JomonStaking

{{
  "language": "Solidity",
  "sources": {
    "@openzeppelin/contracts/access/Ownable.sol": {
      "content": "// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (access/Ownable.sol)

pragma solidity ^0.8.20;

import {Context} from "../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.
 *
 * The initial owner is set to the address provided by the deployer. 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;

    /**
     * @dev The caller account is not authorized to perform an operation.
     */
    error OwnableUnauthorizedAccount(address account);

    /**
     * @dev The owner is not a valid owner account. (eg. `address(0)`)
     */
    error OwnableInvalidOwner(address owner);

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the address provided by the deployer as the initial owner.
     */
    constructor(address initialOwner) {
        if (initialOwner == address(0)) {
            revert OwnableInvalidOwner(address(0));
        }
        _transferOwnership(initialOwner);
    }

    /**
     * @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 {
        if (owner() != _msgSender()) {
            revert OwnableUnauthorizedAccount(_msgSender());
        }
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby disabling 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 {
        if (newOwner == address(0)) {
            revert OwnableInvalidOwner(address(0));
        }
        _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);
    }
}
"
    },
    "@openzeppelin/contracts/interfaces/IERC1363.sol": {
      "content": "// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.4.0) (interfaces/IERC1363.sol)

pragma solidity >=0.6.2;

import {IERC20} from "./IERC20.sol";
import {IERC165} from "./IERC165.sol";

/**
 * @title IERC1363
 * @dev Interface of the ERC-1363 standard as defined in the https://eips.ethereum.org/EIPS/eip-1363[ERC-1363].
 *
 * Defines an extension interface for ERC-20 tokens that supports executing code on a recipient contract
 * after `transfer` or `transferFrom`, or code on a spender contract after `approve`, in a single transaction.
 */
interface IERC1363 is IERC20, IERC165 {
    /*
     * Note: the ERC-165 identifier for this interface is 0xb0202a11.
     * 0xb0202a11 ===
     *   bytes4(keccak256('transferAndCall(address,uint256)')) ^
     *   bytes4(keccak256('transferAndCall(address,uint256,bytes)')) ^
     *   bytes4(keccak256('transferFromAndCall(address,address,uint256)')) ^
     *   bytes4(keccak256('transferFromAndCall(address,address,uint256,bytes)')) ^
     *   bytes4(keccak256('approveAndCall(address,uint256)')) ^
     *   bytes4(keccak256('approveAndCall(address,uint256,bytes)'))
     */

    /**
     * @dev Moves a `value` amount of tokens from the caller's account to `to`
     * and then calls {IERC1363Receiver-onTransferReceived} on `to`.
     * @param to The address which you want to transfer to.
     * @param value The amount of tokens to be transferred.
     * @return A boolean value indicating whether the operation succeeded unless throwing.
     */
    function transferAndCall(address to, uint256 value) external returns (bool);

    /**
     * @dev Moves a `value` amount of tokens from the caller's account to `to`
     * and then calls {IERC1363Receiver-onTransferReceived} on `to`.
     * @param to The address which you want to transfer to.
     * @param value The amount of tokens to be transferred.
     * @param data Additional data with no specified format, sent in call to `to`.
     * @return A boolean value indicating whether the operation succeeded unless throwing.
     */
    function transferAndCall(address to, uint256 value, bytes calldata data) external returns (bool);

    /**
     * @dev Moves a `value` amount of tokens from `from` to `to` using the allowance mechanism
     * and then calls {IERC1363Receiver-onTransferReceived} on `to`.
     * @param from The address which you want to send tokens from.
     * @param to The address which you want to transfer to.
     * @param value The amount of tokens to be transferred.
     * @return A boolean value indicating whether the operation succeeded unless throwing.
     */
    function transferFromAndCall(address from, address to, uint256 value) external returns (bool);

    /**
     * @dev Moves a `value` amount of tokens from `from` to `to` using the allowance mechanism
     * and then calls {IERC1363Receiver-onTransferReceived} on `to`.
     * @param from The address which you want to send tokens from.
     * @param to The address which you want to transfer to.
     * @param value The amount of tokens to be transferred.
     * @param data Additional data with no specified format, sent in call to `to`.
     * @return A boolean value indicating whether the operation succeeded unless throwing.
     */
    function transferFromAndCall(address from, address to, uint256 value, bytes calldata data) external returns (bool);

