// File: @openzeppelin/contracts/token/ERC20/IERC20.sol

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
  /**
   * @dev Returns the amount of tokens in existence.
   */
  function totalSupply() external view returns (uint256);

  /**
   * @dev Returns the amount of tokens owned by `account`.
   */
  function balanceOf(address account) external view returns (uint256);

  /**
   * @dev Moves `amount` tokens from the caller's account to `recipient`.
   *
   * Returns a boolean value indicating whether the operation succeeded.
   *
   * Emits a {Transfer} event.
   */
  function transfer(address recipient, uint256 amount) external returns (bool);

  /**
   * @dev Returns the remaining number of tokens that `spender` will be
   * allowed to spend on behalf of `owner` through {transferFrom}. This is
   * zero by default.
   *
   * This value changes when {approve} or {transferFrom} are called.
   */
  function allowance(address owner, address spender) external view returns (uint256);

  /**
   * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
   *
   * Returns a boolean value indicating whether the operation succeeded.
   *
   * IMPORTANT: Beware that changing an allowance with this method brings the risk
   * that someone may use both the old and the new allowance by unfortunate
   * transaction ordering. One possible solution to mitigate this race
   * condition is to first reduce the spender's allowance to 0 and set the
   * desired value afterwards:
   * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
   *
   * Emits an {Approval} event.
   */
  function approve(address spender, uint256 amount) external returns (bool);

  /**
   * @dev Moves `amount` tokens from `sender` to `recipient` using the
   * allowance mechanism. `amount` is then deducted from the caller's
   * allowance.
   *
   * Returns a boolean value indicating whether the operation succeeded.
   *
   * Emits a {Transfer} event.
   */
  function transferFrom(
    address sender,
    address recipient,
    uint256 amount
  ) external returns (bool);

  /**
   * @dev Emitted when `value` tokens are moved from one account (`from`) to
   * another (`to`).
   *
   * Note that `value` may be zero.
   */
  event Transfer(address indexed from, address indexed to, uint256 value);

  /**
   * @dev Emitted when the allowance of a `spender` for an `owner` is set by
   * a call to {approve}. `value` is the new allowance.
   */
  event Approval(address indexed owner, address indexed spender, uint256 value);
}

// File: @openzeppelin/contracts/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) {
    this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
    return msg.data;
  }
}

// File: @openzeppelin/contracts/token/ERC20/ERC20.sol

pragma solidity ^0.8.0;

/**
 * @dev Implementation of the {IERC20} interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using {_mint}.
 * For a generic mechanism see {ERC20PresetMinterPauser}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * We have followed general OpenZeppelin guidelines: functions revert instead
 * of returning `false` on failure. This behavior is nonetheless conventional
 * and does not conflict with the expectations of ERC20 applications.
 *
 * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
 * This allows applications to reconstruct the allowance for all accounts just
 * by listening to said events. Other implementations of the EIP may not emit
 * these events, as it isn't required by the specification.
 *
 * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
 * functions have been added to mitigate the well-known issues around setting
 * allowances. See {IERC20-approve}.
 */
contract ERC20 is Context, IERC20 {
  mapping(address => uint256) private _balances;

  mapping(address => mapping(address => uint256)) private _allowances;

  uint256 private _totalSupply;

  string private _name;
  string private _symbol;

  /**
   * @dev Sets the values for {name} and {symbol}.
   *
   * The defaut value of {decimals} is 18. To select a different value for
   * {decimals} you should overload it.
   *
   * All three of these values are immutable: they can only be set once during
   * construction.
   */
  constructor(string memory name_, string memory symbol_) {
    _name = name_;
    _symbol = symbol_;
  }

  /**
   * @dev Returns the name of the token.
   */
  function name() public view virtual returns (string memory) {
    return _name;
  }

  /**
   * @dev Returns the symbol of the token, usually a shorter version of the
   * name.
   */
  function symbol() public view virtual returns (string memory) {
    return _symbol;
  }

