pragma solidity ^0.4.13;

 
contract Ownable {
  address public owner;

  function Ownable() {
    owner = msg.sender;
  }

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

  function transferOwnership(address newOwner) onlyOwner {
    if (newOwner != address(0)) {
      owner = newOwner;
    }
  }
}

 
contract ERC20 {
  uint public totalSupply;
  function balanceOf(address who) constant returns (uint);
  function allowance(address owner, address spender) constant returns (uint);
  function mint(address receiver, uint amount);
  function transfer(address to, uint value) returns (bool ok);
  function transferFrom(address from, address to, uint value) returns (bool ok);
  function approve(address spender, uint value) returns (bool ok);
  event Transfer(address indexed from, address indexed to, uint value);
  event Approval(address indexed owner, address indexed spender, uint value);
}

 
contract SafeMath {
  function safeMul(uint a, uint b) internal returns (uint) {
    uint c = a * b;
    assert(a == 0 || c / a == b);
    return c;
  }

  function safeDiv(uint a, uint b) internal returns (uint) {
    assert(b > 0);
    uint c = a / b;
    assert(a == b * 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;
  }

  function max64(uint64 a, uint64 b) internal constant returns (uint64) {
    return a >= b ? a : b;
  }

  function min64(uint64 a, uint64 b) internal constant returns (uint64) {
    return a < b ? a : b;
  }

  function max256(uint256 a, uint256 b) internal constant returns (uint256) {
    return a >= b ? a : b;
  }

  function min256(uint256 a, uint256 b) internal constant returns (uint256) {
    return a < b ? a : b;
  }

}



contract PayFairToken is SafeMath, ERC20, Ownable {
 string public name = "PayFair Token";
 string public symbol = "PFR";
 uint public constant decimals = 8;
 uint public constant FROZEN_TOKENS = 11e6;
 uint public constant FREEZE_PERIOD = 1 years;
 uint public constant MULTIPLIER = 10 ** decimals;
 uint public crowdSaleOverTimestamp;

 
 address public crowdsaleAgent;
 
 bool public released = false;
 
 mapping (address => mapping (address => uint)) allowed;
 
 mapping(address => uint) balances;

 
 modifier canTransfer() {
   if(!released) {
      require(msg.sender == crowdsaleAgent);
   }
   _;
 }

 modifier checkFrozenAmount(address source, uint amount) {
   if (source == owner && now < crowdSaleOverTimestamp + FREEZE_PERIOD) {
     var frozenTokens = 10 ** decimals * FROZEN_TOKENS;
     require(safeSub(balances[owner], amount) > frozenTokens);
   }
   _;
 }

 
 
 modifier inReleaseState(bool _released) {
   require(_released == released);
   _;
 }

 
 modifier onlyCrowdsaleAgent() {
   require(msg.sender == crowdsaleAgent);
   _;
 }

 
 
 modifier onlyPayloadSize(uint size) {
    require(msg.data.length >= size + 4);
    _;
 }

 
 modifier canMint() {
    require(!released);
    _;
  }

 
 function PayFairToken() {
   owner = msg.sender;
 }

 
 function() payable {
   revert();
 }
 
 
 
 function mint(address receiver, uint amount) onlyCrowdsaleAgent canMint public {
    totalSupply = safeAdd(totalSupply, amount);
    balances[receiver] = safeAdd(balances[receiver], amount);
    Transfer(0, receiver, amount);
 }

 
 
 function setCrowdsaleAgent(address _crowdsaleAgent) onlyOwner inReleaseState(false) public {
   crowdsaleAgent = _crowdsaleAgent;
 }
 
 function releaseTokenTransfer() public onlyCrowdsaleAgent {
   crowdSaleOverTimestamp = now;
   released = true;
 }

 
 
 function convertToDecimal(uint amount) public constant returns (uint) {
   return safeMul(amount, MULTIPLIER);
 }

 
 
 
 
 function transfer(address _to, uint _value) onlyPayloadSize(2 * 32) canTransfer checkFrozenAmount(msg.sender, _value) returns (bool success) {
   balances[msg.sender] = safeSub(balances[msg.sender], _value);
   balances[_to] = safeAdd(balances[_to], _value);

   Transfer(msg.sender, _to, _value);
   return true;
 }

 
 
 
 
 
 function transferFrom(address _from, address _to, uint _value) onlyPayloadSize(2 * 32) canTransfer checkFrozenAmount(_from, _value) returns (bool success) {
    var _allowance = allowed[_from][msg.sender];

    balances[_to] = safeAdd(balances[_to], _value);
    balances[_from] = safeSub(balances[_from], _value);
    allowed[_from][msg.sender] = safeSub(_allowance, _value);
    Transfer(_from, _to, _value);
    return true;
 }
 
 
 
 function balanceOf(address _owner) constant returns (uint balance) {
   return balances[_owner];
 }

 
 
 
 
 function approve(address _spender, uint _value) returns (bool success) {
   
   
   
   
   require ((_value == 0) || (allowed[msg.sender][_spender] == 0));

   allowed[msg.sender][_spender] = _value;
   Approval(msg.sender, _spender, _value);
   return true;
 }

 
 
 
 
 function allowance(address _owner, address _spender) constant returns (uint remaining) {
   return allowed[_owner][_spender];
 }
}