smom-dbis-138/connectors/cacti-xrpl/bridge-handler.ts

/**
 * @file bridge-handler.ts
 * @notice Bridge handler for EVM to XRPL transfers
 */

import { ethers } from 'ethers';
import { XRPLConnector, XRPLTransferRequest } from './xrpl-connector';
import { WorkflowEngine, TransferStatus } from '../../orchestration/bridge/workflow-engine';

export interface BridgeHandlerConfig {
    xrplConfig: {
        server: string;
        account: string;
        secret: string;
    };
    evmProvider: ethers.Provider;
    escrowVaultAddress: string;
    escrowVaultAbi: any[];
    workflowEngine: WorkflowEngine;
}

export class XRPLBridgeHandler {
    private xrplConnector: XRPLConnector;
    private provider: ethers.Provider;
    private escrowVault: ethers.Contract;
    private workflowEngine: WorkflowEngine;

    constructor(config: BridgeHandlerConfig) {
        this.xrplConnector = new XRPLConnector(config.xrplConfig);
        this.provider = config.evmProvider;
        this.escrowVault = new ethers.Contract(
            config.escrowVaultAddress,
            config.escrowVaultAbi,
            config.evmProvider
        );
        this.workflowEngine = config.workflowEngine;
    }

    /**
     * Handle bridge transfer from EVM to XRPL
     */
    async handleTransfer(
        transferId: string,
        destinationAddress: string,
        amount: string,
        destinationTag?: number
    ): Promise<{ txHash: string; ledgerIndex: number }> {
        // Get transfer from escrow vault
        const transfer = await this.escrowVault.getTransfer(transferId);
        
        // Verify transfer status
        const status = this.workflowEngine.getStatus(transferId);
        if (status !== TransferStatus.ROUTE_SELECTED) {
            throw new Error(`Invalid transfer status: ${status}`);
        }

        // Convert amount to XRP drops (assuming 1:1 ratio, adjust as needed)
        // For native ETH, convert wei to XRP drops
        // For ERC-20, use token decimals
        const xrpAmount = this.convertToXRP(transfer.asset, transfer.amount.toString());

        // Prepare XRPL payment
        const xrplRequest: XRPLTransferRequest = {
            destination: destinationAddress,
            amount: XRPLConnector.xrpToDrops(xrpAmount),
            destinationTag,
            memo: `Bridge transfer ${transferId}`
        };

        // Execute XRPL payment
        const result = await this.xrplConnector.sendPayment(xrplRequest);

        // Update workflow status
        await this.workflowEngine.markDestinationSent(transferId, {
            xrplTxHash: result.txHash
        });

        // Wait for finality
        await this.xrplConnector.waitForFinality(result.ledgerIndex);

        // Confirm finality
        await this.workflowEngine.confirmFinality(transferId);
        await this.workflowEngine.completeTransfer(transferId);

        return {
            txHash: result.txHash,
            ledgerIndex: result.ledgerIndex
        };
    }

    /**
     * Convert EVM amount to XRP
     * This is a simplified conversion - in production, use price oracles
     */
    private convertToXRP(asset: string, amount: string): string {
        // For native ETH (address(0)), convert wei to XRP
        // This is a placeholder - use actual price oracle in production
        if (asset === ethers.ZeroAddress) {
            // 1 ETH = 1 XRP (placeholder - use oracle)
            const ethAmount = ethers.formatEther(amount);
            return ethAmount;
        }

        // For ERC-20 tokens, use token decimals and conversion rate
        // This is a placeholder - implement proper conversion
        return ethers.formatEther(amount);
    }

    /**
     * Handle refund (if transfer fails)
     */
    async handleRefund(transferId: string): Promise<void> {
        // Refund logic would be handled by the escrow vault
        // This is just a placeholder for XRPL-specific refund handling
        await this.workflowEngine.initiateRefund(transferId);
    }

    /**
     * Get XRPL account balance
     */
    async getBalance(): Promise<string> {
        const balance = await this.xrplConnector.getBalance();
        return XRPLConnector.dropsToXrp(balance);
    }

    /**
     * Verify XRPL transaction
     */
    async verifyTransaction(txHash: string): Promise<boolean> {
        const status = await this.xrplConnector.getTransactionStatus(txHash);
        return status.validated && status.result === 'tesSUCCESS';
    }
}