/* GNU Mailutils -- a suite of utilities for electronic mail
   Copyright (C) 1999, 2000, 2001, 2002, 2005 Free Software Foundation, Inc.

   GNU Mailutils is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2, or (at your option)
   any later version.

   GNU Mailutils is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with GNU Mailutils; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
   MA 02110-1301 USA */

#include "mail.h"
#include <mailutils/folder.h>

#ifdef WITH_READLINE
static char **ml_command_completion (char *cmd, int start, int end);
static char *ml_command_generator (const char *text, int state);
#endif

static volatile int _interrupted;

static RETSIGTYPE
sig_handler (int signo)
{
  switch (signo)
    {
    case SIGINT:
      if (util_getenv (NULL, "quit", Mail_env_boolean, 0) == 0)
	exit (0);
      _interrupted++;
      break;
#if defined (SIGWINCH)
    case SIGWINCH:
      util_do_command ("set screen=%d", util_getlines());
      util_do_command ("set columns=%d", util_getcols());
      page_invalidate (1);
      break;
#endif
    }
#ifndef HAVE_SIGACTION
  signal (signo, sig_handler);
#endif
}

void
ml_clear_interrupt ()
{
  _interrupted = 0;
}

int
ml_got_interrupt ()
{
  int rc = _interrupted;
  _interrupted = 0;
  return rc;
}

static int
ml_getc (FILE *stream)
{
    unsigned char c;

    while (1)
      {
	if (read (fileno (stream), &c, 1) == 1)
	  return c;
	if (errno == EINTR)
	  {
	    if (_interrupted)
	      break;
	    /* keep going if we handled the signal */
	  }
	else
	  break;
      }
    return EOF;
}

void
ml_readline_init ()
{
  if (!interactive)
    return;

#ifdef WITH_READLINE
  rl_readline_name = "mail";
  rl_attempted_completion_function = (CPPFunction*)ml_command_completion;
  rl_getc_function = ml_getc;
#endif
#ifdef HAVE_SIGACTION
  {
    struct sigaction act;
    act.sa_handler = sig_handler;
    sigemptyset (&act.sa_mask);
    act.sa_flags = 0;
    sigaction (SIGINT, &act, NULL);
#if defined(SIGWINCH)
    sigaction (SIGWINCH, &act, NULL);
#endif
  }
#else
  signal (SIGINT, sig_handler);
#if defined(SIGWINCH)
  signal (SIGWINCH, sig_handler);
#endif
#endif
}

char *
ml_readline_internal ()
{
  char *line;
  char *p;
  size_t alloclen, linelen;

  p = line = xcalloc (1, 255);
  alloclen = 255;
  linelen = 0;
  for (;;)
    {
      size_t n;

      p = fgets (p, alloclen - linelen, stdin);

      if (p)
	n = strlen(p);
      else if (_interrupted)
	{
	  free (line);
	  return NULL;
	}
      else
	n = 0;

      linelen += n;

      /* Error.  */
      if (linelen == 0)
	{
	  free (line);
	  return NULL;
	}

      /* Ok.  */
      if (line[linelen - 1] == '\n')
	{
	  line[linelen - 1] = '\0';
	  return line;
	}
      else
        {
	  char *tmp;
	  alloclen *= 2;
	  tmp = realloc (line, alloclen);
	  if (tmp == NULL)
	    {
	      free (line);
	      return NULL;
	    }
	  line = tmp;
	  p = line + linelen;
	}
    }
}

char *
ml_readline (char *prompt)
{
  if (interactive)
    return readline (prompt);
  return ml_readline_internal ();
}

char *
ml_readline_with_intr (char *prompt)
{
  char *str = ml_readline (prompt);
  if (_interrupted)
    printf ("\n");
  return str;
}

#ifdef WITH_READLINE

static char *insert_text;

static int
ml_insert_hook (void)
{
  if (insert_text)
    rl_insert_text (insert_text);
  return 0;
}

int
ml_reread (const char *prompt, char **text)
{
  char *s;

  ml_clear_interrupt ();
  insert_text = *text;
  rl_startup_hook = ml_insert_hook;
  s = readline ((char *)prompt);
  if (!ml_got_interrupt ())
    {
      if (*text)
	free (*text);
      *text = s;
    }
  else
    {
      putc('\n', stdout);
    }
  rl_startup_hook = NULL;
  return 0;
}

