/*
 * This file is part of the KDE Baloo Project
 * Copyright (C) 2013  Vishesh Handa <me@vhanda.in>
 *
 * This library 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 2.1 of the License, or (at your option) version 3, or any
 * later version accepted by the membership of KDE e.V. (or its
 * successor approved by the membership of KDE e.V.), which shall
 * act as a proxy defined in Section 6 of version 3 of the license.
 *
 * This library 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 library.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

#ifndef QUERY_H
#define QUERY_H

#include "core_export.h"
#include "resultiterator.h"

#include <QVariant>

namespace Baloo {

class Term;

/**
 * The Query class is the central class to query to search for files from the Index.
 * This class can be used in multiple ways -
 *
 * \section "Query Parser" - This can be used by setting the search string via setSearchString.
 * The parser recognizes words along with AND / OR and parenthesis and specific properties.
 *
 * @example -
 * "Fire" -> Looks for all files which contain the word "Fire"
 *
 * @example -
 * "Fire OR water" -> Looks for files which contain either "Fire" or "Water". The capitalization
 * of the words doesn't matter as that will be ignored internally. However, OR and AND have to
 * be in upper case.
 *
 * @example -
 * "artist:Coldplay" -> Look for any files with the artist "Coldplay"
 *
 * @example -
 * "artist:(Coldplay OR Maroon5) power" -> Look for files with the artist Coldplay or Maroon5 and
 * the word "power"
 *
 * @example -
 * "artist:'Noah and the Whale'" -> Look for files with the artist "Noah and the Whale"
 *
 * @example -
 * "type:Audio title:Fix" -> Look for Audio files which contains the title "Fix" in its title.
 *
 * The Query Parser recognizes a large number of properties. These property names can be looked
 * up in KFileMetaData::Property::Property. The type of the file can mentioned with the property
 * 'type' or 'kind'.
 *
 *  \section "Manual Query Creation" - The query can also be created by manually using the Term
 * class and generate an entire query. Either this approach or the Query Parser approach should
 * be used. They both cannot be used at the same time, as the Query Parser will overwrite the main
 * Term.
 */
class BALOO_CORE_EXPORT Query
{
public:
    Query();
    Query(const Term& t);
    Query(const Query& rhs);
    ~Query();

    void setTerm(const Term& t);
    Term term() const;

    /**
     * Add a type to the results of the query.
     *
     * Every file has a higher level type such as "Audio", "Video", "Image", "Document", etc.
     *
     * Please note that the types are ANDed together. So searching for "Image"
     * and "Video" will probably never return any results. Have a look at
     * KFileMetaData::TypeInfo for a list of type names.
     */
    void addType(const QString& type);
    void addTypes(const QStringList& typeList);
    void setType(const QString& type);
    void setTypes(const QStringList& types);

    QStringList types() const;

    /**
     * Set some text which should be used to search for Items. This
     * contain a single word or an entire sentence.
     *
     * This will OVERRIDE any Term that has been set
     */
    void setSearchString(const QString& str);
    QString searchString() const;

    /**
     * Only a maximum of \p limit results will be returned.
     * By default the limit is 100000.
     */
    void setLimit(uint limit);
    uint limit() const;

    void setOffset(uint offset);
    uint offset() const;

    /**
     * Filter the results in the specified date range.
     *
     * The year/month/day may be set to -1 in order to ignore it.
     */
    void setDateFilter(int year, int month = -1, int day = -1);

    int yearFilter() const;
    int monthFilter() const;
    int dayFilter() const;

    enum SortingOption {
        /**
         * The results are returned in the most efficient order. They can
         * be returned in any order.
         */
        SortNone,

        /**
         * The results are returned in the order Baloo decides
         * should be ideal. This criteria is based on the mtime of the
         * file and internal word frequency.
         *
         * This is the default sorting mechanism.
         */
        SortAuto
    };

    void setSortingOption(SortingOption option);
    SortingOption sortingOption() const;

    /**
     * Only files in this folder will be returned
     */
    void setIncludeFolder(const QString& folder);
    QString includeFolder() const;

    ResultIterator exec();

    QByteArray toJSON();
    static Query fromJSON(const QByteArray& arr);

    QUrl toSearchUrl(const QString& title = QString());
    static Query fromSearchUrl(const QUrl& url);
    static QString titleFromQueryUrl(const QUrl& url);

    bool operator == (const Query& rhs) const;
    bool operator != (const Query& rhs) const;

    Query& operator=(const Query& rhs);

private:
    class Private;
    Private* d;
};

}
#endif // QUERY_H
