/**
 * Aave v3: Single-asset flash loan
 * 
 * This example demonstrates how to execute a flash loan for a single asset.
 * Flash loans must be repaid within the same transaction, including a premium.
 */

import { createWalletRpcClient } from '../../src/utils/chain-config.js';
import { getAavePoolAddress } from '../../src/utils/addresses.js';
import { getTokenMetadata, parseTokenAmount } from '../../src/utils/tokens.js';
import { waitForTransaction } from '../../src/utils/rpc.js';
import type { Address, Hex } from 'viem';

const CHAIN_ID = 1; // Mainnet
const PRIVATE_KEY = process.env.PRIVATE_KEY as `0x${string}`;

// Aave Pool ABI
const POOL_ABI = [
  {
    name: 'flashLoanSimple',
    type: 'function',
    stateMutability: 'nonpayable',
    inputs: [
      { name: 'receiverAddress', type: 'address' },
      { name: 'asset', type: 'address' },
      { name: 'amount', type: 'uint256' },
      { name: 'params', type: 'bytes' },
      { name: 'referralCode', type: 'uint16' },
    ],
    outputs: [],
  },
] as const;

// Flash loan receiver contract ABI (you need to deploy this)
interface IFlashLoanReceiver {
  executeOperation: (
    asset: Address,
    amount: bigint,
    premium: bigint,
    initiator: Address,
    params: Hex
  ) => Promise<boolean>;
}

/**
 * Example flash loan receiver contract address
 * 
 * In production, you would deploy your own flash loan receiver contract
 * that implements IFlashLoanReceiver and performs your desired logic.
 */
const FLASH_LOAN_RECEIVER = process.env.FLASH_LOAN_RECEIVER as `0x${string}`;

async function flashLoanSimple() {
  const walletClient = createWalletRpcClient(CHAIN_ID, PRIVATE_KEY);
  const publicClient = walletClient as any;
  const account = walletClient.account?.address;
  
  if (!account) {
    throw new Error('No account available');
  }

  const poolAddress = getAavePoolAddress(CHAIN_ID);
  const token = getTokenMetadata(CHAIN_ID, 'USDC');
  const amount = parseTokenAmount('10000', token.decimals); // 10,000 USDC

  console.log(`Executing flash loan for ${amount} ${token.symbol}`);
  console.log(`Pool: ${poolAddress}`);
  console.log(`Receiver: ${FLASH_LOAN_RECEIVER}`);

  if (!FLASH_LOAN_RECEIVER) {
    throw new Error('FLASH_LOAN_RECEIVER environment variable not set');
  }

  // Execute flash loan
  // The receiver contract must:
  // 1. Receive the loaned tokens
  // 2. Perform desired operations
  // 3. Approve the pool for (amount + premium)
  // 4. Return true from executeOperation
  const tx = await walletClient.writeContract({
    address: poolAddress,
    abi: POOL_ABI,
    functionName: 'flashLoanSimple',
    args: [
      FLASH_LOAN_RECEIVER, // Your flash loan receiver contract
      token.address,
      amount,
      '0x' as Hex, // Optional params
      0, // Referral code
    ],
  });

  await waitForTransaction(publicClient, tx);
  console.log(`Flash loan executed: ${tx}`);
  console.log('\n✅ Flash loan completed successfully!');
}

// Run if executed directly
if (import.meta.url === `file://${process.argv[1]}`) {
  flashLoanSimple().catch(console.error);
}

export { flashLoanSimple };