/**
 * @file vga.h
 * @brief VGA text-mode driver interface.
 *
 * Provides functions to write text to the VGA text-mode framebuffer
 * (typically at 0xB8000). Supports an 80x25 character display with
 * 16 foreground and 16 background colors.
 */

#ifndef VGA_H
#define VGA_H

#include <stdint.h>
#include <stddef.h>

/** VGA color constants. */
typedef enum {
    VGA_BLACK         = 0,
    VGA_BLUE          = 1,
    VGA_GREEN         = 2,
    VGA_CYAN          = 3,
    VGA_RED           = 4,
    VGA_MAGENTA       = 5,
    VGA_BROWN         = 6,
    VGA_LIGHT_GREY    = 7,
    VGA_DARK_GREY     = 8,
    VGA_LIGHT_BLUE    = 9,
    VGA_LIGHT_GREEN   = 10,
    VGA_LIGHT_CYAN    = 11,
    VGA_LIGHT_RED     = 12,
    VGA_LIGHT_MAGENTA = 13,
    VGA_YELLOW        = 14,
    VGA_WHITE         = 15,
} vga_color_t;

/** VGA screen dimensions. */
#define VGA_WIDTH  80
#define VGA_HEIGHT 25

/**
 * Initialize the VGA driver.
 *
 * Clears the screen and sets the default colors.
 *
 * @return 0 on success.
 */
int vga_init(void);

/**
 * Clear the VGA screen.
 */
void vga_clear(void);

/**
 * Set the foreground and background color for subsequent writes.
 *
 * @param fg Foreground color.
 * @param bg Background color.
 */
void vga_set_color(vga_color_t fg, vga_color_t bg);

/**
 * Write a single character at the current cursor position.
 *
 * @param c Character to write.
 */
void vga_putchar(char c);

/**
 * Write a null-terminated string at the current cursor position.
 *
 * @param str String to write.
 */
void vga_puts(const char *str);

/**
 * Write a 32-bit value in hexadecimal to the VGA display.
 *
 * @param val Value to display.
 */
void vga_put_hex(uint32_t val);

/**
 * Write a 32-bit value in decimal to the VGA display.
 *
 * @param val Value to display.
 */
void vga_put_dec(uint32_t val);

/**
 * Display boot memory statistics on VGA.
 *
 * Shows detected memory, kernel size, and free pages.
 */
void vga_show_mem_stats(void);

#endif /* VGA_H */