// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

import {Script, console} from "forge-std/Script.sol";
import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import {IERC3156FlashBorrower} from "@openzeppelin/contracts/interfaces/IERC3156FlashBorrower.sol";
import {SimpleERC3156FlashVault} from "../../contracts/flash/SimpleERC3156FlashVault.sol";
import {MinimalERC3156FlashBorrower} from "../../contracts/flash/MinimalERC3156FlashBorrower.sol";

/**
 * @title TestOneUSDTFlash
 * @notice Live / fork: deploy minimal borrower, pre-fund fee, execute 1 USDT flash against an existing vault.
 *
 * Env:
 *   PRIVATE_KEY        — deployer (pays gas; seeds fee to borrower)
 *   FLASH_VAULT        — deployed SimpleERC3156FlashVault
 *   FLASH_VAULT_TOKEN  — optional; default official USDT Chain 138
 *   FLASH_TEST_AMOUNT  — optional raw amount (default 1e6 = 1 USDT with 6 decimals)
 *
 * Usage:
 *   forge script script/flash/TestOneUSDTFlash.s.sol:TestOneUSDTFlash --rpc-url $RPC_URL_138 --broadcast -vvvv
 */
contract TestOneUSDTFlash is Script {
    address internal constant DEFAULT_USDT_138 = 0x004b63A7B5b0E06f6bB6adb4a5F9f590BF3182D1;

    function run() external {
        uint256 pk = vm.envUint("PRIVATE_KEY");
        address deployer = vm.addr(pk);
        address vaultAddr = vm.envAddress("FLASH_VAULT");
        address token = vm.envOr("FLASH_VAULT_TOKEN", DEFAULT_USDT_138);
        uint256 amount = vm.envOr("FLASH_TEST_AMOUNT", uint256(1_000_000)); // 1 USDT (6 dp)

        SimpleERC3156FlashVault vault = SimpleERC3156FlashVault(vaultAddr);
        require(!vault.borrowerAllowlistEnabled() || vault.owner() == deployer, "allowlist on: deployer must be vault owner");

        uint256 fee = vault.previewFlashFee(token, amount);
        uint256 vaultBal = IERC20(token).balanceOf(vaultAddr);

        console.log("Deployer:", deployer);
        console.log("Vault:", vaultAddr);
        console.log("Token:", token);
        console.log("Amount (raw):", amount);
        console.log("Fee (raw):", fee);
        console.log("Vault token balance (raw):", vaultBal);
        require(vaultBal >= amount, "vault liquidity < amount");

        vm.startBroadcast(pk);

        MinimalERC3156FlashBorrower borrower = new MinimalERC3156FlashBorrower(vaultAddr);
        console.log("MinimalERC3156FlashBorrower:", address(borrower));

        if (vault.borrowerAllowlistEnabled()) {
            vault.setBorrowerApproved(address(borrower), true);
        }

        // Callback must return amount+fee; vault only credits `amount` before callback — need `fee` pre-funded on borrower.
        IERC20(token).transfer(address(borrower), fee);
        vault.flashLoan(IERC3156FlashBorrower(address(borrower)), token, amount, "");

        vm.stopBroadcast();

        console.log("Done. Vault balance after (raw):", IERC20(token).balanceOf(vaultAddr));
    }
}