#include <kernel/scheduler.h>
#include <kernel/atomic.h>
#include <kernel/util.h>

//TODO: assembly !
// @note: This part *SHOULD* be exeption safe !
int sched_schedule(common_context_t **context_current, common_context_t **context_next)
{
	extern struct sched_task *sched_task_current;
	extern struct sched_task *sched_task_queue;
	struct sched_task *task_current;
	struct sched_task *task_next;
	
	// Check current task
	// TODO: check process status !!
	if (sched_task_current == NULL)
	{
		task_current = NULL;
		task_next = (sched_task_queue != NULL) ? sched_task_queue : NULL;
	} else {
		task_current = sched_task_current;
		task_next = (sched_task_current->next != NULL)
			? sched_task_current->next
			: sched_task_queue;
	}

	// Check potantial error
	if (task_next == NULL || task_next == sched_task_current)
		return (-1);
	
	// Update internal scheduler task cursor
	sched_task_current = task_next;

	// Get context
	*context_current = (task_current != NULL) ? &task_current->process->context : NULL;
	*context_next = &task_next->process->context;

	// DEBUG !
	/*kvram_clear();
	printk(0, 0, "Scheduler_schudele !");
	printk(0, 1, "task current = %p", task_current);
	printk(0, 2, "task next = %p", task_next);
	printk(0, 3, "context current = %p", *context_current);
	printk(0, 4, "context next = %p", *context_next);
	kvram_display();
	DBG_WAIT;*/
	return (0);
}