  /**
   * @dev Returns the number of decimals used to get its user representation.
   * For example, if `decimals` equals `2`, a balance of `505` tokens should
   * be displayed to a user as `5,05` (`505 / 10 ** 2`).
   *
   * Tokens usually opt for a value of 18, imitating the relationship between
   * Ether and Wei. This is the value {ERC20} uses, unless this function is
   * overloaded;
   *
   * NOTE: This information is only used for _display_ purposes: it in
   * no way affects any of the arithmetic of the contract, including
   * {IERC20-balanceOf} and {IERC20-transfer}.
   */
  function decimals() public view virtual returns (uint8) {
    return 18;
  }

  /**
   * @dev See {IERC20-totalSupply}.
   */
  function totalSupply() public view virtual override returns (uint256) {
    return _totalSupply;
  }

  /**
   * @dev See {IERC20-balanceOf}.
   */
  function balanceOf(address account) public view virtual override returns (uint256) {
    return _balances[account];
  }

  /**
   * @dev See {IERC20-transfer}.
   *
   * Requirements:
   *
   * - `recipient` cannot be the zero address.
   * - the caller must have a balance of at least `amount`.
   */
  function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
    _transfer(_msgSender(), recipient, amount);
    return true;
  }

  /**
   * @dev See {IERC20-allowance}.
   */
  function allowance(address owner, address spender) public view virtual override returns (uint256) {
    return _allowances[owner][spender];
  }

  /**
   * @dev See {IERC20-approve}.
   *
   * Requirements:
   *
   * - `spender` cannot be the zero address.
   */
  function approve(address spender, uint256 amount) public virtual override returns (bool) {
    _approve(_msgSender(), spender, amount);
    return true;
  }

  /**
   * @dev See {IERC20-transferFrom}.
   *
   * Emits an {Approval} event indicating the updated allowance. This is not
   * required by the EIP. See the note at the beginning of {ERC20}.
   *
   * Requirements:
   *
   * - `sender` and `recipient` cannot be the zero address.
   * - `sender` must have a balance of at least `amount`.
   * - the caller must have allowance for ``sender``'s tokens of at least
   * `amount`.
   */
  function transferFrom(
    address sender,
    address recipient,
    uint256 amount
  ) public virtual override returns (bool) {
    _transfer(sender, recipient, amount);

    uint256 currentAllowance = _allowances[sender][_msgSender()];
    require(currentAllowance >= amount, 'ERC20: transfer amount exceeds allowance');
    _approve(sender, _msgSender(), currentAllowance - amount);

    return true;
  }

  /**
   * @dev Atomically increases the allowance granted to `spender` by the caller.
   *
   * This is an alternative to {approve} that can be used as a mitigation for
   * problems described in {IERC20-approve}.
   *
   * Emits an {Approval} event indicating the updated allowance.
   *
   * Requirements:
   *
   * - `spender` cannot be the zero address.
   */
  function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
    _approve(_msgSender(), spender, _allowances[_msgSender()][spender] + addedValue);
    return true;
  }

  /**
   * @dev Atomically decreases the allowance granted to `spender` by the caller.
   *
   * This is an alternative to {approve} that can be used as a mitigation for
   * problems described in {IERC20-approve}.
   *
   * Emits an {Approval} event indicating the updated allowance.
   *
   * Requirements:
   *
   * - `spender` cannot be the zero address.
   * - `spender` must have allowance for the caller of at least
   * `subtractedValue`.
   */
  function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
    uint256 currentAllowance = _allowances[_msgSender()][spender];
    require(currentAllowance >= subtractedValue, 'ERC20: decreased allowance below zero');
    _approve(_msgSender(), spender, currentAllowance - subtractedValue);

    return true;
  }

  /**
   * @dev Moves tokens `amount` from `sender` to `recipient`.
   *
   * This is internal function is equivalent to {transfer}, and can be used to
   * e.g. implement automatic token fees, slashing mechanisms, etc.
   *
   * Emits a {Transfer} event.
   *
   * Requirements:
   *
   * - `sender` cannot be the zero address.
   * - `recipient` cannot be the zero address.
   * - `sender` must have a balance of at least `amount`.
   */
  function _transfer(
    address sender,
    address recipient,
    uint256 amount
  ) internal virtual {
    require(sender != address(0), 'ERC20: transfer from the zero address');
    require(recipient != address(0), 'ERC20: transfer to the zero address');

