/* ============================================================
 *
 * This file is a part of digiKam project
 * https://www.digikam.org
 *
 * Date        : 2012-23-06
 * Description : Sort settings for camera item infos
 *
 * SPDX-FileCopyrightText: 2012 by Islam Wazery <wazery at ubuntu dot com>
 *
 * SPDX-License-Identifier: GPL-2.0-or-later
 *
 * ============================================================ */

#pragma once

// Qt includes

#include <QString>
#include <QVariant>

// Local includes

#include "itemsortcollator.h"

namespace Digikam
{

class CamItemInfo;

class CamItemSortSettings
{
public:

    enum SortOrder
    {
        AscendingOrder  = Qt::AscendingOrder,
        DescendingOrder = Qt::DescendingOrder,
        DefaultOrder    ///< sort order depends on the chosen sort role
    };

    enum CategorizationMode
    {
        NoCategories,
        CategoryByFolder,
        CategoryByFormat,
        CategoryByDate
    };

    enum SortRole
    {
        SortByFileName,
        SortByFilePath,
        SortByCreationDate,
        SortByFileSize,
        SortByDownloadState,
        SortByRating
    };

public:

    CamItemSortSettings()  = default;
    ~CamItemSortSettings() = default;

    bool operator==(const CamItemSortSettings& other) const;

    /**
     * Compares the categories of left and right camItemInfos.
     * It returns -1 if the left camItemInfo is less than right, and 0 if both fall
     * in the same category, and 1 if the left camItemInfo is greater than right.
     * Adheres to set categorization mode and current category sort order.
     */
    int compareCategories(const CamItemInfo& left, const CamItemInfo& right) const;

    /**
     * Returns true if left is less than right.
     * Adheres to current sort role and sort order.
     */
    bool lessThan(const CamItemInfo& left, const CamItemInfo& right) const;

    /**
     * Returns true if left QVariant is less than right.
     * Adheres to current sort role and sort order.
     */
    bool lessThan(const QVariant& left, const QVariant& right) const;

    /**
     * Compares the camItemInfos left and right.
     * Return -1 if left is less than right, 1 if left is greater than right,
     * and 0 if left equals right comparing the current sort role's value.
     * Adheres to set sort role and sort order.
     */
    int compare(const CamItemInfo& left, const CamItemInfo& right) const;

    void setCategorizationMode(CategorizationMode mode);
    void setCategorizationSortOrder(SortOrder order);

    bool isCategorized() const
    {
         return (categorizationMode >= CategoryByFolder);
    }

    void setSortRole(SortRole role);
    void setSortOrder(SortOrder order);
    void setStringTypeNatural(bool natural);

    int compare(const CamItemInfo& left, const CamItemInfo& right, SortRole sortRole) const;

    static Qt::SortOrder defaultSortOrderForCategorizationMode(CategorizationMode mode);
    static Qt::SortOrder defaultSortOrderForSortRole(SortRole role);

    /**
     * Returns a < b if sortOrder is Ascending, or b < a if order is descending
     */
    template <typename T>
    static inline bool lessThanByOrder(const T& a, const T& b, Qt::SortOrder sortOrder)
    {
        if (sortOrder == Qt::AscendingOrder)
        {
            return (a < b);
        }

        return (b < a);
    }

    /**
     * Returns the usual compare result of -1, 0, or 1 for lessThan, equals and greaterThan.
     */
    template <typename T>
    static inline int compareValue(const T& a, const T &b)
    {
        if (a == b)
        {
            return 0;
        }

        if (a > b)
        {
            return 1;
        }

        return (-1);
    }

    /**
     * Takes a typical result from a compare method (0 is equal, -1 is less than, 1 is greater than)
     * and applies the given sort order to it.
     */
    static inline int compareByOrder(int compareResult,  Qt::SortOrder sortOrder)
    {
        if (sortOrder == Qt::AscendingOrder)
        {
            return compareResult;
        }

        return (- compareResult);
    }

    template <typename T>
    static inline int compareByOrder(const T& a, const T& b, Qt::SortOrder sortOrder)
    {
        return compareByOrder(compareValue(a, b), sortOrder);
    }

    /**
     * Compares the two string by natural comparison and adheres to given sort order
     */
    static inline int naturalCompare(const QString& a,
                                     const QString& b,
                                     Qt::SortOrder sortOrder,
                                     Qt::CaseSensitivity caseSensitive = Qt::CaseSensitive,
                                     bool natural = true)
    {
        ItemSortCollator* const sorter = ItemSortCollator::instance();

        return compareByOrder(sorter->itemCompare(a, b, caseSensitive, natural), sortOrder);
    }

public:

    CategorizationMode   categorizationMode             = NoCategories;
    SortOrder            categorizationSortOrder        = DefaultOrder;

    /// Only Ascending or Descending, never be DefaultOrder
    Qt::SortOrder        currentCategorizationSortOrder = Qt::AscendingOrder;
    Qt::CaseSensitivity  categorizationCaseSensitivity  = Qt::CaseSensitive;

    /// Camera Items Sorting
    SortOrder            sortOrder                      = DefaultOrder;
    SortRole             sortRole                       = SortByFileName;
    bool                 strTypeNatural                 = true;

    Qt::SortOrder        currentSortOrder               = Qt::AscendingOrder;
    Qt::CaseSensitivity  sortCaseSensitivity            = Qt::CaseSensitive;
};

} // namespace Digikam
