pragma solidity ^0.4.18;
//MiningRigRentals Token

contract owned {
    address public owner;

    //constructor
    function owned() public {
        owner = msg.sender;
    }

    modifier onlyOwner {
        require(msg.sender == owner);
        _;
    }

    function transferOwnership(address newOwner) onlyOwner public {
        owner = newOwner;
    }
}

interface tokenRecipient { 
    function receiveApproval(address _from, uint256 _value, address _token, bytes _extraData) external; 
    }

contract TokenERC20 {
    // Public variables of the token
    string public name;
    string public symbol;
    uint8 public decimals = 18;
    // 18 decimals is the strongly suggested default, avoid changing it
    uint256 public totalSupply;

    // This creates an array with all balances
    mapping (address => uint256) public balanceOf;
    mapping (address => mapping (address => uint256)) public allowance;

    // This generates a public event on the blockchain that will notify clients
    event Transfer(address indexed from, address indexed to, uint256 value);

    // This notifies clients about the amount burnt
    event Burn(address indexed from, uint256 value);

    function TokenERC20(uint256 initialSupply, string tokenName, string tokenSymbol) public {
        totalSupply = initialSupply * 10 ** uint256(decimals);  // Update total supply with the decimal amount
        balanceOf[msg.sender] = totalSupply;                // Give the creator all initial tokens
        name = tokenName;                                   // Set the name for display purposes
        symbol = tokenSymbol;                               // Set the symbol for display purposes
    }

    function _transfer(address _from, address _to, uint _value) internal {
        // Prevent transfer to 0x0 address. Use burn() instead
        require(_to != 0x0);
        // Check if the sender has enough
        require(balanceOf[_from] >= _value);
        // Check for overflows
        require(balanceOf[_to] + _value > balanceOf[_to]);
        // Subtract from the sender
        balanceOf[_from] -= _value;
        // Add the same to the recipient
        balanceOf[_to] += _value;
        emit Transfer(_from, _to, _value);
    }

    function transfer(address _to, uint256 _value) public {
        _transfer(msg.sender, _to, _value);
    }

    function transferFrom(address _from, address _to, uint256 _value) public returns (bool success) {
        require(_value <= allowance[_from][msg.sender]);     // Check allowance
        allowance[_from][msg.sender] -= _value;
        _transfer(_from, _to, _value);
        return true;
    }

    function approve(address _spender, uint256 _value) public returns (bool success) {
        allowance[msg.sender][_spender] = _value;
        return true;
    }

    function approveAndCall(address _spender, uint256 _value, bytes _extraData) public returns (bool success) {
        tokenRecipient spender = tokenRecipient(_spender);
        if (approve(_spender, _value)) {
            spender.receiveApproval(msg.sender, _value, this, _extraData);
            return true;
        }
    }

    function burn(uint256 _value) public returns (bool success) {
        require(balanceOf[msg.sender] >= _value);   // Check if the sender has enough
        balanceOf[msg.sender] -= _value;            // Subtract from the sender
        totalSupply -= _value;                      // Updates totalSupply
        emit Burn(msg.sender, _value);
        return true;
    }

    function burnFrom(address _from, uint256 _value) public returns (bool success) {
        require(balanceOf[_from] >= _value);                // Check if the targeted balance is enough
        require(_value <= allowance[_from][msg.sender]);    // Check allowance
        balanceOf[_from] -= _value;                         // Subtract from the targeted balance
        allowance[_from][msg.sender] -= _value;             // Subtract from the sender's allowance
        totalSupply -= _value;                              // Update totalSupply
        emit Burn(_from, _value);
        return true;
    }
}

/******************************************/
/*       ADVANCED TOKEN STARTS HERE       */
/******************************************/

contract MiningRigRentalsToken is owned, TokenERC20 {
    uint256 public buyPrice;
    bool public canBuy;
    bool public canMint;

    mapping (address => bool) public frozenAccount;

    /* This generates a public event on the blockchain that will notify clients */
    event FrozenFunds(address target, bool frozen);

    /* Initializes contract with initial supply tokens to the creator of the contract */
    function MiningRigRentalsToken() TokenERC20(uint256(3120000000), "MiningRigRentals Token", "MRR") public {
        canBuy = true;
        canMint = true;
        buyPrice = uint256(10000);//Tokens per ETH per 
    }

    /* Internal transfer, only can be called by this contract */
    function _transfer(address _from, address _to, uint _value) internal {
        require (_to != 0x0);                               // Prevent transfer to 0x0 address. Use burn() instead
        require (balanceOf[_from] >= _value);               // Check if the sender has enough
        require (balanceOf[_to] + _value > balanceOf[_to]); // Check for overflows
        require(!frozenAccount[_from]);                     // Check if sender is frozen
        require(!frozenAccount[_to]);                       // Check if recipient is frozen
        balanceOf[_from] -= _value;                         // Subtract from the sender
        balanceOf[_to] += _value;                           // Add the same to the recipient
        emit Transfer(_from, _to, _value);
    }

    function mintToken(address target, uint256 mintedAmount) onlyOwner public {
        if (!canMint) {
            return;
        }
        balanceOf[target] += mintedAmount;
        totalSupply += mintedAmount;
        emit Transfer(0, this, mintedAmount);
        emit Transfer(this, target, mintedAmount);
    }

    //Disable any minting forever. Likley Requirement for exchange listing.
    function disableMintForever() onlyOwner public {
        canMint = false;
    }

    function freezeAccount(address target, bool freeze) onlyOwner public {
        frozenAccount[target] = freeze;
        emit FrozenFunds(target, freeze);
    }


    function setPrices(uint256 newBuyPrice) onlyOwner public {
        buyPrice = newBuyPrice;
    }

    function setCanBuy(bool cb) onlyOwner public {
        canBuy = cb;
    }

    //Buy tokens from the owner
    function buy() payable public {
        if(canBuy) {
            uint amount = msg.value * buyPrice;               // calculates the amount
            _transfer(owner, msg.sender, amount);              // makes the transfers
        }
    }
    
    //sending in eth will purchase these tokens, 
    function () public payable { 
        buy();
    }

    //Transffers out ethereum sent to this contract.
    function withdraw(uint256 _value)  onlyOwner public {
        owner.transfer(_value);//Transfer to the owner of the contract
    }

    //Transffers out ALL ethereum sent to this contract.
    function withdrawAll()  onlyOwner public {
        address myAddress = this;
        owner.transfer(myAddress.balance);//Transfer to the owner of the contract
    }
}