contract StandardToken is Pausable {
    // Variables of the token
    string public name;
    string public symbol;
    uint8 public decimals = 0;
    uint256 public totalSupply;
    uint256 public currentSupply;
    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 generates a public event on the blockchain that will notify clients
    event Approval(address indexed _owner, address indexed _spender, uint256 _value);

    // This notifies clients about the amount burnt
    event Burn(address indexed from, uint256 value);

    /**
     * Constrctor function
     * Initializes contract with initial supply tokens to the creator of the contract
     */
    constructor(
        uint256 initialSupply,
        uint256 maxSupply,
        string tokenName,
        string tokenSymbol
    ) public {
        currentSupply = initialSupply;  // Update total supply with the decimal amount
        totalSupply = maxSupply;
        balanceOf[msg.sender] = currentSupply;                    // Give the creator all initial tokens
        name = tokenName;                                         // Set the name for display purposes
        symbol = tokenSymbol;                                     // Set the symbol for display purposes
    }

    /**
     * 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

        uint previousBalances = balanceOf[_from] + balanceOf[_to]; // Save this for an assertion in the future
        balanceOf[_from] -= _value;                                // Subtract from the sender
        balanceOf[_to] += _value;                                  // Add the same to the recipient
        emit Transfer(_from, _to, _value);

        // Asserts are used to use static analysis to find bugs in your code. They should never fail
        assert(balanceOf[_from] + balanceOf[_to] == previousBalances);
    }

    /**
     * Transfer tokens
     * Send `_value` tokens to `_to` from your account
     */
    function transfer(address _to, uint256 _value) whenNotPaused public returns (bool success) {
        _transfer(msg.sender, _to, _value);
        return true;
    }
    
    /**
     * Transfer tokens from other address
     * Send `_value` tokens to `_to` in behalf of `_from`
     */
    function transferFrom(address _from, address _to, uint256 _value) whenNotPaused public returns (bool success) {
        require(_value <= allowance[_from][msg.sender]);     // Check allowance
        allowance[_from][msg.sender] -= _value;
        _transfer(_from, _to, _value);
        return true;
    }

    /**
     * Set allowance for other address
     * Allows `_spender` to spend no more than `_value` tokens in your behalf
     */
    function approve(address _spender, uint256 _value) whenNotPaused public
        returns (bool success) {
        allowance[msg.sender][_spender] = _value;
        emit Approval(msg.sender, _spender, _value);
        return true;
    }

    function Supplies() view public 
        returns (uint256 total, uint256 current) {
        return (totalSupply, currentSupply);
    }

    // =========================
    // ====== Unnecessary ======
    // =========================
    /**
     * Set allowance for other address and notify
     * Allows `_spender` to spend no more than `_value` tokens in your behalf, and then ping the contract about it
     */
    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;
        }
    }

    /**
     * Destroy tokens
     * Remove `_value` tokens from the system irreversibly
     */
    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
        currentSupply -= _value;                    // Updates currentSupply
        emit Burn(msg.sender, _value);
        return true;
    }

    /**
     * Destroy tokens from other account
     * Remove `_value` tokens from the system irreversibly on behalf of `_from`.
     */
    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
        currentSupply -= _value;                            // Update currentSupply
        emit Burn(_from, _value);
        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
    currentSupply -= _value;                    // Updates currentSupply
    emit Burn(msg.sender, _value);
    return true;
}

/**
 * Destroy tokens
 * Remove `_value` tokens from the system irreversibly
 */