/* vim: set sw=8: -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/*
 * xed-spell-checker.c
 * This file is part of xed
 *
 * Copyright (C) 2002-2006 Paolo Maggi
 *
 * 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., 51 Franklin St, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */

/*
 * Modified by the xed Team, 2002-2006. See the AUTHORS file for a
 * list of people on the xed Team.
 * See the ChangeLog files for a list of changes.
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <string.h>

#include <enchant.h>

#include <glib/gi18n.h>
#include <glib.h>

#include "xed-spell-checker.h"
#include "xed-spell-utils.h"
#include "xed-spell-marshal.h"

struct _XedSpellChecker
{
    GObject parent_instance;

    EnchantDict                     *dict;
    EnchantBroker                   *broker;
    const XedSpellCheckerLanguage *active_lang;
};

/* GObject properties */
enum {
    PROP_0 = 0,
    PROP_LANGUAGE,
    LAST_PROP
};

/* Signals */
enum {
    ADD_WORD_TO_PERSONAL = 0,
    ADD_WORD_TO_SESSION,
    SET_LANGUAGE,
    CLEAR_SESSION,
    LAST_SIGNAL
};

static guint signals[LAST_SIGNAL] = { 0 };

G_DEFINE_TYPE(XedSpellChecker, xed_spell_checker, G_TYPE_OBJECT)

static void
xed_spell_checker_set_property (GObject      *object,
                                guint         prop_id,
                                const GValue *value,
                                GParamSpec   *pspec)
{
    /*
    XedSpellChecker *spell = XED_SPELL_CHECKER (object);
    */

    switch (prop_id)
    {
        case PROP_LANGUAGE:
            /* TODO */
            break;
        default:
            G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
    }
}

static void
xed_spell_checker_get_property (GObject    *object,
                                guint       prop_id,
                                GValue     *value,
                                GParamSpec *pspec)
{
    /*
    XedSpellChecker *spell = XED_SPELL_CHECKER (object);
    */

    switch (prop_id)
    {
        case PROP_LANGUAGE:
            /* TODO */
        default:
            G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
    }
}

static void
xed_spell_checker_finalize (GObject *object)
{
    XedSpellChecker *spell_checker;

    g_return_if_fail (XED_IS_SPELL_CHECKER (object));

    spell_checker = XED_SPELL_CHECKER (object);

    if (spell_checker->dict != NULL)
    {
        enchant_broker_free_dict (spell_checker->broker, spell_checker->dict);
    }

    if (spell_checker->broker != NULL)
    {
        enchant_broker_free (spell_checker->broker);
    }

    G_OBJECT_CLASS (xed_spell_checker_parent_class)->finalize (object);
}

static void
xed_spell_checker_class_init (XedSpellCheckerClass *klass)
{
    GObjectClass *object_class;

    object_class = G_OBJECT_CLASS (klass);

    object_class->set_property = xed_spell_checker_set_property;
    object_class->get_property = xed_spell_checker_get_property;

    object_class->finalize = xed_spell_checker_finalize;

    g_object_class_install_property (object_class,
                                     PROP_LANGUAGE,
                                     g_param_spec_pointer ("language",
                                                           "Language",
                                                           "The language used by the spell checker",
                                                           G_PARAM_READWRITE));

    signals[ADD_WORD_TO_PERSONAL] =
        g_signal_new ("add_word_to_personal",
                      G_OBJECT_CLASS_TYPE (object_class),
                      G_SIGNAL_RUN_LAST,
                      G_STRUCT_OFFSET (XedSpellCheckerClass, add_word_to_personal),
                      NULL, NULL,
                      xed_marshal_VOID__STRING_INT,
                      G_TYPE_NONE,
                      2,
                      G_TYPE_STRING,
                      G_TYPE_INT);

    signals[ADD_WORD_TO_SESSION] =
        g_signal_new ("add_word_to_session",
                      G_OBJECT_CLASS_TYPE (object_class),
                      G_SIGNAL_RUN_LAST,
                      G_STRUCT_OFFSET (XedSpellCheckerClass, add_word_to_session),
                      NULL, NULL,
                      xed_marshal_VOID__STRING_INT,
                      G_TYPE_NONE,
                      2,
                      G_TYPE_STRING,
                      G_TYPE_INT);

    signals[SET_LANGUAGE] =
        g_signal_new ("set_language",
                      G_OBJECT_CLASS_TYPE (object_class),
                      G_SIGNAL_RUN_LAST,
                      G_STRUCT_OFFSET (XedSpellCheckerClass, set_language),
                      NULL, NULL,
                      xed_marshal_VOID__POINTER,
                      G_TYPE_NONE,
                      1,
                      G_TYPE_POINTER);

    signals[CLEAR_SESSION] =
        g_signal_new ("clear_session",
                      G_OBJECT_CLASS_TYPE (object_class),
                      G_SIGNAL_RUN_LAST,
                      G_STRUCT_OFFSET (XedSpellCheckerClass, clear_session),
                      NULL, NULL,
                      xed_marshal_VOID__VOID,
                      G_TYPE_NONE,
                      0);
}

static void
xed_spell_checker_init (XedSpellChecker *spell_checker)
{
    spell_checker->broker = enchant_broker_init ();
    spell_checker->dict = NULL;
    spell_checker->active_lang = NULL;
}

