#ifndef STA_RTOS_THREAD_HPP
#define STA_RTOS_THREAD_HPP

#include <sta/rtos/defs.hpp>

#include <cmsis_os2.h>

/**
 * @defgroup STA_RTOS_THREAD Thread
 * @ingroup STA_RTOS_API
 * @brief RTOS Thread.
 */

/**
 * @ingroup STA_RTOS_THREAD
 * @{
 */

/**
 * @brief Number of bits in task notification flags used internally.
 */
#define STA_RTOS_MAX_BITS_THREAD_SYS_NOTIFY         1U
/**
 * @brief Number of user usable bits in task notification flags.
 */
#define STA_RTOS_MAX_BITS_THREAD_USER_NOTIFY        ( STA_RTOS_MAX_BITS_THREAD_NOTIFY - STA_RTOS_MAX_BITS_THREAD_SYS_NOTIFY )
/**
 * @brief Mask for valid system task notification flag bits.
 */
#define STA_RTOS_THREAD_FLAGS_VALID_SYS_BITS        ( ( ( 1UL << STA_RTOS_MAX_BITS_THREAD_SYS_NOTIFY ) - 1U ) << STA_RTOS_MAX_BITS_THREAD_USER_NOTIFY )
/**
 * @brief Mask for valid user task notification flag bits.
 */
#define STA_RTOS_THREAD_FLAGS_VALID_USER_BITS       ( ( 1UL << STA_RTOS_MAX_BITS_THREAD_USER_NOTIFY ) - 1U )


/**
 * @brief Indicate error code instead of flag values.
 */
#define STA_RTOS_THREAD_FLAG_ERROR_CODE             ( 1UL << 31 )

/**
 * @brief Request thread start.
 */
#define STA_RTOS_THREAD_FLAG_START					( 1UL << 30 )


#define STA_RTOS_THREAD_FLAGS_ERROR_CODE_BITS       UINT32_C( 0x0000000F )
#define STA_RTOS_THREAD_FLAGS_ERROR_CODE_EXT_BITS   UINT32_C( 0x7FFFFFF0 )

/**
 * @brief Error code from flags.
 */
#define STA_RTOS_THREAD_FLAGS_GET_EXT_ERROR_CODE(flags) (~flags & STA_RTOS_THREAD_FLAGS_ERROR_CODE_EXT_BITS)

/**
 * @brief Wait for any of the given flags to be set.
 */
#define STA_RTOS_THREAD_FLAGS_WAIT_ANY(timeout) osThreadFlagsWait(STA_RTOS_THREAD_FLAGS_VALID_BITS, osFlagsWaitAny, timeout)


/** @} */


namespace sta
{
	/**
	 * @brief Wrapper for RTOS thread control.
	 *
	 * @ingroup STA_RTOS_THREAD
	 */
	class RtosThread
	{
	public:
		/**
		 * @brief Create an RtosThread.
		 * 
		 * @param name The thread's name. Will be used for debugging.
		 * @param prio The thread's priority.
		 * @param stack_size The thread's stack size. Default of 0 refers to the RTOS2 default stack size specified in the IOC.
		 * @param cb_size The thread's control block size. Default of 0 refers to the RTOS2 default control block size specified in the IOC.
		 */
		RtosThread(const char* name, osPriority_t prio, uint32_t stack_size = 0, uint32_t cb_size = 0);

		/**
		 * @brief Get the currently running instance.
		 * 
		 * @return The currently running instance id.
		 */
		osThreadId_t getInstance();

		/**
		 * @brief Get the name of this thread.
		 */
		const char* getName() const;

		/**
		 * @brief Start the execution of this thread.
		 */
		virtual void start();

		/**
		 * @brief Sets the thread to BLOCKED for a given number of ticks. 
		 * Other threads can run in the meantime.
		 * 
		 * @param ticks The number of ticks before setting the thread to READY again.
		 */
		void sleep(uint32_t ticks);

		/**
		 * @brief Send user notification flags to thread.
		 *
		 * @param flags     User flags
		 */
		void notify(uint32_t flags);

		/**
		 * @return Returns the flags that were set for this thread.
		 */
		uint32_t getFlags();

		/**
		 * @brief Wait for certain thread flags.
		 *
		 * @return Returns the flags triggering the activation.
		 */
		uint32_t wait(uint32_t flags);

		/**
		 * @brief Clears the thread flags set for this thread.
		 *
		 * @return Returns the thread flags that set before clearing.
		 */
		uint32_t clear(uint32_t flags);

		/**
		 * @brief Forcibly terminate thread.
		 */
		void kill();

		/**
		 * @brief Send system notification flags to thread.
		 *
		 * @param flags     System flags
		 */
		void sysNotify(uint32_t flags);
	protected:
		/**
		 * @brief A function that wraps this task's functionality.
		 */
		virtual void loop() = 0;

	private:
		/**
		 * @brief Static function to pass to RTOS to run as a thread. Calls the loop function implemented here.
		 */
		static void entry_point(void* arg);

	private:
		osThreadId_t instance_;
		osThreadAttr_t attribs_;
	};
} // namespace sta

#endif // STA_RTOS_THREAD_HPP