// File: @openzeppelin/contracts/access/Ownable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (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. 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 {
        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/interfaces/IERC20Metadata.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (interfaces/IERC20Metadata.sol)

pragma solidity ^0.8.0;

import "../token/ERC20/extensions/IERC20Metadata.sol";

// File: @openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)

pragma solidity ^0.8.0;

import "../IERC20.sol";

/**
 * @dev Interface for the optional metadata functions from the ERC20 standard.
 *
 * _Available since v4.1._
 */
interface IERC20Metadata is IERC20 {
    /**
     * @dev Returns the name of the token.
     */
    function name() external view returns (string memory);

    /**
     * @dev Returns the symbol of the token.
     */
    function symbol() external view returns (string memory);

    /**
     * @dev Returns the decimals places of the token.
     */
    function decimals() external view returns (uint8);
}

// File: @openzeppelin/contracts/token/ERC20/IERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (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/structs/EnumerableMap.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (utils/structs/EnumerableMap.sol)
// This file was procedurally generated from scripts/generate/templates/EnumerableMap.js.

pragma solidity ^0.8.0;

import "./EnumerableSet.sol";

/**
 * @dev Library for managing an enumerable variant of Solidity's
 * https://solidity.readthedocs.io/en/latest/types.html#mapping-types[`mapping`]
 * type.
 *
 * Maps have the following properties:
 *
 * - Entries are added, removed, and checked for existence in constant time
 * (O(1)).
 * - Entries are enumerated in O(n). No guarantees are made on the ordering.
 *
 * ```solidity
 * contract Example {
 *     // Add the library methods
 *     using EnumerableMap for EnumerableMap.UintToAddressMap;
 *
 *     // Declare a set state variable
 *     EnumerableMap.UintToAddressMap private myMap;
 * }
 * ```
 *
 * The following map types are supported:
 *
 * - `uint256 -> address` (`UintToAddressMap`) since v3.0.0
 * - `address -> uint256` (`AddressToUintMap`) since v4.6.0
 * - `bytes32 -> bytes32` (`Bytes32ToBytes32Map`) since v4.6.0
 * - `uint256 -> uint256` (`UintToUintMap`) since v4.7.0
 * - `bytes32 -> uint256` (`Bytes32ToUintMap`) since v4.7.0
 *
 * [WARNING]
 * ====
 * Trying to delete such a structure from storage will likely result in data corruption, rendering the structure
 * unusable.
 * See https://github.com/ethereum/solidity/pull/11843[ethereum/solidity#11843] for more info.
 *
 * In order to clean an EnumerableMap, you can either remove all elements one by one or create a fresh instance using an
 * array of EnumerableMap.
 * ====
 */
library EnumerableMap {
    using EnumerableSet for EnumerableSet.Bytes32Set;

    // To implement this library for multiple types with as little code
    // repetition as possible, we write it in terms of a generic Map type with
    // bytes32 keys and values.
    // The Map implementation uses private functions, and user-facing
    // implementations (such as Uint256ToAddressMap) are just wrappers around
    // the underlying Map.
    // This means that we can only create new EnumerableMaps for types that fit
    // in bytes32.

    struct Bytes32ToBytes32Map {
        // Storage of keys
        EnumerableSet.Bytes32Set _keys;
        mapping(bytes32 => bytes32) _values;
    }

    /**
     * @dev Adds a key-value pair to a map, or updates the value for an existing
     * key. O(1).
     *
     * Returns true if the key was added to the map, that is if it was not
     * already present.
     */
    function set(Bytes32ToBytes32Map storage map, bytes32 key, bytes32 value) internal returns (bool) {
        map._values[key] = value;
        return map._keys.add(key);
    }

    /**
     * @dev Removes a key-value pair from a map. O(1).
     *
     * Returns true if the key was removed from the map, that is if it was present.
     */
    function remove(Bytes32ToBytes32Map storage map, bytes32 key) internal returns (bool) {
        delete map._values[key];
        return map._keys.remove(key);
    }

    /**
     * @dev Returns true if the key is in the map. O(1).
     */
    function contains(Bytes32ToBytes32Map storage map, bytes32 key) internal view returns (bool) {
        return map._keys.contains(key);
    }

    /**
     * @dev Returns the number of key-value pairs in the map. O(1).
     */
    function length(Bytes32ToBytes32Map storage map) internal view returns (uint256) {
        return map._keys.length();
    }

    /**
     * @dev Returns the key-value pair stored at position `index` in the map. O(1).
     *
     * Note that there are no guarantees on the ordering of entries inside the
     * array, and it may change when more entries are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(Bytes32ToBytes32Map storage map, uint256 index) internal view returns (bytes32, bytes32) {
        bytes32 key = map._keys.at(index);
        return (key, map._values[key]);
    }

