/* -*- Mode: C; indent-tabs-mode: t; c-basic-offset: 8; tab-width: 8 -*- */
/*
 * Copyright (C) 2005 Mr Jamie McCracken
 *
 * Caja 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.
 *
 * Caja 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; see the file COPYING.  If not,
 * write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 *
 * Author: Jamie McCracken <jamiemcc@gnome.org>
 *
 */

#include <config.h>
#include "caja-search-engine-tracker.h"
#include <eel/eel-gtk-macros.h>
#include <gmodule.h>
#include <string.h>

typedef struct _TrackerClient TrackerClient;

typedef enum
{
    TRACKER_0_6 = 1 << 0,
    TRACKER_0_7 = 1 << 1,
    TRACKER_0_8 = 1 << 2
} TrackerVersion;


/* tracker 0.6 API */
typedef void (*TrackerArrayReply) (char **result, GError *error, gpointer user_data);

static TrackerClient *	(*tracker_connect)		(gboolean enable_warnings,
        gint     timeout) = NULL;
static void		(*tracker_disconnect)		(TrackerClient *client) = NULL;
static void		(*tracker_cancel_last_call)	(TrackerClient *client) = NULL;
static int		(*tracker_get_version)		(TrackerClient *client, GError **error) = NULL;


static void (*tracker_search_metadata_by_text_async) (TrackerClient *client,
        const char *query,
        TrackerArrayReply callback,
        gpointer user_data) = NULL;
static void (*tracker_search_metadata_by_text_and_mime_async) (TrackerClient *client,
        const char *query,
        const char **mimes,
        TrackerArrayReply callback,
        gpointer user_data) = NULL;
static void (*tracker_search_metadata_by_text_and_location_async) (TrackerClient *client,
        const char *query,
        const char *location,
        TrackerArrayReply callback,
        gpointer user_data) = NULL;
static void (*tracker_search_metadata_by_text_and_mime_and_location_async) (TrackerClient *client,
        const char *query,
        const char **mimes,
        const char *location,
        TrackerArrayReply callback,
        gpointer user_data) = NULL;


/* tracker 0.8 API */
typedef enum
{
    TRACKER_CLIENT_ENABLE_WARNINGS = 1 << 0
} TrackerClientFlags;

typedef void (*TrackerReplyGPtrArray) (GPtrArray *result,
                                       GError    *error,
                                       gpointer   user_data);

static TrackerClient *	(*tracker_client_new)			(TrackerClientFlags      flags,
        gint                    timeout) = NULL;
static gchar *		(*tracker_sparql_escape)		(const gchar            *str) = NULL;
static guint		(*tracker_resources_sparql_query_async)	(TrackerClient          *client,
        const gchar            *query,
        TrackerReplyGPtrArray   callback,
        gpointer                user_data) = NULL;


static struct TrackerDlMapping
{
    const char	*fn_name;
    gpointer	*fn_ptr_ref;
    TrackerVersion	versions;
} tracker_dl_mapping[] =
{
#define MAP(a,v) { #a, (gpointer *)&a, v }
    MAP (tracker_connect, TRACKER_0_6 | TRACKER_0_7),
    MAP (tracker_disconnect, TRACKER_0_6 | TRACKER_0_7),
    MAP (tracker_get_version, TRACKER_0_6),
    MAP (tracker_cancel_last_call, TRACKER_0_6 | TRACKER_0_7 | TRACKER_0_8),
    MAP (tracker_search_metadata_by_text_async, TRACKER_0_6 | TRACKER_0_7),
    MAP (tracker_search_metadata_by_text_and_location_async, TRACKER_0_6 | TRACKER_0_7),
    MAP (tracker_client_new, TRACKER_0_8),
    MAP (tracker_sparql_escape, TRACKER_0_8),
    MAP (tracker_resources_sparql_query_async, TRACKER_0_8)
#undef MAP
};


static TrackerVersion
open_libtracker (void)
{
    static gboolean done = FALSE;
    static TrackerVersion version = 0;
    gpointer x;

