#include <main.h>
#include <console.h>

unsigned long volatile timer_ticks;

void timer_handler(struct cpu_state *r)
{
	timer_ticks++;
	if(timer_ticks % 1000 == 0) // eine neue Sekunde bricht herein :D
	{
		int oldSecs  = system_time.tm_sec;
		int oldMins  = system_time.tm_min;
		int oldHours = system_time.tm_hour;
		int oldDays  = system_time.tm_mday;
		int oldMonth = system_time.tm_mon;
		int oldYear  = system_time.tm_year;
		system_time.tm_timestamp++;
		
		if(oldSecs < 59)
		{
			system_time.tm_sec++;
		}	
		else
		{	
			system_time.tm_sec = 0;
			if(oldMins < 59)
			{
				system_time.tm_min++;
			}
			else
			{
				system_time.tm_min = 0;
				if(oldHours < 23)
				{
					system_time.tm_hour++;
				}
				else
				{
					system_time.tm_hour = 0;
					if(oldDays < tage_pro_monat[oldMonth]-1 || (oldMonth == 2 && oldYear%4==0 && (oldYear%100!=0 || oldYear%400==0) && oldDays < 28))
					{
						system_time.tm_mday++;
					}
					else
					{
						if(oldMonth < 12)
						{
							system_time.tm_mon++;
						}
						else
						{
							system_time.tm_mon = 0;
							system_time.tm_year++;
						}
					}
				}
			}
		}
	}
}

void timer_phase(int hz)
{
    int divisor = 1193180 / hz;       /* Calculate our divisor */
    outb(0x43, 0x36);             /* Set our command byte 0x36 */
    outb(0x40, divisor & 0xFF);   /* Set low byte of divisor */
    outb(0x40, divisor >> 8);     /* Set high byte of divisor */
}

void install_timer()
{
	timer_phase(1000);
	timer_ticks = 0;
	irq_install_handler(0, timer_handler);
}

void timer_wait(int ticks)
{
	long waitTicks = timer_ticks + ticks;
	while(timer_ticks < waitTicks);
}