/*

 * compl.c      -- Completion system

 *

 * Copyright (C) 2005-2010 Mikael Berthe <mikael@lilotux.net>

 * Copyright (C) 2009,2010 Myhailo Danylenko <isbear@ukrpost.net>

 *

 * 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 of the License, 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307

 * USA

 */

/*  Usage, basically:

 * - new_completion();      // 1.   Initialization

 * - complete();            // 2.   1st completion

 * - cancel_completion();   // 3a.  2nd completion / cancel previous

 * - complete();            // 3b.  2nd completion / complete

 *   ...

 * - done_completion();     // n.   finished -- free allocated areas

 *

 */

#include <string.h>

#include "compl.h"

#include "utf8.h"

#include "roster.h"

#include "events.h"

#include "settings.h"

#include "logprint.h"

// Completion structure

typedef struct {

  GSList *list;         // list of matches

  guint len_prefix;     // length of text already typed by the user

  guint len_compl;      // length of the last completion

  GSList *next;         // pointer to next completion to try

} compl;

// Category structure

typedef struct {

  guint64 flag;

  GSList *words;

} category;

static GSList *Categories;

static compl *InputCompl;

#ifdef MODULES_ENABLE

static guint64 registered_cats;

static inline void register_builtin_cat(guint c) {

  registered_cats |= 1UL << (c-1);

}

void compl_init_system(void)

{

  // Builtin completion categories:

  register_builtin_cat(COMPL_CMD);

  register_builtin_cat(COMPL_JID);

  register_builtin_cat(COMPL_URLJID);

  register_builtin_cat(COMPL_NAME);

  register_builtin_cat(COMPL_STATUS);

  register_builtin_cat(COMPL_FILENAME);

  register_builtin_cat(COMPL_ROSTER);

  register_builtin_cat(COMPL_BUFFER);

  register_builtin_cat(COMPL_GROUP);

  register_builtin_cat(COMPL_GROUPNAME);

  register_builtin_cat(COMPL_MULTILINE);

  register_builtin_cat(COMPL_ROOM);

  register_builtin_cat(COMPL_RESOURCE);

  register_builtin_cat(COMPL_AUTH);

  register_builtin_cat(COMPL_REQUEST);

  register_builtin_cat(COMPL_EVENTS);

  register_builtin_cat(COMPL_EVENTSID);

  register_builtin_cat(COMPL_PGP);

  register_builtin_cat(COMPL_COLOR);

  register_builtin_cat(COMPL_OTR);

  register_builtin_cat(COMPL_OTRPOLICY);

  register_builtin_cat(COMPL_MODULE);

}

//  compl_new_category()

// Reserves id for new completion category.

// Returns 0, if no more categories can be allocated.

// Note, that user should not make any assumptions about id nature,

// as it is likely to change in future.

guint compl_new_category(void)

{

  guint i = 0;

  while ((registered_cats >> i) & 1)

    i++;

  if (i >= 8 * sizeof (registered_cats))

    return 0;

  else {

    guint64 id = 1 << i;

    registered_cats |= id;

    return i+1;

  }

}

//  compl_del_category(id)

// Frees reserved id for category.

// Note, that for now it not validates its input, so, be careful

// and specify exactly what you get from compl_new_category.

void compl_del_category(guint id)

{

  if (!id) {

    scr_log_print(LPRINT_LOGNORM, "Error: compl_del_category() - "

                  "Invalid category.");

    return;

  }

  id--;

  registered_cats &= ~(1<<id);

}

#endif

//  new_completion(prefix, compl_cat, suffix)

// . prefix    = beginning of the word, typed by the user

// . compl_cat = pointer to a completion category list (list of *char)

// . suffix    = string to append to all completion possibilities (i.e. ":")

// Set the InputCompl pointer to an allocated compl structure.

// done_completion() must be called when finished.

// Returns the number of possible completions.

guint new_completion(const char *prefix, GSList *compl_cat, const gchar *suffix)

{

  compl *c;

  GSList *sl_cat;

  gint (*cmp)(const char *s1, const char *s2, size_t n);

  size_t len = strlen(prefix);

  if (InputCompl) { // This should not happen, but hey...

    cancel_completion();

  }

  if (settings_opt_get_int("completion_ignore_case"))

    cmp = &strncasecmp;

  else

    cmp = &strncmp;

  c = g_new0(compl, 1);

  // Build the list of matches

  for (sl_cat = compl_cat; sl_cat; sl_cat = g_slist_next(sl_cat)) {

    char *word = sl_cat->data;

    if (!cmp(prefix, word, len)) {

      if (strlen(word) != len) {

        gchar *compval;

        if (suffix)

          compval = g_strdup_printf("%s%s", word+len, suffix);

        else

          compval = g_strdup(word+len);

        c->list = g_slist_insert_sorted(c->list, compval,

                                        (GCompareFunc)g_ascii_strcasecmp);

      }

    }

  }

  c->next = c->list;

  InputCompl = c;

  return g_slist_length(c->list);

}

//  done_completion();

void done_completion(void)

{

  GSList *clp;

  if (!InputCompl)  return;

  // Free the current completion list

  for (clp = InputCompl->list; clp; clp = g_slist_next(clp))

    g_free(clp->data);

  g_slist_free(InputCompl->list);

  g_free(InputCompl);

