// 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;
    }
}

// File: @openzeppelin/contracts/access/Ownable.sol


// OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol)

pragma solidity ^0.8.0;


/**
 * @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: contracts/Subscription.sol

/**
 * @dev Wrappers over Solidity's arithmetic operations.
 *
 * NOTE: `SafeMath` is no longer needed starting with Solidity 0.8. 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 substraction 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. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * 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;
        }
    }
}


pragma solidity ^0.8.6;

/**
 * @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);
}

pragma solidity ^0.8.0;

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize, which returns 0 for contracts in
        // construction, since the code is only stored at the end of the
        // constructor execution.

        uint256 size;
        assembly {
            size := extcodesize(account)
        }
        return size > 0;
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain `call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCall(target, data, "Address: low-level call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }

    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        require(isContract(target), "Address: call to non-contract");

        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");

        (bool success, bytes memory returndata) = target.staticcall(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(isContract(target), "Address: delegate call to non-contract");

        (bool success, bytes memory returndata) = target.delegatecall(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

    function _verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) private pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly

                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

pragma solidity ^0.8.0;
/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    using Address for address;

    function safeTransfer(
        IERC20 token,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    function safeTransferFrom(
        IERC20 token,
        address from,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }

    /**
     * @dev Deprecated. This function has issues similar to the ones found in
     * {IERC20-approve}, and its usage is discouraged.
     *
     * Whenever possible, use {safeIncreaseAllowance} and
     * {safeDecreaseAllowance} instead.
     */
    function safeApprove(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero. To increase and decrease it, use
        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
        require(
            (value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }

    function safeIncreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        uint256 newAllowance = token.allowance(address(this), spender) + value;
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    function safeDecreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        unchecked {
            uint256 oldAllowance = token.allowance(address(this), spender);
            require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
            uint256 newAllowance = oldAllowance - value;
            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
        }
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
        // the target address contains contract code and also asserts for success in the low-level call.

        bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
        if (returndata.length > 0) {
            // Return data is optional
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}

contract SubscriptionPayment is Ownable {
    using SafeMath for uint256;
    using SafeERC20 for IERC20;

    uint256 public nextPlanId;
    uint256 public commission = 3;

    struct Plan {
        address merchant;
        address token;
        uint256 amount;
        uint256 frequency;
    }

    struct Subscription {
        address subscriber;
        uint256 start;
        uint256 nextPayment;
        uint256 nextPayAmount;
    }

    struct SubscriptionResponse {
        Subscription subscription;
        Plan plan;
        bool isActive;
    }

    mapping(uint256 => Plan) public plans;
    mapping(address => mapping(uint256 => Subscription)) public subscriptions;
    mapping(address => uint256) private lockedBalances;
    mapping(address => uint256[]) public merchantPlans;
    mapping(address => address[]) public merchantToSubscribers;


    event PlanCreated(address merchant, uint256 planId, uint256 date);
    event SubscriptionCreated(address subscriber, uint256 planId, uint256 date);
    event SubscriptionCancelled(address subscriber, uint256 planId, uint256 date);
    event PaymentSent(address from, address to, uint256 amount, uint256 planId, uint256 date);
    event TokensWithdraw(address indexed tokenAddress, address indexed to);

    function createPlan(address token, uint256 amount, uint256 frequency) external {
        require(token != address(0), 'Address cannot be null address');
        require(amount > 0, 'Amount needs to be > 0');
        require(frequency > 0, 'Frequency needs to be > 0');
        plans[nextPlanId] = Plan(msg.sender, token, amount, frequency);
        merchantPlans[msg.sender].push(nextPlanId);
        nextPlanId++;
    }

    function createPlanSuperAdmin(address merchant, address token, uint256 amount, uint256 frequency) public onlyOwner {
        require(token != address(0), 'Address cannot be null address');
        require(amount > 0, 'Amount needs to be > 0');
        require(frequency > 0, 'Frequency needs to be > 0');
        plans[nextPlanId] = Plan(merchant, token, amount, frequency);
        merchantPlans[merchant].push(nextPlanId);
        nextPlanId++;
    }

    function blackListPlan(uint256 planId) public onlyOwner {
        delete plans[planId];
    }

