/*

 * Copyright (c) 2021, Linus Groh <linusg@serenityos.org>

 *

 * SPDX-License-Identifier: BSD-2-Clause

 */

#pragma once

#include <AK/Forward.h>

#include <LibGfx/Forward.h>

#include <LibGfx/ImageFormats/ImageDecoder.h>

namespace Gfx {

// Decoder for the "Quite OK Image" format (v1.0).

// https://qoiformat.org/qoi-specification.pdf

struct [[gnu::packed]] QOIHeader {

    char magic[4];

    u32 width;

    u32 height;

    u8 channels;

    u8 colorspace;

};

struct QOILoadingContext {

    enum class State {

        NotDecoded = 0,

        HeaderDecoded,

        ImageDecoded,

        Error,

    };

    State state { State::NotDecoded };

    OwnPtr<Stream> stream {};

    QOIHeader header {};

    RefPtr<Bitmap> bitmap;

};

class QOIImageDecoderPlugin final : public ImageDecoderPlugin {

public:

    static bool sniff(ReadonlyBytes);

    static ErrorOr<NonnullOwnPtr<ImageDecoderPlugin>> create(ReadonlyBytes);

    virtual ~QOIImageDecoderPlugin() override = default;

    virtual IntSize size() override;

    virtual ErrorOr<ImageFrameDescriptor> frame(size_t index, Optional<IntSize> ideal_size = {}) override;

private:

    ErrorOr<void> decode_header_and_update_context();

    ErrorOr<void> decode_image_and_update_context();

    QOIImageDecoderPlugin(NonnullOwnPtr<Stream>);

    OwnPtr<QOILoadingContext> m_context;

};

}

template<>

struct AK::Traits<Gfx::QOIHeader> : public DefaultTraits<Gfx::QOIHeader> {

    static constexpr bool is_trivially_serializable() { return true; }

};