    /**
     * @dev Tries to returns the value associated with `key`. O(1).
     * Does not revert if `key` is not in the map.
     */
    function tryGet(Bytes32ToBytes32Map storage map, bytes32 key) internal view returns (bool, bytes32) {
        bytes32 value = map._values[key];
        if (value == bytes32(0)) {
            return (contains(map, key), bytes32(0));
        } else {
            return (true, value);
        }
    }

    /**
     * @dev Returns the value associated with `key`. O(1).
     *
     * Requirements:
     *
     * - `key` must be in the map.
     */
    function get(Bytes32ToBytes32Map storage map, bytes32 key) internal view returns (bytes32) {
        bytes32 value = map._values[key];
        require(value != 0 || contains(map, key), "EnumerableMap: nonexistent key");
        return value;
    }

    /**
     * @dev Same as {get}, with a custom error message when `key` is not in the map.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryGet}.
     */
    function get(
        Bytes32ToBytes32Map storage map,
        bytes32 key,
        string memory errorMessage
    ) internal view returns (bytes32) {
        bytes32 value = map._values[key];
        require(value != 0 || contains(map, key), errorMessage);
        return value;
    }

    /**
     * @dev Return the an array containing all the keys
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the map grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function keys(Bytes32ToBytes32Map storage map) internal view returns (bytes32[] memory) {
        return map._keys.values();
    }

    // UintToUintMap

    struct UintToUintMap {
        Bytes32ToBytes32Map _inner;
    }

    /**
     * @dev Adds a key-value pair to a map, or updates the value for an existing
     * key. O(1).
     *
     * Returns true if the key was added to the map, that is if it was not
     * already present.
     */
    function set(UintToUintMap storage map, uint256 key, uint256 value) internal returns (bool) {
        return set(map._inner, bytes32(key), bytes32(value));
    }

    /**
     * @dev Removes a value from a map. O(1).
     *
     * Returns true if the key was removed from the map, that is if it was present.
     */
    function remove(UintToUintMap storage map, uint256 key) internal returns (bool) {
        return remove(map._inner, bytes32(key));
    }

    /**
     * @dev Returns true if the key is in the map. O(1).
     */
    function contains(UintToUintMap storage map, uint256 key) internal view returns (bool) {
        return contains(map._inner, bytes32(key));
    }

    /**
     * @dev Returns the number of elements in the map. O(1).
     */
    function length(UintToUintMap storage map) internal view returns (uint256) {
        return length(map._inner);
    }

    /**
     * @dev Returns the element stored at position `index` in the map. O(1).
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(UintToUintMap storage map, uint256 index) internal view returns (uint256, uint256) {
        (bytes32 key, bytes32 value) = at(map._inner, index);
        return (uint256(key), uint256(value));
    }

    /**
     * @dev Tries to returns the value associated with `key`. O(1).
     * Does not revert if `key` is not in the map.
     */
    function tryGet(UintToUintMap storage map, uint256 key) internal view returns (bool, uint256) {
        (bool success, bytes32 value) = tryGet(map._inner, bytes32(key));
        return (success, uint256(value));
    }

    /**
     * @dev Returns the value associated with `key`. O(1).
     *
     * Requirements:
     *
     * - `key` must be in the map.
     */
    function get(UintToUintMap storage map, uint256 key) internal view returns (uint256) {
        return uint256(get(map._inner, bytes32(key)));
    }

    /**
     * @dev Same as {get}, with a custom error message when `key` is not in the map.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryGet}.
     */
    function get(UintToUintMap storage map, uint256 key, string memory errorMessage) internal view returns (uint256) {
        return uint256(get(map._inner, bytes32(key), errorMessage));
    }

    /**
     * @dev Return the an array containing all the keys
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the map grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function keys(UintToUintMap storage map) internal view returns (uint256[] memory) {
        bytes32[] memory store = keys(map._inner);
        uint256[] memory result;

        /// @solidity memory-safe-assembly
        assembly {
            result := store
        }

        return result;
    }

    // UintToAddressMap

    struct UintToAddressMap {
        Bytes32ToBytes32Map _inner;
    }

    /**
     * @dev Adds a key-value pair to a map, or updates the value for an existing
     * key. O(1).
     *
     * Returns true if the key was added to the map, that is if it was not
     * already present.
     */
    function set(UintToAddressMap storage map, uint256 key, address value) internal returns (bool) {
        return set(map._inner, bytes32(key), bytes32(uint256(uint160(value))));
    }

