pragma solidity ^0.4.24;

// File: zos-lib/contracts/migrations/Migratable.sol

/**
 * @title Migratable
 * Helper contract to support intialization and migration schemes between
 * different implementations of a contract in the context of upgradeability.
 * To use it, replace the constructor with a function that has the
 * `isInitializer` modifier starting with `"0"` as `migrationId`.
 * When you want to apply some migration code during an upgrade, increase
 * the `migrationId`. Or, if the migration code must be applied only after
 * another migration has been already applied, use the `isMigration` modifier.
 * This helper supports multiple inheritance.
 * WARNING: It is the developer's responsibility to ensure that migrations are
 * applied in a correct order, or that they are run at all.
 * See `Initializable` for a simpler version.
 */
contract Migratable {
  /**
   * @dev Emitted when the contract applies a migration.
   * @param contractName Name of the Contract.
   * @param migrationId Identifier of the migration applied.
   */
  event Migrated(string contractName, string migrationId);

  /**
   * @dev Mapping of the already applied migrations.
   * (contractName => (migrationId => bool))
   */
  mapping (string => mapping (string => bool)) internal migrated;

  /**
   * @dev Internal migration id used to specify that a contract has already been initialized.
   */
  string constant private INITIALIZED_ID = "initialized";


  /**
   * @dev Modifier to use in the initialization function of a contract.
   * @param contractName Name of the contract.
   * @param migrationId Identifier of the migration.
   */
  modifier isInitializer(string contractName, string migrationId) {
    validateMigrationIsPending(contractName, INITIALIZED_ID);
    validateMigrationIsPending(contractName, migrationId);
    _;
    emit Migrated(contractName, migrationId);
    migrated[contractName][migrationId] = true;
    migrated[contractName][INITIALIZED_ID] = true;
  }

  /**
   * @dev Modifier to use in the migration of a contract.
   * @param contractName Name of the contract.
   * @param requiredMigrationId Identifier of the previous migration, required
   * to apply new one.
   * @param newMigrationId Identifier of the new migration to be applied.
   */
  modifier isMigration(string contractName, string requiredMigrationId, string newMigrationId) {
    require(isMigrated(contractName, requiredMigrationId), "Prerequisite migration ID has not been run yet");
    validateMigrationIsPending(contractName, newMigrationId);
    _;
    emit Migrated(contractName, newMigrationId);
    migrated[contractName][newMigrationId] = true;
  }

  /**
   * @dev Returns true if the contract migration was applied.
   * @param contractName Name of the contract.
   * @param migrationId Identifier of the migration.
   * @return true if the contract migration was applied, false otherwise.
   */
  function isMigrated(string contractName, string migrationId) public view returns(bool) {
    return migrated[contractName][migrationId];
  }

  /**
   * @dev Initializer that marks the contract as initialized.
   * It is important to run this if you had deployed a previous version of a Migratable contract.
   * For more information see https://github.com/zeppelinos/zos-lib/issues/158.
   */
  function initialize() isInitializer("Migratable", "1.2.1") public {
  }

  /**
   * @dev Reverts if the requested migration was already executed.
   * @param contractName Name of the contract.
   * @param migrationId Identifier of the migration.
   */
  function validateMigrationIsPending(string contractName, string migrationId) private {
    require(!isMigrated(contractName, migrationId), "Requested target migration ID has already been run");
  }
}

// File: openzeppelin-zos/contracts/token/ERC20/ERC20Basic.sol

/**
 * @title ERC20Basic
 * @dev Simpler version of ERC20 interface
 * @dev see https://github.com/ethereum/EIPs/issues/179
 */
contract ERC20Basic {
  function totalSupply() public view returns (uint256);
  function balanceOf(address who) public view returns (uint256);
  function transfer(address to, uint256 value) public returns (bool);
  event Transfer(address indexed from, address indexed to, uint256 value);
}

// File: openzeppelin-zos/contracts/token/ERC20/ERC20.sol

/**
 * @title ERC20 interface
 * @dev see https://github.com/ethereum/EIPs/issues/20
 */
contract ERC20 is ERC20Basic {
  function allowance(address owner, address spender) public view returns (uint256);
  function transferFrom(address from, address to, uint256 value) public returns (bool);
  function approve(address spender, uint256 value) public returns (bool);
  event Approval(address indexed owner, address indexed spender, uint256 value);
}

// File: openzeppelin-zos/contracts/token/ERC20/DetailedERC20.sol

contract DetailedERC20 is Migratable, ERC20 {
  string public name;
  string public symbol;
  uint8 public decimals;

  function initialize(string _name, string _symbol, uint8 _decimals) public isInitializer("DetailedERC20", "1.9.0") {
    name = _name;
    symbol = _symbol;
    decimals = _decimals;
  }
}

// File: openzeppelin-zos/contracts/math/SafeMath.sol

/**
 * @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) {
    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;
  }
}

// File: openzeppelin-zos/contracts/token/ERC20/BasicToken.sol

/**
 * @title Basic token
 * @dev Basic version of StandardToken, with no allowances.
 */
contract BasicToken is ERC20Basic {
  using SafeMath for uint256;

  mapping(address => uint256) balances;

  uint256 totalSupply_;

  /**
  * @dev total number of tokens in existence
  */
  function totalSupply() public view returns (uint256) {
    return totalSupply_;
  }

  /**
  * @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(_to != address(0));
    require(_value <= balances[msg.sender]);

    balances[msg.sender] = balances[msg.sender].sub(_value);
    balances[_to] = balances[_to].add(_value);
    emit Transfer(msg.sender, _to, _value);
    return true;
  }

