pragma solidity ^0.4.8;

/**
 * Math operations with safety checks
 */
contract SafeMath {
  function safeMul(uint256 a, uint256 b) internal returns (uint256) {
    uint256 c = a * b;
    assert(a == 0 || c / a == b);
    return c;
  }

  function safeDiv(uint256 a, uint256 b) internal returns (uint256) {
    assert(b > 0);
    uint256 c = a / b;
    assert(a == b * c + a % b);
    return c;
  }

  function safeSub(uint256 a, uint256 b) internal returns (uint256) {
    assert(b <= a);
    return a - b;
  }

  function safeAdd(uint256 a, uint256 b) internal returns (uint256) {
    uint256 c = a + b;
    assert(c>=a && c>=b);
    return c;
  }

  function assert(bool assertion) internal {
    if (!assertion) {
      throw;
    }
  }
}
contract CCTHCoin is 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 balanceOf;
	mapping (address => uint256) public freezeOf;
    
    /* This generates a public event on the blockchain that will notify clients */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /* 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);
        
        string tokenName;
        uint8 decimalUnits;
        string tokenSymbol;
        uint256 public mined_coin_supply = 0;
        uint256 public pre_mined_supply = 0;
        uint256 public circulating_supply = 0;
        uint256 public reward = 5000000000;
        uint256 public timeOfLastHalving = now;
        uint public timeOfLastIncrease = now;
    
    /* Initializes contract with initial supply tokens to the creator of the contract */
    function CCTHCoin() {
        //balanceOf[msg.sender] = 2100000000000000;              // Give the creator all initial tokens
        totalSupply = 2100000000000000;                        // Update total supply
        name = "CryptoChips Coin";                            // Set the name for display purposes
        symbol = "CCTH";                               // Set the symbol for display purposes
        decimals = 8;                            // Amount of decimals for display purposes
		owner = msg.sender;
        timeOfLastHalving = now;
    }

    function updateSupply() internal returns (uint256) {

      if (now - timeOfLastHalving >= 2100000 minutes) {
        reward /= 2;
        timeOfLastHalving = now;
      }

      if (now - timeOfLastIncrease >= 150 seconds) {
        uint256 increaseAmount = ((now - timeOfLastIncrease) / 60 seconds) * reward;
      if (totalSupply>(pre_mined_supply+increaseAmount))
        {
          pre_mined_supply += increaseAmount;
          mined_coin_supply += increaseAmount;
          timeOfLastIncrease = now;
        }
      }

      circulating_supply = pre_mined_supply - mined_coin_supply;

      return circulating_supply;
    }
    
    /* Send coins */
    function transfer(address _to, uint256 _value) public {
        require(balanceOf[msg.sender] >= _value);           // Check if the sender has enough
        require(balanceOf[_to] + _value >= balanceOf[_to]); // Check for overflows
        balanceOf[msg.sender] = SafeMath.safeSub(balanceOf[msg.sender], _value);               // Subtract from the sender
        balanceOf[_to] = SafeMath.safeAdd(balanceOf[_to], _value);                            // Add the same to the recipient

        /* Notify anyone listening that the transfer took place */
        Transfer(msg.sender, _to, _value);

    }
    function burn(uint256 _value) returns (bool success) {
        if (balanceOf[msg.sender] < _value) throw;                                           // Check if the sender has enough
		if (_value <= 0) throw; 
        balanceOf[msg.sender] = SafeMath.safeSub(balanceOf[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 (balanceOf[msg.sender] < _value) throw;                                       // Check if the sender has enough
		if (_value <= 0) throw; 
        balanceOf[msg.sender] = SafeMath.safeSub(balanceOf[msg.sender], _value);        // Subtract from the sender
        freezeOf[msg.sender] = SafeMath.safeAdd(freezeOf[msg.sender], _value);                                // Updates totalSupply
        Freeze(msg.sender, _value);
        return true;
    }
	
	function unfreeze(uint256 _value) returns (bool success) {
        if (freezeOf[msg.sender] < _value) throw;                                       // Check if the sender has enough
		if (_value <= 0) throw; 
        freezeOf[msg.sender] = SafeMath.safeSub(freezeOf[msg.sender], _value);          // Subtract from the sender
		balanceOf[msg.sender] = SafeMath.safeAdd(balanceOf[msg.sender], _value);
        Unfreeze(msg.sender, _value);
        return true;
    }
	
	// transfer balance to owner
	function withdrawEther(uint256 amount) {
		if(msg.sender != owner)throw;
		owner.transfer(amount);
	}


    
    function mint(uint256 _value) {
        if(msg.sender != owner)throw;
        else{
            mined_coin_supply -= _value; // Remove from unspent supply
            balanceOf[msg.sender] =SafeMath.safeAdd(balanceOf[msg.sender], _value);  // Add the same to the recipient
            updateSupply();
        }

    }
	
	// can accept ether
	function() payable {
    }
}