    /**
     * @dev Removes a value from a map. O(1).
     *
     * Returns true if the key was removed from the map, that is if it was present.
     */
    function remove(UintToAddressMap storage map, uint256 key) internal returns (bool) {
        return remove(map._inner, bytes32(key));
    }

    /**
     * @dev Returns true if the key is in the map. O(1).
     */
    function contains(UintToAddressMap storage map, uint256 key) internal view returns (bool) {
        return contains(map._inner, bytes32(key));
    }

    /**
     * @dev Returns the number of elements in the map. O(1).
     */
    function length(UintToAddressMap storage map) internal view returns (uint256) {
        return length(map._inner);
    }

    /**
     * @dev Returns the element stored at position `index` in the map. O(1).
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(UintToAddressMap storage map, uint256 index) internal view returns (uint256, address) {
        (bytes32 key, bytes32 value) = at(map._inner, index);
        return (uint256(key), address(uint160(uint256(value))));
    }

    /**
     * @dev Tries to returns the value associated with `key`. O(1).
     * Does not revert if `key` is not in the map.
     */
    function tryGet(UintToAddressMap storage map, uint256 key) internal view returns (bool, address) {
        (bool success, bytes32 value) = tryGet(map._inner, bytes32(key));
        return (success, address(uint160(uint256(value))));
    }

    /**
     * @dev Returns the value associated with `key`. O(1).
     *
     * Requirements:
     *
     * - `key` must be in the map.
     */
    function get(UintToAddressMap storage map, uint256 key) internal view returns (address) {
        return address(uint160(uint256(get(map._inner, bytes32(key)))));
    }

    /**
     * @dev Same as {get}, with a custom error message when `key` is not in the map.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryGet}.
     */
    function get(
        UintToAddressMap storage map,
        uint256 key,
        string memory errorMessage
    ) internal view returns (address) {
        return address(uint160(uint256(get(map._inner, bytes32(key), errorMessage))));
    }

    /**
     * @dev Return the an array containing all the keys
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the map grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function keys(UintToAddressMap storage map) internal view returns (uint256[] memory) {
        bytes32[] memory store = keys(map._inner);
        uint256[] memory result;

        /// @solidity memory-safe-assembly
        assembly {
            result := store
        }

        return result;
    }

    // AddressToUintMap

    struct AddressToUintMap {
        Bytes32ToBytes32Map _inner;
    }

    /**
     * @dev Adds a key-value pair to a map, or updates the value for an existing
     * key. O(1).
     *
     * Returns true if the key was added to the map, that is if it was not
     * already present.
     */
    function set(AddressToUintMap storage map, address key, uint256 value) internal returns (bool) {
        return set(map._inner, bytes32(uint256(uint160(key))), bytes32(value));
    }

    /**
     * @dev Removes a value from a map. O(1).
     *
     * Returns true if the key was removed from the map, that is if it was present.
     */
    function remove(AddressToUintMap storage map, address key) internal returns (bool) {
        return remove(map._inner, bytes32(uint256(uint160(key))));
    }

    /**
     * @dev Returns true if the key is in the map. O(1).
     */
    function contains(AddressToUintMap storage map, address key) internal view returns (bool) {
        return contains(map._inner, bytes32(uint256(uint160(key))));
    }

    /**
     * @dev Returns the number of elements in the map. O(1).
     */
    function length(AddressToUintMap storage map) internal view returns (uint256) {
        return length(map._inner);
    }

    /**
     * @dev Returns the element stored at position `index` in the map. O(1).
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(AddressToUintMap storage map, uint256 index) internal view returns (address, uint256) {
        (bytes32 key, bytes32 value) = at(map._inner, index);
        return (address(uint160(uint256(key))), uint256(value));
    }

    /**
     * @dev Tries to returns the value associated with `key`. O(1).
     * Does not revert if `key` is not in the map.
     */
    function tryGet(AddressToUintMap storage map, address key) internal view returns (bool, uint256) {
        (bool success, bytes32 value) = tryGet(map._inner, bytes32(uint256(uint160(key))));
        return (success, uint256(value));
    }

    /**
     * @dev Returns the value associated with `key`. O(1).
     *
     * Requirements:
     *
     * - `key` must be in the map.
     */
    function get(AddressToUintMap storage map, address key) internal view returns (uint256) {
        return uint256(get(map._inner, bytes32(uint256(uint160(key)))));
    }

    /**
     * @dev Same as {get}, with a custom error message when `key` is not in the map.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryGet}.
     */
    function get(
        AddressToUintMap storage map,
        address key,
        string memory errorMessage
    ) internal view returns (uint256) {
        return uint256(get(map._inner, bytes32(uint256(uint160(key))), errorMessage));
    }

