/**
ARIRANG
*/

pragma solidity 0.4.11;

contract SafeMath {

  function safeMul(uint a, uint b) internal returns (uint) {
    uint c = a * b;
    assert(a == 0 || c / a == b);
    return c;
  }
  function safeSub(uint a, uint b) internal returns (uint) {
    assert(b <= a);
    return a - b;
  }
  function safeAdd(uint a, uint b) internal returns (uint) {
    uint c = a + b;
    assert(c>=a && c>=b);
    return c;
  }

  // mitigate short address attack
  // thanks to https://github.com/numerai/contract/blob/c182465f82e50ced8dacb3977ec374a892f5fa8c/contracts/Safe.sol#L30-L34.
  // TODO: doublecheck implication of >= compared to ==
  modifier onlyPayloadSize(uint numWords) {
     assert(msg.data.length >= numWords * 32 + 4);
     _;
  }

}


contract Token { // ERC20 standard

    function balanceOf(address _owner) constant returns (uint256 balance);
    function transfer(address _to, uint256 _value) returns (bool success);
    function transferFrom(address _from, address _to, uint256 _value) returns (bool success);
    function approve(address _spender, uint256 _value) returns (bool success);
    function allowance(address _owner, address _spender) constant returns (uint256 remaining);
    event Transfer(address indexed _from, address indexed _to, uint256 _value);
    event Approval(address indexed _owner, address indexed _spender, uint256 _value);

}


contract StandardToken is Token, SafeMath {

    uint256 public totalSupply;

    // TODO: update tests to expect throw
    function transfer(address _to, uint256 _value) onlyPayloadSize(2) returns (bool success) {
        require(_to != address(0));
        require(balances[msg.sender] >= _value && _value > 0);
        balances[msg.sender] = safeSub(balances[msg.sender], _value);
        balances[_to] = safeAdd(balances[_to], _value);
        Transfer(msg.sender, _to, _value);

        return true;
    }

    // TODO: update tests to expect throw
    function transferFrom(address _from, address _to, uint256 _value) onlyPayloadSize(3) returns (bool success) {
        require(_to != address(0));
        require(balances[_from] >= _value && allowed[_from][msg.sender] >= _value && _value > 0);
        balances[_from] = safeSub(balances[_from], _value);
        balances[_to] = safeAdd(balances[_to], _value);
        allowed[_from][msg.sender] = safeSub(allowed[_from][msg.sender], _value);
        Transfer(_from, _to, _value);

        return true;
    }

    function balanceOf(address _owner) constant returns (uint256 balance) {
        return balances[_owner];
    }

    // 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 here:
    //  https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
    function approve(address _spender, uint256 _value) onlyPayloadSize(2) returns (bool success) {
        require((_value == 0) || (allowed[msg.sender][_spender] == 0));
        allowed[msg.sender][_spender] = _value;
        Approval(msg.sender, _spender, _value);

        return true;
    }

    function changeApproval(address _spender, uint256 _oldValue, uint256 _newValue) onlyPayloadSize(3) returns (bool success) {
        require(allowed[msg.sender][_spender] == _oldValue);
        allowed[msg.sender][_spender] = _newValue;
        Approval(msg.sender, _spender, _newValue);

        return true;
    }

    function allowance(address _owner, address _spender) constant returns (uint256 remaining) {
      return allowed[_owner][_spender];
    }

    mapping (address => uint256) balances;
    mapping (address => mapping (address => uint256)) allowed;

}


/*------------------------------------
ARIRANG
 SYMBOL : ARI
 decimal : 8 
 issue amount :  1,000,000,000 
--------------------------------------*/

contract ARIRANG  is StandardToken { 

    /* Public variables of the token */

    string public name;                   // 
    uint8 public decimals;                // 
    string public symbol;                 // 
    string public version = 'C1.0';  
    uint256 public unitsOneEthCanBuy;     
    uint256 public totalEthInWei;         
    address public fundsWallet;          

   

    function ARIRANG() {                        //** funtion name **/
        balances[msg.sender] = 100000000000000000;          
        totalSupply = 100000000000000000;              
        name = "ARIRANG";                                 
        decimals = 8 ;                                  
        symbol = "ARI";                               
        unitsOneEthCanBuy = 10;                        
        fundsWallet = msg.sender;                     
    }


    function() payable{
        totalEthInWei = totalEthInWei + msg.value;
        uint256 amount = msg.value * unitsOneEthCanBuy;
        require(balances[fundsWallet] >= amount);

        balances[fundsWallet] = balances[fundsWallet] - amount;
        balances[msg.sender] = balances[msg.sender] + amount;

        Transfer(fundsWallet, msg.sender, amount); // Broadcast a message to the blockchain

        //Transfer ether to fundsWallet
        fundsWallet.transfer(msg.value);                               
    }

    /* Approves and then calls the receiving contract */
    function approveAndCall(address _spender, uint256 _value, bytes _extraData) returns (bool success) {
        allowed[msg.sender][_spender] = _value;
        Approval(msg.sender, _spender, _value);

        //call the receiveApproval function on the contract you want to be notified. This crafts the function signature manually so one doesn't have to include a contract in here just for this.
        //receiveApproval(address _from, uint256 _value, address _tokenContract, bytes _extraData)
        //it is assumed that when does this that the call *should* succeed, otherwise one would use vanilla approve instead.
        if(!_spender.call(bytes4(bytes32(sha3("receiveApproval(address,uint256,address,bytes)"))), msg.sender, _value, this, _extraData)) { throw; }
        return true;
    }
}