    function subscribe(uint256 planId) external {
        Plan storage plan = plans[planId];
        require(plan.merchant != address(0), 'This plan does not exist');
        uint256 txCommission = commission.mul(plan.amount).div(100);
        IERC20(plan.token).safeTransferFrom(msg.sender, plan.merchant, plan.amount.sub(txCommission));
        IERC20(plan.token).safeTransferFrom(msg.sender, owner(), txCommission);
        emit PaymentSent(msg.sender, plan.merchant, plan.amount, planId, block.timestamp);
        subscriptions[msg.sender][planId] = Subscription(msg.sender, block.timestamp, block.timestamp + plan.frequency, plan.amount);
        if (!isSubscriberForMerchant(plan.merchant, msg.sender)) {
            merchantToSubscribers[plan.merchant].push(msg.sender);
        }
        emit SubscriptionCreated(msg.sender, planId, block.timestamp);
    }

    function isSubscriberForMerchant(address merchant, address subscriber) internal view returns (bool) {
        address[] memory subs = merchantToSubscribers[merchant];
        for (uint256 i = 0; i < subs.length; i++) {
            if (subs[i] == subscriber) {
                return true;
            }
        }
        return false;
    }

    function getDiscountedPrice(uint256 planId, uint256 noOfEpochs) public view returns (uint256 discountedPrice) {
        Plan storage plan = plans[planId];
        if(noOfEpochs > 12) {
            discountedPrice = plan.amount.mul(noOfEpochs).div(100).mul(100 - 12);
        }
        else {
            discountedPrice = plan.amount.mul(noOfEpochs).div(100).mul(100 - noOfEpochs);
        }
        return discountedPrice;
    }

    function subscribeInAdvance(uint256 planId, uint256 noOfEpochs) external {
        Plan storage plan = plans[planId];
        require(plan.merchant != address(0), 'this plan does not exist');
        require(IERC20(plan.token).balanceOf(msg.sender) >= plan.amount.mul(noOfEpochs), "Insufficient balance");
        
        uint256 discountedPrice;

        if(noOfEpochs > 12) {
            discountedPrice = plan.amount.mul(noOfEpochs).div(100).mul(100 - 12);
        }
        else {
            discountedPrice = plan.amount.mul(noOfEpochs).div(100).mul(100 - noOfEpochs);
        }

        uint256 discountedMonthlyFee = discountedPrice.div(noOfEpochs);

        IERC20(plan.token).safeTransferFrom(msg.sender, address(this), discountedPrice);
        lockedBalances[msg.sender] += discountedPrice;

        
        uint256 txCommission = commission.mul(discountedMonthlyFee).div(100);
        
        IERC20(plan.token).safeTransfer(plan.merchant, discountedMonthlyFee.sub(txCommission));
        IERC20(plan.token).safeTransfer(owner(), txCommission);
        
        lockedBalances[msg.sender] -= discountedMonthlyFee;

        emit PaymentSent(
            address(this),
            plan.merchant,
            discountedMonthlyFee,
            planId,
            block.timestamp
        );

        subscriptions[msg.sender][planId] = Subscription(
            msg.sender,
            block.timestamp,
            block.timestamp + plan.frequency,
            discountedMonthlyFee
        );

        emit SubscriptionCreated(msg.sender, planId, block.timestamp);
    
    }

    function getSubscriptionsForMerchant(address _merchant) public view returns (SubscriptionResponse[][] memory) {
        address[] memory subs = merchantToSubscribers[_merchant];
        SubscriptionResponse[][] memory allResponses = new SubscriptionResponse[][](subs.length);

        for (uint256 i = 0; i < subs.length; i++) {
            address subscriber = subs[i];
        
            // Count how many subscriptions the subscriber has for this merchant
            uint256 count = 0;
            for (uint256 j = 0; j < nextPlanId; j++) {
                if (subscriptions[subscriber][j].subscriber != address(0) && plans[j].merchant == _merchant) {
                    count++;
                }
            }

            SubscriptionResponse[] memory responses = new SubscriptionResponse[](count);
            uint256 index = 0;
            for (uint256 j = 0; j < nextPlanId; j++) {
                if (subscriptions[subscriber][j].subscriber != address(0) && plans[j].merchant == _merchant) {
                    responses[index].subscription = subscriptions[subscriber][j];
                    responses[index].plan = plans[j];
                    responses[index].isActive = (subscriptions[subscriber][j].start < block.timestamp) && (block.timestamp < subscriptions[subscriber][j].nextPayment);
                    index++;
                }
            }
            allResponses[i] = responses;
        }
        return allResponses;
    }


    function unsubscribe(uint256 planId) external {
        Subscription storage subscription = subscriptions[msg.sender][planId];
        Plan storage plan = plans[planId];
        require(
            subscription.subscriber != address(0),
            'this subscription does not exist'
        );

        delete subscriptions[msg.sender][planId];