    _beforeTokenTransfer(sender, recipient, amount);

    uint256 senderBalance = _balances[sender];
    require(senderBalance >= amount, 'ERC20: transfer amount exceeds balance');
    _balances[sender] = senderBalance - amount;
    _balances[recipient] += amount;

    emit Transfer(sender, recipient, amount);
  }

  /** @dev Creates `amount` tokens and assigns them to `account`, increasing
   * the total supply.
   *
   * Emits a {Transfer} event with `from` set to the zero address.
   *
   * Requirements:
   *
   * - `to` cannot be the zero address.
   */
  function _mint(address account, uint256 amount) internal virtual {
    require(account != address(0), 'ERC20: mint to the zero address');

    _beforeTokenTransfer(address(0), account, amount);

    _totalSupply += amount;
    _balances[account] += amount;
    emit Transfer(address(0), account, amount);
  }

  /**
   * @dev Destroys `amount` tokens from `account`, reducing the
   * total supply.
   *
   * Emits a {Transfer} event with `to` set to the zero address.
   *
   * Requirements:
   *
   * - `account` cannot be the zero address.
   * - `account` must have at least `amount` tokens.
   */
  function _burn(address account, uint256 amount) internal virtual {
    require(account != address(0), 'ERC20: burn from the zero address');

    _beforeTokenTransfer(account, address(0), amount);

    uint256 accountBalance = _balances[account];
    require(accountBalance >= amount, 'ERC20: burn amount exceeds balance');
    _balances[account] = accountBalance - amount;
    _totalSupply -= amount;

    emit Transfer(account, address(0), amount);
  }

  /**
   * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
   *
   * This internal function is equivalent to `approve`, and can be used to
   * e.g. set automatic allowances for certain subsystems, etc.
   *
   * Emits an {Approval} event.
   *
   * Requirements:
   *
   * - `owner` cannot be the zero address.
   * - `spender` cannot be the zero address.
   */
  function _approve(
    address owner,
    address spender,
    uint256 amount
  ) internal virtual {
    require(owner != address(0), 'ERC20: approve from the zero address');
    require(spender != address(0), 'ERC20: approve to the zero address');

    _allowances[owner][spender] = amount;
    emit Approval(owner, spender, amount);
  }

  /**
   * @dev Hook that is called before any transfer of tokens. This includes
   * minting and burning.
   *
   * Calling conditions:
   *
   * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
   * will be to transferred to `to`.
   * - when `from` is zero, `amount` tokens will be minted for `to`.
   * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
   * - `from` and `to` are never both zero.
   *
   * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
   */
  function _beforeTokenTransfer(
    address from,
    address to,
    uint256 amount
  ) internal virtual {}
}

// File: @openzeppelin/contracts/token/ERC20/extensions/ERC20Capped.sol

pragma solidity ^0.8.0;

/**
 * @dev Extension of {ERC20} that adds a cap to the supply of tokens.
 */
abstract contract ERC20Capped is ERC20 {
  uint256 private immutable _cap;

  /**
   * @dev Sets the value of the `cap`. This value is immutable, it can only be
   * set once during construction.
   */
  constructor(uint256 cap_) {
    require(cap_ > 0, 'ERC20Capped: cap is 0');
    _cap = cap_;
  }

  /**
   * @dev Returns the cap on the token's total supply.
   */
  function cap() public view virtual returns (uint256) {
    return _cap;
  }

  /**
   * @dev See {ERC20-_mint}.
   */
  function _mint(address account, uint256 amount) internal virtual override {
    require(ERC20.totalSupply() + amount <= cap(), 'ERC20Capped: cap exceeded');
    super._mint(account, amount);
  }
}

// File: @openzeppelin/contracts/utils/introspection/IERC165.sol

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC165 standard, as defined in the
 * https://eips.ethereum.org/EIPS/eip-165[EIP].
 *
 * 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[EIP 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);
}

