// SPDX-License-Identifier: MIT
pragma solidity >=0.6.8;

library Operations {
	function safeApprove(
		address token,
		address to,
		uint256 value
	) internal {
		// bytes4(keccak256(bytes('approve(address,uint256)')));
		(bool success, bytes memory data) = token.call(abi.encodeWithSelector(0x095ea7b3, to, value));
		require(success && (data.length == 0 || abi.decode(data, (bool))), "TransferHelper::safeApprove: approve failed");
	}

	function safeTransfer(
		address token,
		address to,
		uint256 value
	) internal {
		// bytes4(keccak256(bytes('transfer(address,uint256)')));
		(bool success, bytes memory data) = token.call(abi.encodeWithSelector(0xa9059cbb, to, value));
		require(success && (data.length == 0 || abi.decode(data, (bool))), "TransferHelper::safeTransfer: transfer failed");
	}

	function safeTransferFrom(
		address token,
		address from,
		address to,
		uint256 value
	) internal {
		// bytes4(keccak256(bytes('transferFrom(address,address,uint256)')));
		(bool success, bytes memory data) = token.call(abi.encodeWithSelector(0x23b872dd, from, to, value));
		require(success && (data.length == 0 || abi.decode(data, (bool))), "TransferHelper::transferFrom: transferFrom failed");
	}

	function safeTransferETH(address to, uint256 value) internal {
		(bool success, ) = to.call{ value: value }(new bytes(0));
		require(success, "TransferHelper::safeTransferETH: ETH transfer failed");
	}
}