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

   This program 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.

   This program 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 this program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */

#include "mail.h"
#include <mailutils/mutil.h>
#include <pwd.h>
#ifdef HAVE_TERMIOS_H
# include <termios.h>
#endif
#include <sys/ioctl.h>
#include <sys/fcntl.h>

typedef struct _node {
  /* for the msglist expander */
  int data;
  /* for the environment table */
  struct mail_env_entry env_entry;
  struct _node *next;
} node;

static node *environment = NULL;
static node *env_cursor = NULL;

/*
 * add a new node to the list
 */
static node *
util_ll_add (node *c, int data)
{
  c->next = util_malloc (sizeof (node));
  c->data = data;
  c->next->env_entry.var = NULL;
  c->next->env_entry.set = 0;
  c->next->env_entry.value = NULL;
  c->next->next = NULL;
  return c->next;
}

/*
 * free a linked list
 */
static void
util_ll_free (node *c)
{
  node *t = c;
  while (t != NULL)
    {
      c = t;
      t = t->next;
      free (c);
    }
}

/*
 * expands a standard message list into an array of numbers
 * argc is the number of elements being passed in
 * argv is the array of strings to parse
 * list will be populated with message numbers
 * returns the number of items in list
 */

int
util_expand_msglist (const int argc, char **argv, int **list)
{
  int i = 0, lc = 0;
  int undelete = 0;
  int *ret = NULL;
  /* let's try a linked list */
  node *first = util_malloc (sizeof (node));
  node *current = first;
  first->next = NULL;

  if (util_command_get (argv[0]) == util_command_get ("undelete"))
    undelete = 1;

  for (i = 1; i < argc; i++)
    {
      if (!strcmp (argv[i], "+"))
	{
	  /* first [un]deleted message */
	  int n = realcursor + 1;
	  while (n <= total)
	    {
	      if (util_isdeleted (n) && !undelete)
		n++;
	      else
		break;
	    }
	  current = util_ll_add (current, n);
	}
      else if (!strcmp (argv[i], "-"))
	{
	  /* previous [un]deleted message */
	  int n = realcursor - 1;
	  while (n > 0)
	    {
	      if (util_isdeleted (n) && !undelete)
		n--;
	      else
		break;
	    }
	  current = util_ll_add (current, n);
	}
      else if (!strcmp (argv[i], "."))
	{
	  /* the current cursor location */
	  current = util_ll_add (current, realcursor);
	}
      else if (!strcmp (argv[i], "^"))
	{
	  /* first [un]deleted message */
	  int n = 1;
	  while (n <= total)
	    {
	      if (util_isdeleted (n) && !undelete)
		n++;
	      else
		break;
	    }
	  current = util_ll_add (current, 1);
	}
      else if (!strcmp (argv[i], "$"))
	{
	  /* last [un]deleted message */
	  int n = total;
	  while (n > 0)
	    {
	      if (util_isdeleted (n) && !undelete)
		n--;
	      else
		break;
	    }
	  current = util_ll_add (current, total);
	}
      else if (!strcmp (argv[i], "*"))
	{
	  /* all messages */
	  util_ll_free (first);
	  current = first = util_malloc (sizeof (node));
	  for (i = 1; i <= total; i++)
	    current = util_ll_add (current, i);
	  i = argc + 1;
	}
      else if (argv[i][0] == '/')
	{
	  /* All messages with pattern following / in
	     the subject line, case insensitive */
	  int j;
	  char *pattern;

	  pattern = strdup (&argv[i][1]);
	  util_strupper (pattern);

	  for (j = 1; j <= total; j++)
	    {
	      message_t msg = NULL;
	      header_t hdr = NULL;
	      char *subject = NULL;
	      size_t subjlen;
	      int k;

	      mailbox_get_message (mbox, j, &msg);
	      message_get_header (msg, &hdr);

	      header_aget_value (hdr, MU_HEADER_SUBJECT, &subject);
	      util_strupper (subject);

