BRIDGE_SERVICE_PROTOTYPE.ts

// src/services/bridge/bridgeService.ts
// Bridge Service Prototype - Core orchestrator

import { BigNumber } from "ethers";
import { Asset, Keypair, Network, Server } from "stellar-sdk";
import logger from "../../logger";
import { BridgeTransaction, BridgeTransactionStatus } from "./types";
import { StellarLockService } from "./stellarLockService";
import { EVMMintService } from "./evmMintService";
import { ValidatorService } from "./validatorService";
import { ComplianceService } from "./complianceService";
import { BridgeMonitorService } from "./bridgeMonitorService";

export interface LockRequest {
  userId: string;
  amount: BigNumber;
  assetCode: string;
  sourceChain: "stellar" | "ethereum" | "polygon";
  targetChain: "stellar" | "ethereum" | "polygon";
  evmRecipient?: string;
  memo?: string;
}

export interface RedeemRequest {
  userId: string;
  bridgeTxId: string;
  evmTxHash: string;
}

export class BridgeService {
  private stellarLock: StellarLockService;
  private evmMint: EVMMintService;
  private validators: ValidatorService;
  private compliance: ComplianceService;
  private monitor: BridgeMonitorService;

  constructor() {
    this.stellarLock = new StellarLockService();
    this.evmMint = new EVMMintService();
    this.validators = new ValidatorService();
    this.compliance = new ComplianceService();
    this.monitor = new BridgeMonitorService();
  }

  /**
   * Initiate a bridge lock transaction
   * Flow: KYC Check -> Compliance Validation -> Stellar Lock -> Validator Consensus
   */
  async initiatelock(request: LockRequest): Promise<BridgeTransaction> {
    const txId = this.generateTxId();
    logger.info(`[Bridge] Initiating lock: ${txId}`, { request });

    try {
      // 1. KYC/Compliance Check
      logger.debug(`[Bridge:${txId}] Starting KYC verification...`);
      const kycResult = await this.compliance.verifyUserKYC(request.userId);
      if (!kycResult.approved) {
        throw new Error(`KYC verification failed: ${kycResult.reason}`);
      }

      // 2. Validate transaction amount and limits
      logger.debug(`[Bridge:${txId}] Checking transaction limits...`);
      const limitCheck = await this.compliance.checkTransactionLimits(
        request.userId,
        request.amount,
        kycResult.tier,
      );
      if (!limitCheck.allowed) {
        throw new Error(`Transaction exceeds limits: ${limitCheck.reason}`);
      }

      // 3. AML/Sanctions check
      logger.debug(`[Bridge:${txId}] Running AML/Sanctions check...`);
      const amlResult = await this.compliance.checkSanctions(request.userId);
      if (!amlResult.passed) {
        throw new Error(`Sanctions check failed: ${amlResult.reason}`);
      }

      // 4. Create bridge transaction record
      const dbTx = await this.createBridgeTransaction({
        id: txId,
        userId: request.userId,
        sourceChain: request.sourceChain,
        targetChain: request.targetChain,
        assetCode: request.assetCode,
        amount: request.amount,
        status: "kyc_verified",
        evmRecipientAddress: request.evmRecipient || "",
        createdAt: new Date(),
        updatedAt: new Date(),
        validatorSignatures: [],
        consensusRatio: 0,
        feeAmount: this.calculateFee(request.amount),
        feePercent: Number(process.env.BRIDGE_FEE_PERCENT) || 0.5,
      });

      // 5. Lock asset on Stellar
      logger.debug(`[Bridge:${txId}] Locking asset on Stellar...`);
      const lockResult = await this.stellarLock.lock({
        userId: request.userId,
        amount: request.amount,
        assetCode: request.assetCode,
        memo: txId,
        escrowAccount: process.env.STELLAR_BRIDGE_ESCROW_KEY!,
      });

      // Update transaction with lock details
      await this.updateBridgeTransaction(txId, {
        status: "stellar_locked",
        stellarLockTxHash: lockResult.transactionHash,
        metadata: {
          lockTimestamp: new Date(),
          escrowAccount: lockResult.escrowAccount,
        },
      });

      // 6. Initiate validator consensus collection
      logger.debug(`[Bridge:${txId}] Collecting validator signatures...`);
      const consensusResult = await this.validators.collectSignatures({
        bridgeTxId: txId,
        sourceChain: request.sourceChain,
        targetChain: request.targetChain,
        amount: request.amount,
        assetCode: request.assetCode,
        recipient: request.evmRecipient || "",
        stellarTxHash: lockResult.transactionHash,
      });

      // Update with validator consensus
      await this.updateBridgeTransaction(txId, {
        status: "validator_consensus",
        validatorSignatures: consensusResult.signatures,
        consensusRatio: consensusResult.ratio,
      });

      // 7. If consensus reached, mint on EVM
      if (consensusResult.consensusReached) {
        logger.debug(
          `[Bridge:${txId}] Consensus reached, initiating EVM mint...`,
        );
        await this.processMint(txId, consensusResult.signatures);
      } else {
        logger.warn(
          `[Bridge:${txId}] Consensus not yet reached, awaiting more signatures`,
        );
      }

