pragma solidity 0.4.18;


/**
 * @title SafeMath
 * @dev Math operations with safety checks that throw on error
 */
library SafeMath {
    function mul(uint256 a, uint256 b) internal constant returns (uint256) {
        uint256 c = a * b;
        assert(a == 0 || c / a == b);
        return c;
    }

    function div(uint256 a, uint256 b) internal constant 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;
    }

    function sub(uint256 a, uint256 b) internal constant returns (uint256) {
        assert(b <= a);
        return a - b;
    }

    function add(uint256 a, uint256 b) internal constant returns (uint256) {
        uint256 c = a + b;
        assert(c >= a);
        return c;
    }
}

/**
 * @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 {
    //Variables
    address public owner;

    address public newOwner;

    //    Modifiers
    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(msg.sender == owner);
        _;
    }

    /**
     * @dev The Ownable constructor sets the original `owner` of the contract to the sender
     * account.
     */
    function Ownable() public {
        owner = msg.sender;
    }

    /**
     * @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));
        newOwner = _newOwner;

    }

    function acceptOwnership() public {
        if (msg.sender == newOwner) {
            owner = newOwner;
        }
    }
}

contract ERC20Basic {
    uint256 public totalSupply;
    function balanceOf(address who) public constant returns (uint256);
    function transfer(address to, uint256 value) public returns (bool);
    event Transfer(address indexed from, address indexed to, uint256 value);
}

contract ERC20 is ERC20Basic {
    function allowance(address owner, address spender) public constant 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);
}

contract BasicToken is ERC20Basic {
    using SafeMath for uint256;

    mapping(address => uint256) balances;

    /**
    * @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);
        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 constant returns (uint256 balance) {
        return balances[_owner];
    }

}

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);
        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;
        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);
        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);
        }
        Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
        return true;
    }

}

contract BiddableERC20 is StandardToken, Ownable {
    /* Public variables of the token */
    uint256 public creationBlock;

    uint8 public decimals;

    string public name;

    string public symbol;

    string public standard;

    bool public locked;

    /* Initializes contract with initial supply tokens to the creator of the contract */
    function BiddableERC20(
        uint256 _totalSupply,
        string _tokenName,
        uint8 _decimalUnits,
        string _tokenSymbol,
        bool _transferAllSupplyToOwner,
        bool _locked
    ) public {
        standard = "ERC20 0.1";
        locked = _locked;
        totalSupply = _totalSupply;

        if (_transferAllSupplyToOwner) {
            balances[msg.sender] = totalSupply;
        } else {
            balances[this] = totalSupply;
        }
        name = _tokenName;
        // Set the name for display purposes
        symbol = _tokenSymbol;
        // Set the symbol for display purposes
        decimals = _decimalUnits;
        // Amount of decimals for display purposes
        creationBlock = block.number;
    }

    /* public methods */
    function transfer(address _to, uint256 _value) public returns (bool) {
        require(locked == false);
        return super.transfer(_to, _value);
    }

    function approve(address _spender, uint256 _value) public returns (bool success) {
        if (locked) {
            return false;
        }
        return super.approve(_spender, _value);
    }

    function increaseApproval(address _spender, uint _addedValue) public returns (bool success) {
        if (locked) {
            return false;
        }
        return super.increaseApproval(_spender, _addedValue);
    }

    function decreaseApproval(address _spender, uint _subtractedValue) public returns (bool success) {
        if (locked) {
            return false;
        }
        return super.decreaseApproval(_spender, _subtractedValue);
    }

    function transferFrom(address _from, address _to, uint256 _value) public returns (bool success) {
        if (locked) {
            return false;
        }

        return super.transferFrom(_from, _to, _value);
    }
}

contract MintingERC20 is BiddableERC20 {

    //Variables
    mapping (address => bool) public minters;

    uint256 public maxSupply;
    bool public disableMinting;

    //    Modifiers
    modifier onlyMinters () {
        require(true == minters[msg.sender]);
        _;
    }

    function MintingERC20(
        uint256 _initialSupply,
        uint256 _maxSupply,
        string _tokenName,
        uint8 _decimals,
        string _symbol,
        bool _transferAllSupplyToOwner,
        bool _locked
    )
    public
    BiddableERC20(_initialSupply, _tokenName, _decimals, _symbol, _transferAllSupplyToOwner, _locked)
    {
        standard = "MintingERC20 0.1";
        minters[msg.sender] = true;
        maxSupply = _maxSupply;
    }

    function addMinter(address _newMinter) public onlyOwner {
        minters[_newMinter] = true;
    }

    function removeMinter(address _minter) public onlyOwner {
        minters[_minter] = false;
    }

    function mint(address _addr, uint256 _amount) public onlyMinters returns (uint256) {
        if (true == disableMinting) {
            return uint256(0);
        }

        if (_amount == uint256(0)) {
            return uint256(0);
        }

        if (totalSupply.add(_amount) > maxSupply) {
            return uint256(0);
        }

        totalSupply = totalSupply.add(_amount);
        balances[_addr] = balances[_addr].add(_amount);
        Transfer(address(0), _addr, _amount);

        return _amount;
    }
}

contract Biddable is MintingERC20 {

    bool public transferFrozen;

    uint256 public maxSupply = (200 * uint(10) ** 6) * uint(10) ** 18; // 200,000,000

    function Biddable(
        uint256 _initialSupply,
        bool _locked
    )
    public
    MintingERC20(_initialSupply, maxSupply, "BidDex", 18, "BDX", false, _locked)
    {
        standard = "Biddable 0.1";
    }

    // Lock contract
    function setLocked(bool _locked) public onlyOwner {
        locked = _locked;
    }

    // Allow token transfer.
    function freezing(bool _transferFrozen) public onlyOwner {
        transferFrozen = _transferFrozen;
    }

    // ERC20 functions
    // =========================
    function transfer(address _to, uint _value) public returns (bool) {
        require(!transferFrozen);
        return super.transfer(_to, _value);
    }

    function transferFrom(address _from, address _to, uint _value) public returns (bool success) {
        require(!transferFrozen);
        return super.transferFrom(_from, _to, _value);
    }
}