	      if (pattern && subject && strstr (subject, pattern))
		current = util_ll_add (current, j);
	      free (subject);
	    }
	  free (pattern);
	}
      else if (argv[i][0] == ':')
	{
	  /* All messages of type argv[i][1] */
	  int j;
	  for (j = 1; j <= total; j++)
	    {
	      message_t msg = NULL;
	      attribute_t attr= NULL;

	      mailbox_get_message (mbox, j, &msg);
	      message_get_attribute (msg, &attr);
	      if ((argv[i][1] == 'd' && attribute_is_deleted (attr))
		  || (argv[i][1] == 'n' && attribute_is_recent (attr))
		  || (argv[i][1] == 'o' && attribute_is_seen (attr))
		  || (argv[i][1] == 'r' && attribute_is_read (attr))
		  || (argv[i][1] == 'u' && !attribute_is_read (attr)))
		current = util_ll_add (current, j);
	    }
	}
      else if (isalpha(argv[i][0]))
	{
	  /* FIXME: all messages from sender argv[i] */
	  /* Annoying we can use address_create() for that
	     but to compare against what? The email ?  */
	}
      else if (strchr (argv[i], '-') != NULL)
	{
	  /* Message range.  */
	  int j, x, y;
	  char *arg = strdup (argv[i]);
	  for (j=0; j < strlen (arg); j++)
	    if (arg[j] == '-')
	      break;
	  arg[j] = '\0';
	  x = strtol (arg, NULL, 10);
	  y = strtol (&(arg[j + 1]), NULL, 10);
	  for (; x <= y; x++)
	    current = util_ll_add (current, x);
	  free (arg);
	}
      else if (strchr (argv[i], '[') != NULL)
	{
	  /* attachments - GNU extension */
	  /*
	   * This is a general extension to the msglist format. Basicallay,
	   * it adds C-like array subscripting to msg numbers to allow access
	   * to just a single part of a MIME multipart message. I.e.:
	   * print 7[1],8[1-2]
	   * should print the first attachment of message 7 and the first
	   * and second attachments of message 8. The format inside the
	   * brackets is the same as a msglist, so we should be able to 
	   * reuse this function for its expansion. This will primarily
	   * be used by the new decode command, which needs discussion on
	   * the mailing list to nail its syntax down (should it default to
	   * saving to a file, printing to stdout, or piping?)
	   * -- sparky
	   */
	}
      else
	{
	  /* Single message.  */
	  current = util_ll_add (current, strtol (argv[i], NULL, 10));
	}
    }

  for (current = first; current->next != NULL; current = current->next)
    lc++;

  if (!lc)
    {
      ret = util_calloc (1, sizeof (int));
      ret [0] = cursor;
      lc = 1;
    }
  else
    {
      ret = util_malloc (lc * sizeof (int));
      lc = 0;
      for (current = first; current->next != NULL; current = current->next)
	ret [lc++] = current->data;
    }
  util_ll_free (first);
  *list = ret;
  return lc;
}

/*
 * expands command into its command and arguments, then runs command
 * cmd is the command to parse and run
 * returns exit status of the command
 */
int
util_do_command (const char *c, ...)
{
  int argc = 0;
  char **argv = NULL;
  int status = 0;
  function_t *command;
  char *cmd = NULL;
  va_list ap;
  static const char *delim = "=";

  va_start (ap, c);
  status = vasprintf (&cmd, c, ap);
  va_end (ap);
  if (status < 0)
    return 0;

  if (cmd)
    {
      struct mail_command_entry entry;

      if (cmd[0] == '#')
	return 0;

      if (argcv_get (cmd, delim, &argc, &argv) != 0)
	return argcv_free (argc, argv);

      entry = util_find_entry (mail_command_table, argv[0]);

      if (if_cond() == 0 && (entry.flags & EF_FLOW) == 0)
	{
	  argcv_free (argc, argv);
	  return 0;
	}
      command = entry.func;
    }
  else
    command = util_command_get ("quit");

  if (command != NULL)
    status = command (argc, argv);
  else
    {
      util_error("Unknown command: %s", argv[0]);
      status = 1;
    }

