//SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
pragma experimental ABIEncoderV2;

/**
 * @title 1InchV4.
 * @dev On-chain DEX Aggregator.
 */

// import files from common directory
import { TokenInterface, MemoryInterface } from "../../common/interfaces.sol";
import { Stores } from "../../common/stores.sol";
import { OneInchInterace, OneInchData } from "./interface.sol";
import { Helpers } from "./helpers.sol";
import { Events } from "./events.sol";

abstract contract OneInchResolver is Helpers, Events {
	/**
	 * @dev 1inch API swap handler
	 * @param oneInchData - contains data returned from 1inch API. Struct defined in interfaces.sol
	 * @param ftmAmt - Eth to swap for .value()
	 */
	function oneInchSwap(OneInchData memory oneInchData, uint256 ftmAmt)
		internal
		returns (uint256 buyAmt)
	{
		TokenInterface buyToken = oneInchData.buyToken;
		(uint256 _buyDec, uint256 _sellDec) = getTokensDec(
			buyToken,
			oneInchData.sellToken
		);
		uint256 _sellAmt18 = convertTo18(_sellDec, oneInchData._sellAmt);
		uint256 _slippageAmt = convert18ToDec(
			_buyDec,
			wmul(oneInchData.unitAmt, _sellAmt18)
		);

		uint256 initalBal = getTokenBal(buyToken);

		// solium-disable-next-line security/no-call-value
		(bool success, ) = oneInchAddr.call{ value: ftmAmt }(
			oneInchData.callData
		);
		if (!success) revert("1Inch-swap-failed");

		uint256 finalBal = getTokenBal(buyToken);

		buyAmt = sub(finalBal, initalBal);

		require(_slippageAmt <= buyAmt, "Too much slippage");
	}
}

abstract contract OneInchResolverHelpers is OneInchResolver {
	/**
	 * @dev Gets the swapping data from 1inch's API.
	 * @param oneInchData Struct with multiple swap data defined in interfaces.sol
	 * @param setId Set token amount at this ID in `InstaMemory` Contract.
	 */
	function _sell(OneInchData memory oneInchData, uint256 setId)
		internal
		returns (OneInchData memory)
	{
		TokenInterface _sellAddr = oneInchData.sellToken;

		uint256 ftmAmt;
		if (address(_sellAddr) == ftmAddr) {
			ftmAmt = oneInchData._sellAmt;
		} else {
			approve(
				TokenInterface(_sellAddr),
				oneInchAddr,
				oneInchData._sellAmt
			);
		}

		oneInchData._buyAmt = oneInchSwap(oneInchData, ftmAmt);
		setUint(setId, oneInchData._buyAmt);

		return oneInchData;
	}
}

abstract contract OneInch is OneInchResolverHelpers {
	/**
	 * @dev Sell ETH/ERC20_Token using 1Inch.
	 * @notice Swap tokens from exchanges like kyber, 0x etc, with calculation done off-chain.
	 * @param buyAddr The address of the token to buy.(For FTM: 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE)
	 * @param sellAddr The address of the token to sell.(For FTM: 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE)
	 * @param sellAmt The amount of the token to sell.
	 * @param unitAmt The amount of buyAmt/sellAmt with slippage.
	 * @param callData Data from 1inch API.
	 * @param setId ID stores the amount of token brought.
	 */
	function sell(
		address buyAddr,
		address sellAddr,
		uint256 sellAmt,
		uint256 unitAmt,
		bytes calldata callData,
		uint256 setId
	)
		external
		payable
		returns (string memory _eventName, bytes memory _eventParam)
	{
		OneInchData memory oneInchData = OneInchData({
			buyToken: TokenInterface(buyAddr),
			sellToken: TokenInterface(sellAddr),
			unitAmt: unitAmt,
			callData: callData,
			_sellAmt: sellAmt,
			_buyAmt: 0
		});

		oneInchData = _sell(oneInchData, setId);

		_eventName = "LogSell(address,address,uint256,uint256,uint256,uint256)";
		_eventParam = abi.encode(
			buyAddr,
			sellAddr,
			oneInchData._buyAmt,
			oneInchData._sellAmt,
			0,
			setId
		);
	}
}

contract ConnectV2OneInchV4Fantom is OneInch {
	string public name = "1Inch-v4";
}