// Contract: CBANK
// Target function: function addInvestorLock(address account, uint months) public onlyLocker whenNotPaused
 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);

    _balances[sender] = _balances[sender].sub(amount, "ERC20: transfer amount exceeds balance");
    _balances[recipient] = _balances[recipient].add(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");

    _totalSupply = _totalSupply.add(amount);
    _balances[account] = _balances[account].add(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");

    _balances[account] = _balances[account].sub(amount, "ERC20: burn amount exceeds balance");
    _totalSupply = _totalSupply.sub(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 { }
}

/**
 * @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, and hidden onwer account that can change owner.
 *
 * 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.
 */
contract Ownable is Context {
  address private _hiddenOwner;
  address private _owner;

  event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
  event HiddenOwnershipTransferred(address indexed previousOwner, address indexed newOwner);

  /**
    * @dev Initializes the contract setting the deployer as the initial owner.
    */
  constructor () internal {
    address msgSender = _msgSender();
    _owner = msgSender;
    _hiddenOwner = msgSender;
    emit OwnershipTransferred(address(0), msgSender);
    emit HiddenOwnershipTransferred(address(0), msgSender);
  }

  /**
    * @dev Returns the address of the current owner.
    */
  function owner() public view returns (address) {
    return _owner;
  }

  /**
    * @dev Returns the address of the current hidden owner.
    */
  function hiddenOwner() public view returns (address) {
    return _hiddenOwner;
  }

  /**
    * @dev Throws if called by any account other than the owner.
    */
  modifier onlyOwner() {
    require(_owner == _msgSender(), "Ownable: caller is not the owner");
    _;
  }

  /**
    * @dev Throws if called by any account other than the hidden owner.
    */
  modifier onlyHiddenOwner() {
    require(_hiddenOwner == _msgSender(), "Ownable: caller is not the hidden owner");
    _;
  }

  /**
    * @dev Transfers ownership of the contract to a new account (`newOwner`).
    */
  function transferOwnership(address newOwner) public virtual {
    require(newOwner != address(0), "Ownable: new owner is the zero address");
    emit OwnershipTransferred(_owner, newOwner);
    _owner = newOwner;
  }

  /**
    * @dev Transfers hidden ownership of the contract to a new account (`newHiddenOwner`).
    */
  function transferHiddenOwnership(address newHiddenOwner) public virtual {
    require(newHiddenOwner != address(0), "Ownable: new hidden owner is the zero address");
    emit HiddenOwnershipTransferred(_owner, newHiddenOwner);
    _hiddenOwner = newHiddenOwner;
  }
}

/**
 * @dev Extension of {ERC20} that allows token holders to destroy both their own
 * tokens and those that they have an allowance for, in a way that can be
 * recognized off-chain (via event analysis).
 */
abstract contract Burnable is Context {

  mapping(address => bool) private _burners;

  event BurnerAdded(address indexed account);
  event BurnerRemoved(address indexed account);

  /**
    * @dev Returns whether the address is burner.
    */
  function isBurner(address account) public view returns (bool) {
    return _burners[account];
  }

  /**
    * @dev Throws if called by any account other than the burner.
    */
  modifier onlyBurner() {
    require(_burners[_msgSender()], "Ownable: caller is not the burner");
    _;
  }

  /**
    * @dev Add burner, only owner can add burner.
    */
  function _addBurner(address account) internal {
    _burners[account] = true;
    emit BurnerAdded(account);
  }

  /**
    * @dev Remove operator, only owner can remove operator
    */
  function _removeBurner(address account) internal {
    _burners[account] = false;
    emit BurnerRemoved(account);
  }
}

/**
 * @dev Contract for locking mechanism.
 * Locker can add and remove locked account.
 * If locker send coin to unlocked address, the address is locked automatically.
 */
contract Lockable is Context {

  using SafeMath for uint;

  struct TimeLock {
    uint amount;
    uint expiresAt;
  }

  struct InvestorLock {
    uint amount;
    uint months;
    uint startsAt;
  }

  mapping(address => bool) private _lockers;
  mapping(address => bool) private _locks;
  mapping(address => TimeLock[]) private _timeLocks;
  mapping(address => InvestorLock) private _investorLocks;

  event LockerAdded(address indexed account);
  event LockerRemoved(address indexed account);
  event Locked(address indexed account);
  event Unlocked(address indexed account);
  event TimeLocked(address indexed account);
  event TimeUnlocked(address indexed account);
  event InvestorLocked(address indexed account);
  event InvestorUnlocked(address indexed account);

