/*
 * gui-completion.c - word completion according to context (used by all GUI)
 *
 * Copyright (C) 2003-2014 Sébastien Helleu <flashcode@flashtux.org>
 *
 * This file is part of WeeChat, the extensible chat client.
 *
 * WeeChat 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 3 of the License, or
 * (at your option) any later version.
 *
 * WeeChat 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 WeeChat.  If not, see <http://www.gnu.org/licenses/>.
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <stdlib.h>
#include <stddef.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <dirent.h>
#include <limits.h>
#include <unistd.h>

#include "../core/weechat.h"
#include "../core/wee-completion.h"
#include "../core/wee-config.h"
#include "../core/wee-hdata.h"
#include "../core/wee-hook.h"
#include "../core/wee-list.h"
#include "../core/wee-log.h"
#include "../core/wee-string.h"
#include "../core/wee-utf8.h"
#include "../plugins/plugin.h"
#include "gui-completion.h"
#include "gui-buffer.h"


int gui_completion_freeze = 0;         /* 1 to freeze completions (do not   */
                                       /* stop partial completion on key)   */


/*
 * Initializes completion for a buffer.
 */

void
gui_completion_buffer_init (struct t_gui_completion *completion,
                            struct t_gui_buffer *buffer)
{
    completion->buffer = buffer;
    completion->context = GUI_COMPLETION_NULL;
    completion->base_command = NULL;
    completion->base_command_arg_index = 0;
    completion->base_word = NULL;
    completion->base_word_pos = 0;
    completion->position = -1;
    completion->args = NULL;
    completion->direction = 0;
    completion->add_space = 1;
    completion->force_partial_completion = 0;

    completion->completion_list = weelist_new ();

    completion->word_found = NULL;
    completion->word_found_is_nick = 0;
    completion->position_replace = 0;
    completion->diff_size = 0;
    completion->diff_length = 0;

    completion->partial_completion_list = NULL;
    completion->last_partial_completion = NULL;
}

/*
 * Adds an item to partial completion list.
 *
 * Returns pointer to new item, NULL if error.
 */

struct t_gui_completion_partial *
gui_completion_partial_list_add (struct t_gui_completion *completion,
                                 const char *word, int count)
{
    struct t_gui_completion_partial *new_item;

    new_item = malloc (sizeof (*new_item));
    if (new_item)
    {
        new_item->word = strdup (word);
        new_item->count = count;

        new_item->prev_item = completion->last_partial_completion;
        if (completion->partial_completion_list)
            (completion->last_partial_completion)->next_item = new_item;
        else
            completion->partial_completion_list = new_item;
        completion->last_partial_completion = new_item;
        new_item->next_item = NULL;
    }
    return new_item;
}

/*
 * Removes an item from partial completion list.
 */

void
gui_completion_partial_list_free (struct t_gui_completion *completion,
                                  struct t_gui_completion_partial *item)
{
    /* remove partial completion item from list */
    if (item->prev_item)
        (item->prev_item)->next_item = item->next_item;
    if (item->next_item)
        (item->next_item)->prev_item = item->prev_item;
    if (completion->partial_completion_list == item)
        completion->partial_completion_list = item->next_item;
    if (completion->last_partial_completion == item)
        completion->last_partial_completion = item->prev_item;

    /* free data */
    if (item->word)
        free (item->word);

    free (item);
}

/*
 * Removes partial completion list.
 */

void
gui_completion_partial_list_free_all (struct t_gui_completion *completion)
{
    while (completion->partial_completion_list)
    {
        gui_completion_partial_list_free (completion,
                                          completion->partial_completion_list);
    }
}

/*
 * Frees data in completion.
 */

void
gui_completion_free_data (struct t_gui_completion *completion)
{
    if (completion->base_command)
        free (completion->base_command);
    completion->base_command = NULL;

    if (completion->base_word)
        free (completion->base_word);
    completion->base_word = NULL;

    if (completion->args)
        free (completion->args);
    completion->args = NULL;

    if (completion->completion_list)
    {
        weelist_free (completion->completion_list);
        completion->completion_list = NULL;
    }

    if (completion->word_found)
        free (completion->word_found);
    completion->word_found = NULL;

    gui_completion_partial_list_free_all (completion);
}

/*
 * Frees completion.
 */

void
gui_completion_free (struct t_gui_completion *completion)
{
    gui_completion_free_data (completion);
    free (completion);
}

/*
 * Stops completion (for example after 1 argument of command with 1 argument).
 */

void
gui_completion_stop (struct t_gui_completion *completion)
{
    if (!completion)
        return;

    completion->context = GUI_COMPLETION_NULL;
    completion->position = -1;

    if (completion->partial_completion_list)
    {
        gui_completion_partial_list_free_all (completion);
        hook_signal_send ("partial_completion",
                          WEECHAT_HOOK_SIGNAL_STRING, NULL);
    }
}

