/*
 * Copyright (C) 2005 Novell, Inc.
 *
 * Nautilus 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.
 *
 * Nautilus 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,
 * see <http://www.gnu.org/licenses/>.
 *
 * Author: Anders Carlsson <andersca@imendio.com>
 *
 */

#include <config.h>

#include <glib/gi18n.h>
#include "nautilus-search-provider.h"
#include "nautilus-search-engine.h"
#include "nautilus-search-engine-simple.h"
#include "nautilus-search-engine-model.h"
#define DEBUG_FLAG NAUTILUS_DEBUG_SEARCH
#include "nautilus-debug.h"
#include "nautilus-search-engine-tracker.h"

typedef struct
{
    GQueue *providers;

    GHashTable *uris;
    guint providers_error;

    gboolean running;
    gboolean restart;

    NautilusDirectory *directory;
    NautilusQuery *query;
    gboolean recursive;
} NautilusSearchEnginePrivate;

enum
{
    PROP_0,
    PROP_RECURSIVE,
    PROP_RUNNING,
    LAST_PROP
};

static void nautilus_search_provider_init (NautilusSearchProviderInterface *iface);

static gboolean nautilus_search_engine_is_running (NautilusSearchProvider *provider);

static void connect_provider_signals (NautilusSearchEngine   *engine,
                                      NautilusSearchProvider *provider);

static void disconnect_provider_signals (NautilusSearchEngine   *engine,
                                         NautilusSearchProvider *provider);

G_DEFINE_TYPE_WITH_CODE (NautilusSearchEngine,
                         nautilus_search_engine,
                         G_TYPE_OBJECT,
                         G_ADD_PRIVATE (NautilusSearchEngine)
                         G_IMPLEMENT_INTERFACE (NAUTILUS_TYPE_SEARCH_PROVIDER,
                                                nautilus_search_provider_init))

static void
clear_providers_queue (NautilusSearchEngine *engine)
{
    NautilusSearchEnginePrivate *priv;
    GList *l;

    priv = nautilus_search_engine_get_instance_private (engine);

    for (l = g_queue_peek_head_link (priv->providers); l != NULL; l = l->next)
    {
        disconnect_provider_signals (engine, NAUTILUS_SEARCH_PROVIDER (l->data));
        g_clear_object (&l->data);
    }

    g_queue_clear (priv->providers);
}

void
nautilus_search_engine_set_model (NautilusSearchEngine *engine,
                                  NautilusDirectory    *directory)
{
    NautilusSearchEnginePrivate *priv;

    priv = nautilus_search_engine_get_instance_private (engine);

    g_clear_object (&priv->directory);
    priv->directory = g_object_ref (directory);
}

static void
nautilus_search_engine_set_query (NautilusSearchProvider *provider,
                                  NautilusQuery          *query)
{
    NautilusSearchEngine *engine;
    NautilusSearchEnginePrivate *priv;

    engine = NAUTILUS_SEARCH_ENGINE (provider);
    priv = nautilus_search_engine_get_instance_private (engine);

    g_object_ref (query);
    g_clear_object (&priv->query);
    priv->query = query;
}

static void
search_engine_start_real (NautilusSearchEngine *engine)
{
    NautilusSearchEnginePrivate *priv;
    NautilusSearchEngineTracker *tracker;
    NautilusSearchEngineSimple *simple;
    NautilusSearchEngineModel *model;
    GList *l;

    priv = nautilus_search_engine_get_instance_private (engine);

    clear_providers_queue (engine);

    tracker = nautilus_search_engine_tracker_new ();
    g_queue_push_head (priv->providers, tracker);
    connect_provider_signals (engine, NAUTILUS_SEARCH_PROVIDER (tracker));

    simple = nautilus_search_engine_simple_new ();
    connect_provider_signals (engine, NAUTILUS_SEARCH_PROVIDER (simple));
    g_object_set (simple, "recursive", priv->recursive, NULL);
    g_queue_push_head (priv->providers, simple);

    if (priv->directory)
    {
        model = nautilus_search_engine_model_new ();
        connect_provider_signals (engine, NAUTILUS_SEARCH_PROVIDER (model));
        nautilus_search_engine_model_set_model (model, priv->directory);
        g_queue_push_head (priv->providers, model);
    }

    priv->providers_error = 0;

    priv->restart = FALSE;

    DEBUG ("Search engine start real");

    g_object_ref (engine);

    for (l = g_queue_peek_head_link (priv->providers); l != NULL; l = l->next)
    {
        nautilus_search_provider_set_query (NAUTILUS_SEARCH_PROVIDER (l->data),
                                            priv->query);
        nautilus_search_provider_start (NAUTILUS_SEARCH_PROVIDER (l->data));
    }
}

static void
nautilus_search_engine_start (NautilusSearchProvider *provider)
{
    NautilusSearchEngine *engine;
    NautilusSearchEnginePrivate *priv;
    gboolean all_providers_finished;
    GList *l;

    engine = NAUTILUS_SEARCH_ENGINE (provider);
    priv = nautilus_search_engine_get_instance_private (engine);

