#ifndef VGA_H
#define VGA_H

#include <stdbool.h>

#include "string.h"
#include <stddef.h>

#include "interrupts.h"
#include "port.h"

#include "driver.h"

#define NOF_MODE_REGS 66

typedef enum {
	VGA_MODE_TYPE_TEXT,
	VGA_MODE_TYPE_GRAPHICS
} vga_mode_type_t;

typedef struct {
	vga_mode_type_t mode_type;
	int x;
	int y;
	int color_depth;
	uint8_t regs[NOF_MODE_REGS];
	uint8_t *segment;
	size_t segment_size;
} vga_mode_t;

typedef struct {
	driver_t base;
	interrupt_t *interrupts;
	port8_t misc_port;
	port8_t crtc_index_port;
	port8_t crtc_data_port;
	port8_t sequencer_index_port;
	port8_t sequencer_data_port;
	port8_t graphics_controller_index_port;
	port8_t graphics_controller_data_port;
	port8_t attribute_controller_index_port;
	port8_t attribute_controller_read_port;
	port8_t attribute_controller_write_port;
	port8_t attribute_controller_reset_port;
	vga_mode_t mode;
	bool use_z_buffer;
	uint8_t *zbuffer;
	// stores either the address to the beginning of the segment
	// (real mapped I/O memory or the beginning of the Z buffer
	uint8_t *base_addr;
} vga_t;

typedef struct {
	driver_vtable_t base;
} vga_vtable_t;

void vga_init( vga_t *vga, interrupt_t *interrupt, void *context );
void vga_activate( void *obj );
void vga_deactivate( void *obj );
void vga_deinit( void *obj );
void vga_print_info( void *obj );

vga_mode_t vga_make_mode( const vga_mode_type_t mode_type, const int x, const int y, const int color_depth );
bool vga_set_mode( vga_t *vga, const vga_mode_t mode );
bool vga_supports_mode( const vga_mode_t mode );

typedef struct {
	int R;
	int G;
	int B;
} vga_color_t;

extern const vga_color_t VGA_COLOR_BLACK;
extern const vga_color_t VGA_COLOR_BLUE;
extern const vga_color_t VGA_COLOR_GREEN;
extern const vga_color_t VGA_COLOR_CYAN;
extern const vga_color_t VGA_COLOR_RED;
extern const vga_color_t VGA_COLOR_MAGENTA;
extern const vga_color_t VGA_COLOR_BROWN;
extern const vga_color_t VGA_COLOR_LIGHT_GREY;
extern const vga_color_t VGA_COLOR_WHITE;

vga_color_t vga_make_RGB( int R, int G, int B );

void vga_set_pixel( vga_t *vga, const int x, const int y, const vga_color_t color );
void vga_draw_rectangle( vga_t *vga, const int x, const int y, const int w, const int h, const vga_color_t color );
void vga_clear_screen( vga_t *vga, const vga_color_t color );
void vga_draw_char( vga_t *vga, const unsigned char c, const int x, const int y, const vga_color_t background, const vga_color_t foreground );
void vga_wait_for_retrace( vga_t *vga );
void vga_use_z_buffer( vga_t *vga, bool use );
void vga_refresh( vga_t *vga );

#endif // VGA_H