/*
 * Searches for a command hook.
 *
 * Returns pointer to hook found, NULL if not found.
 */

struct t_hook *
gui_completion_search_command (struct t_weechat_plugin *plugin,
                               const char *command)
{
    struct t_hook *ptr_hook, *hook_for_other_plugin;

    hook_for_other_plugin = NULL;

    for (ptr_hook = weechat_hooks[HOOK_TYPE_COMMAND]; ptr_hook;
         ptr_hook = ptr_hook->next_hook)
    {
        if (!ptr_hook->deleted
            && HOOK_COMMAND(ptr_hook, command)
            && HOOK_COMMAND(ptr_hook, command)[0]
            && (string_strcasecmp (HOOK_COMMAND(ptr_hook, command),
                                   command) == 0))
        {
            if (ptr_hook->plugin == plugin)
                return ptr_hook;

            hook_for_other_plugin = ptr_hook;
        }
    }

    return hook_for_other_plugin;
}

/*
 * Checks if nick has one or more ignored chars (for nick comparison).
 *
 * Returns:
 *   1: nick has one or more ignored chars
 *   0: nick has no ignored chars
 */

int
gui_completion_nick_has_ignored_chars (const char *string)
{
    int char_size;
    char utf_char[16];

    while (string[0])
    {
        char_size = utf8_char_size (string);
        memcpy (utf_char, string, char_size);
        utf_char[char_size] = '\0';

        if (strstr (CONFIG_STRING(config_completion_nick_ignore_chars),
                    utf_char))
            return 1;

        string += char_size;
    }
    return 0;
}

/*
 * Duplicates a nick and ignores some chars.
 *
 * Note: result must be freed after use.
 */

char *
gui_completion_nick_strdup_ignore_chars (const char *string)
{
    int char_size;
    char *result, *pos, utf_char[16];

    result = malloc (strlen (string) + 1);
    pos = result;
    while (string[0])
    {
        char_size = utf8_char_size (string);
        memcpy (utf_char, string, char_size);
        utf_char[char_size] = '\0';

        if (!strstr (CONFIG_STRING(config_completion_nick_ignore_chars),
                     utf_char))
        {
            memcpy (pos, utf_char, char_size);
            pos += char_size;
        }

        string += char_size;
    }
    pos[0] = '\0';
    return result;
}

/*
 * Locale and case independent string comparison with max length for nicks
 * (alpha or digits only).
 *
 * Returns:
 *   < 0: base_word < nick
 *     0: base_word == nick
 *   > 0: base_word > nick
 */

int
gui_completion_nickncmp (const char *base_word, const char *nick, int max)
{
    char *base_word2, *nick2;
    int return_cmp;

    if (!CONFIG_STRING(config_completion_nick_ignore_chars)
        || !CONFIG_STRING(config_completion_nick_ignore_chars)[0]
        || !base_word || !nick || !base_word[0] || !nick[0]
        || gui_completion_nick_has_ignored_chars (base_word))
        return string_strncasecmp (base_word, nick, max);

    base_word2 = gui_completion_nick_strdup_ignore_chars (base_word);
    nick2 = gui_completion_nick_strdup_ignore_chars (nick);

    return_cmp = string_strncasecmp (base_word2, nick2,
                                     utf8_strlen (base_word2));

    free (base_word2);
    free (nick2);

    return return_cmp;
}

/*
 * Adds a word to completion list.
 */

void
gui_completion_list_add (struct t_gui_completion *completion, const char *word,
                         int nick_completion, const char *where)
{
    char buffer[512];

    if (!word || !word[0])
        return;

    if (!completion->base_word || !completion->base_word[0]
        || (nick_completion && (gui_completion_nickncmp (completion->base_word, word,
                                                         utf8_strlen (completion->base_word)) == 0))
        || (!nick_completion && (string_strncasecmp (completion->base_word, word,
                                                     utf8_strlen (completion->base_word)) == 0)))
    {
        if (nick_completion && (completion->base_word_pos == 0))
        {
            snprintf (buffer, sizeof (buffer), "%s%s",
                      word, CONFIG_STRING(config_completion_nick_completer));
            weelist_add (completion->completion_list, buffer, where,
                         (nick_completion) ? (void *)1 : (void *)0);
        }
        else
        {
            weelist_add (completion->completion_list, word, where,
                         (nick_completion) ? (void *)1 : (void *)0);
        }
    }
}

