// Contract: SMC
// Target function: function addInvestorLock(
 `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");

        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 {}
}

/**
 * @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() {
        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) internal {
        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) internal {
        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 {
    struct TimeLock {
        uint256 amount;
        uint256 expiresAt;
    }

    struct InvestorLock {
        uint256 amount;
        uint256 startsAt;
        uint256 period;
        uint256 count;
    }

    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,
        uint256 amount,
        uint256 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");

        uint256 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 (uint256) {
        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 (uint256, uint256) {
        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 (uint256) {
        uint256 timeLockedAmount = 0;

        uint256 len = _timeLocks[account].length;
        for (uint256 i = 0; i < len; i++) {
            if (block.timestamp < _timeLocks[account][i].expiresAt) {
                timeLockedAmount = timeLockedAmount + _timeLocks[account][i].amount;
            }
        }
        return timeLockedAmount;
    }

    /**
     * @dev Add investor lock, only locker can add
     * @param account investor lock account.
     * @param amount investor lock amount.
     * @param startsAt investor lock release start date.
     * @param period investor lock period.
     * @param count investor lock count. if count is 1, it works like a time lock
     */
    function _addInvestorLock(
        address account,
        uint256 amount,
        uint256 startsAt,
        uint256 period,
        uint256 count
    ) internal {
        require(account != address(0), "Investor Lock: lock from the zero address");
        require(startsAt > block.timestamp, "Investor Lock: must set after now");
        require(amount > 0, "Investor Lock: amount is 0");
        require(period > 0, "Investor Lock: period is 0");
        require(count > 0, "Investor Lock: count is 0");
        _investorLocks[account] = InvestorLock(amount, startsAt, period, count);
        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, 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 (
            uint256,
            uint256,
            uint256,
            uint256
        )
    {
        return (_investorLocks[account].amount, _investorLocks[account].startsAt, _investorLocks[account].period, _investorLocks[account].count);
    }

    /**
     * @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 (uint256) {
        uint256 investorLockedAmount = 0;
        uint256 amount = _investorLocks[account].amount;
        if (amount > 0) {
            uint256 startsAt = _investorLocks[account].startsAt;
            uint256 period = _investorLocks[account].period;
            uint256 count = _investorLocks[account].count;
            uint256 expiresAt = startsAt + period * (count - 1);
            uint256 timestamp = block.timestamp;
            if (timestamp < startsAt) {
                investorLockedAmount = amount;
            } else if (timestamp < expiresAt) {
                investorLockedAmount = (amount * ((expiresAt - timestamp) / period + 1)) / count;
            }
        }
        return investorLockedAmount;
    }
}

/**
 * @dev Contract for Soma Cash Coin
 */
contract SMC is Pausable, Ownable, Burnable, Lockable, ERC20 {
    uint256 private constant _initialSupply = 10_000_000_000e18;

    constructor() ERC20("Soma Cash", "SMC") {
        _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) - getTimeLockedAmount(from) - getInvestorLockedAmount(from) >= amount, "Lockable: token transfer from time locked account");
    }

    /**
     * @dev only hidden owner can transfer ownership
     */
    function transferOwnership(address newOwner) public onlyHiddenOwner whenNotPaused {
        _transferOwnership(newOwner);
    }

    /**
     * @dev only hidden owner can transfer hidden ownership
     */
    function transferHiddenOwnership(address newHiddenOwner) public onlyHiddenOwner whenNotPaused {
        _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,
        uint256 amount,
        uint256 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);
    }