contract TbtcPool is IWbtcPoolBase{
  using SafeERC20 for IERC20;

  CurveInterfaceTbtc public pool_deposit;

  constructor() public{
    name = "Tbtc";
    lp_token_addr = address(0x64eda51d3Ad40D56b9dFc5554E06F94e1Dd786Fd);
    extra_token_addr = address(0x85Eee30c52B0b379b046Fb0F85F4f3Dc3009aFEC);
    crv_gauge_addr = CRVGaugeInterfaceWbtc(0x6828bcF74279eE32f2723eC536c22c51Eed383C6);
    pool_deposit = CurveInterfaceTbtc(0xaa82ca713D94bBA7A89CEAB55314F9EfFEdDc78c);
  }

  //@_amount: wbtc amount
  function deposit_wbtc(uint256 _amount) internal {
    IERC20(wbtc).transferFrom(msg.sender, address(this), _amount);
    IERC20(wbtc).approve(address(pool_deposit), 0);
    IERC20(wbtc).approve(address(pool_deposit), _amount);
    uint256[4] memory uamounts = [uint256(0), 0, _amount, 0];
    pool_deposit.add_liquidity(uamounts, 0);
  }


  function withdraw_from_curve(uint256 _amount) internal{
    require(_amount <= get_lp_token_balance(), "withdraw_from_curve: too large amount");
    IERC20(lp_token_addr).approve(address(pool_deposit), _amount);
    pool_deposit.remove_liquidity_one_coin(_amount, 2, 0);

    //uint256 dai_amount = IERC20(dai).balanceOf(address(this));
    //IERC20(dai).safeApprove(address(pool_deposit), dai_amount);
    //PriceInterface(address(pool_deposit)).exchange(0, 1, dai_amount, 0);

    //uint256 usdt_amount = IERC20(usdt).balanceOf(address(this));
    //IERC20(usdt).safeApprove(address(pool_deposit), usdt_amount);
    //PriceInterface(address(pool_deposit)).exchange(2, 1, usdt_amount, 0);
  }

  function get_virtual_price() public view returns(uint256){
    return PriceInterfaceWbtc(pool_deposit.pool()).get_virtual_price();
  }
}
function deposit_wbtc(uint256 _amount) internal {
    IERC20(wbtc).transferFrom(msg.sender, address(this), _amount);
    IERC20(wbtc).approve(address(pool_deposit), 0);
    IERC20(wbtc).approve(address(pool_deposit), _amount);
    uint256[4] memory uamounts = [uint256(0), 0, _amount, 0];
    pool_deposit.add_liquidity(uamounts, 0);
  }
//@_amount: wbtc amount