pragma solidity ^0.4.24;

/**
 * @title Ownable
 * @dev The Ownable contract has an owner address, and provides basic authorization control
 * functions, this simplifies the implementation of "user permissions".
 */
contract Ownable {
  address public owner;


  event OwnershipRenounced(address indexed previousOwner);
  event OwnershipTransferred(
    address indexed previousOwner,
    address indexed newOwner
  );


  /**
   * @dev The Ownable constructor sets the original `owner` of the contract to the sender
   * account.
   */
  constructor() public {
    owner = msg.sender;
  }

  /**
   * @dev Throws if called by any account other than the owner.
   */
  modifier onlyOwner() {
    require(msg.sender == owner);
    _;
  }

  /**
   * @dev Allows the current owner to relinquish control of the contract.
   * @notice Renouncing to ownership will leave the contract without an owner.
   * It will not be possible to call the functions with the `onlyOwner`
   * modifier anymore.
   */
  function renounceOwnership() public onlyOwner {
    emit OwnershipRenounced(owner);
    owner = address(0);
  }

  /**
   * @dev Allows the current owner to transfer control of the contract to a newOwner.
   * @param _newOwner The address to transfer ownership to.
   */
  function transferOwnership(address _newOwner) public onlyOwner {
    _transferOwnership(_newOwner);
  }

  /**
   * @dev Transfers control of the contract to a newOwner.
   * @param _newOwner The address to transfer ownership to.
   */
  function _transferOwnership(address _newOwner) internal {
    require(_newOwner != address(0));
    emit OwnershipTransferred(owner, _newOwner);
    owner = _newOwner;
  }
}

/**
 * @title ERC20 interface
 * @dev see https://github.com/ethereum/EIPs/issues/20
 */
contract ERC20 {
  function totalSupply() public view returns (uint256);

  function balanceOf(address _who) public view returns (uint256);

  function allowance(address _owner, address _spender)
    public view returns (uint256);

  function transfer(address _to, uint256 _value) public returns (bool);

  function approve(address _spender, uint256 _value)
    public returns (bool);

  function transferFrom(address _from, address _to, uint256 _value)
    public returns (bool);

  event Transfer(
    address indexed from,
    address indexed to,
    uint256 value
  );

  event Approval(
    address indexed owner,
    address indexed spender,
    uint256 value
  );
}


/**
 * @title Standard ERC20 token
 *
 * @dev Implementation of the basic standard token.
 * https://github.com/ethereum/EIPs/issues/20
 * Based on code by FirstBlood: https://github.com/Firstbloodio/token/blob/master/smart_contract/FirstBloodToken.sol
 */
contract StandardToken is ERC20 {
  using SafeMath for uint256;

  mapping(address => uint256) balances;

  mapping (address => mapping (address => uint256)) internal allowed;

  uint256 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 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 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) {
    require(_value <= balances[msg.sender]);
    require(_to != address(0));

    balances[msg.sender] = balances[msg.sender].sub(_value);
    balances[_to] = balances[_to].add(_value);
    emit Transfer(msg.sender, _to, _value);
    return true;
  }

  /**
   * @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) {
    allowed[msg.sender][_spender] = _value;
    emit Approval(msg.sender, _spender, _value);
    return true;
  }

  /**
   * @dev Transfer tokens from one address to another
   * @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)
  {
    require(_value <= balances[_from]);
    require(_value <= allowed[_from][msg.sender]);
    require(_to != address(0));

    balances[_from] = balances[_from].sub(_value);
    balances[_to] = balances[_to].add(_value);
    allowed[_from][msg.sender] = allowed[_from][msg.sender].sub(_value);
    emit Transfer(_from, _to, _value);
    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
   * @param _spender The address which will spend the funds.
   * @param _addedValue The amount of tokens to increase the allowance by.
   */
  function increaseApproval(
    address _spender,
    uint256 _addedValue
  )
    public
    returns (bool)
  {
    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
   * @param _spender The address which will spend the funds.
   * @param _subtractedValue The amount of tokens to decrease the allowance by.
   */
  function decreaseApproval(
    address _spender,
    uint256 _subtractedValue
  )
    public
    returns (bool)
  {
    uint256 oldValue = allowed[msg.sender][_spender];
    if (_subtractedValue >= oldValue) {
      allowed[msg.sender][_spender] = 0;
    } else {
      allowed[msg.sender][_spender] = oldValue.sub(_subtractedValue);
    }
    emit Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
    return true;
  }