  argcv_free (argc, argv);
  return status;
}

/*
 * runs a function repeatedly on a msglist
 * func is the function to run
 * argc is the number of arguments inculding the command and msglist
 * argv is the list of strings containing the command and msglist
 * set_cursor means whether the function should set the cursor to
 * the number of the last message processed. If set_cursor = 0, the
 * cursor is not altered.
 */

int
util_msglist_command (function_t *func, int argc, char **argv, int set_cursor)
{
  int i;
  int *list = NULL;
  int status = 0;
  int number = util_expand_msglist (argc, argv, &list);
  realcursor = cursor;

  for (i = 0; i < number; i++)
    {
      cursor = list[i];
      if (func (1, argv) != 0)
	status = 1;
    }
  free (list);

  if (set_cursor)
    realcursor = cursor;
  else
    cursor = realcursor;
  return status;
}

/*
 * returns the function to run for command
 */
function_t *
util_command_get (char *cmd)
{
  struct mail_command_entry entry = util_find_entry (mail_command_table, cmd);
  return entry.func;
}

/*
 * returns the mail_command_entry structure for the command matching cmd
 */
struct mail_command_entry
util_find_entry (const struct mail_command_entry *table, char *cmd)
{
  int i = 0, ll = 0, sl = 0;
  int len = strlen (cmd);

  while (table[i].shortname != 0)
    {
      sl = strlen (table[i].shortname);
      ll = strlen (table[i].longname);
      if (sl > ll && !strncmp (table[i].shortname, cmd, sl))
	return table[i];
      else if (sl == len && !strcmp (table[i].shortname, cmd))
	return table[i];
      else if (sl < len && !strncmp (table[i].longname, cmd, len))
	return table[i];
      i++;
    }
  return table[i];
}

/*
 * removes whitespace from the beginning and end of a string
 */
char *
util_stripwhite (char *string)
{
  register char *s, *t;
  for (s = string; isspace ((unsigned)*s); s++)
    ;
  if (*s == 0)
    return s;
  t = s + strlen (s) - 1;
  while (t > s && isspace ((unsigned)*t))
    t--;
  *++t = '\0';
  return s;
}

/*
 * Get the number of columns on the screen
 * First try an ioctl() call not all shells set the COLUMNS environ.
 */
int
util_getcols (void)
{
  struct winsize ws;

  ws.ws_col = ws.ws_row = 0;
  if ((ioctl(1, TIOCGWINSZ, (char *) &ws) < 0)
      || ws.ws_row == 0)
    ws.ws_col = strtol (getenv("COLUMNS"), NULL, 10);

  /* FIXME: Should we exit()/abort() if col <= 0 ?  */
  return ws.ws_col;
}

/*
 * Get the number of lines on the screen
 * First try an ioctl() call not all shells set the LINES environ.
 */
int
util_getlines (void)
{
  struct winsize ws;

  ws.ws_col = ws.ws_row = 0;
  if ((ioctl(1, TIOCGWINSZ, (char *) &ws) < 0)
      || ws.ws_row == 0)
    ws.ws_row = strtol (getenv("LINES"), NULL, 10);

  /* FIXME: Should we exit()/abort() if row <= 0 ?  */

  /* Reserve at least 2 line for the prompt.  */
  return ws.ws_row - 2;
}

int
util_screen_lines()
{
  struct mail_env_entry *ep = util_find_env("screen");
  size_t n;

  if (ep && ep->set && (n = atoi(ep->value)) != 0)
    return n;
  return util_getlines();
}


/*
 * Find environment entry var

 FIXME: We should probably call this util_getenv to be consitent with
 util_printenv(), util_setenv() etc ..
 */
struct mail_env_entry *
util_find_env (const char *variable)
{
  /* Annoying, variable "ask" is equivalent to "asksub".  */
  static const char *asksub = "asksub";
  const char *var = variable;
  int len = strlen (var);
  node *t;

  if (len < 1)
    return NULL;

