/* GNU mailutils - a suite of utilities for electronic mail
   Copyright (C) 1999, 2000 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"

typedef struct _node {
  int data;
  struct _node *next;
} node;

static node *
util_ll_add (node *c, int data)
{
  c->next = malloc (sizeof (node));
  c->data = data;
  c->next->next = NULL;
  return c->next;
}

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 = 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], "+"))
	{
	  /* FIXME: next [un]deleted message */
	  current = util_ll_add (current, realcursor + 1);
	}
      else if (!strcmp (argv[i], "-"))
	{
	  /* FIXME: prev [un]deleted message */
	  current = util_ll_add (current, realcursor - 1);
	}
      else if (!strcmp (argv[i], "."))
	{
	  /* the current cursor location */
	  current = util_ll_add (current, realcursor);
	}
      else if (!strcmp (argv[i], "^"))
	{
	  /* FIXME: first [un]deleted message */
	  current =util_ll_add (current, 1);
	}
      else if (!strcmp (argv[i], "$"))
	{
	  /* FIXME: should this be last [un]deleted? */
	  current = util_ll_add (current, total);
	}
      else if (!strcmp (argv[i], "*"))
	{
	  util_ll_free (first);
	  current = first = malloc (sizeof (node));
	  for (i = 1; i <= total; i++)
	    current = util_ll_add (current, i);
	  i = argc + 1;
	}
      else if (argv[i][0] == '/')
	{
	  /* FIXME: all messages with pattern following / in
	     the subject line, case insensitive */
	}
      else if (argv[i][0] == ':')
	{
	  /* FIXME: all messages of type argv[i][1] */
	}
      else if (isalpha(argv[i][0]))
	{
	  /* FIXME: all messages from argv[i] */
	}
      else if (strchr (argv[i], '-') != NULL)
	{
	  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
	{
	  current = util_ll_add (current, strtol (argv[i], NULL, 10));
	}
    }

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

  ret = malloc (lc * sizeof (int));
  lc = 0;
  for (current = first; current != NULL; current = current->next)
    ret [lc++] = current->data;
  util_ll_free (first);
  *list = ret;
  return lc-1;
}

/*
 * 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 *cmd)
{
  int argc = 0;
  char **argv = NULL;
  int status = 0;
  function_t *command;

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

  if (cmd)
    {
      if (argcv_get (cmd, &argc, &argv) != 0)
	return argcv_free (argc, argv);
      command = util_command_get (argv[0]);
    }
  else
    command = util_command_get ("quit");

  if (command != NULL)
    status = command (argc, argv);
  else
    {
      printf ("Unknown command: %s\n", 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
 */

int
util_msglist_command (function_t *func, int argc, char **argv)
{
  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);

  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 (cmd);
  return entry.func;
}

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

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

/*
 * readline tab completion
 */
char **
util_command_completion (char *cmd, int start, int end)
{
  if (start == 0)
    return completion_matches (cmd, util_command_generator);
  return NULL;
}

/*
 * more readline
 */
char *
util_command_generator (char *text, int state)
{
  static int i, len;
  char *name;

  if (!state)
    {
      i = 0;
      len = strlen (text);
    }

  while ((name = mail_command_table[i].longname))
    {
      if (strlen (mail_command_table[i].shortname) > strlen(name))
	name = mail_command_table[i].shortname;
      i++;
      if (strncmp (name, text, len) == 0)
	return (strdup(name));
    }

  return NULL;
}

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

/*
 * get the number of columns on the screen
 */
int
util_getcols (void)
{
  int columns = 80;
  char *col = getenv ("COLUMNS");
  if (col)
    columns = strtol (col, NULL, 10);
  return columns;
}

/*
 * get the number of lines on the screen
 */
int
util_getlines (void)
{
  int lines = 24;
  char *lin = getenv ("LINES");
  if (lin)
    lines = strtol (lin, NULL, 10);
  return lines;
}