<?php
namespace Vichan\Service\Media;


class MagickImageFormatReader implements ImageFormatReader {
	private string $prefix;

	public static function createImageMagickReader(): MagickImageFormatReader {
		return new self('');
	}

	public static function createGraphicsMagickReader(): MagickImageFormatReader {
		return new self('gm ');
	}

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

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

		if (!\is_string($ret_exec)) {
			throw new \RuntimeException("Error while executing identify");
		}
		$ret_match = \preg_match('/^(\d+) (\d+)$/', $ret_exec, $m);
		if (!$ret_match) {
			throw new \RuntimeException("Could not parse identify output");
		}
		return [ $m[1], $m[2] ];
	}
}