// 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/token/ERC20/IERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @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);

    /**
     * @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);
}

// 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/math/SafeMath.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (utils/math/SafeMath.sol)

pragma solidity ^0.8.0;

// CAUTION
// This version of SafeMath should only be used with Solidity 0.8 or later,
// because it relies on the compiler's built in overflow checks.

/**
 * @dev Wrappers over Solidity's arithmetic operations.
 *
 * NOTE: `SafeMath` is generally not needed starting with Solidity 0.8, since the compiler
 * now has built in overflow checking.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            uint256 c = a + b;
            if (c < a) return (false, 0);
            return (true, c);
        }
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b > a) return (false, 0);
            return (true, a - b);
        }
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
            // benefit is lost if 'b' is also tested.
            // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
            if (a == 0) return (true, 0);
            uint256 c = a * b;
            if (c / a != b) return (false, 0);
            return (true, c);
        }
    }

    /**
     * @dev Returns the division of two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a / b);
        }
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a % b);
        }
    }

    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        return a + b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return a - b;
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        return a * b;
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator.
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return a / b;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return a % b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {trySub}.
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b <= a, errorMessage);
            return a - b;
        }
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a / b;
        }
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting with custom message when dividing by zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryMod}.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a % b;
        }
    }
}

// File: contracts/MidgetVotingContract.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.17;

import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/utils/math/SafeMath.sol";

contract MidgetVotingContract is Ownable {
    using SafeMath for uint256;

    /* EVENTS  */
    event VoteCasted(address voter, uint256 pollID, bool vote);
    event PollCreated(address creator, uint256 pollID, string description);
    event PollEdited(uint256 pollID, bool isValid);
    event UserProfileImgEdited(address user);

    /* ContractInfo */
    struct ContractInfo {
        uint256 pollCount;
        uint256 minTokenBalanceToVote;
        uint256 minTokenBalanceToCreatePoll;
        uint256 maxCreatingCountPerWeek;
        uint256 currentBlockTime;
        address contractOwner;
    }

    /* UserInfo */
    struct UserInfo {
        uint256 userVoteCount;
        uint256 userPollCount;
        uint256 userWeekPollCount;
        string userProfileImg;
    }

    /* POLL */
    struct Poll {
        uint256 pollId;
        uint256 yeaVotes;
        uint256 nayVotes;
        string description;
        address creator;
        address[] voters;
        bool isValid;
    }

    uint8 private constant _decimals = 18;
    uint256 public pollCount;
    uint256 public startedAt;
    uint256 public minTokenBalanceToVote = 1 * 10 ** _decimals;
    uint256 public minTokenBalanceToCreatePoll = 10 * 10 ** _decimals;
    uint256 public maxCreatingCountPerWeek = 1;

    uint256 public constant WEEK_IN_SECOND = 7 * 86400;

    mapping(address => uint256) public _userVoteCount;
    mapping(address => uint256) public _userPollCount;
    mapping(address => string) public _userProfileImg;
    mapping(address => mapping(uint256 => bool)) public _userHasVoted;
    mapping(address => uint256) public _userWeekPollCount;

    Poll[] public polls;
    IERC20 public token;

    constructor(address _token) {
        require(_token != address(0));
        token = IERC20(_token);
        startedAt = block.timestamp;
    }

    /*
     * Modifier that checks for a valid poll ID.
     */
    modifier validPoll(uint256 _pollId) {
        require(_pollId >= 0 && _pollId < pollCount, "Not a valid poll Id.");
        _;
    }

    /* CALL METHODS */

    /*
     * Creates a new poll.
     */
    function createPoll(
        string memory _description
    ) external returns (uint256 pollId) {
        if (msg.sender != owner()) {
            require(
                token.balanceOf(msg.sender) >= minTokenBalanceToCreatePoll,
                "Insufficient token balance."
            );

            require(
                _userWeekPollCount[msg.sender] < maxCreatingCountPerWeek,
                "Exceeded max creating count per week"
            );
        }

        pollId = pollCount++;

        polls.push();
        Poll storage newPoll = polls[pollId];

        newPoll.pollId = pollId;
        newPoll.creator = msg.sender;
        newPoll.description = _description;
        newPoll.isValid = true;

