// Vulnerability label: ARTHM
pragma solidity ^0.4.17;

/* New ERC23 contract interface */
/* Recommended implementation used at https://github.com/Dexaran/ERC223-token-standard/tree/Recommended */
/* Fully backward compatible with ERC20 */
contract ERC223 {
    uint public totalSupply;
    function balanceOf(address who) public constant returns (uint);

    function name() constant public returns (string _name);
    function symbol() constant public returns (string _symbol);
    function decimals() constant public returns (uint8 _decimals);
    function totalSupply() constant public returns (uint256 _supply);

    function transfer(address to, uint value) public returns (bool ok);
    function transfer(address to, uint value, bytes data) public returns (bool ok);
    function transfer(address to, uint value, bytes data, string custom_fallback) public returns (bool ok);
    event Transfer(address indexed from, address indexed to, uint value, bytes indexed data);
}

/**
 * Include SafeMath Lib
 */
contract SafeMath {
    uint256 constant public MAX_UINT256 =
    0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF;

    function safeAdd(uint256 x, uint256 y) constant internal returns (uint256 z) {
        if (x > MAX_UINT256 - y)
            revert();
        return x + y;
    }

    function safeSub(uint256 x, uint256 y) constant internal returns (uint256 z) {
        if (x < y) {
            revert();
        }
        return x - y;
    }

    function safeMul(uint256 x, uint256 y) constant internal returns (uint256 z) {
        if (y == 0) {
            return 0;
        }
        if (x > MAX_UINT256 / y) {
            revert();
        }
        return x * y;
    }
}


/*
 * Contract that is working with ERC223 tokens
 */
 contract ContractReceiver {

    struct TKN {
        address sender;
        uint value;
        bytes data;
        bytes4 sig;
    }

    function tokenFallback(address _from, uint _value, bytes _data) public {
      TKN memory tkn;
      tkn.sender = _from;
      tkn.value = _value;
      tkn.data = _data;
      uint32 u = uint32(_data[3]) + (uint32(_data[2]) << 8) + (uint32(_data[1]) << 16) + (uint32(_data[0]) << 24);
      tkn.sig = bytes4(u);

      /* tkn variable is analogue of msg variable of Ether transaction
      *  tkn.sender is person who initiated this token transaction   (analogue of msg.sender)
      *  tkn.value the number of tokens that were sent   (analogue of msg.value)
      *  tkn.data is data of token transaction   (analogue of msg.data)
      *  tkn.sig is 4 bytes signature of function
      *  if data of token transaction is a function execution
      */
    }
}

contract EDOGE is ERC223, SafeMath {

    string public name = "eDogecoin";

    string public symbol = "EDOGE";

    uint8 public decimals = 8;

    uint256 public totalSupply = 100000000000 * 10**8;

    address public owner;

    bool public unlocked = false;

    bool public tokenCreated = false;

    mapping(address => uint256) balances;

    mapping(address => mapping (address => uint256)) allowed;

    // Initialize to have owner have 100,000,000,000 EDOGE on contract creation
    // Constructor is called only once and can not be called again (Ethereum Solidity specification)
    function EDOGE() public {

        // Security check in case EVM has future flaw or exploit to call constructor multiple times
        // Ensure token gets created once only
        require(tokenCreated == false);
        tokenCreated = true;

        owner = msg.sender;
        balances[owner] = totalSupply;

        // Final sanity check to ensure owner balance is greater than zero
        require(balances[owner] > 0);
    }

    modifier onlyOwner() {
        require(msg.sender == owner);
        _;
    }

    // Function to distribute tokens to list of addresses by the provided amount
    // Verify and require that:
    // - Balance of owner cannot be negative
    // - All transfers can be fulfilled with remaining owner balance
    // - No new tokens can ever be minted except originally created 100,000,000,000
    function distributeAirdrop(address[] addresses, uint256 amount) onlyOwner public{
        // Only proceed if there are enough tokens to be distributed to all addresses
        // Never allow balance of owner to become negative
        require(balances[owner] >= safeMul(addresses.length, amount));
        for (uint i = 0; i < addresses.length; i++) {
            balances[owner] = safeSub(balanceOf(owner), amount);
            // Another sanity check to make sure owner balance can never be negative
            require(balances[owner] >= 0);
            balances[addresses[i]] = safeAdd(balanceOf(addresses[i]), amount);
            transfer(addresses[i], amount);
        }
    }