/*
 * Custom completion by a plugin.
 */

void
gui_completion_custom (struct t_gui_completion *completion,
                       const char *custom_completion,
                       struct t_weechat_plugin *plugin)
{
    hook_completion_exec (plugin,
                          custom_completion,
                          completion->buffer,
                          completion);
}

/*
 * Builds data list according to a template.
 */

void
gui_completion_build_list_template (struct t_gui_completion *completion,
                                    const char *template,
                                    struct t_weechat_plugin *plugin)
{
    char *word, *custom_completion;
    const char *pos, *pos_end;
    int word_offset;

    word = strdup (template);
    word_offset = 0;
    pos = template;
    while (pos)
    {
        switch (pos[0])
        {
            case '\0':
            case ' ':
            case '|':
                if (word_offset > 0)
                {
                    word[word_offset] = '\0';
                    gui_completion_list_add (completion, word,
                                             0, WEECHAT_LIST_POS_SORT);
                }
                word_offset = 0;
                break;
            case '%':
                pos++;
                if (pos && pos[0])
                {
                    switch (pos[0])
                    {
                        case '-': /* stop completion */
                            gui_completion_stop (completion);
                            free (word);
                            return;
                            break;
                        case '*': /* repeat last completion (do nothing there) */
                            break;
                        case '(': /* custom completion by a plugin */
                            pos++;
                            pos_end = strchr (pos, ')');
                            if (pos_end)
                            {
                                if (pos_end > pos)
                                {
                                    custom_completion = string_strndup (pos,
                                                                        pos_end - pos);
                                    if (custom_completion)
                                    {
                                        gui_completion_custom (completion,
                                                               custom_completion,
                                                               plugin);
                                        free (custom_completion);
                                    }
                                }
                                pos = pos_end + 1;
                            }
                    }
                }
                break;
            default:
                word[word_offset++] = pos[0];
        }
        /* end of argument in template? */
        if (!pos[0] || (pos[0] == ' '))
            pos = NULL;
        else
            pos++;
    }
    free (word);
}

/*
 * Gets template matching arguments for command.
 */

int
gui_completion_get_matching_template (struct t_gui_completion *completion,
                                      struct t_hook *hook_command)
{
    int i, length, fallback;

    /* without at least one argument, we can't find matching template! */
    if (completion->base_command_arg_index <= 1)
        return -1;

    fallback = -1;

    for (i = 0; i < HOOK_COMMAND(hook_command, cplt_num_templates); i++)
    {
        length = strlen (HOOK_COMMAND(hook_command, cplt_templates_static)[i]);
        if ((strncmp (HOOK_COMMAND(hook_command, cplt_templates_static)[i],
                      completion->args, length) == 0)
            && (completion->args[length] == ' '))
        {
            return i;
        }
        /*
         * try to find a fallback template if we don't find any matching
         * template, for example with these templates (command /set):
         *   %(config_options) %(config_option_values)
         *   diff %(config_options)|%*
         * if first argument is "diff", the match is OK (second template)
         * if first argument is not "diff", we will fallback on the first
         * template containing "%" (here first template)
         */
        if ((fallback < 0)
            && (strstr (HOOK_COMMAND(hook_command, cplt_templates_static)[i], "%")))
        {
            fallback = i;
        }
    }

    return fallback;
}

/*
 * Gets template according to user arguments for command.
 */

char *
gui_completion_get_template_for_args (struct t_gui_completion *completion,
                                      struct t_hook *hook_command)
{
    int matching_template;

    /*
     * if template refers to another command, search this command and use its
     * template
     */
    if ((HOOK_COMMAND(hook_command, cplt_templates)[0][0] == '%')
        && (HOOK_COMMAND(hook_command, cplt_templates)[0][1] == '%')
        && (HOOK_COMMAND(hook_command, cplt_templates)[0][1]))
    {
        hook_command = gui_completion_search_command (completion->buffer->plugin,
                                                      HOOK_COMMAND(hook_command, cplt_templates)[0] + 2);
        if (!hook_command
            || ((HOOK_COMMAND(hook_command, cplt_templates)[0][0] == '%')
                && (HOOK_COMMAND(hook_command, cplt_templates)[0][1] == '%')))
        {
            return strdup ("");
        }
    }

    /* if only one template available, then use it */
    if (HOOK_COMMAND(hook_command, cplt_num_templates) == 1)
        return strdup (HOOK_COMMAND(hook_command, cplt_templates)[0]);

    /* search which template is matching arguments from user */
    matching_template = gui_completion_get_matching_template (completion,
                                                              hook_command);
    if (matching_template >= 0)
    {
        return strdup (HOOK_COMMAND(hook_command, cplt_templates[matching_template]));
    }
    else
    {
        if (HOOK_COMMAND(hook_command, cplt_template_num_args_concat) >= completion->base_command_arg_index)
            return strdup (HOOK_COMMAND(hook_command, cplt_template_args_concat[completion->base_command_arg_index - 1]));
        else
            return strdup ("");
    }
}

