+})
+export class CrossChainBridgeModule {}

src/blockchain/dto/bridge.dto.ts

@@ -0,0 +1,27 @@
+import { IsString, IsNotEmpty, IsNumberString, IsEnum } from 'class-validator';
+import { ApiProperty } from '@nestjs/swagger';
+import { BlockchainNetwork } from '../entities/blockchain-transaction.entity';
+
+export class BridgeTransferDto {
+  @ApiProperty({ enum: BlockchainNetwork })
+  @IsEnum(BlockchainNetwork)
+  sourceNetwork: BlockchainNetwork;
+
+  @ApiProperty({ enum: BlockchainNetwork })
+  @IsEnum(BlockchainNetwork)
+  destinationNetwork: BlockchainNetwork;
+
+  @ApiProperty()
+  @IsString()
+  @IsNotEmpty()
+  sourceAddress: string;
+
+  @ApiProperty()
+  @IsString()
+  @IsNotEmpty()
+  destinationAddress: string;
+
+  @ApiProperty({ example: '50.00' })
+  @IsNumberString()
+  amount: string;
+}

src/blockchain/entities/cross-chain-bridge.entity.ts

@@ -6,7 +6,7 @@ import {
   UpdateDateColumn,
   Index,
 } from 'typeorm';
-import { BlockchainNetwork } from './blockchain-transaction.entity';
+import { BlockchainNetwork } from '../../blockchain/entities/blockchain-transaction.entity';
 
 export enum BridgeStatus {
   INITIATED = 'initiated',

src/blockchain/services/cross-chain-bridge.service.ts

@@ -2,17 +2,11 @@ import { Injectable, Logger } from '@nestjs/common';
 import { ConfigService } from '@nestjs/config';
 import { InjectRepository } from '@nestjs/typeorm';
 import { Repository } from 'typeorm';
-import {
-  CrossChainBridge,
-  BridgeStatus,
-} from '../entities/cross-chain-bridge.entity';
-import {
-  BlockchainNetwork,
-} from '../entities/blockchain-transaction.entity';
+import { CrossChainBridge, BridgeStatus } from '../entities/cross-chain-bridge.entity';
+import { BlockchainNetwork } from '../entities/blockchain-transaction.entity';
 import { BlockchainException } from '../../error/exceptions/blockchain.exception';
 import { StellarService } from './stellar.service';
 
-/** Minimum bridge reserve in USDC before an alert is raised */
 const BRIDGE_RESERVE_THRESHOLD = 10_000;
 
 @Injectable()
@@ -29,7 +23,6 @@ export class CrossChainBridgeService {
     this.multisigThreshold = this.configService.get<number>('BRIDGE_MULTISIG_THRESHOLD', 2);
   }
 
-  /** Initiate a cross-chain bridge transfer */
   async initiateBridge(
     userId: string,
     sourceNetwork: BlockchainNetwork,
@@ -53,13 +46,19 @@ export class CrossChainBridgeService {
     return this.bridgeRepo.save(record);
   }
 
-  /** Add a multi-sig approval; executes the bridge once threshold is reached */
   async addApproval(bridgeId: string): Promise<CrossChainBridge> {
     const bridge = await this.bridgeRepo.findOne({ where: { id: bridgeId } });
-    if (!bridge) throw BlockchainException.transactionFailed({ reason: 'Bridge record not found', bridgeId });
-
-    if (bridge.status !== BridgeStatus.INITIATED && bridge.status !== BridgeStatus.SOURCE_CONFIRMED) {
-      throw BlockchainException.transactionFailed({ reason: 'Bridge is not awaiting approvals', bridgeId });
+    if (!bridge)
+      throw BlockchainException.transactionFailed({ reason: 'Bridge record not found', bridgeId });
+
+    if (
+      bridge.status !== BridgeStatus.INITIATED &&
+      bridge.status !== BridgeStatus.SOURCE_CONFIRMED
+    ) {
+      throw BlockchainException.transactionFailed({
+        reason: 'Bridge is not awaiting approvals',
+        bridgeId,
+      });
     }
 
     bridge.multisigApprovals += 1;
@@ -73,7 +72,6 @@ export class CrossChainBridgeService {
     return this.bridgeRepo.save(bridge);
   }
 
-  /** Execute the bridge once multi-sig threshold is met */
   private async executeBridge(bridge: CrossChainBridge): Promise<CrossChainBridge> {
     try {
       bridge.status = BridgeStatus.DESTINATION_PENDING;
@@ -88,8 +86,7 @@ export class CrossChainBridgeService {
         );
         bridge.destinationTxHash = tx.txHash;
       } else {
-        // Ethereum destination: log intent and mark pending
-        // Actual ETH signing requires a hot-wallet signer configured externally
+        // Ethereum destination: log intent and mark pending (hot-wallet signer external)
         this.logger.log(
           `Bridge ${bridge.id}: ETH destination tx queued for ${bridge.destinationAddress}`,
         );
@@ -108,7 +105,6 @@ export class CrossChainBridgeService {
     return this.bridgeRepo.save(bridge);
   }
 
-  /** Auto-refund a failed bridge back to source via Stellar */
   private async refundBridge(bridge: CrossChainBridge): Promise<void> {
     try {
       if (bridge.sourceNetwork === BlockchainNetwork.STELLAR) {
@@ -127,17 +123,16 @@ export class CrossChainBridgeService {
     }
   }
 
-  /** Returns bridge health: whether reserves are above threshold */
   async getBridgeHealth(): Promise<{ healthy: boolean; alertMessage?: string }> {
-    const pendingBridges = await this.bridgeRepo.count({
-      where: { status: BridgeStatus.BRIDGE_PROCESSING },
-    });
-
     const totalLockedResult = await this.bridgeRepo
       .createQueryBuilder('b')
       .select('COALESCE(SUM(CAST(b.amount AS DECIMAL)), 0)', 'total')
       .where('b.status IN (:...statuses)', {
-        statuses: [BridgeStatus.INITIATED, BridgeStatus.SOURCE_CONFIRMED, BridgeStatus.BRIDGE_PROCESSING],
+        statuses: [
+          BridgeStatus.INITIATED,
+          BridgeStatus.SOURCE_CONFIRMED,
+          BridgeStatus.BRIDGE_PROCESSING,
+        ],
       })
       .getRawOne<{ total: string }>();
 
@@ -148,7 +143,7 @@ export class CrossChainBridgeService {
       healthy,
       alertMessage: healthy
         ? undefined
-        : `Bridge reserves critically low: ${totalLocked} USDC locked across ${pendingBridges} pending operations`,
+        : `Bridge reserves critically low: ${totalLocked} USDC locked in pending operations`,
     };
   }
 
@@ -157,9 +152,6 @@ export class CrossChainBridgeService {
   }
 
   async getBridgeHistory(userId: string): Promise<CrossChainBridge[]> {
-    return this.bridgeRepo.find({
-      where: { userId },
-      order: { createdAt: 'DESC' },
-    });
+    return this.bridgeRepo.find({ where: { userId }, order: { createdAt: 'DESC' } });
   }
 }