    /**
     * @dev Return the an array containing all the keys
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the map grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function keys(AddressToUintMap storage map) internal view returns (address[] memory) {
        bytes32[] memory store = keys(map._inner);
        address[] memory result;

        /// @solidity memory-safe-assembly
        assembly {
            result := store
        }

        return result;
    }

    // Bytes32ToUintMap

    struct Bytes32ToUintMap {
        Bytes32ToBytes32Map _inner;
    }

    /**
     * @dev Adds a key-value pair to a map, or updates the value for an existing
     * key. O(1).
     *
     * Returns true if the key was added to the map, that is if it was not
     * already present.
     */
    function set(Bytes32ToUintMap storage map, bytes32 key, uint256 value) internal returns (bool) {
        return set(map._inner, key, bytes32(value));
    }

    /**
     * @dev Removes a value from a map. O(1).
     *
     * Returns true if the key was removed from the map, that is if it was present.
     */
    function remove(Bytes32ToUintMap storage map, bytes32 key) internal returns (bool) {
        return remove(map._inner, key);
    }

    /**
     * @dev Returns true if the key is in the map. O(1).
     */
    function contains(Bytes32ToUintMap storage map, bytes32 key) internal view returns (bool) {
        return contains(map._inner, key);
    }

    /**
     * @dev Returns the number of elements in the map. O(1).
     */
    function length(Bytes32ToUintMap storage map) internal view returns (uint256) {
        return length(map._inner);
    }

    /**
     * @dev Returns the element stored at position `index` in the map. O(1).
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(Bytes32ToUintMap storage map, uint256 index) internal view returns (bytes32, uint256) {
        (bytes32 key, bytes32 value) = at(map._inner, index);
        return (key, uint256(value));
    }

    /**
     * @dev Tries to returns the value associated with `key`. O(1).
     * Does not revert if `key` is not in the map.
     */
    function tryGet(Bytes32ToUintMap storage map, bytes32 key) internal view returns (bool, uint256) {
        (bool success, bytes32 value) = tryGet(map._inner, key);
        return (success, uint256(value));
    }

    /**
     * @dev Returns the value associated with `key`. O(1).
     *
     * Requirements:
     *
     * - `key` must be in the map.
     */
    function get(Bytes32ToUintMap storage map, bytes32 key) internal view returns (uint256) {
        return uint256(get(map._inner, key));
    }

    /**
     * @dev Same as {get}, with a custom error message when `key` is not in the map.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryGet}.
     */
    function get(
        Bytes32ToUintMap storage map,
        bytes32 key,
        string memory errorMessage
    ) internal view returns (uint256) {
        return uint256(get(map._inner, key, errorMessage));
    }

    /**
     * @dev Return the an array containing all the keys
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the map grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function keys(Bytes32ToUintMap storage map) internal view returns (bytes32[] memory) {
        bytes32[] memory store = keys(map._inner);
        bytes32[] memory result;

        /// @solidity memory-safe-assembly
        assembly {
            result := store
        }

        return result;
    }
}

// File: @openzeppelin/contracts/utils/structs/EnumerableSet.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (utils/structs/EnumerableSet.sol)
// This file was procedurally generated from scripts/generate/templates/EnumerableSet.js.

pragma solidity ^0.8.0;

/**
 * @dev Library for managing
 * https://en.wikipedia.org/wiki/Set_(abstract_data_type)[sets] of primitive
 * types.
 *
 * Sets have the following properties:
 *
 * - Elements are added, removed, and checked for existence in constant time
 * (O(1)).
 * - Elements are enumerated in O(n). No guarantees are made on the ordering.
 *
 * ```solidity
 * contract Example {
 *     // Add the library methods
 *     using EnumerableSet for EnumerableSet.AddressSet;
 *
 *     // Declare a set state variable
 *     EnumerableSet.AddressSet private mySet;
 * }
 * ```
 *
 * As of v3.3.0, sets of type `bytes32` (`Bytes32Set`), `address` (`AddressSet`)
 * and `uint256` (`UintSet`) are supported.
 *
 * [WARNING]
 * ====
 * Trying to delete such a structure from storage will likely result in data corruption, rendering the structure
 * unusable.
 * See https://github.com/ethereum/solidity/pull/11843[ethereum/solidity#11843] for more info.
 *
 * In order to clean an EnumerableSet, you can either remove all elements one by one or create a fresh instance using an
 * array of EnumerableSet.
 * ====
 */
library EnumerableSet {
    // To implement this library for multiple types with as little code
    // repetition as possible, we write it in terms of a generic Set type with
    // bytes32 values.
    // The Set implementation uses private functions, and user-facing
    // implementations (such as AddressSet) are just wrappers around the
    // underlying Set.
    // This means that we can only create new EnumerableSets for types that fit
    // in bytes32.