/*
 * Builds data list according to command and argument index.
 */

void
gui_completion_build_list (struct t_gui_completion *completion)
{
    struct t_hook *ptr_hook;
    char *template, *pos_template, *pos_space;
    int repeat_last, i, length;

    repeat_last = 0;

    ptr_hook = gui_completion_search_command (completion->buffer->plugin,
                                              completion->base_command);
    if (!ptr_hook || !HOOK_COMMAND(ptr_hook, completion))
    {
        completion->context = GUI_COMPLETION_AUTO;
        completion->base_command_arg_index = 0;
        free (completion->base_command);
        completion->base_command = NULL;
        return;
    }

    if (strcmp (HOOK_COMMAND(ptr_hook, completion), "-") == 0)
    {
        gui_completion_stop (completion);
        return;
    }

    template = gui_completion_get_template_for_args (completion, ptr_hook);
    if (!template)
        return;

    length = strlen (template);
    if (length >= 2)
    {
        if (strcmp (template + length - 2, "%*") == 0)
            repeat_last = 1;
    }

    i = 1;
    pos_template = template;
    while (pos_template && pos_template[0])
    {
        pos_space = strchr (pos_template, ' ');
        if (i == completion->base_command_arg_index)
        {
            gui_completion_build_list_template (completion, pos_template,
                                                ptr_hook->plugin);
            free (template);
            return;
        }
        if (pos_space)
        {
            pos_template = pos_space;
            while (pos_template[0] == ' ')
            {
                pos_template++;
            }
        }
        else
            pos_template = NULL;
        i++;
    }
    if (repeat_last)
    {
        pos_space = strrchr (template, ' ');
        gui_completion_build_list_template (completion,
                                            (pos_space) ?
                                            pos_space + 1 : template,
                                            ptr_hook->plugin);
    }
    free (template);
}

/*
 * Finds context for completion.
 */

void
gui_completion_find_context (struct t_gui_completion *completion,
                             const char *data, int size, int pos)
{
    int i, command, command_arg, pos_start, pos_end;
    char *prev_char;

    /* look for context */
    gui_completion_free_data (completion);
    gui_completion_buffer_init (completion, completion->buffer);
    command = (string_is_command_char (data)) ? 1 : 0;
    command_arg = 0;
    i = 0;
    while (i < pos)
    {
        if (data[i] == ' ')
        {
            command_arg++;
            i++;
            while ((i < pos) && (data[i] == ' '))
            {
                i++;
            }
            if (!completion->args)
                completion->args = strdup (data + i);
        }
        else
            i++;
    }
    if (command)
    {
        if (command_arg > 0)
        {
            completion->context = GUI_COMPLETION_COMMAND_ARG;
            completion->base_command_arg_index = command_arg;
        }
        else
        {
            completion->context = GUI_COMPLETION_COMMAND;
            completion->base_command_arg_index = 0;
        }
    }
    else
        completion->context = GUI_COMPLETION_AUTO;

    /* look for word to complete (base word) */
    completion->base_word_pos = 0;
    completion->position_replace = pos;

    if (size > 0)
    {
        i = pos;
        pos_start = i;
        if (data[i] == ' ')
        {
            if ((i > 0) && (data[i-1] != ' '))
            {
                i--;
                while ((i >= 0) && (data[i] != ' '))
                {
                    i--;
                }
                pos_start = i + 1;
            }
        }
        else
        {
            while ((i >= 0) && (data[i] != ' '))
            {
                i--;
            }
            pos_start = i + 1;
        }
        if (CONFIG_BOOLEAN (config_completion_base_word_until_cursor))
        {
            /* base word stops at cursor */
            pos_end = pos - 1;
        }
        else
        {
            /* base word stops after first space found (on or after cursor) */
            i = pos;
            while ((i < size) && (data[i] != ' '))
            {
                i++;
            }
            pos_end = i - 1;
        }

        if (completion->context == GUI_COMPLETION_COMMAND)
        {
            pos_start++;
            if (string_is_command_char (data + pos_start))
                pos_start += utf8_char_size (data + pos_start);
        }

        completion->base_word_pos = pos_start;

        if (pos_start <= pos_end)
        {
            completion->position_replace = pos_start;
            completion->base_word = malloc (pos_end - pos_start + 2);
            for (i = pos_start; i <= pos_end; i++)
            {
                completion->base_word[i - pos_start] = data[i];
            }
            completion->base_word[pos_end - pos_start + 1] = '\0';
        }
    }

    if (!completion->base_word)
        completion->base_word = strdup ("");

