/*! \file piparsehelper.h
 * \ingroup IO
 * \~\brief
 * \~english Helper class to automate structs receive
 * \~russian Класс для автоматизации приема структур
 */
/*
    PIP - Platform Independent Primitives
    Helper class to automate structs receive
    Ivan Pelipenko peri4ko@yandex.ru

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#ifndef PIPARSEHELPER_H
#define PIPARSEHELPER_H

#include "piobject.h"
#include "pip_io_utils_export.h"


/** \class PIParseHelper
 * \brief Helper class to automate structs receive
 *
 *
 * \section PIParseHelper_synopsis Synopsis
 * This class helps to deserialize and invoke neccessarily methods.
 *
 * Data packets with header and various data types can be automated by this class.
 * Every key value mapped to object member function, lambda-function or functor.
 *
 * This class can remove \b switch-case with deserialization code and
 * replace it with several \a assign() calls, binded to ready-to-use event handlers.
 * Moreover data type automatic takes from event handler or lambda argument. One should
 * only make \"PIByteArray & operator <<()\" with used types, deserialization will be
 * performed by %PIParseHelper.
 *
 *
 * \section PIParseHelper_usage Usage
 *
 * Create instance of %PIParseHelper, or subclass.
 *
 * In \a assign() methods you can use object member function, lambda-function
 * or functor with 0 or 1 arguments,
 *
 *
 * \section PIParseHelper_lambda Lambda-functions
 * \code assign(1, [this](const SomeStruct & s){}) \endcode
 *
 *
 * \section PIParseHelper_examples Examples
 * First example describes subclass variant. As one can see, it`s a single place to change
 * type of received data - event handler argument.
 * \snippet piparsehelper.cpp 0
 *
 * Second example show separate variant:
 * \snippet piparsehelper.cpp 1
 *
 **/

template<typename Key>
class PIParseHelper {
public:
	//! \brief Construct %PIParseHelper
	PIParseHelper() {}


	//! \brief Assign key \"key\" to lambda-function \"func\" without arguments
	void assign(Key key, std::function<void()> func) {
		auto lf = [func](PIByteArray) { func(); };
		functions[key] << lf;
	}


	//! \brief Assign key \"key\" to lambda-function \"func\" with 1 argument
	template<typename T>
	void assign(Key key, std::function<void(const T &)> func) {
		auto lf = [func](PIByteArray data) {
			if (!data.isEmpty()) {
				T v;
				data >> v;
				func(v);
			}
		};
		functions[key] << lf;
	}


	//! \brief Assign key \"key\" to member function of object \"obj\" without arguments
	template<typename O>
	void assign(Key key, O * obj, void (O::*member_func)()) {
		auto lf = [member_func, obj](PIByteArray) { (obj->*member_func)(); };
		functions[key] << lf;
	}


	//! \brief Assign key \"key\" to member function of object \"obj\" with 1 argument
	template<typename T, typename O>
	void assign(Key key, O * obj, void (O::*member_func)(const T &)) {
		auto lf = [member_func, obj](PIByteArray data) {
			if (!data.isEmpty()) {
				T v;
				data >> v;
				(obj->*member_func)(v);
			}
		};
		functions[key] << lf;
	}


	//! \brief Assign key \"key\" to functor \"func\" with 0 or 1 argument
	template<typename L>
	void assign(Key key, L func) {
		return assign(key, toStdFunction(func));
	}


	//! \brief Deserialize data and invoke assigned to \"key\" methods
	void parse(Key key, PIByteArray ba) {
		auto fl = functions.value(key);
		for (auto f: fl)
			f(ba);
	}

private:
	PIMap<Key, PIVector<std::function<void(PIByteArray)>>> functions;
};


#endif // PIPARSEHELPER_H