/**
 * Chain138 -> Tezos USDtz route planning API
 */

import { Router, Request, Response } from 'express';

const TEZOS_REGEX = /^(tz[1-4]|KT1)[1-9A-HJ-NP-Za-km-z]{33}$/;
const CHAIN_138 = 138;
const CHAIN_ALL_MAINNET = 651940;
const CUSDC = '0xf22258f57794CC8E06237084b353Ab30fFfa640b';
const AUSDC = '0xa95EeD79f84E6A0151eaEb9d441F9Ffd50e8e881';
/** Active ETH→Tezos bridge (from bridge-capability-matrix) */
const ETH_TO_TEZOS_PROVIDER = 'Wrap Protocol';

interface RoutePlanRequest {
  source_chain_id?: number;
  source_asset?: string;
  source_amount?: string;
  destination_tezos_address?: string;
  max_slippage_bps?: number;
  max_total_fees?: string;
  prefer_non_custodial?: boolean;
}

interface RouteHop {
  chain: string;
  action: string;
  protocol: string;
  asset_in: string;
  amount_in: string;
  asset_out: string;
  min_amount_out: string;
  estimated_fees: string;
}

interface RoutePlan {
  route_id: string;
  hops: RouteHop[];
  totalEstimatedFees: string;
  estimatedTimeSeconds: number;
}

const router: Router = Router();

router.post('/v1/routes/chain138-to-usdtz', (req: Request, res: Response) => {
  try {
    const body = req.body as RoutePlanRequest;
    const sourceChainId = body.source_chain_id ?? 138;
    const sourceAsset = body.source_asset ?? CUSDC;
    const sourceAmount = body.source_amount ?? '0';
    const destAddr = body.destination_tezos_address ?? '';

    if (sourceChainId !== CHAIN_138 && sourceChainId !== CHAIN_ALL_MAINNET) {
      return res.status(400).json({ valid: false, error: 'Only source_chain_id=138 (Chain138) or 651940 (ALL Mainnet) is supported' });
    }
    if (!destAddr.trim() || !TEZOS_REGEX.test(destAddr.trim())) {
      return res.status(400).json({ valid: false, error: 'Invalid destination_tezos_address' });
    }
    const amount = BigInt(sourceAmount);
    if (amount <= 0n) {
      return res.status(400).json({ valid: false, error: 'source_amount must be > 0' });
    }

    const routeId = `route-${Date.now()}-${Math.random().toString(36).slice(2, 9)}`;
    const isChain138 = sourceChainId === CHAIN_138;
    const sourceLabel = isChain138 ? 'CHAIN138' : 'ALL_MAINNET';
    const stableOut = isChain138 ? CUSDC : AUSDC;
    const srcBridge = isChain138 ? 'CCIP' : 'AlltraAdapter';
    const hops: RouteHop[] = [
      { chain: sourceLabel, action: 'SWAP', protocol: isChain138 ? 'EnhancedSwapRouter' : 'AlltraDEX', asset_in: sourceAsset, amount_in: sourceAmount, asset_out: stableOut, min_amount_out: sourceAmount, estimated_fees: '0' },
      { chain: sourceLabel, action: 'BRIDGE', protocol: srcBridge, asset_in: stableOut, amount_in: sourceAmount, asset_out: 'USDC', min_amount_out: sourceAmount, estimated_fees: '0' },
      { chain: 'HUB_EVM', action: 'BRIDGE', protocol: ETH_TO_TEZOS_PROVIDER, asset_in: 'USDC', amount_in: sourceAmount, asset_out: 'USDC', min_amount_out: sourceAmount, estimated_fees: '0' },
      { chain: 'TEZOS', action: 'SWAP', protocol: 'Plenty', asset_in: 'USDC', amount_in: sourceAmount, asset_out: 'USDtz', min_amount_out: sourceAmount, estimated_fees: '0' },
    ];

    const plan: RoutePlan = {
      route_id: routeId,
      hops,
      totalEstimatedFees: '0',
      estimatedTimeSeconds: 1800,
    };

    res.status(200).json({ valid: true, routes: [plan] });
  } catch (e) {
    res.status(500).json({ valid: false, error: e instanceof Error ? e.message : 'Internal error' });
  }
});

export default router;