    DEBUG ("Search engine start");

    all_providers_finished = TRUE;
    for (l = g_queue_peek_head_link (priv->providers); l != NULL; l = l->next)
    {
        all_providers_finished &= nautilus_search_provider_is_finished (NAUTILUS_SEARCH_PROVIDER (l->data));
    }

    if (priv->running)
    {
        if (all_providers_finished &&
            priv->restart)
        {
            search_engine_start_real (engine);
        }

        return;
    }

    priv->running = TRUE;

    g_object_notify (G_OBJECT (provider), "running");

    if (!all_providers_finished)
    {
        priv->restart = TRUE;
    }
    else
    {
        search_engine_start_real (engine);
    }
}

static void
nautilus_search_engine_stop (NautilusSearchProvider *provider)
{
    NautilusSearchEngine *engine;
    NautilusSearchEnginePrivate *priv;
    GList *l;

    engine = NAUTILUS_SEARCH_ENGINE (provider);
    priv = nautilus_search_engine_get_instance_private (engine);

    DEBUG ("Search engine stop");

    for (l = g_queue_peek_head_link (priv->providers); l != NULL; l = l->next)
    {
        nautilus_search_provider_stop (NAUTILUS_SEARCH_PROVIDER (l->data));
    }

    priv->running = FALSE;
    priv->restart = FALSE;

    g_object_notify (G_OBJECT (provider), "running");
}

static void
search_provider_hits_added (NautilusSearchProvider *provider,
                            GList                  *hits,
                            NautilusSearchEngine   *engine)
{
    NautilusSearchEnginePrivate *priv;
    GList *added = NULL;
    GList *l;

    priv = nautilus_search_engine_get_instance_private (engine);

    if (!priv->running || priv->restart)
    {
        DEBUG ("Ignoring hits-added, since engine is %s",
               !priv->running ? "not running" : "waiting to restart");
        return;
    }

    for (l = hits; l != NULL; l = l->next)
    {
        NautilusSearchHit *hit = l->data;
        int count;
        const char *uri;

        uri = nautilus_search_hit_get_uri (hit);
        count = GPOINTER_TO_INT (g_hash_table_lookup (priv->uris, uri));
        if (count == 0)
        {
            added = g_list_prepend (added, hit);
        }
        g_hash_table_replace (priv->uris, g_strdup (uri), GINT_TO_POINTER (++count));
    }
    if (added != NULL)
    {
        added = g_list_reverse (added);
        nautilus_search_provider_hits_added (NAUTILUS_SEARCH_PROVIDER (engine), added);
        g_list_free (added);
    }
}

static void
check_providers_status (NautilusSearchEngine *engine)
{
    NautilusSearchEnginePrivate *priv;
    gboolean all_providers_finished;
    GList *l;

    priv = nautilus_search_engine_get_instance_private (engine);

    all_providers_finished = TRUE;
    for (l = g_queue_peek_head_link (priv->providers); l != NULL; l = l->next)
    {
        all_providers_finished &= nautilus_search_provider_is_finished (NAUTILUS_SEARCH_PROVIDER (l->data));
    }

    if (!all_providers_finished)
    {
        return;
    }

    if (g_queue_get_length (priv->providers) == priv->providers_error)
    {
        DEBUG ("Search engine error");
        nautilus_search_provider_error (NAUTILUS_SEARCH_PROVIDER (engine),
                                        _("Unable to complete the requested search"));
    }
    else
    {
        if (priv->restart)
        {
            DEBUG ("Search engine finished and restarting");
        }
        else
        {
            DEBUG ("Search engine finished");
        }
        nautilus_search_provider_finished (NAUTILUS_SEARCH_PROVIDER (engine),
                                           priv->restart ? NAUTILUS_SEARCH_PROVIDER_STATUS_RESTARTING :
                                           NAUTILUS_SEARCH_PROVIDER_STATUS_NORMAL);
    }

    priv->running = FALSE;
    g_object_notify (G_OBJECT (engine), "running");

    g_hash_table_remove_all (priv->uris);

    if (priv->restart)
    {
        nautilus_search_engine_start (NAUTILUS_SEARCH_PROVIDER (engine));
    }

    g_object_unref (engine);
}

static void
search_provider_error (NautilusSearchProvider *provider,
                       const char             *error_message,
                       NautilusSearchEngine   *engine)
{
    NautilusSearchEnginePrivate *priv;

