#include <mutex>
#include <systemd/sd-event.h>

#include "application.hpp"
#include "../utils/signals.hpp"
#include "low-can-hat.hpp"
#include "../can/message/message.hpp"
#include "../can/can-bus.hpp"



///******************************************************************************
///
///		SystemD event loop Callbacks
///
///*******************************************************************************/

static void push_n_notify(std::shared_ptr<message_t> m)
{
	can_bus_t& cbm = application_t::instance().get_can_bus_manager();
	{
		std::lock_guard<std::mutex> can_message_lock(cbm.get_can_message_mutex());
	 	cbm.push_new_can_message(m);
	}
	cbm.get_new_can_message_cv().notify_one();
}

void on_no_clients(std::shared_ptr<low_can_subscription_t> can_subscription, uint32_t pid, std::map<int, std::shared_ptr<low_can_subscription_t> >& s)
{
	bool is_permanent_recurring_request = false;

	if( ! can_subscription->get_diagnostic_message().empty() && can_subscription->get_diagnostic_message(pid) != nullptr)
	{
		DiagnosticRequest diag_req = can_subscription->get_diagnostic_message(pid)->build_diagnostic_request();
		active_diagnostic_request_t* adr = application_t::instance().get_diagnostic_manager().find_recurring_request(diag_req);
		if( adr != nullptr)
		{
			is_permanent_recurring_request = adr->get_permanent();

			if(! is_permanent_recurring_request)
				application_t::instance().get_diagnostic_manager().cleanup_request(adr, true);
		}
	}

	if(! is_permanent_recurring_request)
		on_no_clients(can_subscription, s);
}


void on_no_clients(std::shared_ptr<low_can_subscription_t> can_subscription, std::map<int, std::shared_ptr<low_can_subscription_t> >& s)
{
	auto it = s.find(can_subscription->get_index());
	s.erase(it);
}

int read_message(sd_event_source *event_source, int fd, uint32_t revents, void *userdata)
{

	low_can_subscription_t* can_subscription = (low_can_subscription_t*)userdata;


	if ((revents & EPOLLIN) != 0)
	{
		utils::signals_manager_t& sm = utils::signals_manager_t::instance();
		std::lock_guard<std::mutex> subscribed_signals_lock(sm.get_subscribed_signals_mutex());
		if(can_subscription->get_index() != -1)
		{
			std::shared_ptr<utils::socketcan_t> s = can_subscription->get_socket();
			if(s->socket() > 0)
			{
				std::shared_ptr<message_t> message = s->read_message();

				// Sure we got a valid CAN message ?
				if (message->get_id() &&
				    message->get_length() &&
				    ! (message->get_flags() & INVALID_FLAG) )
				{
					if(can_subscription->get_signal() != nullptr && can_subscription->get_signal()->get_message()->get_flags() & BYTE_FRAME_IS_BIG_ENDIAN)
						message->frame_swap();
					push_n_notify(message);
				}
			}
		}
	}

	// check if error or hangup
	if ((revents & (EPOLLERR|EPOLLRDHUP|EPOLLHUP)) != 0)
	{
		sd_event_source_unref(event_source);
		can_subscription->get_socket()->close();
	}

	return 0;
}