#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdlib.h>
#include <stdarg.h>
#include <termios.h>
#include <sys/ioctl.h>
#include <sys/select.h>
#include <signal.h>
#include <errno.h>

#include "tty.h"

#include "../config.h"

//////////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////////
// done
void tty_reset(tty_t *tty) {
  tcsetattr(tty->fdin, TCSANOW, &tty->original_termios);
}

void tty_close(tty_t *tty) {
  tty_reset(tty);
  fclose(tty->fout);
  close(tty->fdin);
}

// pretty sure this isn't needed
static void handle_sigwinch(int sig){
  (void)sig;
}

void tty_init(tty_t *tty, const char *tty_filename) {
  tty->fdin = open(tty_filename, O_RDONLY);
  if (tty->fdin < 0) {
    perror("Failed to open tty");
    exit(EXIT_FAILURE);
  }

  tty->fout = fopen(tty_filename, "w");
  if (!tty->fout) {
    perror("Failed to open tty");
    exit(EXIT_FAILURE);
  }

  if (setvbuf(tty->fout, NULL, _IOFBF, 4096)) {
    perror("setvbuf");
    exit(EXIT_FAILURE);
  }

  if (tcgetattr(tty->fdin, &tty->original_termios)) {
    perror("tcgetattr");
    exit(EXIT_FAILURE);
  }

  struct termios new_termios = tty->original_termios;

  /*
   * Disable all of
   * ICANON  Canonical input (erase and kill processing).
   * ECHO    Echo.
   * ISIG    Signals from control characters
   * ICRNL   Conversion of CR characters into NL
   */
  new_termios.c_iflag &= ~(ICRNL);
  new_termios.c_lflag &= ~(ICANON | ECHO | ISIG);

  if (tcsetattr(tty->fdin, TCSANOW, &new_termios))
    perror("tcsetattr");

  tty_getwinsz(tty);

  tty_setnormal(tty);

  signal(SIGWINCH, handle_sigwinch);
}

void tty_getwinsz(tty_t *tty) {
  struct winsize ws;
  if (ioctl(fileno(tty->fout), TIOCGWINSZ, &ws) == -1) {
    tty->maxwidth = 80;
    tty->maxheight = 25;
  } else {
    tty->maxwidth = ws.ws_col;
    tty->maxheight = ws.ws_row;
  }
}

static void tty_sgr(tty_t *tty, int code) {
  tty_printf(tty, "%c%c%im", 0x1b, '[', code);
}

void tty_setfg(tty_t *tty, int fg) {
  if (tty->fgcolor != fg) {
    tty_sgr(tty, 30 + fg);
    tty->fgcolor = fg;
  }
}

void tty_newline(tty_t *tty) {
  tty_printf(tty, "%c%cK\n", 0x1b, '[');
}

void tty_clearline(tty_t *tty) {
  tty_printf(tty, "%c%cK", 0x1b, '[');
}

void tty_printf(tty_t *tty, const char *fmt, ...) {
  va_list args;
  va_start(args, fmt);
  vfprintf(tty->fout, fmt, args);
  va_end(args);
}

void tty_flush(tty_t *tty) {
  fflush(tty->fout);
}

void tty_putc(tty_t *tty, char c) {
  fputc(c, tty->fout);
}

void tty_setinvert(tty_t *tty) {
  tty_sgr(tty, 7);
}

void tty_setunderline(tty_t *tty) {
  tty_sgr(tty, 4);
}

void tty_setnormal(tty_t *tty) {
  tty_sgr(tty, 0);
  tty->fgcolor = 9;
}

void tty_moveup(tty_t *tty, int i) {
  tty_printf(tty, "%c%c%iA", 0x1b, '[', i);
}

void tty_setcol(tty_t *tty, int col) {
  tty_printf(tty, "%c%c%iG", 0x1b, '[', col + 1);
}

void tty_setnowrap(tty_t *tty) {
  tty_printf(tty, "%c%c?7l", 0x1b, '[');
}

void tty_setwrap(tty_t *tty) {
  tty_printf(tty, "%c%c?7h", 0x1b, '[');
}

//////////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////////
// todo

/////////////////////////////////////////////////////////////////////////////////////////
// hard shit
char tty_getchar(tty_t *tty) {
  char ch;
  int size = read(tty->fdin, &ch, 1);
  if (size < 0) {
    perror("error reading from tty");
    exit(EXIT_FAILURE);
  } else if (size == 0) {
    /* EOF */
    exit(EXIT_FAILURE);
  } else {
    return ch;
  }
}

int tty_input_ready(tty_t *tty, long int timeout, int return_on_signal) {
  fd_set readfs;
  FD_ZERO(&readfs);
  FD_SET(tty->fdin, &readfs);

  struct timespec ts = {timeout / 1000, (timeout % 1000) * 1000000};

  sigset_t mask;
  sigemptyset(&mask);
  if (!return_on_signal)
    sigaddset(&mask, SIGWINCH);

  int err = pselect(
    tty->fdin + 1,
    &readfs,
    NULL,
    NULL,
    timeout < 0 ? NULL : &ts,
    return_on_signal ? NULL : &mask
  );

  if (err < 0) {
    if (errno == EINTR) {
      return 0;
    } else {
      perror("select");
      exit(EXIT_FAILURE);
    }
  } else {
    return FD_ISSET(tty->fdin, &readfs);
  }
}