#ifndef _TTY_H
#define _TTY_H


#include <types.h>

#include <fs/vfs.h>

#include <processes.h>
#include <sync.h>


#define TTY_BUFFER_SIZE 4096
#define TTY_RAW_BUFFER_SIZE 16
#define MAX_TTYS        8 /* to make things easy, might change later */

#define TTY_ECHO        0x10 /* 0b00010000 */
#define TTY_PASSWORD    0x20 /* 0b00100000 */
#define TTY_ACTIVE      0x01 /* 0b00000001 */

#define TTY_CANONICAL   0x40 /* 0b01000000 */
#define TTY_RAW         0x04 /* 0b00000100 */

#define TTY_ADDCHAR_ALWAYS 0x02 /* 0b00000010 */

#define TTY_NULL        0x80 /* 0b10000000 --- used to end the list of tty_t structs in the ttys array */

#define TTY_NORMAL      TTY_ECHO | TTY_ACTIVE | TTY_CANONICAL

#define MODIFIER_CAPS   0x01 /* 0b00000001 */
#define MODIFIER_CAPS_DESTROY   0b11111110
#define MODIFIER_SHIFT  0x02 /* 0b00000010 */
#define MODIFIER_SHIFT_DESTROY  0b11111101
#define MODIFIER_ALT    0x04 /* 0b00000100 */
#define MODIFIER_ALT_DESTROY    0b11111011
#define MODIFIER_LCTRL  0x10 /* 0b00010000 */
#define MODIFIER_LCTRL_DESTROY   0b11101111
#define MODIFIER_RCTRL  0x0  /* 0b00100000*/
#define MODIFIER_RCTRL_DESTROY  0b11011111


typedef struct tty_t {
  char input_buffer[TTY_BUFFER_SIZE];
  size_t head;
  size_t tail;
  
  uint32_t flags;

  bool canonical;
  bool line_ready;

  /* for raw mode */
  char raw_buf[TTY_RAW_BUFFER_SIZE];
  size_t raw_head;
  size_t raw_tail;

  spinlock_t lock;

  size_t user_input_start;
  size_t user_input_end;

  struct file_ops f_ops;
  
  pid_t foreground_pgid; /* not used yet */
} tty_t;

/* essentially, key is non-zero if a key like the up arrow is pressed, otherwise c is the char that was entered */
struct keyevent {
  uint8_t key;
  char c;
};

int init_tty(void);

ssize_t tty_read(tty_t* tty, char* buf, size_t count);
ssize_t tty_read_active(char* buf, size_t count);

char tty_get_char(void);

tty_t* get_active_tty(void);
tty_t* tty_get_active(void);

void tty_and_flags(tty_t* tty, uint32_t flags);
uint32_t tty_get_flags(tty_t* tty);

tty_t* make_tty(uint32_t flags);

void tty_receive_char(char c, uint32_t kbd_mod);
char tty_translate_char(char c, uint32_t modifiers);

void tty_input_char(tty_t* tty, char c);

#endif