Auction.sol

pragma solidity ^ 0.5.1;

/// @title Auction abstract contract
/// @author Andrea Bruno 585457
/// @notice This contract implements the shared functionalities between the Dutch and Vickrey auction.
/// @dev The following comments are written using the Solidity NatSpec Format.

contract Auction {

    /// @notice This struct incorporates the basic info about the auction.
    struct Description {
        address payable seller;
        string itemName;
        uint startBlock;
        address winnerAddress;
        uint winnerBid;
    }

    /// @dev The description is public to allow people to read it without paying any gas.
    Description public description;


    /// @dev This modifier allow only the seller to invoke the function.
    modifier onlySeller() {
        require(msg.sender == description.seller, "Only the seller can run this function");
        _;
    }

    /// @notice This event communicate the beginning of the auction.
    event auctionStarted();

    /// @notice This event communicate the end of the auction
    /// @param winnerAddress is the address of the winner
    /// @param winnerBid is the final price that the winner has paid.
    /// @param surplusFounds is the eventual surplus left to the contract.
    event auctionFinished(address winnerAddress, uint winnerBid, uint surplusFounds);


    /// @notice This abstract function allow to activate the auction.
    /// @dev For security reason, it is better to equip this function with `onlySeller` modifier.
    function activateAuction() public;


    /// @notice This abstract function finalize and close the auction.
    /// @dev For security reason, it is better to equip this function with `onlySeller` modifier.
    function finalize() public;
}