#include "process.h"
#include "alloc.h"
#include "interrupts.h"
#include "memory.h"
#include "thread.h"

#include "string.h"

struct pcb *create_process(uint8_t uid)
{
	static uint32_t pid = 1;
	struct pcb *new_pcb = vmalloc(sizeof(struct pcb));
	if (!new_pcb)
		return NULL;
	new_pcb->uid = uid;
	new_pcb->pid = pid++;

	new_pcb->heap = alloc_pages(4096, &new_pcb->cr3);
	if (!new_pcb->heap) {
		vfree(new_pcb);
		return NULL;
	}
	memcpy(new_pcb->heap, current_pd, 4096);

	new_pcb->next = new_pcb;
	new_pcb->prev = new_pcb;

	if (current_pcb) {
		new_pcb->next = current_pcb->next;
		new_pcb->prev = current_pcb;
		current_pcb->next = new_pcb;
		if (current_pcb->prev == current_pcb)
			current_pcb->prev = new_pcb;
	} else {
		current_pcb = new_pcb;
	}
	new_pcb->signals.pending = SIG_IGN;
	new_pcb->thread_list = NULL;

	return new_pcb;
}

void remove_pcb(struct pcb *pcb)
{
	struct pcb *left = pcb->prev;
	struct pcb *right = pcb->next;
	if (pcb->heap)
		free_pages(pcb->heap, 4096);
	left->next = right;
	right->prev = left;
	vfree(pcb);
}