/*

 * Copyright (c) 2024, the SerenityOS developers.

 *

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

 */

#pragma once

#include <AK/StringView.h>

#include <LibGfx/ImageFormats/ImageDecoder.h>

#include <LibGfx/ImageFormats/PortableImageMapLoader.h>

namespace Gfx {

struct PAM {

    static constexpr auto binary_magic_number = '7';

    static constexpr StringView image_type = "PAM"sv;

    u16 max_val { 0 };

    u16 depth { 0 };

    String tupl_type {};

    Optional<NonnullRefPtr<CMYKBitmap>> cmyk_bitmap {};

};

using PAMLoadingContext = PortableImageMapLoadingContext<PAM>;

template<class Context>

ErrorOr<void> read_pam_header(Context& context)

{

    // https://netpbm.sourceforge.net/doc/pam.html

    TRY(read_magic_number(context));

    Optional<u16> width;

    Optional<u16> height;

    Optional<u16> depth;

    Optional<u16> max_val;

    Optional<String> tupltype;

    while (true) {

        TRY(read_whitespace(context));

        auto const token = TRY(read_token(*context.stream));

        if (token == "ENDHDR") {

            auto newline = TRY(context.stream->template read_value<u8>());

            if (newline != '\n')

                return Error::from_string_view("PAM ENDHDR not followed by newline"sv);

            break;

        }

        TRY(read_whitespace(context));

        if (token == "WIDTH") {

            if (width.has_value())

                return Error::from_string_view("Duplicate PAM WIDTH field"sv);

            width = TRY(read_number(*context.stream));

        } else if (token == "HEIGHT") {

            if (height.has_value())

                return Error::from_string_view("Duplicate PAM HEIGHT field"sv);

            height = TRY(read_number(*context.stream));

        } else if (token == "DEPTH") {

            if (depth.has_value())

                return Error::from_string_view("Duplicate PAM DEPTH field"sv);

            depth = TRY(read_number(*context.stream));

        } else if (token == "MAXVAL") {

            if (max_val.has_value())

                return Error::from_string_view("Duplicate PAM MAXVAL field"sv);

            max_val = TRY(read_number(*context.stream));

        } else if (token == "TUPLTYPE") {

            // FIXME: tupltype should be all text until the next newline, with leading and trailing space stripped.

            // FIXME: If there are multiple TUPLTYPE lines, their values are all appended.

            tupltype = TRY(read_token(*context.stream));

        } else {

            return Error::from_string_view("Unknown PAM token"sv);

        }

    }

    if (!width.has_value() || !height.has_value() || !depth.has_value() || !max_val.has_value())

        return Error::from_string_view("Missing PAM header fields"sv);

    context.width = *width;

    context.height = *height;

    context.format_details.depth = *depth;

    context.format_details.max_val = *max_val;

    if (tupltype.has_value())

        context.format_details.tupl_type = *tupltype;

    context.state = Context::State::HeaderDecoded;

    return {};

}

using PAMImageDecoderPlugin = PortableImageDecoderPlugin<PAMLoadingContext>;

ErrorOr<void> read_image_data(PAMLoadingContext& context);

}