#ifndef DARWIN_TTY_H_
#define DARWIN_TTY_H_

#include <stdbool.h>
#include <stdint.h>

#define S_TTY_CTRL_KEY(c) ((c) | S_MOD_CTRL)

struct s_tty;

#define MAKE_VMODE(fg, bg, a) \
	{ \
		.v_fg = fg, \
		.v_bg = bg, \
		.v_attrib = (a) \
	}

#define MAKE_COLOUR_DEFAULT(v) \
	{ \
		.c_mode = TTY_COLOUR_NONE, \
	}

#define MAKE_COLOUR_16(v) \
	{ \
		.c_mode = TTY_COLOUR_16, \
		.c_16 = { \
			.value = (v) \
		} \
	}

#define MAKE_COLOUR_256(v) \
	{ \
		.c_mode = TTY_COLOUR_256, \
		.c_256 = { \
			.value = (v) \
		} \
	}

#define MAKE_COLOUR_TRUE(cr, cg, cb) \
	{ \
		.c_mode = TTY_COLOUR_TRUE, \
		.c_true = { \
			.r = (cr), \
			.g = (cg), \
			.b = (cb) \
		} \
	}

typedef uint32_t s_keycode;

/* codepoints U+F0000 to U+FFFFD are reserved areas in Unicode, free for
 * application use. store special keycodes here */
enum s_keys {
	S_KEY_ARROW_LEFT = 0xF0000,
	S_KEY_ARROW_RIGHT,
	S_KEY_ARROW_UP,
	S_KEY_ARROW_DOWN,
	S_KEY_BACKSPACE,
	S_KEY_RETURN,

	S_MOD_CTRL = 0x10000000,

	S_KEY_EOF = 0xFFFFFFFF,
};

enum s_tty_colour16 {
	TTY_COLOUR16_BLACK = 0,
	TTY_COLOUR16_RED,
	TTY_COLOUR16_GREEN,
	TTY_COLOUR16_YELLOW,
	TTY_COLOUR16_BLUE,
	TTY_COLOUR16_MAGENTA,
	TTY_COLOUR16_CYAN,
	TTY_COLOUR16_WHITE,
	TTY_COLOUR16_GREY,
	TTY_COLOUR16_BRIGHT_RED,
	TTY_COLOUR16_BRIGHT_GREEN,
	TTY_COLOUR16_BRIGHT_YELLOW,
	TTY_COLOUR16_BRIGHT_BLUE,
	TTY_COLOUR16_BRIGHT_MAGENTA,
	TTY_COLOUR16_BRIGHT_CYAN,
	TTY_COLOUR16_BRIGHT_WHITE,
};

enum s_tty_colour_mode {
	TTY_COLOUR_NONE = 0,
	TTY_COLOUR_16,
	TTY_COLOUR_256,
	TTY_COLOUR_TRUE,
};

enum s_tty_position_base {
	TTY_POS_START,
	TTY_POS_CURSOR,
};

enum s_tty_attrib {
	TTY_ATTRIB_NORMAL = 0x00u,
	TTY_ATTRIB_BOLD = 0x01u,
	TTY_ATTRIB_UNDERLINE = 0x02u,
	TTY_ATTRIB_ITALIC = 0x04u,
};

enum s_tty_clear_mode {
	TTY_CLEAR_LINE = 0x01u,
	TTY_CLEAR_SCREEN = 0x02,
	
	TTY_CLEAR_TO_CURSOR = 0x0100u,
	TTY_CLEAR_FROM_CURSOR = 0x0200u,
	TTY_CLEAR_ALL = 0x0400u,
};

struct s_tty_colour {
	enum s_tty_colour_mode c_mode;

	union {
		struct {
			uint8_t value;
		} c_16;

		struct {
			uint8_t value;
		} c_256;

		struct {
			uint8_t r;
			uint8_t g;
			uint8_t b;
		} c_true;
	};
};

struct s_tty_vmode {
	enum s_tty_attrib v_attrib;
	struct s_tty_colour v_fg;
	struct s_tty_colour v_bg;
};

static inline unsigned int s_keycode_get_key(s_keycode v)
{
	return v & 0x0FFFFFFF;
}

extern struct s_tty *s_get_tty(void);
extern bool s_tty_is_interactive(const struct s_tty *tty);

extern void s_tty_set_raw(struct s_tty *tty);
extern void s_tty_set_canon(struct s_tty *tty);
extern void s_tty_reset_vmode(struct s_tty *tty);
extern void s_tty_set_vmode(struct s_tty *tty, const struct s_tty_vmode *vmode);

extern s_keycode s_tty_read_key(struct s_tty *tty);

extern void s_tty_move_cursor_x(
	struct s_tty *tty, enum s_tty_position_base base, int pos);
extern void s_tty_move_cursor_y(
	struct s_tty *tty, enum s_tty_position_base base, int pos);
extern void s_tty_clear(struct s_tty *tty, enum s_tty_clear_mode mode);

#endif