    if (!done)
    {
        int i;
        GModule *tracker;
        GModuleFlags flags;

        done = TRUE;
        flags = G_MODULE_BIND_LAZY | G_MODULE_BIND_LOCAL;

        tracker = g_module_open ("libtracker-client-0.8.so.0", flags);
        version = TRACKER_0_8;

        if (!tracker)
        {
            tracker = g_module_open ("libtracker-client-0.7.so.0", flags);

            if (tracker && !g_module_symbol (tracker, "tracker_resources_sparql_query_async", &x))
            {
                version = TRACKER_0_7;
            }
        }

        if (!tracker)
        {
            tracker = g_module_open ("libtrackerclient.so.0", flags);
            version = TRACKER_0_6;
        }

        if (!tracker)
        {
            tracker = g_module_open ("libtracker.so.0", flags);
            version = TRACKER_0_6;
        }

        if (!tracker)
            return 0;

        for (i = 0; i < G_N_ELEMENTS (tracker_dl_mapping); i++)
        {
            if ((tracker_dl_mapping[i].versions & version) == 0)
                continue;

            if (!g_module_symbol (tracker, tracker_dl_mapping[i].fn_name,
                                  tracker_dl_mapping[i].fn_ptr_ref))
            {
                g_warning ("Missing symbol '%s' in libtracker\n",
                           tracker_dl_mapping[i].fn_name);
                g_module_close (tracker);

                for (i = 0; i < G_N_ELEMENTS (tracker_dl_mapping); i++)
                    tracker_dl_mapping[i].fn_ptr_ref = NULL;

                return 0;
            }
        }
    }

    return version;
}


struct CajaSearchEngineTrackerDetails
{
    CajaQuery 	*query;
    TrackerClient 	*client;
    gboolean 	query_pending;
    TrackerVersion	version;
};


static void  caja_search_engine_tracker_class_init       (CajaSearchEngineTrackerClass *class);
static void  caja_search_engine_tracker_init             (CajaSearchEngineTracker      *engine);

G_DEFINE_TYPE (CajaSearchEngineTracker,
               caja_search_engine_tracker,
               CAJA_TYPE_SEARCH_ENGINE);

static CajaSearchEngineClass *parent_class = NULL;

static void
finalize (GObject *object)
{
    CajaSearchEngineTracker *tracker;

    tracker = CAJA_SEARCH_ENGINE_TRACKER (object);

    if (tracker->details->query)
    {
        g_object_unref (tracker->details->query);
        tracker->details->query = NULL;
    }

    if (tracker->details->version == TRACKER_0_8)
    {
        g_object_unref (tracker->details->client);
    }
    else
    {
        tracker_disconnect (tracker->details->client);
    }

    g_free (tracker->details);

    EEL_CALL_PARENT (G_OBJECT_CLASS, finalize, (object));
}


/* stolen from tracker sources, tracker.c */
static void
sparql_append_string_literal (GString     *sparql,
                              const gchar *str)
{
    char *s;

    s = tracker_sparql_escape (str);

    g_string_append_c (sparql, '"');
    g_string_append (sparql, s);
    g_string_append_c (sparql, '"');

    g_free (s);
}


static void
search_callback (gpointer results, GError *error, gpointer user_data)
{
    CajaSearchEngineTracker *tracker;
    char **results_p;
    GPtrArray *OUT_result;
    GList *hit_uris;
    gint i;
    char *uri;

    tracker = CAJA_SEARCH_ENGINE_TRACKER (user_data);
    hit_uris = NULL;

    tracker->details->query_pending = FALSE;

    if (error)
    {
        caja_search_engine_error (CAJA_SEARCH_ENGINE (tracker), error->message);
        g_error_free (error);
        return;
    }

    if (! results)
    {
        return;
    }

    if (tracker->details->version == TRACKER_0_8)
    {
        /* new tracker 0.8 API */
        OUT_result = (GPtrArray*) results;

        for (i = 0; i < OUT_result->len; i++)
        {
            uri = g_strdup (((gchar **) OUT_result->pdata[i])[0]);
            if (uri)
            {
                hit_uris = g_list_prepend (hit_uris, (char *)uri);
            }
        }

        g_ptr_array_foreach (OUT_result, (GFunc) g_free, NULL);
        g_ptr_array_free (OUT_result, TRUE);