    /* find command (for command argument completion only) */
    if (completion->context == GUI_COMPLETION_COMMAND_ARG)
    {
        pos_start = 0;
        while ((pos_start < size) && !string_is_command_char (data + pos_start))
        {
            pos_start += utf8_char_size (data + pos_start);
        }
        if (string_is_command_char (data + pos_start))
        {
            pos_start += utf8_char_size (data + pos_start);
            if (string_is_command_char (data + pos_start))
                pos_start += utf8_char_size (data + pos_start);
            pos_end = pos_start;
            while ((pos_end < size) && (data[pos_end] != ' '))
            {
                pos_end += utf8_char_size (data + pos_end);
            }
            if (data[pos_end] == ' ')
            {
                prev_char = utf8_prev_char (data, data + pos_end);
                pos_end -= utf8_char_size (prev_char);
            }

            completion->base_command = malloc (pos_end - pos_start + 2);
            for (i = pos_start; i <= pos_end; i++)
            {
                completion->base_command[i - pos_start] = data[i];
            }
            completion->base_command[pos_end - pos_start + 1] = '\0';
            gui_completion_build_list (completion);
        }
    }

    /*
     * auto completion with nothing as base word is disabled,
     * in order to prevent completion when pasting messages with [tab] inside
     */
    if ((completion->context == GUI_COMPLETION_AUTO)
        && ((!completion->base_word) || (!completion->base_word[0])))
    {
        completion->context = GUI_COMPLETION_NULL;
        return;
    }
}

/*
 * Finds common prefix size in matching items (case is ignored).
 *
 * If utf_char is not null, only words beginning with this char are compared
 * (all other words are ignored).
 *
 * For example with items:
 *   FlashCode, flashy, flashouille
 *   => common prefix size is 5 ("flash")
 */

int
gui_completion_common_prefix_size (struct t_weelist *list,
                                   const char *utf_char)
{
    struct t_weelist_item *ptr_item;
    char *ptr_first_item, *ptr_char, *next_char;

    ptr_first_item = list->items->data;
    ptr_char = ptr_first_item;

    while (ptr_char && ptr_char[0])
    {
        next_char = utf8_next_char (ptr_char);

        for (ptr_item = list->items->next_item; ptr_item;
             ptr_item = ptr_item->next_item)
        {
            if (!utf_char
                || (utf8_charcasecmp (utf_char, ptr_item->data) == 0))
            {
                if ((ptr_item->data[ptr_char - ptr_first_item] == '\0')
                    || (utf8_charcasecmp (ptr_char,
                                          ptr_item->data + (ptr_char - ptr_first_item)) != 0))
                {
                    return ptr_char - ptr_first_item;
                }
            }
        }

        ptr_char = next_char;
    }
    return ptr_char - ptr_first_item;
}

/*
 * Builds list with possible completions when a partial completion occurs.
 */

void
gui_completion_partial_build_list (struct t_gui_completion *completion,
                                   int common_prefix_size)
{
    int char_size, items_count;
    char utf_char[16], *word;
    struct t_weelist *weelist_temp;
    struct t_weelist_item *ptr_item, *next_item;

    gui_completion_partial_list_free_all (completion);

    if (!completion->completion_list || !completion->completion_list->items)
        return;

    weelist_temp = weelist_new ();
    if (!weelist_temp)
        return;

    for (ptr_item = completion->completion_list->items; ptr_item;
         ptr_item = ptr_item->next_item)
    {
        weelist_add (weelist_temp, ptr_item->data + common_prefix_size,
                     WEECHAT_LIST_POS_END, NULL);
    }

    while (weelist_temp->items)
    {
        char_size = utf8_char_size (weelist_temp->items->data);
        memcpy (utf_char, weelist_temp->items->data, char_size);
        utf_char[char_size] = '\0';
        word = NULL;
        common_prefix_size = gui_completion_common_prefix_size (weelist_temp,
                                                                utf_char);
        if (common_prefix_size > 0)
        {
            word = string_strndup (weelist_temp->items->data,
                                   common_prefix_size);
        }
        items_count = 0;
        ptr_item = weelist_temp->items;
        while (ptr_item)
        {
            next_item = ptr_item->next_item;

            if (utf8_charcasecmp (utf_char, ptr_item->data) == 0)
            {
                weelist_remove (weelist_temp, ptr_item);
                items_count++;
            }

            ptr_item = next_item;
        }
        if (word)
        {
            gui_completion_partial_list_add (completion,
                                             word,
                                             CONFIG_BOOLEAN(config_completion_partial_completion_count) ?
                                             items_count : -1);
            free (word);
        }
    }