// File: @openzeppelin/contracts/utils/introspection/ERC165.sol

pragma solidity ^0.8.0;

/**
 * @dev Implementation of the {IERC165} interface.
 *
 * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
 * for the additional interface id that will be supported. For example:
 *
 * ```solidity
 * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
 *     return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
 * }
 * ```
 *
 * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
 */
abstract contract ERC165 is IERC165 {
  /**
   * @dev See {IERC165-supportsInterface}.
   */
  function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
    return interfaceId == type(IERC165).interfaceId;
  }
}

// File: @openzeppelin/contracts/access/AccessControl.sol

pragma solidity ^0.8.0;

/**
 * @dev External interface of AccessControl declared to support ERC165 detection.
 */
interface IAccessControl {
  function hasRole(bytes32 role, address account) external view returns (bool);

  function getRoleAdmin(bytes32 role) external view returns (bytes32);

  function grantRole(bytes32 role, address account) external;

  function revokeRole(bytes32 role, address account) external;

  function renounceRole(bytes32 role, address account) external;
}

/**
 * @dev Contract module that allows children to implement role-based access
 * control mechanisms. This is a lightweight version that doesn't allow enumerating role
 * members except through off-chain means by accessing the contract event logs. Some
 * applications may benefit from on-chain enumerability, for those cases see
 * {AccessControlEnumerable}.
 *
 * Roles are referred to by their `bytes32` identifier. These should be exposed
 * in the external API and be unique. The best way to achieve this is by
 * using `public constant` hash digests:
 *
 * ```
 * bytes32 public constant MY_ROLE = keccak256("MY_ROLE");
 * ```
 *
 * Roles can be used to represent a set of permissions. To restrict access to a
 * function call, use {hasRole}:
 *
 * ```
 * function foo() public {
 *     require(hasRole(MY_ROLE, msg.sender));
 *     ...
 * }
 * ```
 *
 * Roles can be granted and revoked dynamically via the {grantRole} and
 * {revokeRole} functions. Each role has an associated admin role, and only
 * accounts that have a role's admin role can call {grantRole} and {revokeRole}.
 *
 * By default, the admin role for all roles is `DEFAULT_ADMIN_ROLE`, which means
 * that only accounts with this role will be able to grant or revoke other
 * roles. More complex role relationships can be created by using
 * {_setRoleAdmin}.
 *
 * WARNING: The `DEFAULT_ADMIN_ROLE` is also its own admin: it has permission to
 * grant and revoke this role. Extra precautions should be taken to secure
 * accounts that have been granted it.
 */
abstract contract AccessControl is Context, IAccessControl, ERC165 {
  struct RoleData {
    mapping(address => bool) members;
    bytes32 adminRole;
  }

  mapping(bytes32 => RoleData) private _roles;

  bytes32 public constant DEFAULT_ADMIN_ROLE = 0x00;

  /**
   * @dev Emitted when `newAdminRole` is set as ``role``'s admin role, replacing `previousAdminRole`
   *
   * `DEFAULT_ADMIN_ROLE` is the starting admin for all roles, despite
   * {RoleAdminChanged} not being emitted signaling this.
   *
   * _Available since v3.1._
   */
  event RoleAdminChanged(bytes32 indexed role, bytes32 indexed previousAdminRole, bytes32 indexed newAdminRole);

  /**
   * @dev Emitted when `account` is granted `role`.
   *
   * `sender` is the account that originated the contract call, an admin role
   * bearer except when using {_setupRole}.
   */
  event RoleGranted(bytes32 indexed role, address indexed account, address indexed sender);

  /**
   * @dev Emitted when `account` is revoked `role`.
   *
   * `sender` is the account that originated the contract call:
   *   - if using `revokeRole`, it is the admin role bearer
   *   - if using `renounceRole`, it is the role bearer (i.e. `account`)
   */
  event RoleRevoked(bytes32 indexed role, address indexed account, address indexed sender);

  /**
   * @dev See {IERC165-supportsInterface}.
   */
  function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
    return interfaceId == type(IAccessControl).interfaceId || super.supportsInterface(interfaceId);
  }

