pragma solidity 0.5.17;

import "../PriceFeeds.sol";
import "../IRSKOracle.sol";
import "../../openzeppelin/Address.sol";

interface Medianizer {
	function peek() external view returns (bytes32, bool);
}

/**
 * @title Price Feed of MoC (Money on Chain) contract.
 *
 * This contract contains the logic to set MoC oracles
 * and query last price update.
 * */
contract PriceFeedsMoC is IPriceFeedsExt, Ownable {
	/* Storage */

	address public mocOracleAddress;
	address public rskOracleAddress;

	/* Events */

	event SetMoCOracleAddress(address indexed mocOracleAddress, address changerAddress);
	event SetRSKOracleAddress(address indexed rskOracleAddress, address changerAddress);

	/* Functions */

	/**
	 * @notice Initialize a new MoC Oracle.
	 *
	 * @param _mocOracleAddress The MoC Oracle address.
	 * @param _rskOracleAddress The RSK Oracle address.
	 * */
	constructor(address _mocOracleAddress, address _rskOracleAddress) public {
		setMoCOracleAddress(_mocOracleAddress);
		setRSKOracleAddress(_rskOracleAddress);
	}

	/**
	 * @notice Get the las time oracle updated the price.
	 * @return The latest time.
	 */
	function latestAnswer() external view returns (uint256) {
		(bytes32 value, bool hasValue) = Medianizer(mocOracleAddress).peek();
		if (hasValue) {
			return uint256(value);
		} else {
			(uint256 price, ) = IRSKOracle(rskOracleAddress).getPricing();
			return price;
		}
	}

	/**
	 * @notice Set the MoC Oracle address.
	 *
	 * @param _mocOracleAddress The MoC Oracle address.
	 */
	function setMoCOracleAddress(address _mocOracleAddress) public onlyOwner {
		require(Address.isContract(_mocOracleAddress), "_mocOracleAddress not a contract");
		mocOracleAddress = _mocOracleAddress;
		emit SetMoCOracleAddress(mocOracleAddress, msg.sender);
	}

	/**
	 * @notice Set the RSK Oracle address.
	 *
	 * @param _rskOracleAddress The RSK Oracle address.
	 */
	function setRSKOracleAddress(address _rskOracleAddress) public onlyOwner {
		require(Address.isContract(_rskOracleAddress), "_rskOracleAddress not a contract");
		rskOracleAddress = _rskOracleAddress;
		emit SetRSKOracleAddress(rskOracleAddress, msg.sender);
	}
}