<?php
namespace Vichan\Service\Media;

use Mimey\MimeTypes;
use Vichan\Data\ImageMetadataResult;


class MagickImageMetadataReader implements ImageMetadataReader {
	private string $prefix;
	private MimeTypes $mime_types;

	public static function createImageMagickReader(MimeTypes $mime_types): MagickImageMetadataReader {
		return new self('', $mime_types);
	}

	public static function createGraphicsMagickReader(MimeTypes $mime_types): MagickImageMetadataReader {
		return new self('gm ', $mime_types);
	}

	private function __construct(string $prefix, MimeTypes $mime_types) {
		$this->prefix = $prefix;
		$this->mime_types = $mime_types;
	}

	public function getMetadata(string $file_path): ImageMetadataResult {
		$arg = escapeshellarg("$file_path[0]");
		$ret_exec = shell_exec_error("{$this->prefix}identify -format \"%w %h %m\" $arg");

		if (!\is_string($ret_exec)) {
			throw new \RuntimeException("Error while executing identify");
		}
		$ret_match = \preg_match('/^(\d+) (\d+) ([\w\d]+)$/', $ret_exec, $m);
		if (!$ret_match) {
			throw new \RuntimeException("Could not parse identify output");
		}

		$mime = $this->mime_types->getMimeType($m[3]) ?? 'application/octet-stream';
		return new ImageMetadataResult($m[1], $m[2], $mime);
	}
}