  /**
   * @dev Returns `true` if `account` has been granted `role`.
   */
  function hasRole(bytes32 role, address account) public view override returns (bool) {
    return _roles[role].members[account];
  }

  /**
   * @dev Returns the admin role that controls `role`. See {grantRole} and
   * {revokeRole}.
   *
   * To change a role's admin, use {_setRoleAdmin}.
   */
  function getRoleAdmin(bytes32 role) public view override returns (bytes32) {
    return _roles[role].adminRole;
  }

  /**
   * @dev Grants `role` to `account`.
   *
   * If `account` had not been already granted `role`, emits a {RoleGranted}
   * event.
   *
   * Requirements:
   *
   * - the caller must have ``role``'s admin role.
   */
  function grantRole(bytes32 role, address account) public virtual override {
    require(hasRole(getRoleAdmin(role), _msgSender()), 'AccessControl: sender must be an admin to grant');

    _grantRole(role, account);
  }

  /**
   * @dev Revokes `role` from `account`.
   *
   * If `account` had been granted `role`, emits a {RoleRevoked} event.
   *
   * Requirements:
   *
   * - the caller must have ``role``'s admin role.
   */
  function revokeRole(bytes32 role, address account) public virtual override {
    require(hasRole(getRoleAdmin(role), _msgSender()), 'AccessControl: sender must be an admin to revoke');

    _revokeRole(role, account);
  }

  /**
   * @dev Revokes `role` from the calling account.
   *
   * Roles are often managed via {grantRole} and {revokeRole}: this function's
   * purpose is to provide a mechanism for accounts to lose their privileges
   * if they are compromised (such as when a trusted device is misplaced).
   *
   * If the calling account had been granted `role`, emits a {RoleRevoked}
   * event.
   *
   * Requirements:
   *
   * - the caller must be `account`.
   */
  function renounceRole(bytes32 role, address account) public virtual override {
    require(account == _msgSender(), 'AccessControl: can only renounce roles for self');

    _revokeRole(role, account);
  }

  /**
   * @dev Grants `role` to `account`.
   *
   * If `account` had not been already granted `role`, emits a {RoleGranted}
   * event. Note that unlike {grantRole}, this function doesn't perform any
   * checks on the calling account.
   *
   * [WARNING]
   * ====
   * This function should only be called from the constructor when setting
   * up the initial roles for the system.
   *
   * Using this function in any other way is effectively circumventing the admin
   * system imposed by {AccessControl}.
   * ====
   */
  function _setupRole(bytes32 role, address account) internal virtual {
    _grantRole(role, account);
  }

  /**
   * @dev Sets `adminRole` as ``role``'s admin role.
   *
   * Emits a {RoleAdminChanged} event.
   */
  function _setRoleAdmin(bytes32 role, bytes32 adminRole) internal virtual {
    emit RoleAdminChanged(role, getRoleAdmin(role), adminRole);
    _roles[role].adminRole = adminRole;
  }

  function _grantRole(bytes32 role, address account) private {
    if (!hasRole(role, account)) {
      _roles[role].members[account] = true;
      emit RoleGranted(role, account, _msgSender());
    }
  }

  function _revokeRole(bytes32 role, address account) private {
    if (hasRole(role, account)) {
      _roles[role].members[account] = false;
      emit RoleRevoked(role, account, _msgSender());
    }
  }
}

// File: contracts/IMXToken.sol

// SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.8.0;

contract IMXToken is ERC20Capped, AccessControl {
  bytes32 public constant MINTER_ROLE = keccak256('MINTER_ROLE');

  constructor(address minter) ERC20('Immutable X', 'IMX') ERC20Capped(20000000000000000000000000) {
    _setupRole(MINTER_ROLE, minter);
  }

  modifier checkRole(
    bytes32 role,
    address account,
    string memory message
  ) {
    require(hasRole(role, account), message);
    _;
  }

  function mint(address to, uint256 amount) external checkRole(MINTER_ROLE, msg.sender, 'Caller is not a minter') {
    super._mint(to, amount);
  }
}