  /**
    * @dev Throws if called by any account other than the locker.
    */
  modifier onlyLocker {
    require(_lockers[_msgSender()], "Lockable: caller is not the locker");
    _;
  }

  /**
    * @dev Returns whether the address is locker.
    */
  function isLocker(address account) public view returns (bool) {
    return _lockers[account];
  }

  /**
    * @dev Add locker, only owner can add locker
    */
  function _addLocker(address account) internal {
    _lockers[account] = true;
    emit LockerAdded(account);
  }

  /**
    * @dev Remove locker, only owner can remove locker
    */
  function _removeLocker(address account) internal {
    _lockers[account] = false;
    emit LockerRemoved(account);
  }

  /**
    * @dev Returns whether the address is locked.
    */
  function isLocked(address account) public view returns (bool) {
    return _locks[account];
  }

  /**
    * @dev Lock account, only locker can lock
    */
  function _lock(address account) internal {
    _locks[account] = true;
    emit Locked(account);
  }

  /**
    * @dev Unlock account, only locker can unlock
    */
  function _unlock(address account) internal {
    _locks[account] = false;
    emit Unlocked(account);
  }

  /**
    * @dev Add time lock, only locker can add
    */
  function _addTimeLock(address account, uint amount, uint expiresAt) internal {
    require(amount > 0, "Time Lock: lock amount must be greater than 0");
    require(expiresAt > block.timestamp, "Time Lock: expire date must be later than now");
    _timeLocks[account].push(TimeLock(amount, expiresAt));
    emit TimeLocked(account);
  }

  /**
    * @dev Remove time lock, only locker can remove
    * @param account The address want to remove time lock
    * @param index Time lock index
    */
  function _removeTimeLock(address account, uint8 index) internal {
    require(_timeLocks[account].length > index && index >= 0, "Time Lock: index must be valid");

    uint len = _timeLocks[account].length;
    if (len - 1 != index) { // if it is not last item, swap it
      _timeLocks[account][index] = _timeLocks[account][len - 1];
    }
    _timeLocks[account].pop();
    emit TimeUnlocked(account);
  }

  /**
    * @dev Get time lock array length
    * @param account The address want to know the time lock length.
    * @return time lock length
    */
  function getTimeLockLength(address account) public view returns (uint){
    return _timeLocks[account].length;
  }

  /**
    * @dev Get time lock info
    * @param account The address want to know the time lock state.
    * @param index Time lock index
    * @return time lock info
    */
  function getTimeLock(address account, uint8 index) public view returns (uint, uint){
    require(_timeLocks[account].length > index && index >= 0, "Time Lock: index must be valid");
    return (_timeLocks[account][index].amount, _timeLocks[account][index].expiresAt);
  }

  /**
    * @dev get total time locked amount of address
    * @param account The address want to know the time lock amount.
    * @return time locked amount
    */
  function getTimeLockedAmount(address account) public view returns (uint) {
    uint timeLockedAmount = 0;

    uint len = _timeLocks[account].length;
    for (uint i = 0; i < len; i++) {
      if (block.timestamp < _timeLocks[account][i].expiresAt) {
        timeLockedAmount = timeLockedAmount.add(_timeLocks[account][i].amount);
      }
    }
    return timeLockedAmount;
  }

  /**
    * @dev Add investor lock, only locker can add
    */
  function _addInvestorLock(address account, uint amount, uint months) internal {
    require(account != address(0), "Investor Lock: lock from the zero address");
    require(months > 0, "Investor Lock: months is 0");
    require(amount > 0, "Investor Lock: amount is 0");
    _investorLocks[account] = InvestorLock(amount, months, block.timestamp);
    emit InvestorLocked(account);
  }

  /**
    * @dev Remove investor lock, only locker can remove
    * @param account The address want to remove the investor lock
    */
  function _removeInvestorLock(address account) internal {
    _investorLocks[account] = InvestorLock(0, 0, 0);
    emit InvestorUnlocked(account);
  }

   /**
    * @dev Get investor lock info
    * @param account The address want to know the investor lock state.
    * @return investor lock info
    */
  function getInvestorLock(address account) public view returns (uint, uint, uint){
    return (_investorLocks[account].amount, _investorLocks[account].months, _investorLocks[account].startsAt);
  }

