// File: contracts/WRLD_Token_Exchanger.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.16;

import "./ERC2771Context_Upgradeable.sol";
import "./IERC20_Game_Currency.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";

contract WRLD_Token_Exchanger is Ownable, ERC2771Context_Upgradeable {
  IERC20 immutable V1_WRLD;
  IERC20_Game_Currency immutable V2_WRLD;
  uint256 exchangeBonusBP = 500; // basis points, 5%

  constructor(address _forwarder, address _V1WRLD, address _V2WRLD)
  ERC2771Context_Upgradeable(_forwarder) {
    V1_WRLD = IERC20(_V1WRLD);
    V2_WRLD = IERC20_Game_Currency(_V2WRLD);
  }

  function exchange(uint256 inputAmount) external {
    uint256 outputAmount = inputAmount + (inputAmount * exchangeBonusBP / 10000);

    // forever locked into exchanger contract since transferFrom cannot transfer to burn addr
    V1_WRLD.transferFrom(_msgSender(), address(this), inputAmount);

    if (V2_WRLD.balanceOf(address(this)) >= outputAmount) {
        V2_WRLD.transfer(_msgSender(), outputAmount);
    } else {
        V2_WRLD.mint(_msgSender(), outputAmount);
    }
  }

  /**
   * @dev Support for gasless transactions
   */

  function upgradeTrustedForwarder(address _newTrustedForwarder) external onlyOwner {
    _upgradeTrustedForwarder(_newTrustedForwarder);
  }

  function _msgSender() internal view override(Context, ERC2771Context_Upgradeable) returns (address) {
    return super._msgSender();
  }

  function _msgData() internal view override(Context, ERC2771Context_Upgradeable) returns (bytes calldata) {
    return super._msgData();
  }
}

// File: contracts/ERC2771Context_Upgradeable.sol



// SPDX-License-Identifier: Commons-Clause-1.0
//  __  __     _        ___     _
// |  \/  |___| |_ __ _| __|_ _| |__
// | |\/| / -_)  _/ _` | _/ _` | '_ \
// |_|  |_\___|\__\__,_|_|\__,_|_.__/
//
// Launch your crypto game or gamefi project's blockchain
// infrastructure & game APIs fast with https://trymetafab.com

pragma solidity ^0.8.16;

import "@openzeppelin/contracts/utils/Context.sol";

/**
 * @dev Context variant with ERC2771 support and upgradeable trusted forwarder.
 */

abstract contract ERC2771Context_Upgradeable is Context {
  address private trustedForwarder;

  constructor(address _trustedForwarder) {
    trustedForwarder = _trustedForwarder;
  }

  function isTrustedForwarder(address forwarder) public view virtual returns (bool) {
    return forwarder == trustedForwarder;
  }

  function _upgradeTrustedForwarder(address _trustedForwarder) internal {
    trustedForwarder = _trustedForwarder;
  }

  function _msgSender() internal view virtual override returns (address sender) {
    if (isTrustedForwarder(msg.sender)) {
      // The assembly code is more direct than the Solidity version using `abi.decode`.
      /// @solidity memory-safe-assembly
      assembly {
        sender := shr(96, calldataload(sub(calldatasize(), 20)))
      }
    } else {
      return super._msgSender();
    }
  }

  function _msgData() internal view virtual override returns (bytes calldata) {
    if (isTrustedForwarder(msg.sender)) {
      return msg.data[:msg.data.length - 20];
    } else {
      return super._msgData();
    }
  }
}

// File: contracts/IERC20_Game_Currency.sol



// SPDX-License-Identifier: Commons-Clause-1.0
//  __  __     _        ___     _
// |  \/  |___| |_ __ _| __|_ _| |__
// | |\/| / -_)  _/ _` | _/ _` | '_ \
// |_|  |_\___|\__\__,_|_|\__,_|_.__/
//
// Launch your crypto game or gamefi project's blockchain
// infrastructure & game APIs fast with https://trymetafab.com

pragma solidity ^0.8.16;

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/utils/introspection/IERC165.sol";

interface IERC20_Game_Currency is IERC20, IERC165  {
  // events
  event TransferRef(address indexed sender, address indexed recipient, uint256 amount, uint256 ref);
  event BatchTransferRef(address indexed sender, address[] recipients, uint256[] amounts, uint256[] refs);

  // autogenerated getters
  function feeBps() external view returns (uint);
  function feeFixed() external view returns (uint);
  function feeCap() external view returns (uint);
  function feeRecipient() external view returns (address);
  function childChainManagerProxy() external view returns (address);
  function supplyCap() external view returns (uint256);

  // functions
  function mint(address _to, uint256 _amount) external;
  function burn(uint256 _amount) external;
  function transferWithRef(address recipient, uint256 amount, uint256 ref) external returns (bool);
  function batchTransfer(address[] calldata recipients, uint256[] calldata amounts) external returns (bool);
  function batchTransferWithRefs(address[] calldata recipients, uint256[] calldata amounts, uint256[] calldata refs) external returns (bool);
  function batchTransferWithFees(address[] calldata recipients, uint256[] calldata amounts) external returns (bool);
  function batchTransferWithFeesRefs(address[] calldata recipients, uint256[] calldata amounts, uint256[] calldata refs) external returns (bool);
  function deposit(address user, bytes calldata depositData) external;
  function withdraw(uint256 amount) external;
  function updateChildChainManager(address _childChainManagerProxy) external;
  function burnWithFee(uint256 amount) external returns (bool);
  function transferWithFee(address recipient, uint256 amount) external returns (bool);
  function transferWithFeeRef(address recipient, uint256 amount, uint256 ref) external returns (bool);
  function setFees(address recipient, uint _feeBps, uint _feeFixed, uint _feeCap) external;
}

// 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/token/ERC20/IERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) external returns (bool);

    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);
}

// 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: @openzeppelin/contracts/utils/introspection/IERC165.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC165 standard, as defined in the
 * https://eips.ethereum.org/EIPS/eip-165[EIP].
 *
 * Implementers can declare support of contract interfaces, which can then be
 * queried by others ({ERC165Checker}).
 *
 * For an implementation, see {ERC165}.
 */
interface IERC165 {
    /**
     * @dev Returns true if this contract implements the interface defined by
     * `interfaceId`. See the corresponding
     * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
     * to learn more about how these ids are created.
     *
     * This function call must use less than 30 000 gas.
     */
    function supportsInterface(bytes4 interfaceId) external view returns (bool);
}