pragma solidity ^0.5.0;
library SafeMath {
/**
* @dev Returns the addition of two unsigned integers, reverting on
* overflow.
*
* Counterpart to Solidity's ` ` operator.
*
* Requirements:
* - Addition cannot overflow.
*/
function add(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 c = a b;
require(c >= a, "SafeMath: addition overflow");
return c;
}

/**
* @dev Returns the subtraction of two unsigned integers, reverting on
* overflow (when the result is negative).
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
* - Subtraction cannot overflow.
*/
function sub(uint256 a, uint256 b) internal pure returns (uint256) {
return sub(a, b, "SafeMath: subtraction overflow");
}

/**
* @dev Returns the subtraction of two unsigned integers, reverting with custom message on
* overflow (when the result is negative).
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
* - Subtraction cannot overflow.
*/
function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b <= a, errorMessage);
uint256 c = a - b;

return c;
}

/**
* @dev Returns the multiplication of two unsigned integers, reverting on
* overflow.
*
* Counterpart to Solidity's `*` operator.
*
* Requirements:
* - Multiplication cannot overflow.
*/
function mul(uint256 a, uint256 b) internal pure returns (uint256) {
// Gas optimization: this is cheaper than requiring 'a' not being zero, but the
// benefit is lost if 'b' is also tested.
// See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
if (a == 0) {
return 0;
}

uint256 c = a * b;
require(c / a == b, "SafeMath: multiplication overflow");

return c;
}

/**
* @dev Returns the integer division of two unsigned integers. Reverts on
* division by zero. The result is rounded towards zero.
*
* Counterpart to Solidity's `/` operator. Note: this function uses a
* `revert` opcode (which leaves remaining gas untouched) while Solidity
* uses an invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
* - The divisor cannot be zero.
*/
function div(uint256 a, uint256 b) internal pure returns (uint256) {
return div(a, b, "SafeMath: division by zero");
}

/**
* @dev Returns the integer division of two unsigned integers. Reverts with custom message on
* division by zero. The result is rounded towards zero.
*
* Counterpart to Solidity's `/` operator. Note: this function uses a
* `revert` opcode (which leaves remaining gas untouched) while Solidity
* uses an invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
* - The divisor cannot be zero.
*/
function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b > 0, errorMessage);
uint256 c = a / b;
// assert(a == b * c a % b); // There is no case in which this doesn't hold

return c;
}

/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* Reverts when dividing by zero.
*
* Counterpart to Solidity's `%` operator. This function uses a `revert`
* opcode (which leaves remaining gas untouched) while Solidity uses an
* invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
* - The divisor cannot be zero.
*/
function mod(uint256 a, uint256 b) internal pure returns (uint256) {
return mod(a, b, "SafeMath: modulo by zero");
}

/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* Reverts with custom message when dividing by zero.
*
* Counterpart to Solidity's `%` operator. This function uses a `revert`
* opcode (which leaves remaining gas untouched) while Solidity uses an
* invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
* - The divisor cannot be zero.
*/
function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b != 0, errorMessage);
return a % b;
}
}

library Roles {
struct Role {
mapping (address => bool) bearer;
}

/**
* @dev give an account access to this role
*/
function add(Role storage role, address account) internal {
require(account != address(0));
require(!has(role, account));

role.bearer[account] = true;
}

/**
* @dev remove an account's access to this role
*/
function remove(Role storage role, address account) internal {
require(account != address(0));
require(has(role, account));

role.bearer[account] = false;
}

/**
* @dev check if an account has this role
* @return bool
*/
function has(Role storage role, address account) internal view returns (bool) {
require(account != address(0));
return role.bearer[account];
}
}

contract Ownable {
address public owner;
address public newOwner;

event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

constructor() public {
owner = msg.sender;
newOwner = address(0);
}

modifier onlyOwner() {
require(msg.sender == owner);
_;
}
modifier onlyNewOwner() {
require(msg.sender != address(0));
require(msg.sender == newOwner);
_;
}

function isOwner(address account) public view returns (bool) {
if( account == owner ){
return true;
}
else {
return false;
}
}

function transferOwnership(address _newOwner) public onlyOwner {
require(_newOwner != address(0));
newOwner = _newOwner;
}

function acceptOwnership() public onlyNewOwner returns(bool) {
emit OwnershipTransferred(owner, newOwner);
owner = newOwner;
newOwner = address(0);
}
}

contract PauserRole is Ownable{
using Roles for Roles.Role;

event PauserAdded(address indexed account);
event PauserRemoved(address indexed account);

