pragma solidity ^0.4.13;

contract owned {
    address public owner;

    function owned() {
        owner = msg.sender;
    }

    modifier onlyOwner {
        require(msg.sender == owner);
        _;
    }

    function transferOwnership(address newOwner) onlyOwner {
        owner = newOwner;
    }
}

contract tokenRecipient { function receiveApproval(address _from, uint256 _value, address _token, bytes _extraData); }

contract PIN is owned {
    /* Public variables of the token */
    string public standard = 'PIN 0.1';
    string public name;
    string public symbol;
    uint8 public decimals = 0;
    uint256 public totalSupply;
    bool public locked;
    uint256 public icoSince;
    uint256 public icoTill;

     /* This creates an array with all balances */
    mapping (address => uint256) public balanceOf;
    mapping (address => mapping (address => uint256)) public allowance;

    /* This generates a public event on the blockchain that will notify clients */
    event Transfer(address indexed from, address indexed to, uint256 value);
    event IcoFinished();
    event Burn(address indexed from, uint256 value);

    uint256 public buyPrice = 0.01 ether;

    /* Initializes contract with initial supply tokens to the creator of the contract */
    function PIN(
        uint256 initialSupply,
        string tokenName,
        string tokenSymbol,
        uint256 _icoSince,
        uint256 _icoTill,
        uint durationInDays
    ) {
        totalSupply = initialSupply;

        balanceOf[this] = totalSupply / 100 * 22;             // Give the smart contract 22% of initial tokens
        name = tokenName;                                     // Set the name for display purposes
        symbol = tokenSymbol;                                 // Set the symbol for display purposes

        balanceOf[msg.sender] = totalSupply / 100 * 78;       // Give remaining total supply to contract owner, will be destroyed

        Transfer(this, msg.sender, balanceOf[msg.sender]);

        if(_icoSince == 0 && _icoTill == 0) {
            icoSince = now;
            icoTill = now + durationInDays * 35 days;
        }
        else {
            icoSince = _icoSince;
            icoTill = _icoTill;
        }
    }

    /* Send coins */
    function transfer(address _to, uint256 _value) {
        require(locked == false);                            // Check if smart contract is locked

        require(balanceOf[msg.sender] >= _value);            // Check if the sender has enough
        require(balanceOf[_to] + _value > balanceOf[_to]);   // Check for overflows

        balanceOf[msg.sender] -= _value;                     // Subtract from the sender
        balanceOf[_to] += _value;                            // Add the same to the recipient
        Transfer(msg.sender, _to, _value);                   // Notify anyone listening that this transfer took place
    }

    /* Allow another contract to spend some tokens in your behalf */
    function approve(address _spender, uint256 _value) returns (bool success) {
        allowance[msg.sender][_spender] = _value;

        return true;
    }

    /* Approve and then communicate the approved contract in a single tx */
    function approveAndCall(address _spender, uint256 _value, bytes _extraData) returns (bool success) {
        tokenRecipient spender = tokenRecipient(_spender);

        if (approve(_spender, _value)) {
            spender.receiveApproval(msg.sender, _value, this, _extraData);
            return true;
        }
    }

    /* A contract attempts to get the coins */
    function transferFrom(address _from, address _to, uint256 _value) returns (bool success) {
        require(locked == false);                            // Check if smart contract is locked
        require(_value > 0);
        require(balanceOf[_from] >= _value);                 // Check if the sender has enough
        require(balanceOf[_to] + _value > balanceOf[_to]);   // Check for overflows
        require(_value <= allowance[_from][msg.sender]);     // Check allowance

        balanceOf[_from] -= _value;                          // Subtract from the sender
        balanceOf[_to] += _value;                            // Add the same to the recipient
        allowance[_from][msg.sender] -= _value;
        Transfer(_from, _to, _value);

        return true;
    }

    function buy(uint256 ethers, uint256 time) internal {
        require(locked == false);                            // Check if smart contract is locked
        require(time >= icoSince && time <= icoTill);        // check for ico dates
        require(ethers > 0);                             // check if ethers is greater than zero

        uint amount = ethers / buyPrice;

        require(balanceOf[this] >= amount);                  // check if smart contract has sufficient number of tokens

        balanceOf[msg.sender] += amount;
        balanceOf[this] -= amount;

        Transfer(this, msg.sender, amount);
    }

    function () payable {
        buy(msg.value, now);
    }

    function internalIcoFinished(uint256 time) internal returns (bool) {
        if(time > icoTill) {
            uint256 unsoldTokens = balanceOf[this];

            balanceOf[owner] += unsoldTokens;
            balanceOf[this] = 0;

            Transfer(this, owner, unsoldTokens);

            IcoFinished();

            return true;
        }

        return false;
    }

    function icoFinished() onlyOwner {
        internalIcoFinished(now);
    }

    function transferEthers() onlyOwner {
        owner.transfer(this.balance);
    }

    function setBuyPrice(uint256 _buyPrice) onlyOwner {
        buyPrice = _buyPrice;
    }

    function setLocked(bool _locked) onlyOwner {
        locked = _locked;
    }

    function burn(uint256 _value) onlyOwner returns (bool success) {
        require (balanceOf[msg.sender] > _value);            // Check if the sender has enough
        balanceOf[msg.sender] -= _value;                      // Subtract from the sender
        totalSupply -= _value;                                // Updates totalSupply
        Burn(msg.sender, _value);
        return true;
    }
}