    // Function to access name of token .sha
    function name() constant public returns (string _name) {
        return name;
    }
    // Function to access symbol of token .
    function symbol() constant public returns (string _symbol) {
        return symbol;
    }
    // Function to access decimals of token .
    function decimals() constant public returns (uint8 _decimals) {
        return decimals;
    }
    // Function to access total supply of tokens .
    function totalSupply() constant public returns (uint256 _totalSupply) {
        return totalSupply;
    }

    // Function that is called when a user or another contract wants to transfer funds .
    function transfer(address _to, uint _value, bytes _data, string _custom_fallback) public returns (bool success) {

        // Only allow transfer once unlocked
        // Once it is unlocked, it is unlocked forever and no one can lock again
        require(unlocked);

        if (isContract(_to)) {
            if (balanceOf(msg.sender) < _value) {
                revert();
            }
            balances[msg.sender] = safeSub(balanceOf(msg.sender), _value);
            balances[_to] = safeAdd(balanceOf(_to), _value);
            ContractReceiver receiver = ContractReceiver(_to);
            receiver.call.value(0)(bytes4(sha3(_custom_fallback)), msg.sender, _value, _data);
            Transfer(msg.sender, _to, _value, _data);
            return true;
        } else {
            return transferToAddress(_to, _value, _data);
        }
    }

    // Function that is called when a user or another contract wants to transfer funds .
    function transfer(address _to, uint _value, bytes _data) public  returns (bool success) {

        // Only allow transfer once unlocked
        // Once it is unlocked, it is unlocked forever and no one can lock again
        require(unlocked);

        if (isContract(_to)) {
            return transferToContract(_to, _value, _data);
        } else {
            return transferToAddress(_to, _value, _data);
        }
    }

    // Standard function transfer similar to ERC20 transfer with no _data .
    // Added due to backwards compatibility reasons .
    function transfer(address _to, uint _value) public returns (bool success) {

        // Only allow transfer once unlocked
        // Once it is unlocked, it is unlocked forever and no one can lock again
        require(unlocked);

        //standard function transfer similar to ERC20 transfer with no _data
        //added due to backwards compatibility reasons
        bytes memory empty;
        if (isContract(_to)) {
            return transferToContract(_to, _value, empty);
        } else {
            return transferToAddress(_to, _value, empty);
        }
    }

    // assemble the given address bytecode. If bytecode exists then the _addr is a contract.
    function isContract(address _addr) private returns (bool is_contract) {
        uint length;
        assembly {
            //retrieve the size of the code on target address, this needs assembly
            length := extcodesize(_addr)
        }
        return (length > 0);
    }

    // function that is called when transaction target is an address
    function transferToAddress(address _to, uint _value, bytes _data) private returns (bool success) {
        if (balanceOf(msg.sender) < _value) {
            revert();
        }
        balances[msg.sender] = safeSub(balanceOf(msg.sender), _value);
        balances[_to] = safeAdd(balanceOf(_to), _value);
        Transfer(msg.sender, _to, _value, _data);
        return true;
    }

    //function that is called when transaction target is a contract
    function transferToContract(address _to, uint _value, bytes _data) private returns (bool success) {
        if (balanceOf(msg.sender) < _value) {
            revert();
        }
        balances[msg.sender] = safeSub(balanceOf(msg.sender), _value);
        balances[_to] = safeAdd(balanceOf(_to), _value);
        ContractReceiver receiver = ContractReceiver(_to);
        receiver.tokenFallback(msg.sender, _value, _data);
        Transfer(msg.sender, _to, _value, _data);
        return true;
    }

    // Get balance of the address provided
    function balanceOf(address _owner) constant public returns (uint256 balance) {
        return balances[_owner];
    }

     // Creator/Owner can unlocked it once and it can never be locked again
     // Use after airdrop is complete
    function unlockForever() onlyOwner public {
        unlocked = true;
    }
}