    struct Set {
        // Storage of set values
        bytes32[] _values;
        // Position of the value in the `values` array, plus 1 because index 0
        // means a value is not in the set.
        mapping(bytes32 => uint256) _indexes;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function _add(Set storage set, bytes32 value) private returns (bool) {
        if (!_contains(set, value)) {
            set._values.push(value);
            // The value is stored at length-1, but we add 1 to all indexes
            // and use 0 as a sentinel value
            set._indexes[value] = set._values.length;
            return true;
        } else {
            return false;
        }
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function _remove(Set storage set, bytes32 value) private returns (bool) {
        // We read and store the value's index to prevent multiple reads from the same storage slot
        uint256 valueIndex = set._indexes[value];

        if (valueIndex != 0) {
            // Equivalent to contains(set, value)
            // To delete an element from the _values array in O(1), we swap the element to delete with the last one in
            // the array, and then remove the last element (sometimes called as 'swap and pop').
            // This modifies the order of the array, as noted in {at}.

            uint256 toDeleteIndex = valueIndex - 1;
            uint256 lastIndex = set._values.length - 1;

            if (lastIndex != toDeleteIndex) {
                bytes32 lastValue = set._values[lastIndex];

                // Move the last value to the index where the value to delete is
                set._values[toDeleteIndex] = lastValue;
                // Update the index for the moved value
                set._indexes[lastValue] = valueIndex; // Replace lastValue's index to valueIndex
            }

            // Delete the slot where the moved value was stored
            set._values.pop();

            // Delete the index for the deleted slot
            delete set._indexes[value];

            return true;
        } else {
            return false;
        }
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function _contains(Set storage set, bytes32 value) private view returns (bool) {
        return set._indexes[value] != 0;
    }

    /**
     * @dev Returns the number of values on the set. O(1).
     */
    function _length(Set storage set) private view returns (uint256) {
        return set._values.length;
    }

    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function _at(Set storage set, uint256 index) private view returns (bytes32) {
        return set._values[index];
    }

    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function _values(Set storage set) private view returns (bytes32[] memory) {
        return set._values;
    }

    // Bytes32Set

    struct Bytes32Set {
        Set _inner;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(Bytes32Set storage set, bytes32 value) internal returns (bool) {
        return _add(set._inner, value);
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(Bytes32Set storage set, bytes32 value) internal returns (bool) {
        return _remove(set._inner, value);
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(Bytes32Set storage set, bytes32 value) internal view returns (bool) {
        return _contains(set._inner, value);
    }

    /**
     * @dev Returns the number of values in the set. O(1).
     */
    function length(Bytes32Set storage set) internal view returns (uint256) {
        return _length(set._inner);
    }

    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(Bytes32Set storage set, uint256 index) internal view returns (bytes32) {
        return _at(set._inner, index);
    }

    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function values(Bytes32Set storage set) internal view returns (bytes32[] memory) {
        bytes32[] memory store = _values(set._inner);
        bytes32[] memory result;

        /// @solidity memory-safe-assembly
        assembly {
            result := store
        }

        return result;
    }

    // AddressSet

    struct AddressSet {
        Set _inner;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(AddressSet storage set, address value) internal returns (bool) {
        return _add(set._inner, bytes32(uint256(uint160(value))));
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(AddressSet storage set, address value) internal returns (bool) {
        return _remove(set._inner, bytes32(uint256(uint160(value))));
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(AddressSet storage set, address value) internal view returns (bool) {
        return _contains(set._inner, bytes32(uint256(uint160(value))));
    }

    /**
     * @dev Returns the number of values in the set. O(1).
     */
    function length(AddressSet storage set) internal view returns (uint256) {
        return _length(set._inner);
    }

    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(AddressSet storage set, uint256 index) internal view returns (address) {
        return address(uint160(uint256(_at(set._inner, index))));
    }

    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function values(AddressSet storage set) internal view returns (address[] memory) {
        bytes32[] memory store = _values(set._inner);
        address[] memory result;

        /// @solidity memory-safe-assembly
        assembly {
            result := store
        }

        return result;
    }

    // UintSet

    struct UintSet {
        Set _inner;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(UintSet storage set, uint256 value) internal returns (bool) {
        return _add(set._inner, bytes32(value));
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(UintSet storage set, uint256 value) internal returns (bool) {
        return _remove(set._inner, bytes32(value));
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(UintSet storage set, uint256 value) internal view returns (bool) {
        return _contains(set._inner, bytes32(value));
    }