    /**
     * @dev Sets a `value` amount of tokens as the allowance of `spender` over the
     * caller's tokens and then calls {IERC1363Spender-onApprovalReceived} on `spender`.
     * @param spender The address which will spend the funds.
     * @param value The amount of tokens to be spent.
     * @return A boolean value indicating whether the operation succeeded unless throwing.
     */
    function approveAndCall(address spender, uint256 value) external returns (bool);

    /**
     * @dev Sets a `value` amount of tokens as the allowance of `spender` over the
     * caller's tokens and then calls {IERC1363Spender-onApprovalReceived} on `spender`.
     * @param spender The address which will spend the funds.
     * @param value The amount of tokens to be spent.
     * @param data Additional data with no specified format, sent in call to `spender`.
     * @return A boolean value indicating whether the operation succeeded unless throwing.
     */
    function approveAndCall(address spender, uint256 value, bytes calldata data) external returns (bool);
}
"
    },
    "@openzeppelin/contracts/interfaces/IERC165.sol": {
      "content": "// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.4.0) (interfaces/IERC165.sol)

pragma solidity >=0.4.16;

import {IERC165} from "../utils/introspection/IERC165.sol";
"
    },
    "@openzeppelin/contracts/interfaces/IERC20.sol": {
      "content": "// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.4.0) (interfaces/IERC20.sol)

pragma solidity >=0.4.16;

import {IERC20} from "../token/ERC20/IERC20.sol";
"
    },
    "@openzeppelin/contracts/token/ERC20/IERC20.sol": {
      "content": "// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.4.0) (token/ERC20/IERC20.sol)

pragma solidity >=0.4.16;

/**
 * @dev Interface of the ERC-20 standard as defined in the ERC.
 */
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 value of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

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

    /**
     * @dev Moves a `value` amount of 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 value) 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 a `value` amount of tokens 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 value) external returns (bool);

    /**
     * @dev Moves a `value` amount of tokens from `from` to `to` using the
     * allowance mechanism. `value` 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 value) external returns (bool);
}
"
    },
    "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol": {
      "content": "// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.3.0) (token/ERC20/utils/SafeERC20.sol)

pragma solidity ^0.8.20;

import {IERC20} from "../IERC20.sol";
import {IERC1363} from "../../../interfaces/IERC1363.sol";

/**
 * @title SafeERC20
 * @dev Wrappers around ERC-20 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 {
    /**
     * @dev An operation with an ERC-20 token failed.
     */
    error SafeERC20FailedOperation(address token);

    /**
     * @dev Indicates a failed `decreaseAllowance` request.
     */
    error SafeERC20FailedDecreaseAllowance(address spender, uint256 currentAllowance, uint256 requestedDecrease);

    /**
     * @dev Transfer `value` amount of `token` from the calling contract to `to`. If `token` returns no value,
     * non-reverting calls are assumed to be successful.
     */
    function safeTransfer(IERC20 token, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeCall(token.transfer, (to, value)));
    }

    /**
     * @dev Transfer `value` amount of `token` from `from` to `to`, spending the approval given by `from` to the
     * calling contract. If `token` returns no value, non-reverting calls are assumed to be successful.
     */
    function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeCall(token.transferFrom, (from, to, value)));
    }

    /**
     * @dev Variant of {safeTransfer} that returns a bool instead of reverting if the operation is not successful.
     */
    function trySafeTransfer(IERC20 token, address to, uint256 value) internal returns (bool) {
        return _callOptionalReturnBool(token, abi.encodeCall(token.transfer, (to, value)));
    }

    /**
     * @dev Variant of {safeTransferFrom} that returns a bool instead of reverting if the operation is not successful.
     */
    function trySafeTransferFrom(IERC20 token, address from, address to, uint256 value) internal returns (bool) {
        return _callOptionalReturnBool(token, abi.encodeCall(token.transferFrom, (from, to, value)));
    }

    /**
     * @dev Increase the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
     * non-reverting calls are assumed to be successful.
     *
     * IMPORTANT: If the token implements ERC-7674 (ERC-20 with temporary allowance), and if the "client"
     * smart contract uses ERC-7674 to set temporary allowances, then the "client" smart contract should avoid using
     * this function. Performing a {safeIncreaseAllowance} or {safeDecreaseAllowance} operation on a token contract
     * that has a non-zero temporary allowance (for that particular owner-spender) will result in unexpected behavior.
     */
    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 oldAllowance = token.allowance(address(this), spender);
        forceApprove(token, spender, oldAllowance + value);
    }

