#include "drv_timer.h"


static struct drv_timer_t *timerHead;


void drv_timer_start (struct drv_timer_t *timer)
{
	ASSERT(timer != NULL);

	timer->start		= 1;
}


void drv_timer_restart (struct drv_timer_t *timer)
{
	ASSERT(timer != NULL);

	timer->start		= 0;
	timer->time_temp	= 0;
	timer->period		= timer->period_temp;
	timer->start		= 1;
}

void drv_timer_pause (struct drv_timer_t *timer)
{
	ASSERT(timer != NULL);

	timer->start		= 0;
	timer->time_temp	= 0;

	return;
}

void drv_timer_detach (struct drv_timer_t *timer)
{
	struct drv_timer_t **now_target;
	struct drv_timer_t *entry;

	ASSERT(timer != NULL);

	for (now_target = &timerHead; *now_target; ) {
		entry = *now_target;

		if (entry == timer) {
			*now_target = entry->next;
			return;
		} else {
			now_target = &entry->next;
		}
	}

	return;
}

static void drv_timer_attach (struct drv_timer_t *timer)
{
	struct drv_timer_t *target;
    
	for (target = timerHead; target != NULL; target = target->next) {
		if (target == timer) {
			return;
		}
	}

	timer->next = timerHead;
	timerHead  = timer;
}

// call in tick interrupt
void drv_timer_handler (uint8_t ms)
{
	struct drv_timer_t *timer;

	for (timer = timerHead; timer != NULL; timer = timer->next) {
		if (timer->start) {
			timer->time_temp += ms;
			if (timer->time_temp >= timer->timeout) {
				timer->time_temp = 0;
				if ((timer->type & TIMER_TYPE_HARDWARE) != 0) {
					if (timer->timerCallback) {
						timer->timerCallback(timer->user_data);
					}

					if ((timer->type & TIMER_ONE_SHOT) != 0) {
						--timer->period;
						if (timer->period == 0) {
							drv_timer_pause(timer);
						}
					}
                } else {
                    timer->timeout_flag = 1;
				}
			}
		}
	}
}

void drv_timer_linkUserData (struct drv_timer_t *timer, void *user_data)
{
    ASSERT(timer != NULL);

    timer->user_data = user_data;
}

void drv_timer_init (struct drv_timer_t *timer,
	void (*timerCallback)(void *user_data),
	uint32_t timeout,
	uint16_t period)
{
	ASSERT(timer != NULL);

	timer->period			= period;
	timer->timeout			= timeout;
	timer->type				= TIMER_TYPE_HARDWARE;
	timer->timerCallback	= timerCallback;

	timer->time_temp		= 0;
	timer->period_temp		= period;

	if (period == 0) {
		timer->type |= TIMER_PERIODIC;
	} else {
		timer->type |= TIMER_ONE_SHOT;
	}

	drv_timer_attach(timer);
}