/*
 * Copyright (C) 2008 Zeeshan Ali <zeenix@gmail.com>.
 * Copyright (C) 2008-2012 Nokia Corporation.
 *
 * Author: Zeeshan Ali <zeenix@gmail.com>
 *         Jens Georg <jensg@openismus.com>
 *
 * This file is part of Rygel.
 *
 * Rygel is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * Rygel 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 */

using GUPnP;
using Gee;
using Tracker;

/**
 * Container listing possible values of a particuler Tracker metadata key.
 * The key needs to be single-valued.
 */
public abstract class Rygel.Tracker.MetadataValues : MetadataContainer {
    private string property;

    public MetadataValues (string         id,
                           MediaContainer parent,
                           string         title,
                           ItemFactory    item_factory,
                           string         property,
                           string?        child_class = null) {
        base (id, parent, title, item_factory, child_class);

        this.property = property;

        this.triplets = new QueryTriplets ();

        this.triplets.add (new QueryTriplet (SelectionQuery.ITEM_VARIABLE,
                                             "a",
                                             this.item_factory.category));
        this.fetch_metadata_values.begin ();
    }

    protected override SelectionQuery create_query () {
        var property_map = UPnPPropertyMap.get_property_map ();
        var selected = new ArrayList<string> ();
        selected.add ("DISTINCT " +
                      property_map[this.property] +
                      " AS x");

        return new SelectionQuery (selected, triplets, null, "?x");
    }

    protected override SearchContainer create_container (string id,
                                                         string title,
                                                         string value) {
        // The child container can use the same triplets we used in our
        // query.
        var child_triplets = new QueryTriplets.clone (this.triplets);

        // However we constrain the object of our last triplet.
        var filters = new ArrayList<string> ();
        var property_map = UPnPPropertyMap.get_property_map ();
        var property = property_map[this.property];
        var filter = this.create_filter (property, value);
        filters.add (filter);

        var child = new SearchContainer (id,
                                         this,
                                         title,
                                         this.item_factory,
                                         child_triplets,
                                         filters);
        if (this.property == "upnp:album") {
            child.sort_criteria = MediaContainer.ALBUM_SORT_CRITERIA;
        }

        return child;
    }
}

