// File: @openzeppelin/contracts/access/Ownable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol)

pragma solidity ^0.8.0;

import "../utils/Context.sol";

/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor() {
        _transferOwnership(_msgSender());
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        _checkOwner();
        _;
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if the sender is not the owner.
     */
    function _checkOwner() internal view virtual {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}

// File: @openzeppelin/contracts/utils/Context.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)

pragma solidity ^0.8.0;

/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}

// File: contracts/CGAuction.sol



// SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.8.18;

import "@openzeppelin/contracts/access/Ownable.sol";

contract CGAuction is Ownable {
    bool public isAuctionOpen = false;
    struct Bid {
        address bidder;
        uint256 value;
    }
    address public winner;
    Bid[] bids;
    constructor(){}
    function setIsAuctionOpen(bool _isAuctionOpen) public onlyOwner {
        isAuctionOpen = _isAuctionOpen;
    }

    function increaseBid() public payable returns (bool success){
        require(isAuctionOpen, "Auction is not open!");
        require(msg.value > 0, "You did not send any ETH!");
        if (bids.length == 0) {
            bids.push(
                Bid(
                    msg.sender,
                    msg.value
                )
            );
            return true;
        }
        for (uint256 i = 0; i < bids.length; i++) {
            if (bids[i].bidder == msg.sender) {
                bids[i].value += msg.value;
                return true;
            } else if (i == bids.length - 1) {
                bids.push(
                    Bid(
                        msg.sender,
                        msg.value
                    )
                );
                return true;
            }
        }
        return false;
    }

    function getAllBids() public view returns(Bid[] memory) {
        return bids;
    }

    function decreaseBid(uint256 _value) public returns (bool success) {
        for (uint256 i = 0; i < bids.length; i++) {
            if (bids[i].bidder == msg.sender) {
                bids[i].value -= _value;
                (bool sent,) = payable(msg.sender).call{value: _value}("");
                require(sent, "Failed to send Ether");
                return sent;
            }
        }
        return false;
    }

    function endAuction() public onlyOwner {
        require(isAuctionOpen, "Auction not open!");
        isAuctionOpen = false;
        Bid memory highestBid;
        for (uint256 i = 0; i < bids.length; i++) {
            if (bids[i].value > highestBid.value) {
                highestBid = bids[i];
            }
        }
        winner = highestBid.bidder;
        for (uint256 i = 0; i < bids.length; i++) {
            if (bids[i].bidder == winner) {
                (bool sent,) = payable(super.owner()).call{value: highestBid.value}("");
                require(sent, "Failed to send Ether");
            } else if (bids[i].value > 0) {
                (bool sent,) = payable(bids[i].bidder).call{value: bids[i].value}("");
                require(sent, "Failed to send Ether");
            }
        }
    }
}