    }
    else
    {
        /* old tracker 0.6 API */
        for (results_p = results; *results_p; results_p++)
        {
            if (tracker->details->version == TRACKER_0_6)
                uri = g_filename_to_uri (*results_p, NULL, NULL);
            else
                uri = g_strdup (*results_p);

            if (uri)
            {
                hit_uris = g_list_prepend (hit_uris, (char *)uri);
            }
        }
        g_strfreev ((gchar **)results);
    }

    caja_search_engine_hits_added (CAJA_SEARCH_ENGINE (tracker), hit_uris);
    caja_search_engine_finished (CAJA_SEARCH_ENGINE (tracker));
    g_list_free_full (hit_uris, g_free);
}


static void
caja_search_engine_tracker_start (CajaSearchEngine *engine)
{
    CajaSearchEngineTracker *tracker;
    GList 	*mimetypes, *l;
    char 	*search_text, *location, *location_uri;
    char 	**mimes;
    int 	i, mime_count;
    GString *sparql;

    tracker = CAJA_SEARCH_ENGINE_TRACKER (engine);


    if (tracker->details->query_pending)
    {
        return;
    }

    if (tracker->details->query == NULL)
    {
        return;
    }

    search_text = caja_query_get_text (tracker->details->query);

    mimetypes = caja_query_get_mime_types (tracker->details->query);

    location_uri = caja_query_get_location (tracker->details->query);

    if (location_uri)
    {
        location = (tracker->details->version == TRACKER_0_6) ?
                   g_filename_from_uri (location_uri, NULL, NULL) :
                   g_strdup (location_uri);
        g_free (location_uri);
    }
    else
    {
        location = NULL;
    }

    mime_count = g_list_length (mimetypes);

    i = 0;
    sparql = NULL;

    if (tracker->details->version == TRACKER_0_8)
    {
        /* new tracker 0.8 API */
        sparql = g_string_new ("SELECT ?url WHERE { ?file a nfo:FileDataObject ; nie:url ?url; ");
        if (mime_count > 0)
            g_string_append (sparql, "nie:mimeType ?mime ; ");
        g_string_append (sparql, "fts:match ");
        sparql_append_string_literal (sparql, search_text);

        if (location || mime_count > 0)
        {
            g_string_append (sparql, " . FILTER (");

            if (location)
            {
                g_string_append (sparql, "fn:starts-with(?url, ");
                sparql_append_string_literal (sparql, location);
                g_string_append (sparql, ")");
            }

            if (mime_count > 0)
            {
                if (location)
                    g_string_append (sparql, " && ");
                g_string_append (sparql, "(");
                for (l = mimetypes; l != NULL; l = l->next)
                {
                    if (l != mimetypes)
                        g_string_append (sparql, " || ");
                    g_string_append (sparql, "?mime = ");
                    sparql_append_string_literal (sparql, l->data);
                }
                g_string_append (sparql, ")");
            }

            g_string_append (sparql, ")");
        }
        g_string_append (sparql, " }");

        tracker_resources_sparql_query_async (tracker->details->client,
                                              sparql->str,
                                              (TrackerReplyGPtrArray) search_callback,
                                              tracker);
        g_string_free (sparql, TRUE);