Roles.Role private _pausers;

constructor () internal {
_addPauser(msg.sender);
}

modifier onlyPauser() {
require(isPauser(msg.sender)|| isOwner(msg.sender));
_;
}

function isPauser(address account) public view returns (bool) {
return _pausers.has(account);
}

function addPauser(address account) public onlyPauser {
_addPauser(account);
}

function removePauser(address account) public onlyOwner {
_removePauser(account);
}

function renouncePauser() public {
_removePauser(msg.sender);
}

function _addPauser(address account) internal {
_pausers.add(account);
emit PauserAdded(account);
}

function _removePauser(address account) internal {
_pausers.remove(account);
emit PauserRemoved(account);
}
}

contract Pausable is PauserRole {
event Paused(address account);
event Unpaused(address account);

bool private _paused;

constructor () internal {
_paused = false;
}

/**
* @return true if the contract is paused, false otherwise.
*/
function paused() public view returns (bool) {
return _paused;
}

/**
* @dev Modifier to make a function callable only when the contract is not paused.
*/
modifier whenNotPaused() {
require(!_paused);
_;
}

/**
* @dev Modifier to make a function callable only when the contract is paused.
*/
modifier whenPaused() {
require(_paused);
_;
}

/**
* @dev called by the owner to pause, triggers stopped state
*/
function pause() public onlyPauser whenNotPaused {
_paused = true;
emit Paused(msg.sender);
}

/**
* @dev called by the owner to unpause, returns to normal state
*/
function unpause() public onlyPauser whenPaused {
_paused = false;
emit Unpaused(msg.sender);
}
}

interface IBEP20 {
function transfer(address to, uint256 value) external returns (bool);

function approve(address spender, uint256 value) external returns (bool);

function transferFrom(address from, address to, uint256 value) external returns (bool);

function totalSupply() external view returns (uint256);

function balanceOf(address who) external view returns (uint256);

function allowance(address owner, address spender) external view returns (uint256);

event Transfer(address indexed from, address indexed to, uint256 value);

event Approval(address indexed owner, address indexed spender, uint256 value);
}

contract BEP20 is IBEP20 {
using SafeMath for uint256;

mapping (address => uint256) internal _balances;

mapping (address => mapping (address => uint256)) internal _allowed;

uint256 private _totalSupply;

/**
* @dev Total number of tokens in existence
*/
function totalSupply() public view returns (uint256) {
return _totalSupply;
}

/**
* @dev Gets the balance of the specified address.
* @param owner The address to query the balance of.
* @return An uint256 representing the amount owned by the passed address.
*/
function balanceOf(address owner) public view returns (uint256) {
return _balances[owner];
}

/**
* @dev Function to check the amount of tokens that an owner allowed to a spender.
* @param owner address The address which owns the funds.
* @param spender address The address which will spend the funds.
* @return A uint256 specifying the amount of tokens still available for the spender.
*/
function allowance(address owner, address spender) public view returns (uint256) {
return _allowed[owner][spender];
}

/**
* @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.
* 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
* @param spender The address which will spend the funds.
* @param value The amount of tokens to be spent.
*/
function approve(address spender, uint256 value) public returns (bool) {
require(spender != address(0));

_allowed[msg.sender][spender] = value;
emit Approval(msg.sender, spender, value);
return true;
}

/**
* @dev Transfer tokens from one address to another.
* Note that while this function emits an Approval event, this is not required as per the specification,
* and other compliant implementations may not emit the event.
* @param from address The address which you want to send tokens from
* @param to address The address which you want to transfer to
* @param value uint256 the amount of tokens to be transferred
*/
function transferFrom(address from, address to, uint256 value) public returns (bool) {
_allowed[from][msg.sender] = _allowed[from][msg.sender].sub(value);
_transfer(from, to, value);
emit Approval(from, msg.sender, _allowed[from][msg.sender]);
return true;
}

/**
* @dev Increase the amount of tokens that an owner allowed to a spender.
* approve should be called when allowed_[_spender] == 0. To increment
* allowed value is better to use this function to avoid 2 calls (and wait until
* the first transaction is mined)
* From MonolithDAO Token.sol
* Emits an Approval event.
* @param spender The address which will spend the funds.
* @param addedValue The amount of tokens to increase the allowance by.
*/
function increaseAllowance(address spender, uint256 addedValue) public returns (bool) {
require(spender != address(0));

