/**
 * Copyright 2017-2020, bZeroX, LLC. All Rights Reserved.
 * Licensed under the Apache License, Version 2.0.
 */

pragma solidity 0.5.17;

import "../../connectors/loantoken/AdvancedTokenStorage.sol";

//@todo can I change this proxy to EIP-1822 proxy standard, please. https://eips.ethereum.org/EIPS/eip-1822. It's really hard to work with this.
contract PreviousLoanToken is AdvancedTokenStorage {
	// It is important to maintain the variables order so the delegate calls can access sovrynContractAddress and wrbtcTokenAddress
	address public sovrynContractAddress;
	address public wrbtcTokenAddress;
	address internal target_;

	constructor(
		address _newOwner,
		address _newTarget,
		address _sovrynContractAddress,
		address _wrbtcTokenAddress
	) public {
		transferOwnership(_newOwner);
		_setTarget(_newTarget);
		_setSovrynContractAddress(_sovrynContractAddress);
		_setWrbtcTokenAddress(_wrbtcTokenAddress);
	}

	function() external payable {
		if (gasleft() <= 2300) {
			return;
		}

		address target = target_;
		bytes memory data = msg.data;
		assembly {
			let result := delegatecall(gas, target, add(data, 0x20), mload(data), 0, 0)
			let size := returndatasize
			let ptr := mload(0x40)
			returndatacopy(ptr, 0, size)
			switch result
				case 0 {
					revert(ptr, size)
				}
				default {
					return(ptr, size)
				}
		}
	}

	function setTarget(address _newTarget) public onlyOwner {
		_setTarget(_newTarget);
	}

	function _setTarget(address _newTarget) internal {
		require(Address.isContract(_newTarget), "target not a contract");
		target_ = _newTarget;
	}

	function _setSovrynContractAddress(address _sovrynContractAddress) internal {
		require(Address.isContract(_sovrynContractAddress), "sovryn not a contract");
		sovrynContractAddress = _sovrynContractAddress;
	}

	function _setWrbtcTokenAddress(address _wrbtcTokenAddress) internal {
		require(Address.isContract(_wrbtcTokenAddress), "wrbtc not a contract");
		wrbtcTokenAddress = _wrbtcTokenAddress;
	}

	//@todo add check for double init, idk but init usually can be called only once.
	function initialize(
		address _loanTokenAddress,
		string memory _name,
		string memory _symbol
	) public onlyOwner {
		loanTokenAddress = _loanTokenAddress;

		name = _name;
		symbol = _symbol;
		decimals = IERC20(loanTokenAddress).decimals();

		initialPrice = 10**18; // starting price of 1
	}
}