contract WpcToken is StandardToken, BurnableToken, Ownable {
	string public constant symbol = "wpc";
	string public constant name = "World Peace Coin";
	uint8 public constant decimals = 18;
	uint256 public constant INITIAL_SUPPLY = 1000000000 * (10 ** uint256(decimals));
	uint256 public constant TOKEN_OFFERING_ALLOWANCE = 400000000 * (10 ** uint256(decimals));
	uint256 public constant ADMIN_ALLOWANCE = INITIAL_SUPPLY - TOKEN_OFFERING_ALLOWANCE;

	// Address of token admin
	address public adminAddr;
	// Address of token offering
	address public tokenOfferingAddr;
	// Enable transfers after conclusion of token offering
	bool public transferEnabled = true;

	/**
	 * Check if transfer is allowed
	 *
	 * Permissions:
	 *														Owner	Admin	OfferingContract	Others
	 * transfer (before transferEnabled is true)			x		x			x				x
	 * transferFrom (before transferEnabled is true)		x		o			o				x
	 * transfer/transferFrom(after transferEnabled is true)	o		x			x				o
	 */
	modifier onlyWhenTransferAllowed() {
		require(transferEnabled || msg.sender == adminAddr || msg.sender == tokenOfferingAddr);
		_;
	}

	/**
	 * Check if token offering address is set or not
	 */
	modifier onlyTokenOfferingAddrNotSet() {
		require(tokenOfferingAddr == address(0x0));
		_;
	}

	/**
	* Check if address is a valid destination to transfer tokens to
	* - must not be zero address
	* - must not be the token address
	* - must not be the owner's address
	* - must not be the admin's address
	* - must not be the token offering contract address
	*/
	modifier validDestination(address to) {
		require(to != address(0x0));
		require(to != address(this));
		require(to != owner);
		require(to != address(adminAddr));
		require(to != address(tokenOfferingAddr));
		_;
	}	

	/**
	* Token contract constructor
	*
	* @param admin Address of admin account
	*/
	function WpcToken(address admin) public {
		totalSupply_ = INITIAL_SUPPLY;

		// Mint tokens
		balances[msg.sender] = totalSupply_;
		Transfer(address(0x0), msg.sender, totalSupply_);

		// Approve allowance for admin account
		adminAddr = admin;
		approve(adminAddr, ADMIN_ALLOWANCE);
	}

	/**
	* Set token offering to approve allowance for offering contract to distribute tokens
	*
	* @param offeringAddr Address of token offering contract
	* @param amountForSale Amount of tokens for sale, set 0 to max out
	*/
	function setTokenOffering(address offeringAddr, uint256 amountForSale) external onlyOwner onlyTokenOfferingAddrNotSet {
		require(!transferEnabled);

		uint256 amount = (amountForSale == 0) ? TOKEN_OFFERING_ALLOWANCE : amountForSale;
		require(amount <= TOKEN_OFFERING_ALLOWANCE);

		approve(offeringAddr, amount);
		tokenOfferingAddr = offeringAddr;
	}

	/**
	* Enable transfers
	*/
	function enableTransfer() external onlyOwner {
		transferEnabled = true;

		// End the offering
		approve(tokenOfferingAddr, 0);
	}

	/**
	* Transfer from sender to another account
	*
	* @param to Destination address
	* @param value Amount of wpctokens to send
	*/
	function transfer(address to, uint256 value) public onlyWhenTransferAllowed validDestination(to) returns (bool) {
		return super.transfer(to, value);
	}

	/**
	* Transfer from `from` account to `to` account using allowance in `from` account to the sender
	*
	* @param from Origin address
	* @param to Destination address
	* @param value Amount of wpctokens to send
	*/
	function transferFrom(address from, address to, uint256 value) public onlyWhenTransferAllowed validDestination(to) returns (bool) {
		return super.transferFrom(from, to, value);
	}

	/**
	* Burn token, only owner is allowed to do this
	*
	* @param value Amount of tokens to burn
	*/
	function burn(uint256 value) public {
		require(transferEnabled || msg.sender == owner);
		super.burn(value);
	}
}
/*
 * WpcToken is a standard ERC20 token with some additional functionalities:
 * - Transfers are only enabled after contract owner enables it (after the ICO)
 * - Contract sets 40% of the total supply as allowance for ICO contract
 *
 * Note: Token Offering == Initial Coin Offering(ICO)
 */
function setTokenOffering(address offeringAddr, uint256 amountForSale) external onlyOwner onlyTokenOfferingAddrNotSet {
	require(!transferEnabled);

	uint256 amount = (amountForSale == 0) ? TOKEN_OFFERING_ALLOWANCE : amountForSale;
	require(amount <= TOKEN_OFFERING_ALLOWANCE);

	approve(offeringAddr, amount);
	tokenOfferingAddr = offeringAddr;
}

/**
 	* Set token offering to approve allowance for offering contract to distribute tokens
 	*
 	* @param offeringAddr Address of token offering contract
 	* @param amountForSale Amount of tokens for sale, set 0 to max out
 	*/