  /* Catch "ask" --> "asksub".  */
  if (len == strlen ("ask") && !strcmp ("ask", var))
    {
      var = asksub;
      len = strlen (var);
    }

  if (environment == NULL)
    {
      environment = util_malloc (sizeof (node));
      environment->env_entry.var = NULL;
      environment->env_entry.set = 0;
      environment->env_entry.value = NULL;
      environment->next = NULL;
    }

  for (env_cursor = environment; env_cursor->next != NULL;
       env_cursor = env_cursor->next)
    {
      if (strlen (env_cursor->env_entry.var) == len &&
	  !strcmp (var, env_cursor->env_entry.var))
	{
	  return &(env_cursor->env_entry);
	}
    }

  env_cursor->env_entry.var = strdup (var);
  env_cursor->env_entry.set = 0;
  env_cursor->env_entry.value = NULL;
  t = env_cursor;
  env_cursor = util_ll_add (env_cursor, 0);
  return &(t->env_entry);
}

/*
 * print the environment
 */
int
util_printenv (int set)
{
  for (env_cursor = environment; env_cursor != NULL;
       env_cursor = env_cursor->next)
    {
      if (env_cursor->env_entry.set == set)
	{
	  fprintf (ofile, "%s", env_cursor->env_entry.var);
	  if (env_cursor->env_entry.value != NULL)
	    fprintf (ofile, "=\"%s\"", env_cursor->env_entry.value);
	  fprintf (ofile, "\n");
	}
    }
  return 0;
}

/*
 * Set environement
 * The  util_setenv() function adds the variable name to the envi-
 * ronment with the value value, if  name  does  not  already
 * exist.   If  name  does exist in the environment, then its
 * value is changed to value if  overwrite  is  non-zero;  if
 * overwrite  is zero, then the value of name is not changed.
 *
 * A side effect of the code is if value is null the variable name
 * will be unset.
 */
int
util_setenv (const char *variable, const char *value, int overwrite)
{
  struct mail_env_entry *ep =  util_find_env (variable);
  if (ep->set)
    {
      if (overwrite)
	{
	  ep->set = 0;
	  if (ep->value)
	    free (ep->value);
	  ep->value = NULL;
	  if (value)
	    {
	      ep->set = 1;
	      ep->value = strdup (value);
	    }
	}
    }
  else
    {
      ep->set = 1;
      if (ep->value)
	free (ep->value);
      ep->value = strdup (value);
    }
  return 0;
}

/*
 * return 1 if a message is deleted
 */
int
util_isdeleted (int n)
{
  message_t msg;
  attribute_t attr;
  if (mailbox_get_message (mbox, n, &msg) != 0)
    return 0;
  message_get_attribute (msg, &attr);
  if (attribute_is_deleted (attr))
    return 1;
  return 0;
}

char *
util_get_homedir()
{
  char *homedir = mu_get_homedir();
  if (!homedir)
    {
      /* Shouldn't happen, but one never knows */
      util_error("can't get homedir");
      exit (EXIT_FAILURE);
    }
  return strdup(homedir);
}

char *
util_fullpath(char *inpath)
{
  return mu_tilde_expansion(inpath, "/", NULL);
}

char *
util_get_sender(int msgno, int strip)
{
  header_t header = NULL;
  address_t addr = NULL;
  message_t msg = NULL;
  char buffer[512], *p;

  mailbox_get_message (mbox, msgno, &msg);
  message_get_header (msg, &header);
  if (header_get_value (header, MU_HEADER_FROM, buffer, sizeof(buffer), NULL)
      || address_create (&addr, buffer))
    {
      envelope_t env = NULL;
      message_get_envelope (msg, &env);
      if (envelope_sender (env, buffer, sizeof (buffer), NULL)
	  || address_create (&addr, buffer))
	{
	  util_error("can't determine sender name (msg %d)", msgno);
	  return NULL;
	}
    }

  if (address_get_email (addr, 1, buffer, sizeof(buffer), NULL))
    {
      util_error("can't determine sender name (msg %d)", msgno);
      address_destroy (&addr);
      return NULL;
    }

  if (strip)
    {
      p = strchr (buffer, '@');
      if (p)
	*p = 0;
    }

  p = strdup (buffer);
  address_destroy (&addr);
  return p;
}

void
util_slist_print(list_t list, int nl)
{
  iterator_t itr;
  char *name;

  if (!list || iterator_create (&itr, list))
    return;

  for (iterator_first (itr); !iterator_is_done (itr); iterator_next (itr))
    {
      iterator_current (itr, (void **)&name);
      fprintf (ofile, "%s%c", name, nl ? '\n' : ' ');

