#include <terminal.h>
#include <memory.h>
#include <ports.h>
#include <multiboot.h>
#include <stddef.h>
#include <debug.h>

#define VGA_ADDRESS_PORT 0x3D4
#define VGA_DATA_PORT 0x3D5
#define VGA_REGISTER_CURSOR_POS_LOW 0xF
#define VGA_REGISTER_CURSOR_POS_HIGH 0xE

static void *vidmem;

static int setup = 0;

void vga_init(struct fbinfo *fbinfo)
{
    (void) fbinfo;
    vidmem = VGA_MEMORY;
    memset(vidmem, 0, VGA_SIZE*sizeof(struct vga_cell));
    setup = 1;
}

void vga_movecursor(unsigned int cursor)
{
    if(!setup) return;
    outb(VGA_ADDRESS_PORT, VGA_REGISTER_CURSOR_POS_LOW);
    outb(VGA_DATA_PORT, (uint8_t)(cursor & 0xFF));
    outb(VGA_ADDRESS_PORT, VGA_REGISTER_CURSOR_POS_HIGH);
    outb(VGA_DATA_PORT, (uint8_t)((cursor >> 8) & 0xFF));
}

void vga_flush(struct vga_cell *buffer)
{
    if(!setup) return;
    memcpy(vidmem, buffer, VGA_SIZE*2);
}