    /**
     * @dev Decrease the calling contract's allowance toward `spender` by `requestedDecrease`. If `token` returns no
     * value, non-reverting calls are assumed to be successful.
     *
     * IMPORTANT: If the token implements ERC-7674 (ERC-20 with temporary allowance), and if the "client"
     * smart contract uses ERC-7674 to set temporary allowances, then the "client" smart contract should avoid using
     * this function. Performing a {safeIncreaseAllowance} or {safeDecreaseAllowance} operation on a token contract
     * that has a non-zero temporary allowance (for that particular owner-spender) will result in unexpected behavior.
     */
    function safeDecreaseAllowance(IERC20 token, address spender, uint256 requestedDecrease) internal {
        unchecked {
            uint256 currentAllowance = token.allowance(address(this), spender);
            if (currentAllowance < requestedDecrease) {
                revert SafeERC20FailedDecreaseAllowance(spender, currentAllowance, requestedDecrease);
            }
            forceApprove(token, spender, currentAllowance - requestedDecrease);
        }
    }

    /**
     * @dev Set the calling contract's allowance toward `spender` to `value`. If `token` returns no value,
     * non-reverting calls are assumed to be successful. Meant to be used with tokens that require the approval
     * to be set to zero before setting it to a non-zero value, such as USDT.
     *
     * NOTE: If the token implements ERC-7674, this function will not modify any temporary allowance. This function
     * only sets the "standard" allowance. Any temporary allowance will remain active, in addition to the value being
     * set here.
     */
    function forceApprove(IERC20 token, address spender, uint256 value) internal {
        bytes memory approvalCall = abi.encodeCall(token.approve, (spender, value));

        if (!_callOptionalReturnBool(token, approvalCall)) {
            _callOptionalReturn(token, abi.encodeCall(token.approve, (spender, 0)));
            _callOptionalReturn(token, approvalCall);
        }
    }

    /**
     * @dev Performs an {ERC1363} transferAndCall, with a fallback to the simple {ERC20} transfer if the target has no
     * code. This can be used to implement an {ERC721}-like safe transfer that rely on {ERC1363} checks when
     * targeting contracts.
     *
     * Reverts if the returned value is other than `true`.
     */
    function transferAndCallRelaxed(IERC1363 token, address to, uint256 value, bytes memory data) internal {
        if (to.code.length == 0) {
            safeTransfer(token, to, value);
        } else if (!token.transferAndCall(to, value, data)) {
            revert SafeERC20FailedOperation(address(token));
        }
    }

    /**
     * @dev Performs an {ERC1363} transferFromAndCall, with a fallback to the simple {ERC20} transferFrom if the target
     * has no code. This can be used to implement an {ERC721}-like safe transfer that rely on {ERC1363} checks when
     * targeting contracts.
     *
     * Reverts if the returned value is other than `true`.
     */
    function transferFromAndCallRelaxed(
        IERC1363 token,
        address from,
        address to,
        uint256 value,
        bytes memory data
    ) internal {
        if (to.code.length == 0) {
            safeTransferFrom(token, from, to, value);
        } else if (!token.transferFromAndCall(from, to, value, data)) {
            revert SafeERC20FailedOperation(address(token));
        }
    }

    /**
     * @dev Performs an {ERC1363} approveAndCall, with a fallback to the simple {ERC20} approve if the target has no
     * code. This can be used to implement an {ERC721}-like safe transfer that rely on {ERC1363} checks when
     * targeting contracts.
     *
     * NOTE: When the recipient address (`to`) has no code (i.e. is an EOA), this function behaves as {forceApprove}.
     * Opposedly, when the recipient address (`to`) has code, this function only attempts to call {ERC1363-approveAndCall}
     * once without retrying, and relies on the returned value to be true.
     *
     * Reverts if the returned value is other than `true`.
     */
    function approveAndCallRelaxed(IERC1363 token, address to, uint256 value, bytes memory data) internal {
        if (to.code.length == 0) {
            forceApprove(token, to, value);
        } else if (!token.approveAndCall(to, value, data)) {
            revert SafeERC20FailedOperation(address(token));
        }
    }

    /**
     * @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).
     *
     * This is a variant of {_callOptionalReturnBool} that reverts if call fails to meet the requirements.
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        uint256 returnSize;
        uint256 returnValue;
        assembly ("memory-safe") {
            let success := call(gas(), token, 0, add(data, 0x20), mload(data), 0, 0x20)
            // bubble errors
            if iszero(success) {
                let ptr := mload(0x40)
                returndatacopy(ptr, 0, returndatasize())
                revert(ptr, returndatasize())
            }
            returnSize := returndatasize()
            returnValue := mload(0)
        }

        if (returnSize == 0 ? address(token).code.length == 0 : returnValue != 1) {
            revert SafeERC20FailedOperation(address(token));
        }
    }

