// Source: contracts/utils/Pausable.sol

pragma solidity ^0.8.0;

// SPDX-License-Identifier: MIT

// File contracts/interfaces/IPausable.sol

/**
 * @title Pausable
 * @notice This contract provides a mechanism to halt the execution of specific functions
 * if a pause condition is activated.
 */
interface IPausable {
    event Paused(address indexed account);
    event Unpaused(address indexed account);

    error Pause();
    error NotPaused();

    /**
     * @notice Check if the contract is paused
     * @return paused A boolean representing the pause status. True if paused, false otherwise.
     */
    function paused() external view returns (bool);
}

// File contracts/utils/Pausable.sol

/**
 * @title Pausable
 * @notice This contract provides a mechanism to halt the execution of specific functions
 * if a pause condition is activated.
 */
contract Pausable is IPausable {
    // uint256(keccak256('paused')) - 1
    uint256 internal constant PAUSE_SLOT = 0xee35723ac350a69d2a92d3703f17439cbaadf2f093a21ba5bf5f1a53eb2a14d8;

    /**
     * @notice A modifier that throws a Paused custom error if the contract is paused
     * @dev This modifier should be used with functions that can be paused
     */
    modifier whenNotPaused() {
        if (paused()) revert Pause();
        _;
    }

    modifier whenPaused() {
        if (!paused()) revert NotPaused();
        _;
    }

    /**
     * @notice Check if the contract is paused
     * @return paused_ A boolean representing the pause status. True if paused, false otherwise.
     */
    function paused() public view returns (bool paused_) {
        assembly {
            paused_ := sload(PAUSE_SLOT)
        }
    }

    /**
     * @notice Pauses the contract
     * @dev This function should be callable by the owner/governance.
     */
    function _pause() internal {
        _setPaused(true);
        emit Paused(msg.sender);
    }

    /**
     * @notice Unpauses the contract
     * @dev This function should be callable by the owner/governance.
     */
    function _unpause() internal {
        _setPaused(false);
        emit Unpaused(msg.sender);
    }

    /**
     * @notice Sets the pause status of the contract
     * @dev This is an internal function, meaning it can only be called from within the contract itself
     * or from derived contracts.
     * @param paused_ The new pause status
     */
    function _setPaused(bool paused_) internal {
        assembly {
            sstore(PAUSE_SLOT, paused_)
        }
    }
}