_allowed[msg.sender][spender] = _allowed[msg.sender][spender].add(addedValue);
emit Approval(msg.sender, spender, _allowed[msg.sender][spender]);
return true;
}

/**
* @dev Decrease the amount of tokens that an owner allowed to a spender.
* approve should be called when allowed_[_spender] == 0. To decrement
* allowed value is better to use this function to avoid 2 calls (and wait until
* the first transaction is mined)
* From MonolithDAO Token.sol
* Emits an Approval event.
* @param spender The address which will spend the funds.
* @param subtractedValue The amount of tokens to decrease the allowance by.
*/
function decreaseAllowance(address spender, uint256 subtractedValue) public returns (bool) {
require(spender != address(0));

_allowed[msg.sender][spender] = _allowed[msg.sender][spender].sub(subtractedValue);
emit Approval(msg.sender, spender, _allowed[msg.sender][spender]);
return true;
}


/**
* @dev Transfer token for a specified address
* @param to The address to transfer to.
* @param value The amount to be transferred.
*/
function transfer(address to, uint256 value) public returns (bool) {
_transfer(msg.sender, to, value);
return true;
}

/**
* @dev Transfer token for a specified addresses
* @param from The address to transfer from.
* @param to The address to transfer to.
* @param value The amount to be transferred.
*/
function _transfer(address from, address to, uint256 value) internal {
require(to != address(0));
require(from != address(0));

_balances[from] = _balances[from].sub(value);
_balances[to] = _balances[to].add(value);
emit Transfer(from, to, value);
}

/**
* @dev Destroys `amount` tokens from the caller.
*
* See {BEP20-_burn}.
*/


/**
* @dev Internal function that burns an amount of the token of a given
* account.
* @param account The account whose tokens will be burnt.
* @param value The amount that will be burnt.
*/
function _burn(address account, uint256 value) internal {
require(account != address(0));

_totalSupply = _totalSupply.sub(value);
_balances[account] = _balances[account].sub(value);
emit Transfer(account, address(0), value);
}


/**
* @dev Internal function that burns an amount of the token of a given
* account, deducting from the sender's allowance for said account. Uses the
* internal burn function.
* Emits an Approval event (reflecting the reduced allowance).
* @param account The account whose tokens will be burnt.
* @param value The amount that will be burnt.
*/
function _burnFrom(address account, uint256 value) internal {
_allowed[account][msg.sender] = _allowed[account][msg.sender].sub(value);
_burn(account, value);
emit Approval(account, msg.sender, _allowed[account][msg.sender]);
}

/**
* @dev Internal function that mints an amount of the token and assigns it to
* an account. This encapsulates the modification of balances such that the
* proper events are emitted.
* @param account The account that will receive the created tokens.
* @param value The amount that will be created.
*/
function _mint(address account, uint256 value) internal {
require(account != address(0));

_totalSupply = _totalSupply.add(value);
_balances[account] = _balances[account].add(value);
emit Transfer(address(0), account, value);
}
}

contract BEP20Pausable is BEP20, Pausable {
function transfer(address to, uint256 value) public whenNotPaused returns (bool) {
return super.transfer(to, value);
}

function transferFrom(address from, address to, uint256 value) public whenNotPaused returns (bool) {
return super.transferFrom(from, to, value);
}
}

contract BEP20Detailed is IBEP20 {
string private _name;
string private _symbol;
uint8 private _decimals;

constructor () public {
_name = "MTO";
_symbol = "MTO";
_decimals = 18;
}

/**
* @return the name of the token.
*/
function name() public view returns (string memory) {
return _name;
}

/**
* @return the symbol of the token.
*/
function symbol() public view returns (string memory) {
return _symbol;
}

