pragma solidity 0.4.21;


/**
 * @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) {
        if (a == 0) {
            return 0;
        }
        uint256 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 c;
    }

    /**
    * @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) {
        uint256 c = a + b;
        assert(c >= a);
        return c;
    }
}

/**
 * @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);
}

/**
 * @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]);

        // SafeMath.sub will throw if there is not enough balance.
        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 balance) {
        return balances[_owner];
    }
}

/**
 * @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);
}

/**
 * @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 constant returns (uint256 remaining) {
        return allowed[_owner][_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
     */
    function increaseApproval (address _spender, uint _addedValue) public returns (bool success) {
        allowed[msg.sender][_spender] = allowed[msg.sender][_spender].add(_addedValue);
        emit Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
        return true;
    }

    function decreaseApproval (address _spender, uint _subtractedValue) public returns (bool success) {
        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;
    }
}

/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure.
 * To use this library you can add a `using SafeERC20 for ERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    function safeTransfer(ERC20Basic token, address to, uint256 value) internal {
        assert(token.transfer(to, value));
    }

    function safeTransferFrom(ERC20 token, address from, address to, uint256 value) internal {
        assert(token.transferFrom(from, to, value));
    }

    function safeApprove(ERC20 token, address spender, uint256 value) internal {
        assert(token.approve(spender, value));
    }
}

/**
 * @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 {
        require(_value > 0);
        require(_value <= balances[msg.sender]);
        // 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

        address burner = msg.sender;
        balances[burner] = balances[burner].sub(_value);
        totalSupply_ = totalSupply_.sub(_value);
        emit Burn(burner, _value);
    }
}

contract Owned {
    address public owner;

    function Owned() public {
        owner = msg.sender;
    }

    modifier onlyOwner {
        require(msg.sender == owner);
        _;
    }
}

contract LigerToken is BurnableToken {
    string public constant name = "LIGER";
    string public constant symbol = "LIC";
    uint8 public constant decimals = 18;

    /// Maximum tokens to be allocated (2.7 billion LIC)
    uint256 public constant HARD_CAP = 2700000000 * 10**uint256(decimals);

    /// The owner of this address will distribute the locked and vested tokens
    address public ligerAdminAddress;

    /// This address holds the initial Liger Team tokens
    address public teamTokensAddress;

    /// This address holds the Liger Advisors tokens
    address public advisorsTokensAddress;

    /// This address is used to keep the tokens for sale
    address public saleTokensAddress;

    /// This address is used to keep the Liger Bounty Tokens
    address public bountyTokensAddress;

    /// Store the whitelisted addresses that the first exchange will use before listing
    mapping(address => bool) public whitelisted;

    /// when the token is listed on an exchange, the trading will be opened
    bool public tradingOpen = false;

    modifier onlyAdmin {
        require(msg.sender == ligerAdminAddress);
        _;
    }

    function LigerToken(address _ligerAdminAddress, address _teamTokensAddress, address _advisorsTokensAddress,
    address _saleTokensAddress, address _bountyTokensAddress) public {
        require(_ligerAdminAddress != address(0));
        require(_teamTokensAddress != address(0));
        require(_advisorsTokensAddress != address(0));
        require(_saleTokensAddress != address(0));
        require(_bountyTokensAddress != address(0));

        ligerAdminAddress = _ligerAdminAddress;
        teamTokensAddress = _teamTokensAddress;
        advisorsTokensAddress = _advisorsTokensAddress;
        saleTokensAddress = _saleTokensAddress;
        bountyTokensAddress = _bountyTokensAddress;

        whitelisted[saleTokensAddress] = true;
        whitelisted[bountyTokensAddress] = true;

        /// Maximum tokens to be allocated on the sale
        /// 2.025 billion LIC
        uint256 saleTokens = 2025000000 * 10**uint256(decimals);
        totalSupply_ = saleTokens;
        balances[saleTokensAddress] = saleTokens;

        /// Team tokens - 405 million LIC
        uint256 teamTokens = 405000000 * 10**uint256(decimals);
        totalSupply_ = totalSupply_.add(teamTokens);
        balances[teamTokensAddress] = teamTokens;

        /// Advisors tokens - 135 million LIC
        uint256 advisorsTokens = 135000000 * 10**uint256(decimals);
        totalSupply_ = totalSupply_.add(advisorsTokens);
        balances[advisorsTokensAddress] = advisorsTokens;

        /// Bounty tokens - 135 million LIC
        uint256 bountyTokens = 135000000 * 10**uint256(decimals);
        totalSupply_ = totalSupply_.add(bountyTokens);
        balances[bountyTokensAddress] = bountyTokens;

        require(totalSupply_ <= HARD_CAP);
    }

    /// @dev whitelist an address so it's able to transfer
    /// before the overall trading is opened
    function whitelist(address _address) external onlyAdmin {
        whitelisted[_address] = true;
    }

    /// @dev open the trading for everyone
    function openTrading() external onlyAdmin {
        tradingOpen = true;
    }

    /// @dev Trading limited - requires the token sale to have closed
    function transferFrom(address _from, address _to, uint256 _value) public returns (bool) {
        if(tradingOpen || whitelisted[msg.sender]) {
            return super.transferFrom(_from, _to, _value);
        }
        return false;
    }

    /// @dev Trading limited - requires the token sale to have closed
    function transfer(address _to, uint256 _value) public returns (bool) {
        if(tradingOpen || whitelisted[msg.sender]) {
            return super.transfer(_to, _value);
        }
        return false;
    }
}