    }
  iterator_destroy (&itr);
}

int
util_slist_lookup(list_t list, char *str)
{
  iterator_t itr;
  char *name;
  int rc = 0;

  if (!list || iterator_create (&itr, list))
    return 0;

  for (iterator_first (itr); !iterator_is_done (itr); iterator_next (itr))
    {
      iterator_current (itr, (void **)&name);
      if (strcasecmp (name, str) == 0)
	{
	  rc = 1;
	  break;
	}
    }
  iterator_destroy (&itr);
  return rc;
}

void
util_slist_add (list_t *list, char *value)
{
  char *p;

  if (!*list && list_create (list))
    return;

  if ((p = strdup(value)) == NULL)
    {
      util_error("not enough memory\n");
      return;
    }
  list_append (*list, p);
}

void
util_slist_destroy (list_t *list)
{
  iterator_t itr;
  char *name;

  if (!*list || iterator_create (&itr, *list))
    return;

  for (iterator_first (itr); !iterator_is_done (itr); iterator_next (itr))
    {
      iterator_current (itr, (void **)&name);
      free (name);
    }
  iterator_destroy (&itr);
  list_destroy (list);
}

char *
util_slist_to_string (list_t list, char *delim)
{
  iterator_t itr;
  char *name;
  char *str = NULL;

  if (!list || iterator_create (&itr, list))
    return NULL;

  for (iterator_first (itr); !iterator_is_done (itr); iterator_next (itr))
    {
      iterator_current (itr, (void **)&name);
      if (str && delim)
	util_strcat(&str, delim);
      util_strcat(&str, name);
    }
  iterator_destroy (&itr);
  return str;
}

void
util_strcat(char **dest, char *str)
{
  if (!*dest)
    *dest = strdup (str);
  else
    {
      int dlen = strlen (*dest) + 1;
      int slen = strlen (str) + 1;
      char *newp = realloc (*dest, dlen + slen);

      if (!newp)
	return;

      *dest = newp;
      memcpy (newp + dlen - 1, str, slen);
    }
}

/* Upper case the entire string.  Assume it is NULL terminated.  */
void
util_strupper (char *s)
{
  if (s)
    {
      int i;
      int len = strlen (s);
      for (i = 0; i < len; i++)
	s[i] = toupper ((int)s[i]);
    }
}


void
util_escape_percent (char **str)
{
  int count;
  char *p, *q;
  char *newstr;

  /* Count ocurrences of % in the string */
  count = 0;
  for (p = *str; *p; p++)
    if (*p == '%')
      count++;

  if (!count)
    return; /* nothing to do */

  /* expand the string */
  newstr = util_malloc (strlen (*str) + 1 + count);

  /* and escape percent signs */
  p = newstr;
  q = *str;
  while (*p = *q++)
    {
      if (*p == '%')
	*++p = '%';
      p++;
    }
  *str = newstr;
}

char *
util_outfolder_name (char *str)
{
  struct mail_env_entry *ep = util_find_env("outfolder");

  switch (*str)
    {
    case '/':
    case '~':
    case '+':
      str = util_fullpath (str);
      break;

    default:
      if (ep && ep->set)
	{
	  char *ns = NULL;
	  asprintf (&ns, "%s/%s", ep->value, str);
	  str = util_fullpath (ns);
	  free (ns);
	}
      break;