      // 8. Start monitoring
      await this.monitor.trackTransactionState(txId);

      logger.info(`[Bridge:${txId}] Lock initiated successfully`);
      return await this.getTransaction(txId);
    } catch (error) {
      logger.error(`[Bridge:${txId}] lock failed:`, error);
      await this.updateBridgeTransaction(txId, {
        status: "failed",
        metadata: { error: (error as Error).message },
      });
      throw error;
    }
  }

  /**
   * Redeem locked assets (reverse flow)
   */
  async initiateRedeem(request: RedeemRequest): Promise<BridgeTransaction> {
    const txId = `redeem-${request.bridgeTxId}`;
    logger.info(`[Bridge] Initiating redemption: ${txId}`);

    try {
      // 1. Verify original transaction
      const originalTx = await this.getTransaction(request.bridgeTxId);
      if (originalTx.status !== "completed") {
        throw new Error("Original transaction not in completed state");
      }

      // 2. Burn wrapped token on EVM
      const burnResult = await this.evmMint.burn({
        bridgeTxId: request.bridgeTxId,
        amount: originalTx.amount,
        txHash: request.evmTxHash,
      });

      // 3. Unlock on Stellar
      const unlockResult = await this.stellarLock.unlock({
        bridgeTxId: request.bridgeTxId,
        userId: originalTx.userId,
        amount: originalTx.amount,
        assetCode: originalTx.assetCode,
      });

      logger.info(`[Bridge:${txId}] Redemption completed`);
      return originalTx;
    } catch (error) {
      logger.error(`[Bridge:${txId}] Redemption failed:`, error);
      throw error;
    }
  }

  /**
   * Process minting after validator consensus
   */
  private async processMint(txId: string, signatures: any[]): Promise<void> {
    try {
      const tx = await this.getTransaction(txId);

      const mintResult = await this.evmMint.mint({
        bridgeTxId: txId,
        recipient: tx.evmRecipientAddress,
        amount: tx.amount,
        assetCode: tx.assetCode,
        signatures: signatures,
      });

      await this.updateBridgeTransaction(txId, {
        status: "evm_minted",
        evmMintTxHash: mintResult.transactionHash,
        metadata: {
          mintTimestamp: new Date(),
          gasUsed: mintResult.gasUsed,
        },
      });

      // Mark as completed
      await this.updateBridgeTransaction(txId, {
        status: "completed",
      });

      logger.info(`[Bridge:${txId}] Mint completed successfully`);
    } catch (error) {
      logger.error(`[Bridge:${txId}] Mint failed:`, error);
      throw error;
    }
  }

  /**
   * Get transaction status
   */
  async getTransactionStatus(txId: string): Promise<{
    status: BridgeTransactionStatus;
    progress: number;
    details: any;
  }> {
    const tx = await this.getTransaction(txId);

    const progressMap = {
      initiated: 10,
      kyc_verified: 20,
      stellar_locked: 40,
      validator_consensus: 60,
      evm_minted: 80,
      completed: 100,
      failed: 0,
      reversed: 0,
    };

    return {
      status: tx.status,
      progress: progressMap[tx.status],
      details: {
        amount: tx.amount.toString(),
        sourceChain: tx.sourceChain,
        targetChain: tx.targetChain,
        stellarTxHash: tx.stellarLockTxHash,
        evmTxHash: tx.evmMintTxHash,
        validatorSignatures: tx.validatorSignatures?.length || 0,
        createdAt: tx.createdAt,
      },
    };
  }

  /**
   * Get user's bridge transactions
   */
  async getUserTransactions(userId: string, limit = 20, offset = 0) {
    // TODO: Implement database query
    return [];
  }

  /**
   * Quote bridge exchange rates and fees
   */
  async getQuote(sourceChain: string, targetChain: string, amount: BigNumber) {
    const feePercent = Number(process.env.BRIDGE_FEE_PERCENT) || 0.5;
    const feeAmount = amount.mul(feePercent).div(100);

    return {
      sourceChain,
      targetChain,
      amountIn: amount.toString(),
      amountOut: amount.sub(feeAmount).toString(),
      fee: feeAmount.toString(),
      feePercent,
      exchangeRate: "1.0",
      estimatedTime: "5 minutes",
      validUntil: new Date(Date.now() + 60000),
    };
  }

  // ========== Private Helper Methods ==========

  private async createBridgeTransaction(
    tx: BridgeTransaction,
  ): Promise<BridgeTransaction> {
    // TODO: Implement database insert
    logger.debug("[Bridge] Creating transaction record:", tx);
    return tx;
  }

  private async updateBridgeTransaction(
    txId: string,
    updates: Partial<BridgeTransaction>,
  ): Promise<void> {
    // TODO: Implement database update
    logger.debug(`[Bridge:${txId}] Updating transaction:`, updates);
  }

  private async getTransaction(txId: string): Promise<BridgeTransaction> {
    // TODO: Implement database query
    throw new Error("Not implemented");
  }

  private calculateFee(amount: BigNumber): BigNumber {
    const feePercent = Number(process.env.BRIDGE_FEE_PERCENT) || 0.5;
    return amount.mul(feePercent).div(100);
  }

  private generateTxId(): string {
    return `BRIDGE-${Date.now()}-${Math.random().toString(36).substr(2, 9)}`;
  }
}

export default new BridgeService();