/*
 * readline tab completion
 */
char **
ml_command_completion (char *cmd, int start, int end)
{
  int argc;
  char **argv;
  char **ret;
  char *p;

  for (p = rl_line_buffer; p < rl_line_buffer + start && isspace (*p); p++)
    ;
  
  if (argcv_get_n (p, end, NULL, NULL, &argc, &argv))
    return NULL;
  rl_completion_append_character = ' ';
  
  if (argc <= 1 && strlen (argv[0]) <= end - start)
    {
      ret = rl_completion_matches (cmd, ml_command_generator);
      rl_attempted_completion_over = 1;
    }
  else
    {
      const struct mail_command_entry *entry = mail_find_command (argv[0]);
      if (entry && entry->command_completion)
	ret = entry->command_completion (argc, argv, start == end);
      else
	ret = NULL;
    }
  argcv_free (argc, argv);
  return ret;
}

/*
 * more readline
 */
char *
ml_command_generator (const char *text, int state)
{
  static int i, len;
  const char *name;
  const struct mail_command *cp;
  
  if (!state)
    {
      i = 0;
      len = strlen (text);
    }

  while ((cp = mail_command_name (i)))
    {
      name = cp->longname;
      if (strlen (cp->shortname) > strlen (name))
	name = cp->shortname;
      i++;
      if (strncmp (name, text, len) == 0)
	return strdup (name);
    }

  return NULL;
}

void
ml_set_completion_append_character (int c)
{
  rl_completion_append_character = c;
}

void
ml_attempted_completion_over ()
{
  rl_attempted_completion_over = 1;
}


/* Completion functions */
char **
no_compl (int argc ARG_UNUSED, char **argv ARG_UNUSED, int ws ARG_UNUSED)
{
  ml_attempted_completion_over ();
  return NULL;
}

char **
msglist_compl (int argc, char **argv, int ws)
{
  /* FIXME */
  ml_attempted_completion_over ();
  return NULL;
}

char **
msglist_file_compl (int argc, char **argv, int ws ARG_UNUSED)
{
  if (argc == 1)
    ml_attempted_completion_over ();
  return NULL;
}

char **
command_compl (int argc, char **argv, int ws)
{
  ml_set_completion_append_character (0);
  if (ws)
    return NULL;
  return rl_completion_matches (argv[argc-1], ml_command_generator);
}

static char *
file_generator (const char *text, int state, char *path, size_t pathlen,
		char repl,
		int flags)
{
  static struct folder_list list;
  static int i;
  
  if (!state)
    {
      char *wcard;
      folder_t folder;
  
      wcard = xmalloc (strlen (text) + 2);
      strcat (strcpy (wcard, text), "*");

      folder_create (&folder, path);
      folder_list (folder, path, wcard, &list);
      free (wcard);
      folder_destroy (&folder);

      if (list.num == 0)
	return NULL;
      else if (list.num == 1)
	ml_set_completion_append_character (0);

      i = 0;
    }

  while (i < list.num)
    {
      if (list.element[i]->type & flags)
	{
	  char *ret;
	  if (repl)
	    {
	      int len = strlen (list.element[i]->name + pathlen);
	      ret = xmalloc (len + 2);
	      ret[0] = repl;
	      memcpy (ret + 1, list.element[i]->name + pathlen, len);
	      ret[len+1] = 0;
	    }
	  else
	    ret = xstrdup (list.element[i]->name);
	  i++;
	  return ret;
	}
      i++;
    }
  
  folder_list_destroy (&list);
  return NULL;
}

static char *
folder_generator (const char *text, int state)
{
  char *ret;
  static size_t pathlen;
  
  if (!state)
    {
      char *path = util_folder_path ("");
      if (!path)
	return NULL;
      
      pathlen = strlen (path);
      ret = file_generator (text, state, path, pathlen, '+',
			    MU_FOLDER_ATTRIBUTE_ALL);
      free (path);
    }
  else
    ret = file_generator (text, state, NULL, pathlen, '+',
			  MU_FOLDER_ATTRIBUTE_ALL);
  return ret;
}

char **
file_compl (int argc, char **argv, int ws)
{
  char *text;

  if (ws)
    {
      ml_set_completion_append_character (0);
      ml_attempted_completion_over ();
      return NULL;
    }
  
  text = argv[argc-1];
  switch (text[0])
    {
    case '+':
      text++;
      break;