/**
* @return the number of decimals of the token.
*/
function decimals() public view returns (uint8) {
return _decimals;
}
}

contract MTO is BEP20Detailed, BEP20Pausable {

struct LockInfo {
uint256 _releaseTime;
uint256 _amount;
}

mapping (address => LockInfo[]) public timelockList;
mapping (address => bool) public frozenAccount;

event Freeze(address indexed holder);
event Unfreeze(address indexed holder);
event Lock(address indexed holder, uint256 value, uint256 releaseTime);
event Unlock(address indexed holder, uint256 value);

modifier notFrozen(address _holder) {
require(!frozenAccount[_holder]);
_;
}

constructor() BEP20Detailed() public {
_mint(msg.sender, 2_000_000_000 * 10 ** 18);
}

function timelockListLength(address owner) public view returns (uint256) {
return timelockList[owner].length;
}

function balanceOf(address owner) public view returns (uint256)
{
uint256 totalBalance = super.balanceOf(owner);
if( timelockList[owner].length >0 )
{
for(uint i=0; i totalBalance = totalBalance.add(timelockList[owner][i]._amount);
}
}
return totalBalance;
}

function balanceOfTimelocked(address owner) public view returns (uint256)
{
uint256 totalLocked = 0;
if( timelockList[owner].length >0 )
{
for(uint i=0; i totalLocked = totalLocked.add(timelockList[owner][i]._amount);
}
}

return totalLocked;
}

function balanceOfAvailable(address owner) public view returns (uint256) {

uint256 totalBalance = super.balanceOf(owner);
return totalBalance;
}

function transfer(address to, uint256 value) public notFrozen(msg.sender) returns (bool) {
if (timelockList[msg.sender].length > 0 ) {
_autoUnlock(msg.sender);
}
return super.transfer(to, value);
}

function transferFrom(address from, address to, uint256 value) public notFrozen(from) returns (bool) {
if (timelockList[from].length > 0) {
_autoUnlock(from);
}
return super.transferFrom(from, to, value);
}

function freezeAccount(address holder) public onlyPauser returns (bool) {
require(!frozenAccount[holder]);
require(timelockList[holder].length == 0);
frozenAccount[holder] = true;
emit Freeze(holder);
return true;
}

function unfreezeAccount(address holder) public onlyPauser returns (bool) {
require(frozenAccount[holder]);
frozenAccount[holder] = false;
emit Unfreeze(holder);
return true;
}

function lockByQuantity(address holder, uint256 value, uint256 releaseTime) public onlyPauser returns (bool) {
require(!frozenAccount[holder]);
_lock(holder,value,releaseTime);
return true;
}

function unlockByQuantity(address holder, uint256 value, uint256 releaseTime) public onlyPauser returns (bool) {
//1
require(!frozenAccount[holder]);
//2
require(timelockList[holder].length >0);

//3
uint256 totalLocked;
for(uint idx = 0; idx < timelockList[holder].length ; idx ){
totalLocked = totalLocked.add(timelockList[holder][idx]._amount);
}
require(totalLocked >value);

//4
for(uint idx = 0; idx < timelockList[holder].length ; idx ) {
if( _unlock(holder, idx) ) {
idx -=1;
}
}

//5
_lock(holder,totalLocked.sub(value),releaseTime);

return true;
}

function transferWithLock(address holder, uint256 value, uint256 releaseTime) public onlyPauser returns (bool) {
_transfer(msg.sender, holder, value);
_lock(holder,value,releaseTime);
return true;
}

function unlock(address holder, uint256 idx) public onlyPauser returns (bool) {
require( timelockList[holder].length > idx, "AhnLog_There is not lock info.");
_unlock(holder,idx);
return true;
}


function _lock(address holder, uint256 value, uint256 releaseTime) internal returns (bool) {
_balances[holder] = _balances[holder].sub(value);
timelockList[holder].push( LockInfo(releaseTime, value) );

emit Lock(holder, value, releaseTime);
return true;
}

function _unlock(address holder, uint256 idx) internal returns(bool) {
LockInfo storage lockinfo = timelockList[holder][idx];
uint256 releaseAmount = lockinfo._amount;

delete timelockList[holder][idx];
timelockList[holder][idx] = timelockList[holder][timelockList[holder].length.sub(1)];
timelockList[holder].length -=1;

emit Unlock(holder, releaseAmount);
_balances[holder] = _balances[holder].add(releaseAmount);

return true;
}

function _autoUnlock(address holder) internal returns (bool) {
for(uint256 idx =0; idx < timelockList[holder].length ; idx ) {
if (timelockList[holder][idx]._releaseTime <= now) {
// If lockupinfo was deleted, loop restart at same position.
if( _unlock(holder, idx) ) {
idx -=1;
}
}
}
return true;
}
}