    /**
     * @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).
     *
     * This is a variant of {_callOptionalReturn} that silently catches all reverts and returns a bool instead.
     */
    function _callOptionalReturnBool(IERC20 token, bytes memory data) private returns (bool) {
        bool success;
        uint256 returnSize;
        uint256 returnValue;
        assembly ("memory-safe") {
            success := call(gas(), token, 0, add(data, 0x20), mload(data), 0, 0x20)
            returnSize := returndatasize()
            returnValue := mload(0)
        }
        return success && (returnSize == 0 ? address(token).code.length > 0 : returnValue == 1);
    }
}
"
    },
    "@openzeppelin/contracts/utils/Context.sol": {
      "content": "// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.1) (utils/Context.sol)

pragma solidity ^0.8.20;

/**
 * @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;
    }

    function _contextSuffixLength() internal view virtual returns (uint256) {
        return 0;
    }
}
"
    },
    "@openzeppelin/contracts/utils/introspection/IERC165.sol": {
      "content": "// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.4.0) (utils/introspection/IERC165.sol)

pragma solidity >=0.4.16;

/**
 * @dev Interface of the ERC-165 standard, as defined in the
 * https://eips.ethereum.org/EIPS/eip-165[ERC].
 *
 * 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[ERC 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);
}
"
    },
    "contracts/JomonStaking.sol": {
      "content": "// SPDX-License-Identifier: MIT\r
pragma solidity ^0.8.20;\r
\r
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";\r
import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";\r
import "@openzeppelin/contracts/access/Ownable.sol";\r
\r
/**\r
 * @title JomonStaking\r
 * @dev Staking contract for Jomon tokens that rewards Collar tokens\r
 * @notice Single pool with 4-year staking period\r
 *         Formula: 4206 Jomon = 1 Collar after 4 years (proportional rewards)\r
 */\r
contract JomonStaking is Ownable {\r
    using SafeERC20 for IERC20;\r
\r
    // Token addresses\r
    IERC20 public immutable jomonToken;\r
    IERC20 public immutable collarToken;\r
\r
    // Staking constants\r
    uint256 public constant STAKING_PERIOD = 4 * 365 days; // 4 years in seconds\r
    uint256 public constant JOMON_PER_COLLAR = 4674; // 4206 Jomon = 1 Collar after 4 years\r
    uint256 public constant WITHDRAWAL_COOLDOWN = 24 hours; // 24-hour withdrawal timer\r
\r
    // Total supply constants for reference\r
    uint256 public constant TOTAL_JOMON_SUPPLY = 420690000000;\r
    uint256 public constant TOTAL_COLLAR_SUPPLY = 100000000;\r
\r
    // User staking information\r
    struct StakeInfo {\r
        uint256 amount;           // Amount of Jomon staked\r
        uint256 startTime;        // Timestamp when staking started\r
        uint256 claimedRewards;   // Total Collar tokens claimed so far\r
    }\r
\r
    // Withdrawal request information\r
    struct WithdrawalRequest {\r
        uint256 requestTime;      // Timestamp when withdrawal was requested\r
        uint256 amount;           // Amount requested for withdrawal\r
        bool pending;             // Whether withdrawal is pending\r
    }\r
\r
    mapping(address => StakeInfo) public stakes;\r
    mapping(address => WithdrawalRequest) public withdrawalRequests;\r
\r
    // Total staked amount\r
    uint256 public totalStaked;\r
\r
    // Events\r
    event Staked(address indexed user, uint256 amount, uint256 timestamp);\r
    event RewardsClaimed(address indexed user, uint256 amount, uint256 timestamp);\r
    event WithdrawalRequested(address indexed user, uint256 amount, uint256 timestamp);\r
    event Withdrawn(address indexed user, uint256 amount, uint256 timestamp);\r
\r
    /**\r
     * @dev Constructor\r
     * @param _jomonToken Address of the Jomon token contract\r
     * @param _collarToken Address of the Collar token contract\r
     */\r
    constructor(address _jomonToken, address _collarToken) Ownable(msg.sender) {\r
        require(_jomonToken != address(0), "Invalid Jomon token address");\r
        require(_collarToken != address(0), "Invalid Collar token address");\r
        \r
        jomonToken = IERC20(_jomonToken);\r
        collarToken = IERC20(_collarToken);\r
    }\r
\r
    /**\r
