/**
 * @file
 * @brief Public interface for CAN driver thread.
 */
#ifndef STA_RTOS_SYSTEM_CAN_BUS_HPP
#define STA_RTOS_SYSTEM_CAN_BUS_HPP

/**
 * @defgroup STA_RTOS_CanBus CAN driver
 * @ingroup STA_RTOS_API
 * @brief CAN bus system task.
 *
 * Check @ref STA_RTOS_BuildConfig for configuration options.
 */

#ifdef DOXYGEN
/**
 * @brief Enable module.
 *
 * @ingroup STA_RTOS_BuildConfig
 */
#  define STA_CAN_BUS_ENABLE
#endif // DOXYGEN


#include <sta/config.hpp>
#ifdef STA_CAN_BUS_ENABLE

#include <sta/bus/can/controller.hpp>
#include <sta/devices/stm32/can.hpp>
#include <sta/rtos/c_api/can_msg.h>
#include <sta/proto/isotp/transmitter.hpp>
#include <sta/proto/isotp/receiver.hpp>
#include <sta/time.hpp>

#include <cstdint>


/**
 * @def STA_RTOS_CAN_BUS_MAX_FILTER
 * @brief Set maximum number of usable filters.
 *
 * @ingroup STA_RTOS_BuildConfig
 */
#ifndef STA_RTOS_CAN_BUS_MAX_FILTER
#  error "Must set STA_RTOS_CAN_BUS_MAX_FILTER in <sta/config.hpp>"
#endif // STA_RTOS_CAN_BUS_MAX_FILTER

/**
 * @def STA_RTOS_CAN_BUS_MAX_PAYLOAD_SIZE
 * @brief Set maximum payload size.
 *
 * @ingroup STA_RTOS_BuildConfig
 */
#ifndef STA_RTOS_CAN_BUS_MAX_PAYLOAD_SIZE
#  error "Must set STA_RTOS_CAN_BUS_MAX_PAYLOAD_SIZE in <sta/config.hpp>"
#endif // STA_RTOS_CAN_BUS_MAX_PAYLOAD_SIZE


/**
 * @ingroup STA_RTOS_CanBus
 * @{
 */

/**
 * @brief CAN frame available.
 */
#define STA_RTOS_CAN_FLAG_MSG_AVAIL     0x1U
/**
 * @brief Send CAN message.
 */
#define STA_RTOS_CAN_FLAG_MSG_SEND      0x1U << 1
/**
 * @brief CAN data message in queue.
 */
#define STA_RTOS_CAN_FLAG_DATA_QUEUED   0x1U << 2
/**
 * @brief CAN system message in queue.
 */
#define STA_RTOS_CAN_FLAG_SYS_QUEUED    0x1U << 3
/**
 * @brief Show ISOTP statistics.
 */
#define STA_RTOS_CAN_FLAG_SHOW_STATS    0x1U << 4

/**
 * @brief CAN SID bits used for system messages.
 */
#define STA_CAN_SID_SYS_BITS            UINT32_C(0x3)

#define STA_RTOS_CAN_ANY STA_RTOS_CAN_FLAG_MSG_AVAIL | STA_RTOS_CAN_FLAG_MSG_AVAIL | STA_RTOS_CAN_FLAG_DATA_QUEUED | STA_RTOS_CAN_FLAG_SYS_QUEUED | STA_RTOS_CAN_FLAG_SHOW_STATS


/** @} */


namespace sta
{
	namespace rtos
	{
		/**
		 * @ingroup STA_RTOS_CanBus
		 * @{
		 */

		/**
		 * @brief Initialize CAN bus.
		 */
		void initCanBus();


		/**
		 * @brief Return CAN_HandleTypeDef for use in CAN system task.
		 *
		 * Implementation must be provided by application.
		 */
		extern CAN_HandleTypeDef * getCanController();

		/** @} */
	} // namespace rtos
} // namespace sta

namespace sta
{

	class AlpakaCanBus
	{
	public:
		using SysMsgHandler = void (*)(const CanRxHeader &, const uint8_t *);
		using DataMsgHandler = void (*)(const IsotpMessage &);

		static const uint8_t FIFO_SYS = 0;
		static const uint8_t FIFO_DATA = 1;

	public:
		AlpakaCanBus(CanController * controller, TimeMsFn timeMs, SysMsgHandler sysMsgHandler, DataMsgHandler dataMsgHandler);


		/**
		 * @brief Send system message.
		 *
		 * @param msg   Message
		 */
		void send(const CanSysMsg & msg);

		/**
		 * @brief Send data message.
		 *
		 * @param msg   Message
		 */
		void send(const CanDataMsg & msg);


		/**
		 * @brief Process transmissions.
		 *
		 * Call regularly to advance transmission.
		 */
		void processTx();

		/**
		 * @brief Process received CAN messages.
		 */
		void processRx();

		/**
		 * @brief Display ISOTP TX/RX statistics.
		 */
		void showStatistics();

	    IsotpTransmitter tx_;
		IsotpReceiver rx_;

	private:
		/**
		 * @brief Configure CAN filters.
		 */
		void setupSubscriptions();

		/**
		 * @brief Handle received data message CAN frames.
		 *
		 * @param header    CAN frame header
		 * @param payload   Payload buffer
		 */
		void receiveDataFrame(const CanRxHeader & header, const uint8_t * payload);

	private:
		CanController * controller_;
		
		SysMsgHandler handleSysMsg_;
		DataMsgHandler handleDataMsg_;
	};

} // namespace sta

namespace debug
{
	/**
	 * @brief Output CAN frame ID to UART.
	 *
	 * @param id    Frame ID
	 */
	void printFrameID(const sta::CanFrameId & id);

	/**
	 * @brief Output CAN frame payload to UART.
	 *
	 * @param payload   Payload buffer
	 * @param size      Payload size
	 */
	void printPayloadHex(const uint8_t * payload, uint8_t size);
} // namespace debug

#endif // STA_CAN_BUS_ENABLE

#endif // STA_RTOS_SYSTEM_CAN_BUS_HPP