    /**
     * @dev Returns the number of values in the set. O(1).
     */
    function length(UintSet storage set) internal view returns (uint256) {
        return _length(set._inner);
    }

    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(UintSet storage set, uint256 index) internal view returns (uint256) {
        return uint256(_at(set._inner, index));
    }

    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function values(UintSet storage set) internal view returns (uint256[] memory) {
        bytes32[] memory store = _values(set._inner);
        uint256[] memory result;

        /// @solidity memory-safe-assembly
        assembly {
            result := store
        }

        return result;
    }
}

// File: contracts/interfaces/ISTBT.sol



// SPDX-License-Identifier: GPL-3.0
pragma solidity ^0.8.0;

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/interfaces/IERC20Metadata.sol";
import "@openzeppelin/contracts/access/Ownable.sol";

interface IERC1644 is IERC20 {
    // Controller Events
    event ControllerTransfer(
        address _controller,
        address indexed _from,
        address indexed _to,
        uint256 _value,
        bytes _data,
        bytes _operatorData
    );

    event ControllerRedemption(
        address _controller,
        address indexed _tokenHolder,
        uint256 _value,
        bytes _data,
        bytes _operatorData
    );

    // Controller Operation
    function isControllable() external view returns (bool);
    function controllerTransfer(address _from, address _to, uint256 _value, bytes calldata _data, bytes calldata _operatorData) external;
    function controllerRedeem(address _tokenHolder, uint256 _value, bytes calldata _data, bytes calldata _operatorData) external;
}

interface IERC1643 {
    // Document Events
    event DocumentRemoved(bytes32 indexed _name, string _uri, bytes32 _documentHash);
    event DocumentUpdated(bytes32 indexed _name, string _uri, bytes32 _documentHash);

    // Document Management
    function getDocument(bytes32 _name) external view returns (string memory, bytes32, uint256);
    function setDocument(bytes32 _name, string calldata _uri, bytes32 _documentHash) external;
    function removeDocument(bytes32 _name) external;
    function getAllDocuments() external view returns (bytes32[] memory);
}

interface IERC1594 is IERC20 {
    // Issuance / Redemption Events
    event Issued(address indexed _operator, address indexed _to, uint256 _value, bytes _data);
    event Redeemed(address indexed _operator, address indexed _from, uint256 _value, bytes _data);

    // Transfers
    function transferWithData(address _to, uint256 _value, bytes calldata _data) external;
    function transferFromWithData(address _from, address _to, uint256 _value, bytes calldata _data) external;

    // Token Issuance
    function isIssuable() external view returns (bool);
    function issue(address _tokenHolder, uint256 _value, bytes calldata _data) external;

    // Token Redemption
    function redeem(uint256 _value, bytes calldata _data) external;
    function redeemFrom(address _tokenHolder, uint256 _value, bytes calldata _data) external;

    // Transfer Validity
    function canTransfer(address _to, uint256 _value, bytes calldata _data) external view returns (bool, uint8, bytes32);
    function canTransferFrom(address _from, address _to, uint256 _value, bytes calldata _data) external view returns (bool, uint8, bytes32);
}

struct Permission {
    bool sendAllowed; // default: true
    bool receiveAllowed;
    // Address holder’s KYC will be validated till this time, after that the holder needs to re-KYC.
    uint64 expiryTime; // default:0 validated forever
}

interface ISTBT is IERC20, IERC20Metadata, IERC1594, IERC1643, IERC1644 {
    event InterestsDistributed(int interest, uint newTotalSupply, uint interestFromTime, uint interestToTime);
    event TransferShares(address indexed from, address indexed to, uint256 sharesValue);

    function issuer() external view returns (address); 
    function controller() external view returns (address); 
    function moderator() external view returns (address); 
    function totalShares() external view returns (uint);
    function allowance(address _owner, address _spender) external view returns (uint256);
    function permissions(address addr) external view returns (bool sendAllowed,
                                                              bool receiveAllowed,
                                                              uint64 expiryTime);
    function lastDistributeTime() external view returns (uint64);
    function minDistributeInterval() external view returns (uint64);
    function maxDistributeRatio() external view returns (uint64);

    function setIssuer(address _issuer) external;
    function setController(address _controller) external;
    function setModerator(address _moderator) external;
    function setMinDistributeInterval(uint64 interval) external;
    function setMaxDistributeRatio(uint64 ratio) external;
    function setPermission(address addr, Permission calldata permission) external;

    function distributeInterests(int256 _distributedInterest, uint interestFromTime, uint interestToTime) external;

    function increaseAllowance(address _spender, uint256 _addedValue) external returns (bool);
    function decreaseAllowance(address _spender, uint256 _subtractedValue) external returns (bool);

    function sharesOf(address _account) external view returns (uint256);
    function getSharesByAmount(uint256 _amount) external view returns (uint256 result);
    function getSharesByAmountRoundUp(uint256 _amount) external view returns (uint256 result);
    function getAmountByShares(uint256 _shares) external view returns (uint256 result);
}