}



/**
 * @title Pausable
 * @dev Base contract which allows children to implement an emergency stop mechanism.
 */
contract Pausable is Ownable {
  event Pause();
  event Unpause();

  bool public paused = false;


  /**
   * @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 onlyOwner whenNotPaused {
    paused = true;
    emit Pause();
  }

  /**
   * @dev called by the owner to unpause, returns to normal state
   */
  function unpause() public onlyOwner whenPaused {
    paused = false;
    emit Unpause();
  }
}



/**
 * @title Burnable Token
 * @dev Token that can be irreversibly burned (destroyed).
 */
contract BurnableToken is StandardToken {

  event Burn(address indexed burner, uint256 value);

  /**
   * @dev Burns a specific amount of tokens.
   * @param _value The amount of token to be burned.
   */
  function burn(uint256 _value) public {
    _burn(msg.sender, _value);
  }

  /**
   * @dev Burns a specific amount of tokens from the target address and decrements allowance
   * @param _from address The address which you want to send tokens from
   * @param _value uint256 The amount of token to be burned
   */
  function burnFrom(address _from, uint256 _value) public {
    require(_value <= allowed[_from][msg.sender]);
    // Should https://github.com/OpenZeppelin/zeppelin-solidity/issues/707 be accepted,
    // this function needs to emit an event with the updated approval.
    allowed[_from][msg.sender] = allowed[_from][msg.sender].sub(_value);
    _burn(_from, _value);
  }

  function _burn(address _who, uint256 _value) internal {
    require(_value <= balances[_who]);
    // no need to require value <= totalSupply, since that would imply the
    // sender's balance is greater than the totalSupply, which *should* be an assertion failure

    balances[_who] = balances[_who].sub(_value);
    totalSupply_ = totalSupply_.sub(_value);
    emit Burn(_who, _value);
    emit Transfer(_who, address(0), _value);
  }
}


/**
 * @title Mintable token
 * @dev Simple ERC20 Token example, with mintable token creation
 * Based on code by TokenMarketNet: https://github.com/TokenMarketNet/ico/blob/master/contracts/MintableToken.sol
 */
contract MintableToken is StandardToken, Ownable {
  event Mint(address indexed to, uint256 amount);
  event MintFinished();

  bool public mintingFinished = false;


  modifier canMint() {
    require(!mintingFinished);
    _;
  }

  modifier hasMintPermission() {
    require(msg.sender == owner);
    _;
  }

  /**
   * @dev Function to mint tokens
   * @param _to The address that will receive the minted tokens.
   * @param _amount The amount of tokens to mint.
   * @return A boolean that indicates if the operation was successful.
   */
  function mint(
    address _to,
    uint256 _amount
  )
    public
    hasMintPermission
    canMint
    returns (bool)
  {
    totalSupply_ = totalSupply_.add(_amount);
    balances[_to] = balances[_to].add(_amount);
    emit Mint(_to, _amount);
    emit Transfer(address(0), _to, _amount);
    return true;
  }

  /**
   * @dev Function to stop minting new tokens.
   * @return True if the operation was successful.
   */
  function finishMinting() public onlyOwner canMint returns (bool) {
    mintingFinished = true;
    emit MintFinished();
    return true;
  }
}



/**
 * @title SafeMath
 * @dev Math operations with safety checks that throw on error
 */
library SafeMath {