        /*
        if (lockedBalances[msg.sender] > 0) {
            IERC20(plan.token).safeTransfer(msg.sender, lockedBalances[msg.sender]);
            lockedBalances[msg.sender] = 0;
        }
        */

        emit SubscriptionCancelled(msg.sender, planId, block.timestamp);

        // Remove subscriber from the subscribers array if they have no other active subscriptions
        bool hasOtherSubscriptions = false;
        for (uint256 i = 0; i < nextPlanId; i++) {
            if (subscriptions[msg.sender][i].subscriber != address(0)) {
                hasOtherSubscriptions = true;
                break;
            }
        }

        if (!hasOtherSubscriptions) {
            _removeSubscriber(plan.merchant, msg.sender);
        }
    }

    function _removeSubscriber(address merchant, address subscriber) internal {
        address[] storage subs = merchantToSubscribers[merchant];
        bool isSubscriberFound = false;
        uint256 index = 0;
        for (uint256 i = 0; i < subs.length; i++) {
            if (subs[i] == subscriber) {
                index = i;
                isSubscriberFound = true;
                break;
            }
        }

        if (isSubscriberFound) {
            subs[index] = subs[subs.length - 1];
            subs.pop();
        }
    }

    function pay(address subscriber, uint256 planId) external {
        Subscription storage subscription = subscriptions[subscriber][planId];
        Plan storage plan = plans[planId];
        require(subscription.subscriber != address(0), 'this subscription does not exist');
        require(block.timestamp > subscription.nextPayment, 'not due yet');

        if (lockedBalances[subscriber] > 0) {
            uint256 amount = subscription.nextPayAmount;
            uint256 txCommission = commission.mul(amount).div(100);
            IERC20(plan.token).safeTransfer(plan.merchant, amount.sub(txCommission));
            IERC20(plan.token).safeTransfer(owner(), txCommission);

            lockedBalances[subscriber] -= amount;

            emit PaymentSent(
                subscriber,
                plan.merchant,
                amount,
                planId,
                block.timestamp
            );
        } else {
            uint256 txCommission = commission.mul(plan.amount).div(100);

            IERC20(plan.token).safeTransferFrom(msg.sender, plan.merchant, plan.amount.sub(txCommission));
            IERC20(plan.token).safeTransferFrom(msg.sender, owner(), txCommission);

            emit PaymentSent(
                subscriber,
                plan.merchant,
                plan.amount,
                planId,
                block.timestamp
            );
        }

        subscription.nextPayment = subscription.nextPayment.add(plan.frequency);
    }

    function getSubscription(address subscriber, uint256 planId) public view returns (SubscriptionResponse memory) {
        Subscription storage subscription = subscriptions[subscriber][planId];
        Plan storage plan = plans[planId];
        require(subscription.subscriber != address(0), 'this subscription does not exist');

        SubscriptionResponse memory subscribeResponse;
        subscribeResponse.subscription = subscription;
        subscribeResponse.plan = plan;
        subscribeResponse.isActive = (subscription.start < block.timestamp) && (block.timestamp < subscription.nextPayment);

        return subscribeResponse;
    }

    function setCommission(uint256 _commission) public onlyOwner {
        require(_commission < 100, "Commission must be less than 100");
        commission = _commission;
    }

    function getLockedBalance(address user) external view returns (uint256) {
        return lockedBalances[user];
    }

    function withdrawTokens(address tokenAddress, address to, uint256 amount) external onlyOwner {
        require(amount > 0, "Amount must be greater than 0");

        IERC20 token = IERC20(tokenAddress);
        require(token.balanceOf(address(this)) >= amount, "Insufficient token balance");

        token.safeTransfer(to, amount);
        emit TokensWithdraw(tokenAddress, to);
    }

    function getPlansByMerchant(address _merchant) public view returns (Plan[] memory) {
        uint256[] memory planIds = merchantPlans[_merchant];
        Plan[] memory result = new Plan[](planIds.length);

        for (uint256 i = 0; i < planIds.length; i++) {
            result[i] = plans[planIds[i]];
        }

        return result;
    }
}