    }
    else
    {
        /* old tracker 0.6 API */
        if (mime_count > 0)
        {
            /* convert list into array */
            mimes = g_new (char *, (mime_count + 1));

            for (l = mimetypes; l != NULL; l = l->next)
            {
                mimes[i] = g_strdup (l->data);
                i++;
            }

            mimes[mime_count] = NULL;

            if (location)
            {
                tracker_search_metadata_by_text_and_mime_and_location_async (tracker->details->client,
                        search_text, (const char **)mimes, location,
                        (TrackerArrayReply) search_callback,
                        tracker);
            }
            else
            {
                tracker_search_metadata_by_text_and_mime_async (tracker->details->client,
                        search_text, (const char**)mimes,
                        (TrackerArrayReply) search_callback,
                        tracker);
            }

            g_strfreev (mimes);

        }
        else
        {
            if (location)
            {
                tracker_search_metadata_by_text_and_location_async (tracker->details->client,
                        search_text,
                        location,
                        (TrackerArrayReply) search_callback,
                        tracker);
            }
            else
            {
                tracker_search_metadata_by_text_async (tracker->details->client,
                                                       search_text,
                                                       (TrackerArrayReply) search_callback,
                                                       tracker);
            }
        }
    }

    g_free (location);

    tracker->details->query_pending = TRUE;
    g_free (search_text);
    g_list_free_full (mimetypes, g_free);
}

static void
caja_search_engine_tracker_stop (CajaSearchEngine *engine)
{
    CajaSearchEngineTracker *tracker;

    tracker = CAJA_SEARCH_ENGINE_TRACKER (engine);

    if (tracker->details->query && tracker->details->query_pending)
    {
        tracker_cancel_last_call (tracker->details->client);
        tracker->details->query_pending = FALSE;
    }
}

static gboolean
caja_search_engine_tracker_is_indexed (CajaSearchEngine *engine)
{
    return TRUE;
}

static void
caja_search_engine_tracker_set_query (CajaSearchEngine *engine, CajaQuery *query)
{
    CajaSearchEngineTracker *tracker;

    tracker = CAJA_SEARCH_ENGINE_TRACKER (engine);

    if (query)
    {
        g_object_ref (query);
    }

    if (tracker->details->query)
    {
        g_object_unref (tracker->details->query);
    }

    tracker->details->query = query;
}

static void
caja_search_engine_tracker_class_init (CajaSearchEngineTrackerClass *class)
{
    GObjectClass *gobject_class;
    CajaSearchEngineClass *engine_class;

    parent_class = g_type_class_peek_parent (class);

    gobject_class = G_OBJECT_CLASS (class);
    gobject_class->finalize = finalize;

    engine_class = CAJA_SEARCH_ENGINE_CLASS (class);
    engine_class->set_query = caja_search_engine_tracker_set_query;
    engine_class->start = caja_search_engine_tracker_start;
    engine_class->stop = caja_search_engine_tracker_stop;
    engine_class->is_indexed = caja_search_engine_tracker_is_indexed;
}

static void
caja_search_engine_tracker_init (CajaSearchEngineTracker *engine)
{
    engine->details = g_new0 (CajaSearchEngineTrackerDetails, 1);
}


CajaSearchEngine *
caja_search_engine_tracker_new (void)
{
    CajaSearchEngineTracker *engine;
    TrackerClient *tracker_client;
    TrackerVersion version;

    version = open_libtracker ();

    if (version == TRACKER_0_8)
    {
        tracker_client = tracker_client_new (TRACKER_CLIENT_ENABLE_WARNINGS, G_MAXINT);
    }
    else
    {
        if (! tracker_connect)
            return NULL;

        tracker_client = tracker_connect (FALSE, -1);
    }

    if (!tracker_client)
    {
        return NULL;
    }

    if (version == TRACKER_0_6)
    {
        GError *err = NULL;

        tracker_get_version (tracker_client, &err);

        if (err != NULL)
        {
            g_error_free (err);
            tracker_disconnect (tracker_client);
            return NULL;
        }
    }

    engine = g_object_new (CAJA_TYPE_SEARCH_ENGINE_TRACKER, NULL);

    engine->details->client = tracker_client;
    engine->details->query_pending = FALSE;
    engine->details->version = version;

    return CAJA_SEARCH_ENGINE (engine);
}