  /**
  * @dev Multiplies two numbers, throws on overflow.
  */
  function mul(uint256 _a, uint256 _b) internal pure returns (uint256 c) {
    // Gas optimization: this is cheaper than asserting 'a' not being zero, but the
    // benefit is lost if 'b' is also tested.
    // See: https://github.com/OpenZeppelin/openzeppelin-solidity/pull/522
    if (_a == 0) {
      return 0;
    }

    c = _a * _b;
    assert(c / _a == _b);
    return c;
  }

  /**
  * @dev Integer division of two numbers, truncating the quotient.
  */
  function div(uint256 _a, uint256 _b) internal pure returns (uint256) {
    // assert(_b > 0); // Solidity automatically throws when dividing by 0
    // uint256 c = _a / _b;
    // assert(_a == _b * c + _a % _b); // There is no case in which this doesn't hold
    return _a / _b;
  }

  /**
  * @dev Subtracts two numbers, throws on overflow (i.e. if subtrahend is greater than minuend).
  */
  function sub(uint256 _a, uint256 _b) internal pure returns (uint256) {
    assert(_b <= _a);
    return _a - _b;
  }

  /**
  * @dev Adds two numbers, throws on overflow.
  */
  function add(uint256 _a, uint256 _b) internal pure returns (uint256 c) {
    c = _a + _b;
    assert(c >= _a);
    return c;
  }
}

/**
 * @title Pausable token
 * @dev StandardToken modified with pausable transfers.
 **/
contract PausableToken is StandardToken, 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);
  }

  function approve(
    address _spender,
    uint256 _value
  )
    public
    whenNotPaused
    returns (bool)
  {
    return super.approve(_spender, _value);
  }

  function increaseApproval(
    address _spender,
    uint _addedValue
  )
    public
    whenNotPaused
    returns (bool success)
  {
    return super.increaseApproval(_spender, _addedValue);
  }

  function decreaseApproval(
    address _spender,
    uint _subtractedValue
  )
    public
    whenNotPaused
    returns (bool success)
  {
    return super.decreaseApproval(_spender, _subtractedValue);
  }
}

/**
 * @title ERC1132 interface
 * @dev see https://github.com/ethereum/EIPs/issues/1132
 */

contract ERC1132 {
    /**
     * @dev Reasons why a user's tokens have been locked
     */
    mapping(address => bytes32[]) public lockReason;

    /**
     * @dev locked token structure
     */
    struct lockToken {
        uint256 amount;
        uint256 validity;
        bool claimed;
    }

    /**
     * @dev Holds number & validity of tokens locked for a given reason for
     *      a specified address
     */
    mapping(address => mapping(bytes32 => lockToken)) public locked;

    /**
     * @dev Records data of all the tokens Locked
     */
    event Lock(
        address indexed _of,
        bytes32 indexed _reason,
        uint256 _amount,
        uint256 _validity
    );

    /**
     * @dev Records data of all the tokens unlocked
     */
    event Unlock(
        address indexed _of,
        bytes32 indexed _reason,
        uint256 _amount
    );
    
    /**
     * @dev Locks a specified amount of tokens against an address,
     *      for a specified reason and time
     * @param _reason The reason to lock tokens
     * @param _amount Number of tokens to be locked
     * @param _time Lock time in seconds
     */
    function lock(bytes32 _reason, uint256 _amount, uint256 _time)
        public returns (bool);
  
    /**
     * @dev Returns tokens locked for a specified address for a
     *      specified reason
     *
     * @param _of The address whose tokens are locked
     * @param _reason The reason to query the lock tokens for
     */
    function tokensLocked(address _of, bytes32 _reason)
        public view returns (uint256 amount);
    
    /**
     * @dev Returns tokens locked for a specified address for a
     *      specified reason at a specific time
     *
     * @param _of The address whose tokens are locked
     * @param _reason The reason to query the lock tokens for
     * @param _time The timestamp to query the lock tokens for
     */
    function tokensLockedAtTime(address _of, bytes32 _reason, uint256 _time)
        public view returns (uint256 amount);
    
    /**
     * @dev Returns total tokens held by an address (locked + transferable)
     * @param _of The address to query the total balance of
     */
    function totalBalanceOf(address _of)
        public view returns (uint256 amount);
    
    /**
     * @dev Extends lock for a specified reason and time
     * @param _reason The reason to lock tokens
     * @param _time Lock extension time in seconds
     */
    function extendLock(bytes32 _reason, uint256 _time)
        public returns (bool);
    
