// 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/GamePrize.sol



// SPDX-License-Identifier: MIT
//
// GamePrize.sol
//
// v1: Players who triggerred in-game events will receive airdrop/drip prizes.
// TODO(v2): External funders can deposit for custom in-game events.
//

pragma solidity ^0.8.17;

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

abstract contract BaseErc20 {
    function balanceOf(address account) public virtual returns (uint256);

    function transfer(address recipient, uint256 amount) public virtual;
}

contract GamePrize is Ownable {
    event Received(address, uint);
    event Drip(address, address, uint256);
    event NewPrizeOperator(address);
    event NewAmount(address, uint256);
    event OwnerWithdrawErc20(address, address, uint256);

    BaseErc20 public token20;
    address public prizeOperator;

    mapping(address => uint256) public amount; // user states set by game

    constructor() {
        prizeOperator = msg.sender; // server operator
    }

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

    function setPrizeOperator(address newPrizeOperator) public onlyOwner {
        prizeOperator = newPrizeOperator;
        emit NewPrizeOperator(prizeOperator);
    }

    function setAmount(
        address erc20Address,
        uint256 newAmount
    ) public onlyOwner {
        amount[erc20Address] = newAmount;
        emit NewAmount(erc20Address, amount[erc20Address]);
    }

    function drip(address erc20Address, address to) external {
        require(prizeOperator == msg.sender, "invalid operator"); // only prizeOperator can airdrop
        token20 = BaseErc20(erc20Address); // erc-20 address
        token20.transfer(to, amount[erc20Address]);
        emit Drip(erc20Address, to, amount[erc20Address]);
    }

    function withdrawErc20(address erc20Address) external onlyOwner {
        require(erc20Address != address(0), "invalid erc20 address");
        token20 = BaseErc20(erc20Address);
        require(token20.balanceOf(address(this)) > 0, "already empty");
        uint256 withdrawAmount = token20.balanceOf(address(this));
        token20.transfer(msg.sender, withdrawAmount);
        emit OwnerWithdrawErc20(msg.sender, erc20Address, withdrawAmount);
    }

    function withdraw() external payable onlyOwner {
        require(payable(msg.sender).send(address(this).balance));
    }
}