// 
// http://en.wikipedia.org/wiki/VT52
//


#include "vt52.h"
#include "kernel/kmalloc.h"


//TODO: check?
#define VT52_WIDTH 80
#define VT52_HEIGHT 25
#define VT52_ESC 0x33 

static uint32_t index(vt52_tty *tty, uint32_t x, uint32_t y)
{
    return tty->width*y+x;
}

static void clear(vt52_tty *tty)
{
    for(int x=0;x<tty->width;x++)
	for(int y=0;y<tty->height;y++)
	{
	    tty->data[index(tty,x,y)]='.';
	    tty->screen->put_char('.',0xf,x,y);
	}
}

vt52_tty vt52_init(term_screen *screen)
{

    vt52_tty tty;

    tty.data=kballoc(1);
    tty.screen=screen;

    tty.x=0;
    tty.y=0;

    tty.width=VT52_WIDTH;
    tty.height=VT52_HEIGHT;

    clear(&tty);

    return tty;
}


static void set_char(vt52_tty *tty, uint32_t x, uint32_t y, uint32_t c)
{
    tty->data[index(tty,x,y)]=c;
}

// send one ASCII character to the terminal
void vt52_put(vt52_tty *tty, uint8_t c)
{   
    if(c!='\n')
    {
        tty->data[index(tty,tty->x,tty->y)]=c;
	tty->screen->put_char(c,0xf,tty->x,tty->y);
    }
    else
    {
	tty->y++;
	tty->x=0;
    }

    tty->x++;

    if(tty->x>=tty->width)
    {
	tty->x=0;
	tty->y++;
    }

    //autoscroll
    if(tty->y>=tty->height)
    {
	tty->y--;
	for(uint32_t y=0;y<tty->height;y++)
	{
	    for(uint32_t x=0;x<tty->width-1;x++)
	    {
		uint32_t c=tty->data[index(tty,x,y+1)];
		tty->data[index(tty,x,y)] = c;
		tty->screen->put_char(c,0xf,x,y);
	    }
	}
	for(uint32_t x=0;x<tty->width;x++)
	{
	}


    }
}