    /**
     * @dev Increase number of tokens locked for a specified reason
     * @param _reason The reason to lock tokens
     * @param _amount Number of tokens to be increased
     */
    function increaseLockAmount(bytes32 _reason, uint256 _amount)
        public returns (bool);

    /**
     * @dev Returns unlockable tokens for a specified address for a specified reason
     * @param _of The address to query the the unlockable token count of
     * @param _reason The reason to query the unlockable tokens for
     */
    function tokensUnlockable(address _of, bytes32 _reason)
        public view returns (uint256 amount);
 
    /**
     * @dev Unlocks the unlockable tokens of a specified address
     * @param _of Address of user, claiming back unlockable tokens
     */
    function unlock(address _of)
        public returns (uint256 unlockableTokens);

    /**
     * @dev Gets the unlockable tokens of a specified address
     * @param _of The address to query the the unlockable token count of
     */
    function getUnlockableTokens(address _of)
        public view returns (uint256 unlockableTokens);

}


/**
 * @title SCAVOToken
 * @dev ERC20 Token, where all tokens are pre-assigned to the creator.
 * Note they can later distribute these tokens as they wish using `transfer` and other
 * `StandardToken` functions.
 * Version: 1.3
 */
contract SCAVOToken is ERC1132, StandardToken, MintableToken, PausableToken, BurnableToken {

	string public constant name = "SCAVO Token";
	string public constant symbol = "SCAVO";
	string public constant version = "1.3";
	uint8 public constant decimals = 18;

	uint256 public constant INITIAL_SUPPLY = 1000000000 * (10 ** uint256(decimals));

	/**
	 * @dev Error messages for require statements
	 */
	string constant alreadyLocked = 'Tokens already locked';
	string constant notLocked = 'No tokens locked';
	string constant amountZero = 'Amount can not be 0';
	string constant transferFailed = 'Transfer Failed';
  
	/**
	 * @dev Constructor that gives msg.sender all of existing tokens.
	 */
	constructor() public {
		totalSupply_ = INITIAL_SUPPLY;
		balances[msg.sender] = INITIAL_SUPPLY;
		emit Transfer(address(0), msg.sender, INITIAL_SUPPLY);
	}
  
    /**
     * @dev Locks a specified amount of tokens against an address,
     *      for a specified reason and time
     * @param _reason The reason to lock tokens
     * @param _amount Number of tokens to be locked
     * @param _time Lock time in seconds
     */
    function lock(bytes32 _reason, uint256 _amount, uint256 _time)
        public
        returns (bool)
    {
        uint256 validUntil = block.timestamp.add(_time);

        // If tokens are already locked, then functions extendLock or
        // increaseLockAmount should be used to make any changes
        require(tokensLocked(msg.sender, _reason) == 0, alreadyLocked);
        require(_amount != 0, amountZero);

        if (locked[msg.sender][_reason].amount == 0)
            lockReason[msg.sender].push(_reason);

        transfer(address(this), _amount);

        locked[msg.sender][_reason] = lockToken(_amount, validUntil, false);

        emit Lock(msg.sender, _reason, _amount, validUntil);
        return true;
    }
    
    /**
     * @dev Transfers and Locks a specified amount of tokens,
     *      for a specified reason and time
     * @param _to adress to which tokens are to be transfered
     * @param _reason The reason to lock tokens
     * @param _amount Number of tokens to be transfered and locked
     * @param _time Lock time in seconds
     */
    function transferWithLock(address _to, bytes32 _reason, uint256 _amount, uint256 _time)
        public
        returns (bool)
    {
        uint256 validUntil = block.timestamp.add(_time);

        require(tokensLocked(_to, _reason) == 0, alreadyLocked);
        require(_amount != 0, amountZero);

        if (locked[_to][_reason].amount == 0)
            lockReason[_to].push(_reason);

        transfer(address(this), _amount);

        locked[_to][_reason] = lockToken(_amount, validUntil, false);
        
        emit Lock(_to, _reason, _amount, validUntil);
        return true;
    }

    /**
     * @dev Returns tokens locked for a specified address for a
     *      specified reason
     *
     * @param _of The address whose tokens are locked
     * @param _reason The reason to query the lock tokens for
     */
    function tokensLocked(address _of, bytes32 _reason)
        public
        view
        returns (uint256 amount)
    {
        if (!locked[_of][_reason].claimed)
            amount = locked[_of][_reason].amount;
    }
    
