// File: contracts/BigNumba.sol



pragma solidity ^0.8.4;

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

interface IERC721 {
    function ownerOf(uint256 tokenId) external view returns (address);
    function price() external view returns (uint);

}

contract BigNumba is Ownable, ReentrancyGuard {
    address public numbaAddress;
    uint public biggest;
    uint public bounty;
    uint public biggestAt;

    uint public fee;
    uint public requiredDuration;
    uint public nextRoundFee;
    uint public nextRoundRequiredDuration;

    constructor() {
        fee = 0.02 ether;
        requiredDuration = 15 minutes;
        nextRoundFee = fee;
        nextRoundRequiredDuration = requiredDuration;
    }

    function setNumba(address _numbaAddress) public onlyOwner {
        require(numbaAddress == address(0));
        numbaAddress = _numbaAddress;
    }

    function setNextRoundFee(uint _nextRoundFee) public onlyOwner {
        require(_nextRoundFee >= 0.01 ether, "That's too little.");
        require(_nextRoundFee < IERC721(numbaAddress).price(), "That's too much.");

        nextRoundFee = _nextRoundFee;
    }
    
    function setNextRoundRequiredDuration(uint _nextRoundRequiredDuration) public onlyOwner {
        require(_nextRoundRequiredDuration > 5 minutes, "That's too quick.");
        require(_nextRoundRequiredDuration < 36 hours, "That's too much.");

        nextRoundRequiredDuration = _nextRoundRequiredDuration;
    }

    function IAmBiggest(uint _numbaId) public payable nonReentrant{
        require(fee == msg.value, "Pay to play.");
        require(IERC721(numbaAddress).ownerOf(_numbaId) == msg.sender);
        require(_numbaId > biggest);
        require(!awaitingWinnerClaim());
        biggestAt = block.timestamp;
        biggest = _numbaId;
        bounty += fee / 3;
    }

    function awaitingWinnerClaim() internal returns(bool) {
        if (biggest == 0) return false;
        return block.timestamp > biggestAt + requiredDuration;
    }

    function claimBounty() public nonReentrant {
        require(block.timestamp > biggestAt + requiredDuration);
        fee = nextRoundFee;
        requiredDuration = nextRoundRequiredDuration;

        if (block.timestamp < biggestAt + requiredDuration * 2) {
            address ownerOfBiggest = IERC721(numbaAddress).ownerOf(biggest);
            (bool success, ) = payable(ownerOfBiggest).call{value: bounty}("");
            require(success, "Transfer failed.");
        }

        biggestAt = block.timestamp;

        uint desired = IERC721(numbaAddress).price() * 6;
        if (desired > address(this).balance) {
            bounty = address(this).balance;
        } else {
            bounty = desired;
        }
    }

    function donateToBounty(uint amount) public payable nonReentrant {
        require(!awaitingWinnerClaim());
        require(amount == msg.value, "Hmm.");
        if (amount > bounty / 10) {
            biggestAt = block.timestamp;
        }
        bounty += amount;
    }

    function increaseBountyFromReserve(uint amount) public onlyOwner {
        require(!awaitingWinnerClaim());
        require(amount + bounty <= address(this).balance, "Not enough in reserve");
        if (amount > bounty / 10) {
            biggestAt = block.timestamp;
        }
        bounty += amount;
    }

    function nextRoundBounty() public view returns (uint) {
        uint desired = IERC721(numbaAddress).price() * 6;
        if (desired > address(this).balance - bounty) {
            return address(this).balance - bounty;
        } else {
            return desired;
        }
    }

    function futureRoundsBountyReserve() public view returns(uint) {
        return address(this).balance - bounty;
    }

    event Received(address, uint256);
    receive() external payable {
        emit Received(msg.sender, msg.value);
    }

}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (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 Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        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/security/ReentrancyGuard.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (security/ReentrancyGuard.sol)

pragma solidity ^0.8.0;

/**
 * @dev Contract module that helps prevent reentrant calls to a function.
 *
 * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
 * available, which can be applied to functions to make sure there are no nested
 * (reentrant) calls to them.
 *
 * Note that because there is a single `nonReentrant` guard, functions marked as
 * `nonReentrant` may not call one another. This can be worked around by making
 * those functions `private`, and then adding `external` `nonReentrant` entry
 * points to them.
 *
 * TIP: If you would like to learn more about reentrancy and alternative ways
 * to protect against it, check out our blog post
 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
 */
abstract contract ReentrancyGuard {
    // Booleans are more expensive than uint256 or any type that takes up a full
    // word because each write operation emits an extra SLOAD to first read the
    // slot's contents, replace the bits taken up by the boolean, and then write
    // back. This is the compiler's defense against contract upgrades and
    // pointer aliasing, and it cannot be disabled.

    // The values being non-zero value makes deployment a bit more expensive,
    // but in exchange the refund on every call to nonReentrant will be lower in
    // amount. Since refunds are capped to a percentage of the total
    // transaction's gas, it is best to keep them low in cases like this one, to
    // increase the likelihood of the full refund coming into effect.
    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;

    uint256 private _status;

    constructor() {
        _status = _NOT_ENTERED;
    }

    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     * Calling a `nonReentrant` function from another `nonReentrant`
     * function is not supported. It is possible to prevent this from happening
     * by making the `nonReentrant` function external, and making it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        // On the first call to nonReentrant, _notEntered will be true
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");

        // Any calls to nonReentrant after this point will fail
        _status = _ENTERED;

        _;

        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _status = _NOT_ENTERED;
    }
}

// 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;
    }
}