    case '#':
    case '&':
      ml_attempted_completion_over ();
      return NULL;
      
    default:
      return NULL; /* Will be expanded by readline itself */
    }
  
  return rl_completion_matches (text, folder_generator);
}

static char *
dir_generator (const char *text, int state)
{
  char *ret;
  static size_t pathlen;
  static int repl;

  if (!state)
    {
      char *path;
      switch (text[0])
	{
	case '+':
	  text++;
	  repl = '+';
	  path = util_folder_path (text);
	  pathlen = strlen (path) - strlen (text);
	  break;

	case '~':
	  repl = '~';
	  if (text[1] == '/')
	    {
	      path = mu_get_homedir ();
	      text += 2;
	      pathlen = strlen (path);
	      break;
	    }
	  /* else FIXME! */

	default:
	  path = strdup (text);
	  pathlen = 0;
	  repl = 0;
	}
      
      ret = file_generator (text, state, path, pathlen, repl,
			    MU_FOLDER_ATTRIBUTE_DIRECTORY);
      free (path);
    }
  else
    ret = file_generator (text, state, NULL, pathlen, repl,
			  MU_FOLDER_ATTRIBUTE_DIRECTORY);
  return ret;
}

char **
dir_compl (int argc, char **argv, int ws)
{
  ml_attempted_completion_over ();
  if (ws)
    {
      ml_set_completion_append_character (0);
      return NULL;
    }
  return rl_completion_matches (argv[argc-1], dir_generator);
}

static char *
alias_generator (const char *text, int state)
{
  static alias_iterator_t itr;
  const char *p;
  
  if (!state)
    p = alias_iterate_first (text, &itr);
  else
    p = alias_iterate_next (itr);

  if (!p)
    {
      alias_iterate_end (&itr);
      return NULL;
    }
  return strdup (p);
}

char **
alias_compl (int argc, char **argv, int ws)
{
  ml_attempted_completion_over ();
  return rl_completion_matches (ws ? "" : argv[argc-1], alias_generator);
}

static char *
var_generator (const char *text, int state)
{
  static var_iterator_t itr;
  const char *p;
  
  if (!state)
    p = var_iterate_first (text, &itr);
  else
    p = var_iterate_next (itr);

  if (!p)
    {
      var_iterate_end (&itr);
      return NULL;
    }
  return strdup (p);
}

char **
var_compl (int argc, char **argv, int ws)
{
  ml_attempted_completion_over ();
  return rl_completion_matches (ws ? "" : argv[argc-1], var_generator);
}

#else

#include <sys/ioctl.h>

#define STDOUT 1
#ifndef TIOCSTI
static int ch_erase;
static int ch_kill;
#endif

#if defined(TIOCSTI)
#elif defined(HAVE_TERMIOS_H)
# include <termios.h>

static struct termios term_settings;

int
set_tty ()
{
  struct termios new_settings;

  if (tcgetattr(STDOUT, &term_settings) == -1)
    return 1;

  ch_erase = term_settings.c_cc[VERASE];
  ch_kill = term_settings.c_cc[VKILL];

  new_settings = term_settings;
  new_settings.c_lflag &= ~(ICANON|ECHO);
#if defined(TAB3)
  new_settings.c_oflag &= ~(TAB3);
#elif defined(OXTABS)
  new_settings.c_oflag &= ~(OXTABS);
#endif
  new_settings.c_cc[VMIN] = 1;
  new_settings.c_cc[VTIME] = 0;
  tcsetattr(STDOUT, TCSADRAIN, &new_settings);
  return 0;
}

void
restore_tty ()
{
  tcsetattr (STDOUT, TCSADRAIN, &term_settings);
}

#elif defined(HAVE_TERMIO_H)
# include <termio.h>

static struct termio term_settings;

int
set_tty ()
{
  struct termio new_settings;

  if (ioctl(STDOUT, TCGETA, &term_settings) < 0)
    return -1;

  ch_erase = term_settings.c_cc[VERASE];
  ch_kill = term_settings.c_cc[VKILL];

  new_settings = term_settings;
  new_settings.c_lflag &= ~(ICANON | ECHO);
  new_settings.c_oflag &= ~(TAB3);
  new_settings.c_cc[VMIN] = 1;
  new_settings.c_cc[VTIME] = 0;
  ioctl(STDOUT, TCSETA, &new_settings);
  return 0;
}