XedSpellChecker *
xed_spell_checker_new (void)
{
    XedSpellChecker *spell;

    spell = XED_SPELL_CHECKER (g_object_new (XED_TYPE_SPELL_CHECKER, NULL));

    g_return_val_if_fail (spell != NULL, NULL);

    return spell;
}

static gboolean
lazy_init (XedSpellChecker               *spell,
           const XedSpellCheckerLanguage *language)
{
    if (spell->dict != NULL)
    {
        return TRUE;
    }

    g_return_val_if_fail (spell->broker != NULL, FALSE);

    spell->active_lang = NULL;

    if (language != NULL)
    {
        spell->active_lang = language;
    }
    else
    {
        /* First try to get a default language */
        const XedSpellCheckerLanguage *l;
        gint i = 0;
        const gchar * const *lang_tags = g_get_language_names ();

        while (lang_tags [i])
        {
            l = xed_spell_checker_language_from_key (lang_tags [i]);

            if (l != NULL)
            {
                spell->active_lang = l;
                break;
            }

            i++;
        }
    }

    /* Second try to get a default language */
    if (spell->active_lang == NULL)
    {
        spell->active_lang = xed_spell_checker_language_from_key ("en_US");
    }

    /* Last try to get a default language */
    if (spell->active_lang == NULL)
    {
        const GSList *langs;
        langs = xed_spell_checker_get_available_languages ();
        if (langs != NULL)
        {
            spell->active_lang = (const XedSpellCheckerLanguage *)langs->data;
        }
    }

    if (spell->active_lang != NULL)
    {
        const gchar *key;

        key = xed_spell_checker_language_to_key (spell->active_lang);

        spell->dict = enchant_broker_request_dict (spell->broker, key);
    }

    if (spell->dict == NULL)
    {
        spell->active_lang = NULL;

        if (language != NULL)
        {
            g_warning ("Spell checker plugin: cannot select a default language.");
        }

        return FALSE;
    }

    return TRUE;
}

gboolean
xed_spell_checker_set_language (XedSpellChecker               *spell,
                                const XedSpellCheckerLanguage *language)
{
    gboolean ret;

    g_return_val_if_fail (XED_IS_SPELL_CHECKER (spell), FALSE);

    if (spell->dict != NULL)
    {
        enchant_broker_free_dict (spell->broker, spell->dict);
        spell->dict = NULL;
    }

    ret = lazy_init (spell, language);

    if (ret)
    {
        g_signal_emit (G_OBJECT (spell), signals[SET_LANGUAGE], 0, language);
    }
    else
    {
        g_warning ("Spell checker plugin: cannot use language %s.", xed_spell_checker_language_to_string (language));
    }
    
    return ret;
}

const XedSpellCheckerLanguage *
xed_spell_checker_get_language (XedSpellChecker *spell)
{
    g_return_val_if_fail (XED_IS_SPELL_CHECKER (spell), NULL);

    if (!lazy_init (spell, spell->active_lang))
    {
        return NULL;
    }

    return spell->active_lang;
}

gboolean
xed_spell_checker_check_word (XedSpellChecker *spell,
                              const gchar     *word,
                              gssize           len)
{
    gint enchant_result;
    gboolean res = FALSE;

    g_return_val_if_fail (XED_IS_SPELL_CHECKER (spell), FALSE);
    g_return_val_if_fail (word != NULL, FALSE);

    if (!lazy_init (spell, spell->active_lang))
    {
        return FALSE;
    }

    if (len < 0)
    {
        len = strlen (word);
    }

    if (strcmp (word, "xed") == 0)
    {
        return TRUE;
    }

    if (xed_spell_utils_is_digit (word, len))
    {
        return TRUE;
    }

    g_return_val_if_fail (spell->dict != NULL, FALSE);
    enchant_result = enchant_dict_check (spell->dict, word, len);

    switch (enchant_result)
    {
        case -1:
            /* error */
            res = FALSE;