    DEBUG ("Search provider error: %s", error_message);

    priv = nautilus_search_engine_get_instance_private (engine);
    priv->providers_error++;

    check_providers_status (engine);
}

static void
search_provider_finished (NautilusSearchProvider       *provider,
                          NautilusSearchProviderStatus  status,
                          NautilusSearchEngine         *engine)
{
    DEBUG ("Search provider finished");

    check_providers_status (engine);
}

static void
connect_provider_signals (NautilusSearchEngine   *engine,
                          NautilusSearchProvider *provider)
{
    g_signal_connect (provider, "hits-added",
                      G_CALLBACK (search_provider_hits_added),
                      engine);
    g_signal_connect (provider, "finished",
                      G_CALLBACK (search_provider_finished),
                      engine);
    g_signal_connect (provider, "error",
                      G_CALLBACK (search_provider_error),
                      engine);
}

static void
disconnect_provider_signals (NautilusSearchEngine   *engine,
                             NautilusSearchProvider *provider)
{
    g_signal_handlers_disconnect_by_func (provider,
                                          search_provider_hits_added,
                                          engine);
    g_signal_handlers_disconnect_by_func (provider,
                                          search_provider_finished,
                                          engine);
    g_signal_handlers_disconnect_by_func (provider,
                                          search_provider_error,
                                          engine);
}

static gboolean
nautilus_search_engine_is_running (NautilusSearchProvider *provider)
{
    NautilusSearchEngine *engine;
    NautilusSearchEnginePrivate *priv;

    engine = NAUTILUS_SEARCH_ENGINE (provider);
    priv = nautilus_search_engine_get_instance_private (engine);

    return priv->running;
}

static void
nautilus_search_provider_init (NautilusSearchProviderInterface *iface)
{
    iface->set_query = nautilus_search_engine_set_query;
    iface->start = nautilus_search_engine_start;
    iface->stop = nautilus_search_engine_stop;
    iface->is_running = nautilus_search_engine_is_running;
}

static void
nautilus_search_engine_finalize (GObject *object)
{
    NautilusSearchEngine *engine;
    NautilusSearchEnginePrivate *priv;

    engine = NAUTILUS_SEARCH_ENGINE (object);
    priv = nautilus_search_engine_get_instance_private (engine);

    g_hash_table_destroy (priv->uris);

    clear_providers_queue (engine);
    g_queue_free (priv->providers);

    g_clear_object (&priv->directory);
    g_clear_object (&priv->query);

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

static void
nautilus_search_engine_get_property (GObject    *object,
                                     guint       prop_id,
                                     GValue     *value,
                                     GParamSpec *pspec)
{
    NautilusSearchEnginePrivate *priv;
    NautilusSearchProvider *self = NAUTILUS_SEARCH_PROVIDER (object);

    priv = nautilus_search_engine_get_instance_private (NAUTILUS_SEARCH_ENGINE (self));

    switch (prop_id)
    {
        case PROP_RUNNING:
        {
            g_value_set_boolean (value, nautilus_search_engine_is_running (self));
        }
        break;

        case PROP_RECURSIVE:
        {
            g_value_set_boolean (value, priv->recursive);
        }
        break;

        default:
            G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
    }
}

static void
nautilus_search_engine_set_property (GObject      *object,
                                     guint         arg_id,
                                     const GValue *value,
                                     GParamSpec   *pspec)
{
    NautilusSearchEnginePrivate *priv;
    NautilusSearchEngine *engine = NAUTILUS_SEARCH_ENGINE (object);

    priv = nautilus_search_engine_get_instance_private (NAUTILUS_SEARCH_ENGINE (engine));

    switch (arg_id)
    {
        case PROP_RECURSIVE:
        {
            priv->recursive = g_value_get_boolean (value);
        }
        break;

        default:
        {
            G_OBJECT_WARN_INVALID_PROPERTY_ID (object, arg_id, pspec);
        }
        break;
    }
}

static void
nautilus_search_engine_class_init (NautilusSearchEngineClass *class)
{
    GObjectClass *object_class;

    object_class = (GObjectClass *) class;

    object_class->finalize = nautilus_search_engine_finalize;
    object_class->get_property = nautilus_search_engine_get_property;
    object_class->set_property = nautilus_search_engine_set_property;

    /**
     * NautilusSearchEngine::recursive:
     *
     * Whether the search is recursive or not.
     */
    g_object_class_install_property (object_class,
                                     PROP_RECURSIVE,
                                     g_param_spec_boolean ("recursive",
                                                           "recursive",
                                                           "recursive",
                                                           FALSE,
                                                           G_PARAM_READWRITE | G_PARAM_CONSTRUCT | G_PARAM_STATIC_STRINGS));

    /**
     * NautilusSearchEngine::running:
     *
     * Whether the search engine is running a search.
     */
    g_object_class_override_property (object_class, PROP_RUNNING, "running");
}

static void
nautilus_search_engine_init (NautilusSearchEngine *engine)
{
    NautilusSearchEnginePrivate *priv;

    priv = nautilus_search_engine_get_instance_private (engine);
    priv->uris = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, NULL);

    priv->providers = g_queue_new ();
}

NautilusSearchEngine *
nautilus_search_engine_new (void)
{
    NautilusSearchEngine *engine;

    engine = g_object_new (NAUTILUS_TYPE_SEARCH_ENGINE, NULL);

    return engine;
}