    weelist_free (weelist_temp);
}

/*
 * Completes word using matching items.
 */

void
gui_completion_complete (struct t_gui_completion *completion)
{
    int length, word_found_seen, other_completion, partial_completion;
    int common_prefix_size, item_is_nick;
    struct t_weelist_item *ptr_item, *ptr_item2;

    length = utf8_strlen (completion->base_word);
    word_found_seen = 0;
    other_completion = 0;

    partial_completion = completion->force_partial_completion;

    if (!partial_completion)
    {
        if (completion->context == GUI_COMPLETION_COMMAND)
        {
            partial_completion = CONFIG_BOOLEAN(config_completion_partial_completion_command);
        }
        else if (completion->context == GUI_COMPLETION_COMMAND_ARG)
        {
            partial_completion = CONFIG_BOOLEAN(config_completion_partial_completion_command_arg);
        }
        else
            partial_completion = CONFIG_BOOLEAN(config_completion_partial_completion_other);
    }

    common_prefix_size = 0;
    if (partial_completion
        && completion->completion_list && completion->completion_list->items)
    {
        common_prefix_size = gui_completion_common_prefix_size (completion->completion_list,
                                                                NULL);
    }

    ptr_item = NULL;
    if (completion->completion_list)
    {
        if (completion->direction < 0)
            ptr_item = completion->completion_list->last_item;
        else
            ptr_item = completion->completion_list->items;
    }

    if (partial_completion
        && completion->word_found
        && (utf8_strlen (completion->word_found) >= common_prefix_size))
    {
        return;
    }

    while (ptr_item)
    {
        item_is_nick = ((long)(ptr_item->user_data) == 1);
        if ((item_is_nick
             && (gui_completion_nickncmp (completion->base_word, ptr_item->data,
                                          length) == 0))
            || ((!item_is_nick)
                && (string_strncasecmp (completion->base_word, ptr_item->data,
                                        length) == 0)))
        {
            if ((!completion->word_found) || word_found_seen)
            {
                if (completion->word_found)
                    free (completion->word_found);
                completion->word_found = strdup (ptr_item->data);
                completion->word_found_is_nick = item_is_nick;
                if (item_is_nick
                    && !CONFIG_BOOLEAN(config_completion_nick_add_space))
                {
                    completion->add_space = 0;
                }

                /* stop after first nick if user asked that */
                if (item_is_nick
                    && CONFIG_BOOLEAN(config_completion_nick_first_only))
                {
                    gui_completion_stop (completion);
                    return;
                }

                if (completion->direction < 0)
                    ptr_item2 = ptr_item->prev_item;
                else
                    ptr_item2 = ptr_item->next_item;

                while (ptr_item2)
                {
                    if ((item_is_nick
                         && (gui_completion_nickncmp (completion->base_word,
                                                      ptr_item2->data,
                                                      length) == 0))
                        || ((!item_is_nick)
                            && (string_strncasecmp (completion->base_word,
                                                    ptr_item2->data,
                                                    length) == 0)))
                    {
                        other_completion++;
                    }

                    if (completion->direction < 0)
                        ptr_item2 = ptr_item2->prev_item;
                    else
                        ptr_item2 = ptr_item2->next_item;
                }

                if (other_completion == 0)
                    completion->position = -1;
                else
                    if (completion->position < 0)
                        completion->position = 0;

                /* stop after common prefix, if asked by user */
                if (partial_completion
                    && ((utf8_strlen (completion->word_found) >= common_prefix_size))
                    && (other_completion > 0))
                {
                    completion->word_found[common_prefix_size] = '\0';
                    completion->word_found_is_nick = 0;
                    completion->add_space = 0;
                    completion->position = -1;
                    string_tolower (completion->word_found);

                    /* alert user of partial completion */
                    if (CONFIG_BOOLEAN(config_completion_partial_completion_alert))
                        printf ("\a");

                    /*
                     * send "partial_completion" signal, to display possible
                     * completions in bar item
                     */
                    gui_completion_partial_build_list (completion,
                                                       common_prefix_size);
                    hook_signal_send ("partial_completion",
                                      WEECHAT_HOOK_SIGNAL_STRING, NULL);
                    return;
                }

                gui_completion_partial_list_free_all (completion);

                return;
            }
            other_completion++;
        }
        if (completion->word_found &&
            (strcmp (ptr_item->data, completion->word_found) == 0))
            word_found_seen = 1;

        if (completion->direction < 0)
            ptr_item = ptr_item->prev_item;
        else
            ptr_item = ptr_item->next_item;
    }

    /*
     * if we was on last completion in list, then complete again, starting from
     * first matching item
     */
    if (completion->word_found && (completion->position >= 0))
    {
        free (completion->word_found);
        completion->word_found = NULL;
        completion->word_found_is_nick = 0;
        gui_completion_complete (completion);
    }
}

