/* ============================================================
 *
 * This file is a part of digiKam project
 * https://www.digikam.org
 *
 * Date        : 2006-01-16
 * Description : image file IO threaded interface.
 *
 * SPDX-FileCopyrightText: 2006-2011 by Marcel Wiesweg <marcel dot wiesweg at gmx dot de>
 * SPDX-FileCopyrightText: 2012-2024 by Gilles Caulier <caulier dot gilles at gmail dot com>
 *
 * SPDX-License-Identifier: GPL-2.0-or-later
 *
 * ============================================================ */

#pragma once

// Qt includes

#include <QFlags>

// Local includes

#include "dimg.h"
#include "digikam_export.h"
#include "previewsettings.h"

namespace Digikam
{

class IccTransform;
class ThumbnailIdentifier;

class DIGIKAM_EXPORT LoadingDescription
{
public:

    enum ColorManagementSettings
    {
        NoColorConversion,
        ApplyTransform,    ///< IccData is an IccTransform
        ConvertForEditor,
        ConvertToSRGB,
        ConvertForDisplay, ///< IccData can be the output profile
        ConvertForOutput   ///< IccData is the output profile
    };

    enum RawDecodingHint
    {
        /**
         * The raw decoding options passed are taken from default, hardcoded settings
         */
        RawDecodingDefaultSettings,
        /**
         * The raw decoding options passed are taken from global settings
         */
        RawDecodingGlobalSettings,
        /**
         * The raw decoding options may be customly edited by the user
         */
        RawDecodingCustomSettings,
        /**
         * The raw decoding options are hardcoded settings optimized for loading time
         * The halfSizeColorImage and 16bit settings can be adjusted separately
         */
        RawDecodingTimeOptimized
    };

public:

    class PreviewParameters
    {
    public:

        enum PreviewType
        {
            NoPreview,
            PreviewImage,
            Thumbnail,
            DetailThumbnail
        };

        enum PreviewFlag
        {
            NoFlags         = 0,
            OnlyPregenerate = 1 << 0,
            OnlyFromStorage = 1 << 1
        };
        Q_DECLARE_FLAGS(PreviewFlags, PreviewFlag)

    public:

        PreviewParameters() = default;

        bool onlyPregenerate()                          const;
        bool onlyFromStorage()                          const;

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

    public:

        PreviewType     type            = NoPreview;
        int             size            = 0;
        PreviewFlags    flags           = NoFlags;
        PreviewSettings previewSettings;
        QVariant        extraParameter;
        QVariant        storageReference;
    };

    // ---------------------------------------------------------------------

    class PostProcessingParameters
    {
    public:

        PostProcessingParameters() = default;

    public:

        bool needsProcessing()                                 const;

        void         setTransform(const IccTransform& transform);
        bool         hasTransform()                            const;
        IccTransform transform()                               const;

        void         setProfile(const IccProfile& profile);
        bool         hasProfile()                              const;
        IccProfile   profile()                                 const;

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

    public:

        ColorManagementSettings colorManagement = NoColorConversion;
        QVariant                iccData;
    };

public:

    /**
     * An invalid LoadingDescription
     */
    LoadingDescription();

    /**
     * Use this for full loading of non-raw files
     */
    explicit LoadingDescription(const QString& filePath,
                                ColorManagementSettings = NoColorConversion);

    /**
     * Use this for full loading of raw files
     */
    LoadingDescription(const QString& filePath,
                       const DRawDecoding& settings,
                       RawDecodingHint rawDecodingHint = RawDecodingCustomSettings,
                       ColorManagementSettings = NoColorConversion);

    /**
     * For preview and thumbnail jobs:
     * Stores preview max size and Exif rotation.
     * Raw files / preview jobs:
     *    If size is not 0, the embedded preview will be loaded if available.
     *    If size is 0, DImg based loading will be used with default raw decoding settings.
     *    You can also adjust raw decoding settings and hint in this case.
     */
    LoadingDescription(const QString& filePath,
                       const PreviewSettings& settings,
                       int size,
                       ColorManagementSettings = NoColorConversion,
                       PreviewParameters::PreviewType = PreviewParameters::PreviewImage);

    /**
     * Return the cache key for this description
     */
    QString             cacheKey()                                      const;

    /**
     * For some RAW images, the same cache key is not enough to say it is the correct result.
     * You must check the raw decoding settings in this case.
     */
    bool                needCheckRawDecoding()                          const;

    /**
     * Return all possible cache keys, starting with the best choice,
     * for which a result may be found in the cache for this description.
     * Included in the list are better quality versions, if this description is reduced.
     */
    QStringList         lookupCacheKeys()                               const;

    /**
     * Returns whether this description describes a loading operation which
     * loads the image in a reduced version (quality, size etc.)
     */
    bool                isReducedVersion()                              const;

    /**
     * Returns if this description will load a thumbnail
     */
    bool                isThumbnail()                                   const;

    /**
     * Returns if this description will load a preview
     */
    bool                isPreviewImage()                                const;

    /**
     * If this referenced a thumbnail, recreate the identifier
     */
    ThumbnailIdentifier thumbnailIdentifier()                           const;

    /**
     * Returns whether the other loading task equals this one
     */
    bool operator==(const LoadingDescription& other)                    const;
    bool operator!=(const LoadingDescription& other)                    const;

    /**
     * Returns whether the other loading task equals this one
     * ignoring parameters used to specify a reduced version.
     */
    bool equalsIgnoreReducedVersion(const LoadingDescription& other)    const;

    /**
     * Returns whether this loading task equals the other one
     * or is superior to it, if the other one is a reduced version
     */
    bool equalsOrBetterThan(const LoadingDescription& other)            const;

public:

    /**
     * Returns all possible cacheKeys for the given file path
     * (all cache keys under which the given file could be stored in the cache).
     */
    static QStringList possibleCacheKeys(const QString& filePath);
    static QStringList possibleThumbnailCacheKeys(const QString& filePath);

public:

    QString                  filePath;
    DRawDecoding             rawDecodingSettings;
    RawDecodingHint          rawDecodingHint            = RawDecodingDefaultSettings;
    PreviewParameters        previewParameters;
    PostProcessingParameters postProcessingParameters;
};

} // namespace Digikam

Q_DECLARE_OPERATORS_FOR_FLAGS(Digikam::LoadingDescription::PreviewParameters::PreviewFlags)
