// SPDX-License-Identifier: MIT

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;
    }
}





/**
 * @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);
    }
}






/**
 * @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 `to`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address to, 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 `from` to `to` 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 from,
        address to,
        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);
}




/**********************************************************
    __  __           __             __          __        
   / / / /___ ______/ /_____  _____/ /   ____ _/ /_  _____
  / /_/ / __ `/ ___/ //_/ _ \/ ___/ /   / __ `/ __ \/ ___/
 / __  / /_/ / /__/ ,< /  __/ /  / /___/ /_/ / /_/ (__  ) 
/_/ /_/\__,_/\___/_/|_|\___/_/  /_____/\__,_/_.___/____/  
                                                          
 *********************************************************/


contract ClaimCrcV2 is Ownable {
    mapping(address => uint256) public snapshot;
    uint256 public snapshotOwnersCount = 0;
    uint256 public snapshotOwnersClaimedCount = 0;

    uint256 public crcUnclaimed = 0;
    uint256 public crcClaimed = 0;

    bool public setTokensAllowed = true;
    bool public migrationOpen = false;

    IERC20 public v1CrcToken =
        IERC20(0xC23fa49b581fFF9a3ea7E49D0504B06D07C6FF2a);
    IERC20 public v2CrcToken;
    address constant DEAD = 0x0000000000000000000000000000000000000000;
    //mainnet: 0xC23fa49b581fFF9a3ea7E49D0504B06D07C6FF2a
    constructor() {}

    function setAddresses(address[] memory accounts, uint256[] memory amount)
        external
        onlyOwner
    {
        require(setTokensAllowed == true, "disabled");
        require(accounts.length == amount.length, "ACCOUNT_LIST_NOT_EQUAL");
        for (uint8 i = 0; i < accounts.length; i++) {
            address _owner = accounts[i];
            require(snapshot[_owner] == 0, "owner !exists");
            snapshot[_owner] = amount[i];
            crcUnclaimed += amount[i];
            snapshotOwnersCount += 1;
        }
    }

    function setCrcToken(address _newCrcToken) external onlyOwner {
        v2CrcToken = IERC20(_newCrcToken);
    }

    function swapMigrationStatus() external onlyOwner {
        migrationOpen = !migrationOpen;
    }

    function disableSetTokens() external onlyOwner {
        require(setTokensAllowed == true, "Already disabled");
        setTokensAllowed = false;
    }

    function claimTokens() external {
        require(migrationOpen == true, "closed");
        address _owner = msg.sender;
        uint256 _v1Balance = snapshot[_owner];

        require(_owner != address(this), "Contract cannot claim tokens");
        require(_v1Balance > 0, "Insufficient V1 balance in account");
        require(v1CrcToken.balanceOf(msg.sender) >= _v1Balance,"SUFFICIENT_TOKEN_NOT_AVAILABLE");
        require(v1CrcToken.allowance(_owner,address(this)) >= _v1Balance,"SUFFICIENT_ALLOWANCE_NOT_GIVEN");

        uint256 _tokensLeft = v2CrcToken.balanceOf(address(this));

        if (_v1Balance > _tokensLeft) {
            _v1Balance = _tokensLeft;
        }

        snapshot[_owner] -= _v1Balance;

        crcUnclaimed -= _v1Balance;
        crcClaimed += _v1Balance;
        snapshotOwnersClaimedCount += 1;

        v1CrcToken.transferFrom(_owner,DEAD,_v1Balance);
        v2CrcToken.transfer(_owner, _v1Balance);
    }

    function claimTokensFor(address _owner) external {
        require(migrationOpen == true, "closed");
        uint256 _v1Balance = snapshot[_owner];

        require(_owner != address(this), "Contract cannot claim tokens");
        require(_v1Balance > 0, "Insufficient V1 balance in account");
        require(v1CrcToken.balanceOf(_owner) >= _v1Balance,"SUFFICIENT_TOKEN_NOT_AVAILABLE");
        require(v1CrcToken.allowance(_owner,address(this)) >= _v1Balance,"SUFFICIENT_ALLOWANCE_NOT_GIVEN");

        uint256 _tokensLeft = v2CrcToken.balanceOf(address(this));

        if (_v1Balance > _tokensLeft) {
            _v1Balance = _tokensLeft;
        }

        snapshot[_owner] -= _v1Balance;

        crcUnclaimed -= _v1Balance;
        crcClaimed += _v1Balance;
        snapshotOwnersClaimedCount += 1;

        v1CrcToken.transferFrom(_owner,DEAD,_v1Balance);
        v2CrcToken.transfer(_owner, _v1Balance);
    }

    function flushLiquidity() external onlyOwner {
        uint256 totalBalance = v2CrcToken.balanceOf(address(this));
        require(totalBalance > 0, "CONTRACT_IS_EMPTY");

        v2CrcToken.transfer(msg.sender, totalBalance);
    }
}