/*
 * Completes a command.
 */

void
gui_completion_command (struct t_gui_completion *completion)
{
    struct t_hook *ptr_hook;

    if (!completion->completion_list->items)
    {
        for (ptr_hook = weechat_hooks[HOOK_TYPE_COMMAND]; ptr_hook;
             ptr_hook = ptr_hook->next_hook)
        {
            if (!ptr_hook->deleted
                && HOOK_COMMAND(ptr_hook, command)
                && HOOK_COMMAND(ptr_hook, command)[0])
            {
                gui_completion_list_add (completion,
                                         HOOK_COMMAND(ptr_hook, command),
                                         0, WEECHAT_LIST_POS_SORT);
            }
        }
    }

    gui_completion_complete (completion);
}

/*
 * Auto-completes: nick, filename or channel.
 */

void
gui_completion_auto (struct t_gui_completion *completion)
{
    /* filename completion */
    if ((completion->base_word[0] == '/')
        || (completion->base_word[0] == '~'))
    {
        if (!completion->completion_list->items)
            completion_list_add_filename_cb (NULL, NULL, NULL, completion);
        gui_completion_complete (completion);
        return;
    }

    /* use default template completion */
    if (!completion->completion_list->items)
    {
        gui_completion_build_list_template (completion,
                                            CONFIG_STRING(config_completion_default_template),
                                            NULL);
    }
    gui_completion_complete (completion);
}

/*
 * Completes word according to context.
 */

void
gui_completion_search (struct t_gui_completion *completion, int direction,
                       const char *data, int size, int pos)
{
    char *old_word_found;

    completion->direction = direction;

    /* if new completion => look for base word */
    if (pos != completion->position)
    {
        if (completion->word_found)
            free (completion->word_found);
        completion->word_found = NULL;
        completion->word_found_is_nick = 0;
        gui_completion_find_context (completion, data, size, pos);
        completion->force_partial_completion = (direction < 0);
    }

    /* completion */
    old_word_found = (completion->word_found) ?
        strdup (completion->word_found) : NULL;
    switch (completion->context)
    {
        case GUI_COMPLETION_NULL:
            /* should never be executed */
            return;
        case GUI_COMPLETION_COMMAND:
            gui_completion_command (completion);
            break;
        case GUI_COMPLETION_COMMAND_ARG:
            if (completion->completion_list->items)
                gui_completion_complete (completion);
            else
            {
                completion->context = GUI_COMPLETION_AUTO;
                gui_completion_auto (completion);
            }
            break;
        case GUI_COMPLETION_AUTO:
            gui_completion_auto (completion);
            break;
    }
    if (completion->word_found)
    {
        if (old_word_found)
        {
            completion->diff_size = strlen (completion->word_found) -
                strlen (old_word_found);
            completion->diff_length = utf8_strlen (completion->word_found) -
                utf8_strlen (old_word_found);
        }
        else
        {
            completion->diff_size = strlen (completion->word_found) -
                strlen (completion->base_word);
            completion->diff_length = utf8_strlen (completion->word_found) -
                utf8_strlen (completion->base_word);
        }
    }
    if (old_word_found)
        free (old_word_found);
}

/*
 * Gets a completion property as string.
 */

const char *
gui_completion_get_string (struct t_gui_completion *completion,
                           const char *property)
{
    if (completion)
    {
        if (string_strcasecmp (property, "base_command") == 0)
            return completion->base_command;
        else if (string_strcasecmp (property, "base_word") == 0)
            return completion->base_word;
        else if (string_strcasecmp (property, "args") == 0)
            return completion->args;
    }

    return NULL;
}

/*
 * Returns hdata for completion.
 */

struct t_hdata *
gui_completion_hdata_completion_cb (void *data, const char *hdata_name)
{
    struct t_hdata *hdata;

    /* make C compiler happy */
    (void) data;