// File: contracts/interfaces/IStbtTimelockController.sol



// SPDX-License-Identifier: GPL-3.0
pragma solidity ^0.8.0;

interface IStbtTimelockController {
    function schedule(
        address target,
        uint256 value,
        bytes calldata data,
        bytes32 predecessor,
        bytes32 salt,
        uint256 /*delay*/
    ) external;
}

// File: contracts/Minter.sol



// SPDX-License-Identifier: GPL-3.0
pragma solidity ^0.8.0;

import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/utils/structs/EnumerableMap.sol";

import "./interfaces/ISTBT.sol";
import "./interfaces/IStbtTimelockController.sol";

contract Minter is Ownable {
	using EnumerableMap for EnumerableMap.AddressToUintMap;

	struct DepositConfig {
		bool   needDivAdjust;
		uint96 adjustUnit;
		uint96 minimumDepositAmount;
	}
	
	struct RedeemConfig {
		bool   needDivAdjust;
		uint96 adjustUnit;
		uint96 minimumRedeemAmount;
	}
	
	address public timeLockContract;
	address public targetContract;
	address public poolAccount;
	uint64 public nonceForRedeem;
	uint64 public virtualCountOfRedeemSettled;
	uint64 public nonceForMint;
	mapping(address => DepositConfig) public depositConfigMap;
	mapping(address => RedeemConfig) public redeemConfigMap;
	mapping(address => uint) public redeemFeeRateMap;
	mapping(uint => address) public redeemTargetMap;
	uint public depositPeriod;
	uint public redeemPeriod;
	EnumerableMap.AddressToUintMap private purchaseInfoMap;
	
	uint private constant UNIT = 10**18;

	event Mint(address indexed requestor, address indexed token, uint indexed nonce,
		   uint depositAmount, uint proposeAmount, bytes32 salt, bytes data);
	event Redeem(address indexed requestor, address indexed token, uint indexed nonce, uint amount,
		    bytes32 salt, bytes data);
	event Settle(address indexed target,  address indexed token, uint indexed nonce, uint amount,
		     bytes32 redeemTxId, uint redeemServiceFeeRate, uint executionPrice);

	constructor(address _timeLockContract, address _targetContract, address _poolAccount) Ownable() {
		timeLockContract = _timeLockContract;
		targetContract = _targetContract;
		poolAccount = _poolAccount;
		uint64 _nonceStart = uint64(1000 * block.timestamp);
		nonceForMint = _nonceStart;
		nonceForRedeem = _nonceStart;
		virtualCountOfRedeemSettled = _nonceStart;
	}

	function setCoinInfo(address token, uint receiverAndRate) onlyOwner external {
		require(uint96(receiverAndRate) < UNIT, "MINTER: FEE_RATE_TOO_LARGE");
		purchaseInfoMap.set(token, receiverAndRate);
	}

	function getCoinInfo(address coin) external view returns (uint) {
		return purchaseInfoMap.get(coin);
	}

	function getCoinsInfo() external view returns (address[] memory coinList, uint[] memory receiverAndRateList) {
		coinList = new address[](purchaseInfoMap.length());
		receiverAndRateList = new uint[](purchaseInfoMap.length());
		for(uint i=0; i<coinList.length; i++) {
			(address coin, uint reveiverAndRate) = purchaseInfoMap.at(i);
			coinList[i] = coin;
			receiverAndRateList[i] = reveiverAndRate;
		}
	}

	function setDepositConfig(address token, DepositConfig calldata config) onlyOwner external {
		depositConfigMap[token] = config;
	}

	function setRedeemConfig(address token, RedeemConfig calldata config) onlyOwner external {
		redeemConfigMap[token] = config;
	}

	function setRedeemFeeRate(address token, uint r) onlyOwner external {
		redeemFeeRateMap[token] = r;
	}

	function setDepositPeriod(uint p) onlyOwner external {
		depositPeriod = p;
	}

	function setRedeemPeriod(uint p) onlyOwner external {
		redeemPeriod = p;
	}

	function setTimeLockContract(address _timeLockContract) onlyOwner external {
		timeLockContract = _timeLockContract;
	}

	function setTargetContract(address _targetContract) onlyOwner external {
		targetContract = _targetContract;
	}

	function setPoolAccount(address _poolAccount) onlyOwner external {
		poolAccount = _poolAccount;
	}

