<?php
namespace Vichan\Service\Media;

use Vichan\Data\Driver\Metadata\ExifReaderFactory;
use Vichan\Data\{Exif, ImageMetadataResult};


/**
 * Do not use this if you can.
 *
 * Some formats may contain no image or may contain multiple images. In these cases, getimagesize() might not be
 * able to properly determine the image size. getimagesize() will return zero for width and height in these cases.
 *
 * The implementation only supports a limited subset of metadata for only the provided exif image formats readers.
 * It won't always be able to correct the orientation, but it will try.
 */
class DefaultImageMetadataReader implements ImageMetadataReader {
	private ExifReaderFactory $exif_reader_factory;

	public function __construct(ExifReaderFactory $exif_reader_factory) {
		$this->exif_reader_factory = $exif_reader_factory;
	}

	public function getMetadata(string $file_path): ImageMetadataResult {
		$ret = \getimagesize($file_path, $info);
		if ($ret === false) {
			throw new \RuntimeException("Could not read image sizes of '$file_path'");
		}
		if ($ret[2] == \IMAGETYPE_UNKNOWN) {
			throw new \RuntimeException("Error '$file_path' is not an image");
		}

		$width = $ret[0];
		$height = $ret[1];
		$mime = $ret['mime'];
		$orientation = null;

		$exif_reader = $this->exif_reader_factory->getReader($mime);
		if ($exif_reader !== null) {
			$orientation = $exif_reader->getOrientation($file_path);
			if ($orientation !== null && Exif::exifOrientationOnSide($orientation)) {
				$tmp = $width;
				$width = $height;
				$height = $tmp;
			}
		}

		return new ImageMetadataResult($width, $height, $mime, $orientation);
	}
}