        _userPollCount[msg.sender] += 1;
        _userWeekPollCount[msg.sender] += 1;

        emit PollCreated(msg.sender, pollCount, _description);

        return pollId;
    }

    /*
     * Casts a vote for a given poll.
     */
    function castVote(uint256 _pollId, bool _vote) external validPoll(_pollId) {
        if (msg.sender != owner()) {
            require(
                token.balanceOf(msg.sender) >= minTokenBalanceToVote,
                "Insufficient token balance."
            );
        }

        require(
            !_getIfUserHasVoted(_pollId, msg.sender),
            "User has already voted."
        );

        require(
            token.balanceOf(msg.sender) / (10 ** _decimals) > _userVoteCount[msg.sender],
            "Voted count has been exceeded."
        );

        Poll storage curPoll = polls[_pollId];

        if (_vote) {
            curPoll.yeaVotes += 1;
        } else {
            curPoll.nayVotes += 1;
        }

        curPoll.voters.push(msg.sender);

        _userVoteCount[msg.sender] += 1;
        _userHasVoted[msg.sender][_pollId] = true;

        emit VoteCasted(msg.sender, _pollId, _vote);
    }

    /*
     * toggle valid status of a specific poll.
     */
    function toggleValidStatus(
        uint256 _pollId,
        bool _isValid
    ) external onlyOwner {
        Poll storage curPoll = polls[_pollId];
        curPoll.isValid = _isValid;

        emit PollEdited(_pollId, _isValid);
    }

    /*
     * update user profile image.
     */
    function updateUserProfileImg(string memory _imgUrl) external {
        _userProfileImg[msg.sender] = _imgUrl;

        emit UserProfileImgEdited(msg.sender);
    }

    /*
     * update minTokenBalanceToVote.
     */
    function updateMinTokenBalanceToVote(
        uint256 _minTokenBalanceToVote
    ) external onlyOwner {
        minTokenBalanceToVote = _minTokenBalanceToVote;
    }

    /*
     * update maxCreatingCountPerWeek.
     */
    function updateMaxCreatingCountPerWeek(
        uint256 _maxCreatingCountPerWeek
    ) external onlyOwner {
        maxCreatingCountPerWeek = _maxCreatingCountPerWeek;
    }

    /*
     * update minTokenBalanceToCreatePoll.
     */
    function updateMinTokenBalanceToCreatePoll(
        uint256 _minTokenBalanceToCreatePoll
    ) external onlyOwner {
        minTokenBalanceToCreatePoll = _minTokenBalanceToCreatePoll;
    }

    /* VIEW METHODS */

    /*
     * Get contract info
     */
    function getContractInfo() public view returns (ContractInfo memory) {
        return ContractInfo({
            pollCount: pollCount,
            minTokenBalanceToVote: minTokenBalanceToVote,
            minTokenBalanceToCreatePoll: minTokenBalanceToCreatePoll,
            maxCreatingCountPerWeek: maxCreatingCountPerWeek,
            currentBlockTime: block.timestamp,
            contractOwner: owner()
        });
    }

    /*
     * Get user info
     */
    function getUserInfo(address _user) public view returns (UserInfo memory) {
        return UserInfo({
            userVoteCount: _userVoteCount[_user],
            userPollCount: _userPollCount[_user],
            userWeekPollCount: _userWeekPollCount[_user],
            userProfileImg: _userProfileImg[_user]
        });
    }

    /*
     * Get valid polls
     */
    function getPolls(
        uint256 _fromIndex,
        uint256 _count,
        bool _isAll
    ) public view returns (Poll[] memory) {
        if (_isAll) {
            return polls;
        } else {
            Poll[] memory validPolls = new Poll[](_count);

            for(uint i = 0; i < _count; i++){
                if(polls[_fromIndex + i].isValid && (_fromIndex + i) < pollCount) {
                    validPolls[i] = polls[_fromIndex + i];
                }
            }

            return validPolls;
        }
    }

    /*
     * Get week index
     */
    function _getWeekIndex() internal view returns (uint256) {
        return (block.timestamp - startedAt) / WEEK_IN_SECOND;
    }

    /*
     * Checks if a user has voted for a specific poll.
     */
    function _getIfUserHasVoted(
        uint256 _pollId,
        address _user
    ) internal view returns (bool) {
        return _userHasVoted[_user][_pollId];
    }
}