pragma solidity ^0.4.9;

contract ERC223 {
  uint public totalSupply;
  function balanceOf(address who) public view returns (uint);
  
  function name() public view returns (string _name);
  function symbol() public view returns (string _symbol);
  function decimals() public view returns (uint8 _decimals);
  function totalSupply() public view 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 data);
  event Transfer(address indexed from, address indexed to, uint value);
  
    
}

contract ContractReceiver {
     
    struct TKN {
        address sender;
        uint value;
        bytes data;
        bytes4 sig;
    }
    
    
    function tokenFallback(address _from, uint _value, bytes _data) public pure {
      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
      */
    }
}

/**
 * Math operations with safety checks
 */
contract SafeMath {
    uint256 constant public MAX_UINT256 =
    0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF;

    function safeAdd(uint256 x, uint256 y) pure internal returns (uint256 z) {
        if (x > MAX_UINT256 - y) revert();
        return x + y;
    }

    function safeSub(uint256 x, uint256 y) pure internal returns (uint256 z) {
        if (x < y) revert();
        return x - y;
    }

    function safeMul(uint256 x, uint256 y) pure internal returns (uint256 z) {
        if (y == 0) return 0;
        if (x > MAX_UINT256 / y) revert();
        return x * y;
    }
}

contract WithdrawableToken {
    function transfer(address _to, uint _value) returns (bool success);
    function balanceOf(address _owner) constant returns (uint balance);
}

contract EFH is ERC223,SafeMath{
    string public name;
    string public symbol;
    uint8 public decimals;
    uint256 public totalSupply;
	address public owner;

    /* This creates an array with all balances */
    mapping (address => uint256) public balances;
	mapping (address => uint256) public freezes;
  

    /* This notifies clients about the amount burnt */
    event Burn(address indexed from, uint256 value);
	
	/* This notifies clients about the amount frozen */
    event Freeze(address indexed from, uint256 value);
	
	/* This notifies clients about the amount unfrozen */
    event Unfreeze(address indexed from, uint256 value);

	
	// Function to access name of token .
  function name() public view returns (string _name) {
      return name;
  }
  // Function to access symbol of token .
  function symbol() public view returns (string _symbol) {
      return symbol;
  }
  // Function to access decimals of token .
  function decimals() public view returns (uint8 _decimals) {
      return decimals;
  }
  // Function to access total supply of tokens .
  function totalSupply() public view returns (uint256 _totalSupply) {
      return totalSupply;
  }
	
    /* Initializes contract with initial supply tokens to the creator of the contract */
    function EFH(uint256 initialSupply,string tokenName,uint8 decimalUnits,string tokenSymbol) {
        balances[msg.sender] = initialSupply * 10 ** uint256(decimalUnits);              // Give the creator all initial tokens
        totalSupply = initialSupply * 10 ** uint256(decimalUnits);                     // Update total supply
        name = tokenName;                                   // Set the name for display purposes
        symbol = tokenSymbol;                               // Set the symbol for display purposes
        decimals = decimalUnits;                            // Amount of decimals for display purposes
		owner = msg.sender;
		Transfer(address(0), owner, totalSupply);
    }


    function burn(uint256 _value) returns (bool success) {
        if (balances[msg.sender] < _value) revert();            // Check if the sender has enough
		if (_value <= 0) revert(); 
        balances[msg.sender] = SafeMath.safeSub(balances[msg.sender], _value);                      // Subtract from the sender
        totalSupply = SafeMath.safeSub(totalSupply,_value);                                // Updates totalSupply
        Burn(msg.sender, _value);
        return true;
    }
	
	function freeze(uint256 _value) returns (bool success) {
        if (balances[msg.sender] < _value) revert();            // Check if the sender has enough
		if (_value <= 0) revert(); 
        balances[msg.sender] = SafeMath.safeSub(balances[msg.sender], _value);                      // Subtract from the sender
        freezes[msg.sender] = SafeMath.safeAdd(freezes[msg.sender], _value);                                // Updates totalSupply
        Freeze(msg.sender, _value);
        return true;
    }
	
	function unfreeze(uint256 _value) returns (bool success) {
        if (freezes[msg.sender] < _value) revert();            // Check if the sender has enough
		if (_value <= 0) revert(); 
        freezes[msg.sender] = SafeMath.safeSub(freezes[msg.sender], _value);                      // Subtract from the sender
		balances[msg.sender] = SafeMath.safeAdd(balances[msg.sender], _value);
        Unfreeze(msg.sender, _value);
        return true;
    }
	
	function withdrawTokens(address tokenContract) external {
		require(msg.sender == owner );
		WithdrawableToken tc = WithdrawableToken(tokenContract);

		tc.transfer(owner, tc.balanceOf(this));
	}
	
	// transfer balance to owner
	function withdrawEther() external {
		require(msg.sender == owner );
		msg.sender.transfer(this.balance);
	}

	 // 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) {
      
    if(isContract(_to)) {
        if (balanceOf(msg.sender) < _value) revert();
        balances[msg.sender] = safeSub(balanceOf(msg.sender), _value);
        balances[_to] = safeAdd(balanceOf(_to), _value);
        assert(_to.call.value(0)(bytes4(keccak256(_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) {
      
    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) {
      
    //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 view 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);
	if (_data.length > 0){
		Transfer(msg.sender, _to, _value, _data);
	}
    else{
		Transfer(msg.sender, _to, _value);
	}
    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;
}
	
	function balanceOf(address _owner) public view returns (uint balance) {
    return balances[_owner];
  }
	
	// can accept ether
	function () payable {
    }
	
}