<?php

declare(strict_types=1);

namespace ZipStream\Zip64;

use ZipStream\PackField;

/**
 * @internal
 */
abstract class ExtendedInformationExtraField
{
    private const TAG = 0x0001;

    public static function generate(
        ?int $originalSize = null,
        ?int $compressedSize = null,
        ?int $relativeHeaderOffset = null,
        ?int $diskStartNumber = null,
    ): string {
        return PackField::pack(
            new PackField(format: 'v', value: self::TAG),
            new PackField(
                format: 'v',
                value: ($originalSize === null ? 0 : 8)
                    + ($compressedSize === null ? 0 : 8)
                    + ($relativeHeaderOffset === null ? 0 : 8)
                    + ($diskStartNumber === null ? 0 : 4)
            ),
            ...($originalSize === null ? [] : [
                new PackField(format: 'P', value: $originalSize),
            ]),
            ...($compressedSize === null ? [] : [
                new PackField(format: 'P', value: $compressedSize),
            ]),
            ...($relativeHeaderOffset === null ? [] : [
                new PackField(format: 'P', value: $relativeHeaderOffset),
            ]),
            ...($diskStartNumber === null ? [] : [
                new PackField(format: 'V', value: $diskStartNumber),
            ]),
        );
    }
}