	// token: which token to deposit?
	// depositAmount: how much to deposit?
	// minProposedAmount: the sender use this value to protect against sudden rise of feeRate
	// salt: a random number that can affect TimelockController's input salt
	// extraData: will be used to call STBT's issue function
	function mint(address token, uint depositAmount, uint minProposedAmount, bytes32 salt,
		      bytes calldata extraData) external {
		{
		(, bool receiveAllowed, uint64 expiryTime) = ISTBT(targetContract).permissions(msg.sender);
		require(receiveAllowed, 'MINTER: NO_RECEIVE_PERMISSION');
		require(expiryTime == 0 || expiryTime > block.timestamp, 'MINTER: RECEIVE_PERMISSION_EXPIRED');
		}

		uint receiverAndRate = purchaseInfoMap.get(token);
		require(receiverAndRate != 0, "MINTER: TOKEN_NOT_SUPPORTED");
		address receiver = address(uint160(receiverAndRate>>96));
		uint feeRate = uint96(receiverAndRate);
		DepositConfig memory config = depositConfigMap[token];
		require(config.minimumDepositAmount != 0 &&
			depositAmount >= config.minimumDepositAmount, "MINTER: DEPOSIT_AMOUNT_TOO_SMALL");
		uint proposeAmount = depositAmount*(UNIT-feeRate)/UNIT;
		proposeAmount = config.needDivAdjust? proposeAmount / config.adjustUnit : proposeAmount * config.adjustUnit;
		require(proposeAmount >= minProposedAmount, "MINTER: PROPOSE_AMOUNT_TOO_SMALL");
		IERC20(token).transferFrom(msg.sender, receiver, depositAmount);
		bytes memory data = abi.encodeWithSignature("issue(address,uint256,bytes)",
							    msg.sender, proposeAmount, extraData);
		uint64 _nonceForMint = nonceForMint;
		salt = keccak256(abi.encodePacked(salt, _nonceForMint));
		nonceForMint = _nonceForMint + 1;
		IStbtTimelockController(timeLockContract).schedule(targetContract, 0, data, bytes32(""), salt, 0);
		emit Mint(msg.sender, token, _nonceForMint, depositAmount, proposeAmount, salt, data);
	}

	// token: which token to receive after redeem?
	// amount: how much STBT to deposit?
	// salt: a random number that can affect TimelockController's input salt
	// extraData: will be used to call STBT's redeemFrom function
	function redeem(uint amount, address token, bytes32 salt, bytes calldata extraData) external {
		RedeemConfig memory config = redeemConfigMap[token];
		require(config.minimumRedeemAmount != 0 &&
			amount >= config.minimumRedeemAmount, "MINTER: REDEEM_AMOUNT_TOO_SMALL");
		IERC20(targetContract).transferFrom(msg.sender, poolAccount, amount);
		bytes memory data = abi.encodeWithSignature("redeemFrom(address,uint256,bytes)",
							    poolAccount, amount, extraData);
		uint adjusted = config.needDivAdjust? amount / config.adjustUnit : amount * config.adjustUnit;
		salt = keccak256(abi.encodePacked(salt, nonceForRedeem));
		IStbtTimelockController(timeLockContract).schedule(targetContract, 0, data, bytes32(""), salt, 0);
		redeemTargetMap[nonceForRedeem] = msg.sender;
		emit Redeem(msg.sender, token, nonceForRedeem, adjusted, salt, data);
		nonceForRedeem = nonceForRedeem + 1;
	}

	// token: which token to refund the customer?
	// amount: how much to refund?
	// nonce: the nonce assigned to this redeem operation
	// redeemTxId: at which tx did the customer call 'redeem'?
	// redeemServiceFeeRate: some of the refunded tokens will be deducted as fee
	// executionPrice: the price of STBT measure by 'token'
	function redeemSettle(address token, uint amount, uint64 nonce, bytes32 redeemTxId,
			      uint redeemServiceFeeRate, uint executionPrice) onlyOwner external {
		virtualCountOfRedeemSettled++;
		address target = redeemTargetMap[nonce];
		require(target != address(0), "MINTER: NULL_TARGET");
		delete redeemTargetMap[nonce];
		IERC20(token).transfer(target, amount);
		emit Settle(target, token, nonce, amount, redeemTxId, redeemServiceFeeRate, executionPrice);
	}

	// the rescue ETH or ERC20 tokens which were accidentally sent to this contract
	function rescue(address token, address receiver, uint amount) onlyOwner external {
		require(virtualCountOfRedeemSettled == nonceForRedeem, "MINTER: PENDING_REDEEM");
		IERC20(token).transfer(receiver, amount);
	}
}