/*
 * Copyright (C) 2015, 2016 "IoT.bzh"
 * Author "Romain Forlot" <romain.forlot@iot.bzh>
  *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *	 http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

  #pragma once

#include <string>
#include <cmath>
#include <utility>

#include "../can/can-signals.hpp"
#include "../diagnostic/diagnostic-message.hpp"
#include "../utils/socketcan-bcm.hpp"

/// @brief Filtering values. Theses values has to be tested into
/// can_bus_t::apply_filter method.
struct event_filter_t
{
	float frequency; ///< frequency - Maximum frequency which will be received and pushed a subscribed event.
	float min; ///< min - Minimum value that the signal don't have to go below to be pushed.
	float max; ///< max - Maximum value that the signal don't have to go above to be pushed.
	event_filter_t() : frequency{NAN}, min{NAN}, max{NAN} {}
};

/// @brief A subscription object used has a context that handle all needed values to describe a subscription
/// to the low-can binding. It can holds a CAN signal or diagnostic message. Diagnostic message for OBD2 is a kind
/// of special because there is only 1 listener to retrieve OBD2 requests. So it's needed that all diagnostic messages
/// subscriptions is to be in 1 object.
class low_can_subscription_t
{
private:
	int index_; ///< index_ - index number is the socket (int) casted
	struct afb_event event_; ///< event_ - application framework event used to push on client

	/// Signal part
	std::shared_ptr<can_signal_t> can_signal_; ///< can_signal_ - the CAN signal subscribed
	std::vector<std::shared_ptr<diagnostic_message_t> > diagnostic_message_; ///< diagnostic_message_ - diagnostic messages meant to received OBD2 responses.
				/// normal diagnostic request and response not tested for now.

	/// Filtering part
	struct event_filter_t event_filter_; ///< event_filter_ - filtering values applied to a subscription

	utils::socketcan_bcm_t socket_; ///< socket_ - socket_ that receives CAN messages.
public:
	low_can_subscription_t();
	low_can_subscription_t(struct event_filter_t event_filter);
	low_can_subscription_t(const low_can_subscription_t& s) = delete;
	low_can_subscription_t(low_can_subscription_t&& s);
	~low_can_subscription_t();

	low_can_subscription_t& operator=(const low_can_subscription_t& s);
	explicit operator bool() const;

	int get_index() const;
	struct afb_event& get_event();
	const std::shared_ptr<can_signal_t> get_can_signal() const;
	const std::shared_ptr<diagnostic_message_t> get_diagnostic_message(uint32_t pid) const;
	const std::vector<std::shared_ptr<diagnostic_message_t> > get_diagnostic_message() const;
	const std::shared_ptr<diagnostic_message_t> get_diagnostic_message(const std::string& name) const;
	const std::string get_name() const;
	const std::string get_name(uint32_t pid) const;
	float get_frequency() const;
	float get_min() const;
	float get_max() const;
	utils::socketcan_bcm_t& get_socket();

	void set_event(struct afb_event event);
	void set_frequency(float freq);
	void set_min(float min);
	void set_max(float max);

	struct utils::simple_bcm_msg make_bcm_head(uint32_t can_id, uint32_t flags, const struct timeval& timeout, const struct timeval& frequency_thinning) const;
	void add_bcm_frame(const struct can_frame& cfd, struct utils::simple_bcm_msg& bcm_msg) const;
	int open_socket();
	int create_rx_filter(std::shared_ptr<can_signal_t> sig);
	int create_rx_filter(std::shared_ptr<diagnostic_message_t> sig);
	int create_rx_filter(utils::simple_bcm_msg& bcm_msg);
};