ImageFormatReader: rework into ImageMetadataReader

inc/Service/Media/DefaultImageMetadataReader.php

@@ -0,0 +1,29 @@
+<?php
+namespace Vichan\Service\Media;
+
+use Vichan\Data\ImageMetadataResult;
+use Vichan\Data\MagickMetadataReader;
+
+
+/**
+ * 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.
+ *
+ * getimagesize() is agnostic of any image metadata.
+ * If e.g. the Exif Orientation flag is set to a value which rotates the image by 90 or 270 degress, index 0 and 1
+ * are swapped, i.e. the contain the height and width, respectively.
+ */
+class DefaultImageMetadataReader implements ImageMetadataReader {
+	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 '$file_path' is not an image");
+		}
+		return new ImageMetadataResult($ret[0], $ret[1], $ret['mime']);
+	}
+}