    }

  return str;
}

/* Save an outgoing message. "savefile" allows to override the setting
   of the "record" variable. */
void
util_save_outgoing (message_t msg, char *savefile)
{
  struct mail_env_entry *ep = util_find_env("record");
  if (ep->set)
    {
      FILE *outfile;
      char *filename = util_outfolder_name (savefile ? savefile : ep->value);

      outfile = fopen (filename, "a");
      if (!outfile)
	{
	  util_error("can't open save file %s: %s",
		     filename, strerror (errno));
	}
      else
	{
	  char *buf;
	  size_t bsize = 0;

	  message_size (msg, &bsize);

	  /* Try to allocate large buffer */
	  for (; bsize > 1; bsize /= 2)
	    if ((buf = malloc (bsize)))
	      break;

	  if (!bsize)
	    {
	      util_error("not enough memory for creating save file");
	    }
	  else
	    {
	      stream_t stream;
	      size_t n, off = 0;
	      time_t t;
	      struct tm *tm;
	      char date[64];

	      time(&t);
	      tm = gmtime(&t);
	      strftime (date, sizeof (date), "%a %b %e %H:%M:%S %Y%n", tm);
	      fprintf (outfile, "From %s %s\n", mail_whoami(), date);

	      message_get_stream (msg, &stream);
	      while (stream_read (stream, buf, bsize, off, &n) == 0
		     && n != 0)
		{
		  fwrite (buf, 1, n, outfile);
		  off += n;
		}
	      free (buf);
	    }
	  fclose (outfile);
	}
      free (filename);
    }
}

#ifdef HAVE_STDARG_H
void
util_error (const char *format, ...)
#else
void
util_error (va_alist)
     va_dcl
#endif
{
  va_list ap;

#ifdef HAVE_STDARG_H
  va_start(ap, format);
#else
  char *format;

  va_start(ap);
  format = va_arg(ap, char *);
#endif

  vfprintf(stderr, format, ap);
  fprintf(stderr, "\n");

  va_end(ap);
}

int
util_help (const struct mail_command_entry *table, char *word)
{
  if (!word)
    {
      int i = 0;
      FILE *out = stdout;

      if ((util_find_env("crt"))->set)
	out = popen (getenv("PAGER"), "w");

      while (table[i].synopsis != 0)
	fprintf (out, "%s\n", table[i++].synopsis);

      if (out != stdout)
	pclose (out);

      return 0;
    }
  else
    {
      int status = 0;
      struct mail_command_entry entry = util_find_entry(table, word);
      if (entry.synopsis != NULL)
	fprintf (stdout, "%s\n", entry.synopsis);
      else
	{
	  status = 1;
	  fprintf (stdout, "Unknown command: %s\n", word);
	}
      return status;
    }
  return 1;
}

int
util_tempfile(char **namep)
{
  char *filename;
  char *tmpdir;
  int fd;

  /* We have to be extra careful about opening temporary files, since we
     may be running with extra privilege i.e setgid().  */
  tmpdir = (getenv ("TMPDIR")) ? getenv ("TMPDIR") : "/tmp";

  filename = malloc (strlen (tmpdir) + /*'/'*/1 + /* "muXXXXXX" */8 + 1);
  if (!filename)
    return -1;
  sprintf (filename, "%s/muXXXXXX", tmpdir);

#ifdef HAVE_MKSTEMP
  {
    int save_mask = umask(077);
    fd = mkstemp (filename);
    umask(save_mask);
  }
#else
  if (mktemp (filename))
    fd = open(filename, O_CREAT|O_EXCL|O_RDWR, 0600);
  else
    fd = -1;
#endif

  if (fd == -1)
    {
      util_error("Can not open temporary file: %s", strerror(errno));
      free(filename);
      return -1;
    }

  if (namep)
    *namep = filename;
  else
    {
      unlink(filename);
      free(filename);
    }

  return fd;
}

void *
util_malloc (size_t size)
{
  void *p = malloc (size);
  if (!p)
    {
      util_error ("not enough memory (allocating %d bytes)", size);
      abort ();
    }
  return p;
}

void *
util_calloc (size_t nitems, size_t size)
{
  void *p;
  
  size *= nitems;
  p = util_malloc (size);
  memset (p, 0, size);
  return p;
}