  InputCompl = NULL;

}

//  cancel_completion()

// Returns the number of chars to delete to cancel the completion

guint cancel_completion(void)

{

  if (!InputCompl)  return 0;

  return InputCompl->len_compl;

}

// Returns pointer to text to insert, NULL if no completion.

const char *complete()

{

  compl* c = InputCompl;

  char *r;

  if (!InputCompl)  return NULL;

  if (!c->next) {

    c->next = c->list;  // back to the beginning

    c->len_compl = 0;

    return NULL;

  }

  r = (char*)c->next->data;

  c->next = g_slist_next(c->next);

  if (!utf8_mode) {

    c->len_compl = strlen(r);

  } else {

    char *wc;

    c->len_compl = 0;

    for (wc = r; *wc; wc = next_char(wc))

      c->len_compl++;

  }

  return r;

}

/* Categories functions */

//  compl_add_category_word(categ, command)

// Adds a keyword as a possible completion in category categ.

void compl_add_category_word(guint categ, const gchar *word)

{

  guint64 catv;

  GSList *sl_cat;

  category *cat;

  char *nword;

  if (!categ) {

    scr_log_print(LPRINT_LOGNORM, "Error: compl_add_category_word() - "

                  "Invalid category.");

    return;

  }

  categ--;

  catv = 1UL << categ;

  // Look for category

  for (sl_cat=Categories; sl_cat; sl_cat = g_slist_next(sl_cat)) {

    if (catv == ((category*)sl_cat->data)->flag)

      break;

  }

  if (!sl_cat) {   // Category not found, let's create it

    cat = g_new0(category, 1);

    cat->flag = catv;

    Categories = g_slist_append(Categories, cat);

  } else

    cat = (category*)sl_cat->data;

  // If word is not space-terminated, we add one trailing space

  for (nword = (char*)word; *nword; nword++)

    ;

  if (nword > word) nword--;

  if (*nword != ' ') {  // Add a space

    nword = g_strdup_printf("%s ", word);

  } else {              // word is fine

    nword = g_strdup(word);

  }

  if (g_slist_find_custom(cat->words, nword, (GCompareFunc)g_strcmp0) != NULL)

    return;

  cat->words = g_slist_insert_sorted(cat->words, nword,

                                     (GCompareFunc)g_ascii_strcasecmp);

}

//  compl_del_category_word(categ, command)

// Removes a keyword from category categ in completion list.

void compl_del_category_word(guint categ, const gchar *word)

{

  guint64 catv;

  GSList *sl_cat, *sl_elt;

  category *cat;

  char *nword;

  if (!categ) {

    scr_log_print(LPRINT_LOGNORM, "Error: compl_del_category_word() - "

                  "Invalid category.");

    return;

  }

  categ--;

  catv = 1UL << categ;

  // Look for category

  for (sl_cat=Categories; sl_cat; sl_cat = g_slist_next(sl_cat)) {

    if (catv == ((category*)sl_cat->data)->flag)

      break;

  }

  if (!sl_cat) return;   // Category not found, finished!

  cat = (category*)sl_cat->data;

  // If word is not space-terminated, we add one trailing space

  for (nword = (char*)word; *nword; nword++)

    ;

  if (nword > word) nword--;

  if (*nword != ' ') {  // Add a space

    nword = g_strdup_printf("%s ", word);

  } else {              // word is fine

    nword = g_strdup(word);

  }

  sl_elt = cat->words;

  while (sl_elt) {

    if (!strcasecmp((char*)sl_elt->data, nword)) {

      g_free(sl_elt->data);

      cat->words = g_slist_delete_link(cat->words, sl_elt);

      break; // Only remove first occurence

    }

    sl_elt = g_slist_next(sl_elt);

  }

}

//  compl_get_category_list()

// Returns a slist of all words in the specified categorie.

// Iff this function sets *dynlist to TRUE, then the caller must free the

// whole list after use.

GSList *compl_get_category_list(guint categ, guint *dynlist)

{

  guint64 cat_flags;

  GSList *sl_cat;

  if (!categ) {

    scr_log_print(LPRINT_LOGNORM, "Error: compl_get_category_list() - "

                  "Invalid category.");

    return NULL;

  }

  *dynlist = FALSE;

  cat_flags = 1UL << (categ - 1);

  // Look for the category

  for (sl_cat=Categories; sl_cat; sl_cat = g_slist_next(sl_cat)) {

    if (cat_flags == ((category*)sl_cat->data)->flag)

      break;

  }

  if (sl_cat)       // Category was found, easy...

    return ((category*)sl_cat->data)->words;

  // Handle dynamic SLists

  *dynlist = TRUE;

  if (categ == COMPL_GROUPNAME) {

    return compl_list(ROSTER_TYPE_GROUP);

  }

  if (categ == COMPL_JID) {

    return compl_list(ROSTER_TYPE_USER);

  }

  if (categ == COMPL_RESOURCE) {

    return buddy_getresources_locale(NULL);

  }

  if (categ == COMPL_EVENTSID) {

    GSList *compl = evs_geteventslist();

    GSList *cel;

    for (cel = compl; cel; cel = cel->next)

      cel->data = g_strdup(cel->data);

    compl = g_slist_append(compl, g_strdup("list"));

    return compl;

  }

  *dynlist = FALSE;

  return NULL;

}

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