     * @dev Stake Jomon tokens\r
     * @param _amount Amount of Jomon tokens to stake\r
     * @notice If user already has a stake, it will add to the existing stake\r
     */\r
    function stake(uint256 _amount) external {\r
        require(_amount > 0, "Amount must be greater than 0");\r
        \r
        StakeInfo storage userStake = stakes[msg.sender];\r
        \r
        // If user has existing stake, claim rewards first to reset the calculation\r
        if (userStake.amount > 0) {\r
            _claimRewardsInternal();\r
        }\r
\r
        // Transfer Jomon tokens from user to contract\r
        jomonToken.safeTransferFrom(msg.sender, address(this), _amount);\r
\r
        // Update stake information\r
        if (userStake.amount == 0) {\r
            // New stake\r
            userStake.startTime = block.timestamp;\r
            userStake.amount = _amount;\r
        } else {\r
            // Add to existing stake\r
            // Reset start time when adding to stake (proportional calculation)\r
            // Weighted average approach for fair reward calculation\r
            uint256 timeElapsed = block.timestamp - userStake.startTime;\r
            uint256 totalAmount = userStake.amount + _amount;\r
            \r
            // Calculate new start time based on weighted average\r
            // This ensures fair rewards when adding to existing stake\r
            if (timeElapsed > 0) {\r
                // Adjust start time to account for new amount\r
                userStake.startTime = block.timestamp - \r
                    (timeElapsed * userStake.amount) / totalAmount;\r
            }\r
            \r
            userStake.amount = totalAmount;\r
        }\r
        \r
        totalStaked += _amount;\r
\r
        emit Staked(msg.sender, _amount, block.timestamp);\r
    }\r
\r
    /**\r
     * @dev Calculate current available rewards for a user\r
     * @param _user Address of the user\r
     * @return Available Collar tokens that can be claimed\r
     */\r
    function calculateRewards(address _user) public view returns (uint256) {\r
        StakeInfo memory userStake = stakes[_user];\r
        \r
        if (userStake.amount == 0) {\r
            return 0;\r
        }\r
\r
        uint256 timeElapsed = block.timestamp - userStake.startTime;\r
        \r
        // Calculate maximum possible rewards for full period\r
        // Formula: (userStake.amount * 1e9) / JOMON_PER_COLLAR\r
        // Jomon has 9 decimals, Collar has 18 decimals\r
        // Example: 4674e9 Jomon * 1e9 / 4674 = 1e18 (1 Collar token with 18 decimals)\r
        uint256 maxRewards = (userStake.amount * 1e9) / JOMON_PER_COLLAR;\r
        \r
        // Calculate proportional rewards based on time elapsed\r
        uint256 proportionalRewards = 0;\r
        if (timeElapsed >= STAKING_PERIOD) {\r
            // Full period completed, user gets full rewards\r
            proportionalRewards = maxRewards;\r
        } else {\r
            // Proportional rewards based on time staked\r
            proportionalRewards = (maxRewards * timeElapsed) / STAKING_PERIOD;\r
        }\r
\r
        // Subtract already claimed rewards\r
        uint256 availableRewards = proportionalRewards - userStake.claimedRewards;\r
        \r
        return availableRewards;\r
    }\r
\r
    /**\r
     * @dev Claim Collar token rewards\r
     * @notice Claims proportional rewards based on staking time\r
     */\r
    function claimRewards() external {\r
        _claimRewardsInternal();\r
    }\r
\r
    /**\r
     * @dev Internal function to claim rewards\r
     */\r
    function _claimRewardsInternal() internal {\r
        uint256 availableRewards = calculateRewards(msg.sender);\r
        \r
        require(availableRewards > 0, "No rewards available");\r
\r
        StakeInfo storage userStake = stakes[msg.sender];\r
        userStake.claimedRewards += availableRewards;\r
\r
        // Transfer Collar tokens to user\r
        collarToken.safeTransfer(msg.sender, availableRewards);\r
\r
        emit RewardsClaimed(msg.sender, availableRewards, block.timestamp);\r
    }\r
\r
    /**\r
     * @dev Request withdrawal of staked Jomon tokens\r
     * @notice Initiates 24-hour cooldown period\r
     */\r
    function requestWithdrawal() external {\r
        StakeInfo memory userStake = stakes[msg.sender];\r