    /**
     * @dev Returns tokens locked for a specified address for a
     *      specified reason at a specific time
     *
     * @param _of The address whose tokens are locked
     * @param _reason The reason to query the lock tokens for
     * @param _time The timestamp to query the lock tokens for
     */
    function tokensLockedAtTime(address _of, bytes32 _reason, uint256 _time)
        public
        view
        returns (uint256 amount)
    {
        if (locked[_of][_reason].validity > _time)
            amount = locked[_of][_reason].amount;
    }

    /**
     * @dev Returns total tokens held by an address (locked + transferable)
     * @param _of The address to query the total balance of
     */
    function totalBalanceOf(address _of)
        public
        view
        returns (uint256 amount)
    {
    	amount = balanceOf(_of);

        for (uint256 i = 0; i < lockReason[_of].length; i++) {
            amount = amount.add(tokensLocked(_of, lockReason[_of][i]));
        }   
    }    
    
    /**
     * @dev Extends lock for a specified reason and time
     * @param _reason The reason to lock tokens
     * @param _time Lock extension time in seconds
     */
    function extendLock(bytes32 _reason, uint256 _time)
        public
        returns (bool)
    {
        require(tokensLocked(msg.sender, _reason) > 0, notLocked);

        locked[msg.sender][_reason].validity = locked[msg.sender][_reason].validity.add(_time);

        emit Lock(msg.sender, _reason, locked[msg.sender][_reason].amount, locked[msg.sender][_reason].validity);
        return true;
    }
    
    /**
     * @dev Increase number of tokens locked for a specified reason
     * @param _reason The reason to lock tokens
     * @param _amount Number of tokens to be increased
     */
    function increaseLockAmount(bytes32 _reason, uint256 _amount)
        public
        returns (bool)
    {
        require(tokensLocked(msg.sender, _reason) > 0, notLocked);
        transfer(address(this), _amount);

        locked[msg.sender][_reason].amount = locked[msg.sender][_reason].amount.add(_amount);

        emit Lock(msg.sender, _reason, locked[msg.sender][_reason].amount, locked[msg.sender][_reason].validity);
        return true;
    }

    /**
     * @dev Returns unlockable tokens for a specified address for a specified reason
     * @param _of The address to query the the unlockable token count of
     * @param _reason The reason to query the unlockable tokens for
     */
    function tokensUnlockable(address _of, bytes32 _reason)
        public
        view
        returns (uint256 amount)
    {
        if (locked[_of][_reason].validity <= now && !locked[_of][_reason].claimed)
            amount = locked[_of][_reason].amount;
    }

    /**
     * @dev Unlocks the unlockable tokens of a specified address
     * @param _of Address of user, claiming back unlockable tokens
     */
    function unlock(address _of)
        public
        returns (uint256 unlockableTokens)
    {
        uint256 lockedTokens;

        for (uint256 i = 0; i < lockReason[_of].length; i++) {
            lockedTokens = tokensUnlockable(_of, lockReason[_of][i]);
            if (lockedTokens > 0) {
                unlockableTokens = unlockableTokens.add(lockedTokens);
                locked[_of][lockReason[_of][i]].claimed = true;
                emit Unlock(_of, lockReason[_of][i], lockedTokens);
            }
        }  

        if(unlockableTokens > 0)
        	this.transfer(_of, unlockableTokens);
    }

    /**
     * @dev Gets the unlockable tokens of a specified address
     * @param _of The address to query the the unlockable token count of
     */
    function getUnlockableTokens(address _of)
        public
        view
        returns (uint256 unlockableTokens)
    {
        for (uint256 i = 0; i < lockReason[_of].length; i++) {
            unlockableTokens = unlockableTokens.add(tokensUnlockable(_of, lockReason[_of][i]));
        }  
    }  

}