#include "../include/task.h"
#include "../include/stdio.h"
#include "../include/paging.h"

#include <stddef.h>

Process* current = 0;
Process* queue = 0;

uint32_t irq_disable_counter = 0;
uint32_t pid_counter;
uint32_t task_count;

#define STACK_SIZE 4096

extern void switchProcess(Process* next);

static void processStartup()
{
	printf("startup\n");
	scheduler_unlock();
}

Process* task_create(EntryPoint func, void** args, uint32_t arg_count)
{
	Process* p = heap_alloc(sizeof(Process));
	p->pid = ++pid_counter;
	p->state = Ready;
	p->programCounter = 0;
	p->stackBase = heap_alloc(STACK_SIZE);
	p->stackPointer = (uintptr_t*)((uint32_t)p->stackBase + STACK_SIZE);

	//put the arguments in stack
	for(int i = arg_count-1; i >=0; i--)
		*(--p->stackPointer) = (uintptr_t)args[i];

	// Добавляем адрес возврата (фиктивный, для выравнивания)
	*(--p->stackPointer) = 0; // Фиктивный адрес возврата (не используется напрямую)

	*(--p->stackPointer) = (uintptr_t)func;
	*(--p->stackPointer) = (uintptr_t)processStartup;
	*(--p->stackPointer) = 0;//ebp
	*(--p->stackPointer) = 0;//edi
	*(--p->stackPointer) = 0;//esi
	*(--p->stackPointer) = 0;//ebx

	p->next = 0;

	if(!queue)
	{
		queue = p;
		current = queue;
	}
	else
	{
		Process* curr = queue;
		while(curr->next)
			curr = curr->next;
		curr->next = p;
	}
	task_count++;
	return p;
}

void scheduler_lock()
{
	asm volatile("cli");
	irq_disable_counter++;
}

void scheduler_unlock()
{
	irq_disable_counter--;
	if(irq_disable_counter == 0)
		asm volatile("sti");
}

void schedule()
{
	if(!current)
		return;

	Process* next = current->next;
	if(!next)
		next = queue;
	if(next != current)
		switchProcess(next);
}

void idle()
{
	while(1){}
}

void task1(int arg1, char* arg2)
{
	while(1){
		if(arg1 == 42)
			printf("task1 0x%x %s\n", arg1, arg2);
		else
			printf("ZHOPA %s\n", arg2);
	}
}

void task2(int arg1, int arg2)
{
	while(1){printf("task2 %X %X\n", arg1, arg2);}
}

void scheduler_init()
{
	//we create this task two times because in other case it just won't start
	task_create((EntryPoint)&idle, NULL, 0);
	task_create((EntryPoint)&idle, NULL, 0);

	void* args1[] = {(void*)42, (void*)"ebalo"};
	task_create((EntryPoint)&task1, args1, 2);
	void* args2[] = {(void*)69, (void*)420};
	task_create((EntryPoint)&task2, args2, 2);
}