        require(userStake.amount > 0, "No stake found");\r
        \r
        WithdrawalRequest storage request = withdrawalRequests[msg.sender];\r
        require(!request.pending, "Withdrawal already requested");\r
\r
        // Claim any available rewards before withdrawal\r
        if (calculateRewards(msg.sender) > 0) {\r
            _claimRewardsInternal();\r
        }\r
\r
        request.requestTime = block.timestamp;\r
        request.amount = userStake.amount;\r
        request.pending = true;\r
\r
        emit WithdrawalRequested(msg.sender, userStake.amount, block.timestamp);\r
    }\r
\r
    /**\r
     * @dev Cancel withdrawal request\r
     */\r
    function cancelWithdrawalRequest() external {\r
        WithdrawalRequest storage request = withdrawalRequests[msg.sender];\r
        require(request.pending, "No pending withdrawal request");\r
        \r
        request.pending = false;\r
        request.amount = 0;\r
        request.requestTime = 0;\r
    }\r
\r
    /**\r
     * @dev Withdraw staked Jomon tokens after cooldown period\r
     * @notice Can only be called after 24-hour cooldown has passed\r
     */\r
    function withdraw() external {\r
        WithdrawalRequest storage request = withdrawalRequests[msg.sender];\r
        require(request.pending, "No withdrawal request found");\r
        require(\r
            block.timestamp >= request.requestTime + WITHDRAWAL_COOLDOWN,\r
            "Cooldown period not completed"\r
        );\r
\r
        uint256 withdrawAmount = request.amount;\r
        StakeInfo storage userStake = stakes[msg.sender];\r
\r
        // Clear withdrawal request\r
        request.pending = false;\r
        request.amount = 0;\r
        request.requestTime = 0;\r
\r
        // Clear stake information\r
        totalStaked -= userStake.amount;\r
        userStake.amount = 0;\r
        userStake.startTime = 0;\r
        userStake.claimedRewards = 0;\r
\r
        // Transfer Jomon tokens back to user\r
        jomonToken.safeTransfer(msg.sender, withdrawAmount);\r
\r
        emit Withdrawn(msg.sender, withdrawAmount, block.timestamp);\r
    }\r
\r
    /**\r
     * @dev Get user's stake information\r
     * @param _user Address of the user\r
     * @return amount Staked amount\r
     * @return startTime Staking start timestamp\r
     * @return claimedRewards Total claimed rewards\r
     * @return availableRewards Current available rewards\r
     */\r
    function getUserStakeInfo(address _user) external view returns (\r
        uint256 amount,\r
        uint256 startTime,\r
        uint256 claimedRewards,\r
        uint256 availableRewards\r
    ) {\r
        StakeInfo memory userStake = stakes[_user];\r
        amount = userStake.amount;\r
        startTime = userStake.startTime;\r
        claimedRewards = userStake.claimedRewards;\r
        availableRewards = calculateRewards(_user);\r
    }\r
\r
    /**\r
     * @dev Get withdrawal request information\r
     * @param _user Address of the user\r
     * @return requestTime Timestamp when withdrawal was requested\r
     * @return amount Amount requested for withdrawal\r
     * @return pending Whether withdrawal is pending\r
     * @return canWithdraw Whether cooldown has passed\r
     */\r
    function getWithdrawalRequestInfo(address _user) external view returns (\r
        uint256 requestTime,\r
        uint256 amount,\r
        bool pending,\r
        bool canWithdraw\r
    ) {\r
        WithdrawalRequest memory request = withdrawalRequests[_user];\r
        requestTime = request.requestTime;\r
        amount = request.amount;\r
        pending = request.pending;\r
        canWithdraw = request.pending && \r
                      block.timestamp >= request.requestTime + WITHDRAWAL_COOLDOWN;\r
    }\r
\r
    /**\r
     * @dev Emergency function to withdraw tokens (owner only)\r
     * @notice Only for emergency situations\r
     */\r
    function emergencyWithdraw(address _token, uint256 _amount) external onlyOwner {\r
        IERC20(_token).safeTransfer(owner(), _amount);\r
    }\r
}\r
"
    }
  },
  "settings": {
    "optimizer": {
      "enabled": true,
      "runs": 200
    },
    "evmVersion": "paris",
    "outputSelection": {
      "*": {
        "*": [
          "evm.bytecode",
          "evm.deployedBytecode",
          "devdoc",
          "userdoc",
          "metadata",
          "abi"
        ]
      }
    }
  }
}}