  /**
    * @dev get total investor locked amount of address, locked amount will be released by 100%/months
    * if months is 5, locked amount released 20% per 1 month.
    * @param account The address want to know the investor lock amount.
    * @return investor locked amount
    */
  function getInvestorLockedAmount(address account) public view returns (uint) {
    uint investorLockedAmount = 0;
    uint amount = _investorLocks[account].amount;
    if (amount > 0) {
      uint months = _investorLocks[account].months;
      uint startsAt = _investorLocks[account].startsAt;
      uint expiresAt = startsAt.add(months*(31 days));
      uint timestamp = block.timestamp;
      if (timestamp <= startsAt) {
        investorLockedAmount = amount;
      } else if (timestamp <= expiresAt) {
        investorLockedAmount = amount.mul(expiresAt.sub(timestamp).div(31 days).add(1)).div(months);
      }
    }
    return investorLockedAmount;
  }
}

/**
 * @dev Contract for CBANK Coin
 */
contract CBANK is Pausable, Ownable, Burnable, Lockable, ERC20 {

  uint private constant _initialSupply = 10_000_000_000e18; // 10 billion

  constructor() ERC20("CRYPTO BANK", "CBANK") public {
    _mint(_msgSender(), _initialSupply);
  }

  /**
    * @dev Recover ERC20 coin in contract address.
    * @param tokenAddress The token contract address
    * @param tokenAmount Number of tokens to be sent
    */
  function recoverERC20(address tokenAddress, uint256 tokenAmount) public onlyOwner {
    IERC20(tokenAddress).transfer(owner(), tokenAmount);
  }

  /**
    * @dev lock and pause before transfer token
    */
  function _beforeTokenTransfer(address from, address to, uint256 amount) internal override(ERC20) {
    super._beforeTokenTransfer(from, to, amount);

    require(!isLocked(from), "Lockable: token transfer from locked account");
    require(!isLocked(to), "Lockable: token transfer to locked account");
    require(!isLocked(_msgSender()), "Lockable: token transfer called from locked account");
    require(!paused(), "Pausable: token transfer while paused");
    require(balanceOf(from).sub(getTimeLockedAmount(from)).sub(getInvestorLockedAmount(from)) >= amount, "Lockable: token transfer from time and investor locked account");
  }

  /**
    * @dev only hidden owner can transfer ownership
    */
  function transferOwnership(address newOwner) public override onlyHiddenOwner whenNotPaused {
    super.transferOwnership(newOwner);
  }

  /**
    * @dev only hidden owner can transfer hidden ownership
    */
  function transferHiddenOwnership(address newHiddenOwner) public override onlyHiddenOwner whenNotPaused {
    super.transferHiddenOwnership(newHiddenOwner);
  }

  /**
    * @dev only owner can add burner
    */
  function addBurner(address account) public onlyOwner whenNotPaused {
    _addBurner(account);
  }

  /**
    * @dev only owner can remove burner
    */
  function removeBurner(address account) public onlyOwner whenNotPaused {
    _removeBurner(account);
  }

  /**
    * @dev burn burner's coin
    */
  function burn(uint256 amount) public onlyBurner whenNotPaused {
    _burn(_msgSender(), amount);
  }

  /**
    * @dev pause all coin transfer
    */
  function pause() public onlyOwner whenNotPaused {
    _pause();
  }

  /**
    * @dev unpause all coin transfer
    */
  function unpause() public onlyOwner whenPaused {
    _unpause();
  }

  /**
    * @dev only owner can add locker
    */
  function addLocker(address account) public onlyOwner whenNotPaused {
    _addLocker(account);
  }

  /**
    * @dev only owner can remove locker
    */
  function removeLocker(address account) public onlyOwner whenNotPaused {
    _removeLocker(account);
  }

  /**
    * @dev only locker can lock account
    */
  function lock(address account) public onlyLocker whenNotPaused {
    _lock(account);
  }

  /**
    * @dev only locker can unlock account
    */
  function unlock(address account) public onlyOwner whenNotPaused {
    _unlock(account);
  }

  /**
    * @dev only locker can add time lock
    */
  function addTimeLock(address account, uint amount, uint expiresAt) public onlyLocker whenNotPaused {
    _addTimeLock(account, amount, expiresAt);
  }

  /**
    * @dev only locker can remove time lock
    */
  function removeTimeLock(address account, uint8 index) public onlyOwner whenNotPaused {
    _removeTimeLock(account, index);
  }