void
restore_tty ()
{
  ioctl(STDOUT, TCSETA, &term_settings);
}

#elif defined(HAVE_SGTTY_H)
# include <sgtty.h>

static struct sgttyb term_settings;

int
set_tty ()
{
  struct sgttyb new_settings;

  if (ioctl(STDOUT, TIOCGETP, &term_settings) < 0)
    return 1;

  ch_erase = term_settings.sg_erase;
  ch_kill = term_settings.sg_kill;

  new_settings = term_settings;
  new_settings.sg_flags |= CBREAK;
  new_settings.sg_flags &= ~(ECHO | XTABS);
  ioctl(STDOUT, TIOCSETP, &new_settings);
  return 0;
}

void
restore_tty ()
{
  ioctl(STDOUT, TIOCSETP, &term_settings);
}

#else
# define DUMB_MODE
#endif


#define LINE_INC 80

int
ml_reread (const char *prompt, char **text)
{
  int ch;
  char *line;
  int line_size;
  int pos;
  char *p;

  if (*text)
    {
      line = strdup (*text);
      if (line)
	{
	  pos = strlen(line);
	  line_size = pos + 1;
	}
    }
  else
    {
      line_size = LINE_INC;
      line = malloc (line_size);
      pos = 0;
    }

  if (!line)
    {
      util_error (_("Not enough memory to edit the line"));
      return -1;
    }

  line[pos] = 0;

  if (prompt)
    {
      fputs (prompt, stdout);
      fflush (stdout);
    }

#ifdef TIOCSTI

  for (p = line; *p; p++)
    {
      ioctl(0, TIOCSTI, p);
    }

  pos = 0;

  while ((ch = ml_getc (stdin)) != EOF && ch != '\n')
    {
      if (pos >= line_size)
	{
	  if ((p = realloc (line, line_size + LINE_INC)) == NULL)
	    {
	      fputs ("\n", stdout);
	      util_error (_("Not enough memory to edit the line"));
	      break;
	    }
	  else
	    {
	      line_size += LINE_INC;
	      line = p;
	    }
	}
      line[pos++] = ch;
    }

#else

  fputs (line, stdout);
  fflush (stdout);

# ifndef DUMB_MODE
  set_tty ();

  while ((ch = ml_getc (stdin)) != EOF)
    {
      if (ch == ch_erase)
	{
	  /* kill last char */
	  if (pos > 0)
	    line[--pos] = 0;
	  putc('\b', stdout);
	}
      else if (ch == ch_kill)
	{
	  /* kill the entire line */
	  pos = 0;
	  line[pos] = 0;
	  putc ('\r', stdout);
	  if (prompt)
	    fputs (prompt, stdout);
	}
      else if (ch == '\n' || ch == EOF)
	break;
      else
	{
	  if (pos >= line_size)
	    {
	      if ((p = realloc (line, line_size + LINE_INC)) == NULL)
		{
		  fputs ("\n", stdout);
		  util_error (_("Not enough memory to edit the line"));
		  break;
		}
	      else
		{
		  line_size += LINE_INC;
		  line = p;
		}
	    }
	  line[pos++] = ch;
	  putc(ch, stdout);
	}
      fflush (stdout);
    }

  putc ('\n', stdout);
  restore_tty ();
# else
  /* Dumb mode: the last resort */

  putc ('\n', stdout);
  if (prompt)
    {
      fputs (prompt, stdout);
      fflush (stdout);
    }

  pos = 0;

  while ((ch = ml_getc (stdin)) != EOF && ch != '\n')
    {
      if (pos >= line_size)
	{
	  if ((p = realloc (line, line_size + LINE_INC)) == NULL)
	    {
	      fputs ("\n", stdout);
	      util_error (_("Not enough memory to edit the line"));
	      break;
	    }
	  else
	    {
	      line_size += LINE_INC;
	      line = p;
	    }
	}
      line[pos++] = ch;
    }
# endif
#endif

  line[pos] = 0;

  if (ml_got_interrupt ())
    free (line);
  else
    {
      if (*text)
	free (*text);
      *text = line;
    }
  return 0;
}

char *
readline (char *prompt)
{
  if (prompt)
    {
      fprintf (ofile, "%s", prompt);
      fflush (ofile);
    }

  return ml_readline_internal ();
}

void
ml_set_completion_append_character (int c ARG_UNUSED)
{
}

void
ml_attempted_completion_over ()
{
}

#endif