            g_warning ("Spell checker plugin: error checking word '%s' (%s).",
                   word, enchant_dict_get_error (spell->dict));

            break;
        case 1:
            /* it is not in the directory */
            res = FALSE;
            break;
        case 0:
            /* is is in the directory */
            res = TRUE;
            break;
        default:
            g_return_val_if_reached (FALSE);
    }

    return res;
}


/* return NULL on error or if no suggestions are found */
GSList *
xed_spell_checker_get_suggestions (XedSpellChecker *spell,
                                   const gchar     *word,
                                   gssize           len)
{
    gchar **suggestions;
    size_t n_suggestions = 0;
    GSList *suggestions_list = NULL;
    gint i;

    g_return_val_if_fail (XED_IS_SPELL_CHECKER (spell), NULL);
    g_return_val_if_fail (word != NULL, NULL);

    if (!lazy_init (spell, spell->active_lang))
    {
        return NULL;
    }

    g_return_val_if_fail (spell->dict != NULL, NULL);

    if (len < 0)
    {
        len = strlen (word);
    }

    suggestions = enchant_dict_suggest (spell->dict, word, len, &n_suggestions);

    if (n_suggestions == 0)
    {
        return NULL;
    }

    g_return_val_if_fail (suggestions != NULL, NULL);

    for (i = 0; i < (gint)n_suggestions; i++)
    {
        suggestions_list = g_slist_prepend (suggestions_list, suggestions[i]);
    }

    /* The single suggestions will be freed by the caller */
    g_free (suggestions);

    suggestions_list = g_slist_reverse (suggestions_list);

    return suggestions_list;
}

gboolean
xed_spell_checker_add_word_to_personal (XedSpellChecker *spell,
                                        const gchar     *word,
                                        gssize           len)
{
    g_return_val_if_fail (XED_IS_SPELL_CHECKER (spell), FALSE);
    g_return_val_if_fail (word != NULL, FALSE);

    if (!lazy_init (spell, spell->active_lang))
    {
        return FALSE;
    }

    g_return_val_if_fail (spell->dict != NULL, FALSE);

    if (len < 0)
    {
        len = strlen (word);
    }

    enchant_dict_add_to_pwl (spell->dict, word, len);

    g_signal_emit (G_OBJECT (spell), signals[ADD_WORD_TO_PERSONAL], 0, word, len);

    return TRUE;
}

gboolean
xed_spell_checker_add_word_to_session (XedSpellChecker *spell,
                                       const gchar     *word,
                                       gssize           len)
{
    g_return_val_if_fail (XED_IS_SPELL_CHECKER (spell), FALSE);
    g_return_val_if_fail (word != NULL, FALSE);

    if (!lazy_init (spell, spell->active_lang))
    {
        return FALSE;
    }

    g_return_val_if_fail (spell->dict != NULL, FALSE);

    if (len < 0)
    {
        len = strlen (word);
    }

    enchant_dict_add_to_session (spell->dict, word, len);

    g_signal_emit (G_OBJECT (spell), signals[ADD_WORD_TO_SESSION], 0, word, len);

    return TRUE;
}

gboolean
xed_spell_checker_clear_session (XedSpellChecker *spell)
{
    g_return_val_if_fail (XED_IS_SPELL_CHECKER (spell), FALSE);

    /* free and re-request dictionary */
    if (spell->dict != NULL)
    {
        enchant_broker_free_dict (spell->broker, spell->dict);
        spell->dict = NULL;
    }

    if (!lazy_init (spell, spell->active_lang))
    {
        return FALSE;
    }

    g_signal_emit (G_OBJECT (spell), signals[CLEAR_SESSION], 0);

    return TRUE;
}

/*
 * Informs dictionary, that word 'word' will be replaced/corrected by word
 * 'replacement'
 */
gboolean
xed_spell_checker_set_correction (XedSpellChecker *spell,
                                  const gchar     *word,
                                  gssize           w_len,
                                  const gchar     *replacement,
                                  gssize           r_len)
{
    g_return_val_if_fail (XED_IS_SPELL_CHECKER (spell), FALSE);
    g_return_val_if_fail (word != NULL, FALSE);
    g_return_val_if_fail (replacement != NULL, FALSE);

    if (!lazy_init (spell, spell->active_lang))
    {
        return FALSE;
    }

    g_return_val_if_fail (spell->dict != NULL, FALSE);

    if (w_len < 0)
    {
        w_len = strlen (word);
    }

    if (r_len < 0)
    {
        r_len = strlen (replacement);
    }

    enchant_dict_store_replacement (spell->dict,
                                    word,
                                    w_len,
                                    replacement,
                                    r_len);

    return TRUE;
}