    hdata = hdata_new (NULL, hdata_name, NULL, NULL,
                       0, 0, NULL, NULL);
    if (hdata)
    {
        HDATA_VAR(struct t_gui_completion, buffer, POINTER, 0, NULL, "buffer");
        HDATA_VAR(struct t_gui_completion, context, INTEGER, 0, NULL, NULL);
        HDATA_VAR(struct t_gui_completion, base_command, STRING, 0, NULL, NULL);
        HDATA_VAR(struct t_gui_completion, base_command_arg_index, INTEGER, 0, NULL, NULL);
        HDATA_VAR(struct t_gui_completion, base_word, STRING, 0, NULL, NULL);
        HDATA_VAR(struct t_gui_completion, base_word_pos, INTEGER, 0, NULL, NULL);
        HDATA_VAR(struct t_gui_completion, position, INTEGER, 0, NULL, NULL);
        HDATA_VAR(struct t_gui_completion, args, STRING, 0, NULL, NULL);
        HDATA_VAR(struct t_gui_completion, direction, INTEGER, 0, NULL, NULL);
        HDATA_VAR(struct t_gui_completion, add_space, INTEGER, 0, NULL, NULL);
        HDATA_VAR(struct t_gui_completion, force_partial_completion, INTEGER, 0, NULL, NULL);
        HDATA_VAR(struct t_gui_completion, completion_list, POINTER, 0, NULL, NULL);
        HDATA_VAR(struct t_gui_completion, word_found, STRING, 0, NULL, NULL);
        HDATA_VAR(struct t_gui_completion, word_found_is_nick, INTEGER, 0, NULL, NULL);
        HDATA_VAR(struct t_gui_completion, position_replace, INTEGER, 0, NULL, NULL);
        HDATA_VAR(struct t_gui_completion, diff_size, INTEGER, 0, NULL, NULL);
        HDATA_VAR(struct t_gui_completion, diff_length, INTEGER, 0, NULL, NULL);
        HDATA_VAR(struct t_gui_completion, partial_completion_list, POINTER, 0, NULL, "completion_partial");
        HDATA_VAR(struct t_gui_completion, last_partial_completion, POINTER, 0, NULL, "completion_partial");
    }
    return hdata;
}

/*
 * Returns hdata for partial completion.
 */

struct t_hdata *
gui_completion_hdata_completion_partial_cb (void *data, const char *hdata_name)
{
    struct t_hdata *hdata;

    /* make C compiler happy */
    (void) data;

    hdata = hdata_new (NULL, hdata_name, "prev_item", "next_item",
                       0, 0, NULL, NULL);
    if (hdata)
    {
        HDATA_VAR(struct t_gui_completion_partial, word, STRING, 0, NULL, NULL);
        HDATA_VAR(struct t_gui_completion_partial, count, INTEGER, 0, NULL, NULL);
        HDATA_VAR(struct t_gui_completion_partial, prev_item, POINTER, 0, NULL, hdata_name);
        HDATA_VAR(struct t_gui_completion_partial, next_item, POINTER, 0, NULL, hdata_name);
    }
    return hdata;
}

/*
 * Prints completion list in WeeChat log file (usually for crash dump).
 */

void
gui_completion_print_log (struct t_gui_completion *completion)
{
    struct t_gui_completion_partial *ptr_item;

    log_printf ("[completion (addr:0x%lx)]", completion);
    log_printf ("  buffer. . . . . . . . . : 0x%lx", completion->buffer);
    log_printf ("  context . . . . . . . . : %d",    completion->context);
    log_printf ("  base_command. . . . . . : '%s'",  completion->base_command);
    log_printf ("  base_command_arg_index. : %d",    completion->base_command_arg_index);
    log_printf ("  base_word . . . . . . . : '%s'",  completion->base_word);
    log_printf ("  base_word_pos . . . . . : %d",    completion->base_word_pos);
    log_printf ("  position. . . . . . . . : %d",    completion->position);
    log_printf ("  args. . . . . . . . . . : '%s'",  completion->args);
    log_printf ("  direction . . . . . . . : %d",    completion->direction);
    log_printf ("  add_space . . . . . . . : %d",    completion->add_space);
    log_printf ("  force_partial_completion: %d",    completion->force_partial_completion);
    log_printf ("  completion_list . . . . : 0x%lx", completion->completion_list);
    log_printf ("  word_found. . . . . . . : '%s'",  completion->word_found);
    log_printf ("  word_found_is_nick. . . : %d",    completion->word_found_is_nick);
    log_printf ("  position_replace. . . . : %d",    completion->position_replace);
    log_printf ("  diff_size . . . . . . . : %d",    completion->diff_size);
    log_printf ("  diff_length . . . . . . : %d",    completion->diff_length);
    if (completion->completion_list)
    {
        log_printf ("");
        weelist_print_log (completion->completion_list,
                           "completion list element");
    }
    if (completion->partial_completion_list)
    {
        log_printf ("");
        for (ptr_item = completion->partial_completion_list;
             ptr_item; ptr_item = ptr_item->next_item)
        {
            log_printf ("[partial completion item (addr:0x%lx)]", ptr_item);
            log_printf ("  word. . . . . . . . . . : '%s'",  ptr_item->word);
            log_printf ("  count . . . . . . . . . : %d",    ptr_item->count);
            log_printf ("  prev_item . . . . . . . : 0x%lx", ptr_item->prev_item);
            log_printf ("  next_item . . . . . . . : 0x%lx", ptr_item->next_item);
        }
    }
}
