pragma solidity 0.4.24;

// File: contracts/commons/SafeMath.sol

/**
 * @title SafeMath
 * @dev Math operations with safety checks that throw on error
 */
library SafeMath {
    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;
    }

    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a / b;
        return c;
    }

    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        assert(b <= a);
        return a - b;
    }

    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        assert(c >= a);
        return c;
    }
}

// File: contracts/flavours/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 {

    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.
     */
    constructor() public {
        owner = msg.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: contracts/flavours/Lockable.sol

/**
 * @title Lockable
 * @dev Base contract which allows children to
 *      implement main operations locking mechanism.
 */
contract Lockable is Ownable {
    event Lock();
    event Unlock();

    bool public locked = false;

    /**
     * @dev Modifier to make a function callable
    *       only when the contract is not locked.
     */
    modifier whenNotLocked() {
        require(!locked);
        _;
    }

    /**
     * @dev Modifier to make a function callable
     *      only when the contract is locked.
     */
    modifier whenLocked() {
        require(locked);
        _;
    }

    /**
     * @dev called by the owner to locke, triggers locked state
     */
    function lock() public onlyOwner whenNotLocked {
        locked = true;
        emit Lock();
    }

    /**
     * @dev called by the owner
     *      to unlock, returns to unlocked state
     */
    function unlock() public onlyOwner whenLocked {
        locked = false;
        emit Unlock();
    }
}

// File: contracts/base/BaseFixedERC20Token.sol

contract BaseFixedERC20Token is Lockable {
    using SafeMath for uint;

    /// @dev ERC20 Total supply
    uint public totalSupply;

    mapping(address => uint) public balances;

    mapping(address => mapping(address => uint)) private allowed;

    /// @dev Fired if token is transferred according to ERC20 spec
    event Transfer(address indexed from, address indexed to, uint value);

    /// @dev Fired if token withdrawal is approved according to ERC20 spec
    event Approval(address indexed owner, address indexed spender, uint value);

    /**
     * @dev Gets the balance of the specified address
     * @param owner_ The address to query the the balance of
     * @return An uint representing the amount owned by the passed address
     */
    function balanceOf(address owner_) public view returns (uint balance) {
        return balances[owner_];
    }

    /**
     * @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_, uint value_) public whenNotLocked returns (bool) {
        require(to_ != address(0) && value_ <= balances[msg.sender]);
        // SafeMath.sub will throw an exception 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 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_ uint the amount of tokens to be transferred
     */
    function transferFrom(address from_, address to_, uint value_) public whenNotLocked returns (bool) {
        require(to_ != address(0) && value_ <= balances[from_] && 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
     *
     * To change the approve amount you first have to reduce the addresses
     * allowance to zero by calling `approve(spender_, 0)` if it is not
     * already 0 to mitigate the race condition described in:
     * 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_, uint value_) public whenNotLocked returns (bool) {
        if (value_ != 0 && allowed[msg.sender][spender_] != 0) {
            revert();
        }
        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 uint specifying the amount of tokens still available for the spender
     */
    function allowance(address owner_, address spender_) public view returns (uint) {
        return allowed[owner_][spender_];
    }
}

// File: contracts/IonChain.sol

/**
 * @title IONC token contract.
 */
contract IonChain is BaseFixedERC20Token {
    using SafeMath for uint;

    string public constant name = "IonChain";

    string public constant symbol = "IONC";

    uint8 public constant decimals = 6;

    uint internal constant ONE_TOKEN = 1e6;

    constructor(uint totalSupplyTokens_) public {
        locked = false;
        totalSupply = totalSupplyTokens_ * ONE_TOKEN;
        address creator = msg.sender;
        balances[creator] = totalSupply;

        emit Transfer(0, this, totalSupply);
        emit Transfer(this, creator, balances[creator]);
    }

    // Disable direct payments
    function() external payable {
        revert();
    }

}