  /**
  * @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];
  }

}

// File: openzeppelin-zos/contracts/token/ERC20/StandardToken.sol

/**
 * @title Standard ERC20 token
 *
 * @dev Implementation of the basic standard token.
 * @dev https://github.com/ethereum/EIPs/issues/20
 * @dev Based on code by FirstBlood: https://github.com/Firstbloodio/token/blob/master/smart_contract/FirstBloodToken.sol
 */
contract StandardToken is ERC20, BasicToken {

  mapping (address => mapping (address => uint256)) internal allowed;


  /**
   * @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(_to != address(0));
    require(_value <= balances[_from]);
    require(_value <= allowed[_from][msg.sender]);

    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 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 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 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, uint _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, uint _subtractedValue) public returns (bool) {
    uint 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;
  }

}

// File: openzeppelin-zos/contracts/ownership/Ownable.sol

/**
 * @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 is Migratable {
  address public owner;


  event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

  /**
   * @dev The Ownable constructor sets the original `owner` of the contract to the sender
   * account.
   */
  function initialize(address _sender) public isInitializer("Ownable", "1.9.0") {
    owner = _sender;
  }

  /**
   * @dev Throws if called by any account other than the owner.
   */
  modifier onlyOwner() {
    require(msg.sender == owner);
    _;
  }

  /**
   * @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 {
    require(newOwner != address(0));
    emit OwnershipTransferred(owner, newOwner);
    owner = newOwner;
  }

}

// File: openzeppelin-zos/contracts/token/ERC20/MintableToken.sol

/**
 * @title Mintable token
 * @dev Simple ERC20 Token example, with mintable token creation
 * @dev Issue: * https://github.com/OpenZeppelin/openzeppelin-solidity/issues/120
 * Based on code by TokenMarketNet: https://github.com/TokenMarketNet/ico/blob/master/contracts/MintableToken.sol
 */
contract MintableToken is Migratable, Ownable, StandardToken {
  event Mint(address indexed to, uint256 amount);
  event MintFinished();

  bool public mintingFinished = false;


  modifier canMint() {
    require(!mintingFinished);
    _;
  }

  function initialize(address _sender) isInitializer("MintableToken", "1.9.0")  public {
    Ownable.initialize(_sender);
  }

  /**
   * @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) onlyOwner canMint public 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() onlyOwner canMint public returns (bool) {
    mintingFinished = true;
    emit MintFinished();
    return true;
  }
}

// File: openzeppelin-zos/contracts/token/ERC20/DetailedPremintedToken.sol

contract DetailedPremintedToken is Migratable, DetailedERC20, StandardToken {
  function initialize(
    address _sender,
    string _name,
    string _symbol,
    uint8 _decimals,
    uint256 _initialBalance
  )
    isInitializer("DetailedPremintedToken", "1.9.0")
    public
  {
    DetailedERC20.initialize(_name, _symbol, _decimals);

    _premint(_sender, _initialBalance);
  }

  function _premint(address _to, uint256 _value) internal {
    totalSupply_ += _value;
    balances[_to] += _value;
    emit Transfer(0, _to, _value);
  }
}

// File: contracts/S4FE.sol

/**
 * @title S4FE
 * @dev ERC20 Token, where all tokens are pre-assigned to the creator.
 * Note they can later distribute these tokens as they wish using `transfer`
 */
contract S4FE is Ownable, DetailedPremintedToken {
	uint256 public INITIAL_SUPPLY;

	bool public transferLocked;
	mapping (address => bool) public transferWhitelist;

	/**
	 * @dev Constructor that gives msg.sender all of existing tokens.
	 */
	constructor() public {

	}

	/**
	 * @dev initialize method to start constructor logic
	 * 
	 * @param _owner address of owner
	 */
	function initializeS4FE(address _owner) isInitializer('S4FE', '0') public {
		INITIAL_SUPPLY = 1000000000 * (10 ** uint256(18));

		Ownable.initialize(_owner);
		DetailedPremintedToken.initialize(_owner, "S4FE", "S4F", 18, INITIAL_SUPPLY);
	}

	/**
	* @dev if ether is sent to this address, send it back.
	*/
	function () public {
		revert();
	}

	/**
	 * @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(msg.sender == owner || transferLocked == false || transferWhitelist[msg.sender] == true);

		bool result = super.transfer(_to , _value);
		return result;
	}

	/**
	 * @dev transfer lock status
	 * @param _transferLocked Boolean indicating if transfer is locked
	 */
	function setTransferLocked(bool _transferLocked) onlyOwner public returns (bool) {
		transferLocked = _transferLocked;
		return transferLocked;
	}

	/**
	 * @dev transfer lock status
	 * @param _address Address of account indicating if allowed
	 * @param _transferLocked Boolean indicating if transfer is locked
	 */
	function setTransferWhitelist(address _address, bool _transferLocked) onlyOwner public returns (bool) {
		transferWhitelist[_address] = _transferLocked;
		return _transferLocked;
	}

	/**
	 * @dev whitelist addresses
	 * @param _addresses Array of address of account for whitelist
	 */
	function whitelist(address[] _addresses) onlyOwner public {
		for(uint i = 0; i < _addresses.length ; i ++) {
			transferWhitelist[_addresses[i]] = true;
		}
	}

	/**
	 * @dev blacklist addresses
	 * @param _addresses Array of address of account for whitelist
	 */
	function blacklist(address[] _addresses) onlyOwner public {
		for(uint i = 0; i < _addresses.length ; i ++) {
			transferWhitelist[_addresses[i]] = false;
		}
	}
}