#include <stdint.h>
#include <stddef.h>
#include <vga.h>
#include "lib/string.h"

struct vga_display display;

void
vga_set_color(uint16_t c)
{
	display.color = c;
}

void
vga_set_pos(size_t r, size_t c)
{
	display.row = r;
	display.col = c;
}

static uint16_t
vga_build_char(char c, char color)
{
	return (uint16_t)((color << 8) | c);
}

void
vga_put_char(size_t row, size_t col, char c, uint16_t color)
{
	size_t pos = (VGA_WIDTH * row) + col;
	display.buf[pos] = vga_build_char(c, color);
}

void
vga_write_char(char c)
{
	switch (c) {
	case '\n':
		vga_set_pos(++display.row, 0);
		break;
	default:
		vga_put_char(display.row, display.col, c, display.color);
		display.col++;
	}


	if (display.col == VGA_WIDTH)
		vga_set_pos(++display.row, 0);
}

void
vprintl(char *str)
{
	int i = 0;
	size_t len = strlen(str);

	for (i = 0; i <= len; i++) {
		vga_write_char(str[i]);
	}
}

static void
clean_display(void)
{
	int row, col;

	for (row = 0; row < VGA_HEIGHT; row++)
		for (col = 0; col < VGA_WIDTH; col++)
			vga_put_char(row, col, ' ', 0);
}

void
init_display(uint16_t color)
{
	display.buf = (uint16_t *)VGA_ADDRESS;
	vga_set_pos(0, 0);
	clean_display();
	vga_set_color(color);
	vga_set_pos(0, 0);
}