contract PropertyFactory is UsingConfig, IPropertyFactory {
	event Create(address indexed _from, address _property);
	event ChangeAuthor(
		address indexed _property,
		address _beforeAuthor,
		address _afterAuthor
	);
	event ChangeName(address indexed _property, string _old, string _new);
	event ChangeSymbol(address indexed _property, string _old, string _new);

	/**
	 * @dev Initialize the passed address as AddressConfig address.
	 * @param _config AddressConfig address.
	 */
	constructor(address _config) public UsingConfig(_config) {}

	/**
	 * @dev Throws if called by any account other than Properties.
	 */
	modifier onlyProperty() {
		require(
			IPropertyGroup(config().propertyGroup()).isGroup(msg.sender),
			"illegal address"
		);
		_;
	}

	/**
	 * @dev Creates a new Property contract.
	 * @param _name Name of the new Property.
	 * @param _symbol Symbol of the new Property.
	 * @param _author Author address of the new Property.
	 * @return Address of the new Property.
	 */
	function create(
		string calldata _name,
		string calldata _symbol,
		address _author
	) external returns (address) {
		return _create(_name, _symbol, _author);
	}

	/**
	 * @dev Creates a new Property contract and authenticate.
	 * There are too many local variables, so when using this method limit the number of arguments that can be used to authenticate to a maximum of 3.
	 * @param _name Name of the new Property.
	 * @param _symbol Symbol of the new Property.
	 * @param _market Address of a Market.
	 * @param _args1 First argument to pass through to Market.
	 * @param _args2 Second argument to pass through to Market.
	 * @param _args3 Third argument to pass through to Market.
	 * @return The transaction fail/success.
	 */
	function createAndAuthenticate(
		string calldata _name,
		string calldata _symbol,
		address _market,
		string calldata _args1,
		string calldata _args2,
		string calldata _args3
	) external returns (bool) {
		return
			IMarket(_market).authenticateFromPropertyFactory(
				_create(_name, _symbol, msg.sender),
				msg.sender,
				_args1,
				_args2,
				_args3,
				"",
				""
			);
	}

	/**
	 * @dev Creates a new Property contract.
	 * @param _name Name of the new Property.
	 * @param _symbol Symbol of the new Property.
	 * @param _author Author address of the new Property.
	 * @return Address of the new Property.
	 */
	function _create(
		string memory _name,
		string memory _symbol,
		address _author
	) private returns (address) {
		/**
		 * Creates a new Property contract.
		 */
		Property property =
			new Property(address(config()), _author, _name, _symbol);

		/**
		 * Adds the new Property contract to the Property address set.
		 */
		IPropertyGroup(config().propertyGroup()).addGroup(address(property));

		emit Create(msg.sender, address(property));
		return address(property);
	}

	/**
	 * @dev Emit ChangeAuthor event.
	 * @param _old The old author of the Property.
	 * @param _new The new author of the Property.
	 */
	function createChangeAuthorEvent(address _old, address _new)
		external
		onlyProperty
	{
		emit ChangeAuthor(msg.sender, _old, _new);
	}

	/**
	 * @dev Emit ChangeName event.
	 * @param _old The old name of the Property.
	 * @param _new The new name of the Property.
	 */
	function createChangeNameEvent(string calldata _old, string calldata _new)
		external
		onlyProperty
	{
		emit ChangeName(msg.sender, _old, _new);
	}

	/**
	 * @dev Emit ChangeSymbol event.
	 * @param _old The symbol name of the Property.
	 * @param _new The symbol name of the Property.
	 */
	function createChangeSymbolEvent(string calldata _old, string calldata _new)
		external
		onlyProperty
	{
		emit ChangeSymbol(msg.sender, _old, _new);
	}
}
/**
 * A factory contract that creates a new Property contract.
 */
function createChangeSymbolEvent(string calldata _old, string calldata _new)
	external
	onlyProperty
{
	emit ChangeSymbol(msg.sender, _old, _new);
}

/**
 	 * @dev Emit ChangeSymbol event.
 	 * @param _old The symbol name of the Property.
 	 * @param _new The symbol name of the Property.
 	 */