<?php

/*
 * This file is part of the overtrue/wechat.
 *
 * (c) overtrue <i@overtrue.me>
 *
 * This source file is subject to the MIT license that is bundled
 * with this source code in the file LICENSE.
 */

namespace EasyWeChat\Kernel\Support;

use finfo;

/**
 * Class File.
 */
class File
{
 /**
 * MIME mapping.
 *
 * @var array
 */
 protected static $extensionMap = [
 'audio/wav' => '.wav',
 'audio/x-ms-wma' => '.wma',
 'video/x-ms-wmv' => '.wmv',
 'video/mp4' => '.mp4',
 'audio/mpeg' => '.mp3',
 'audio/amr' => '.amr',
 'application/vnd.rn-realmedia' => '.rm',
 'audio/mid' => '.mid',
 'image/bmp' => '.bmp',
 'image/gif' => '.gif',
 'image/png' => '.png',
 'image/tiff' => '.tiff',
 'image/jpeg' => '.jpg',
 'application/pdf' => '.pdf',

 // 列举更多的文件 mime, 企业号是支持的,公众平台这边之后万一也更新了呢
 'application/msword' => '.doc',

 'application/vnd.openxmlformats-officedocument.wordprocessingml.document' => '.docx',
 'application/vnd.openxmlformats-officedocument.wordprocessingml.template' => '.dotx',
 'application/vnd.ms-word.document.macroEnabled.12' => '.docm',
 'application/vnd.ms-word.template.macroEnabled.12' => '.dotm',

 'application/vnd.ms-excel' => '.xls',

 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' => '.xlsx',
 'application/vnd.openxmlformats-officedocument.spreadsheetml.template' => '.xltx',
 'application/vnd.ms-excel.sheet.macroEnabled.12' => '.xlsm',
 'application/vnd.ms-excel.template.macroEnabled.12' => '.xltm',
 'application/vnd.ms-excel.addin.macroEnabled.12' => '.xlam',
 'application/vnd.ms-excel.sheet.binary.macroEnabled.12' => '.xlsb',

 'application/vnd.ms-powerpoint' => '.ppt',

 'application/vnd.openxmlformats-officedocument.presentationml.presentation' => '.pptx',
 'application/vnd.openxmlformats-officedocument.presentationml.template' => '.potx',
 'application/vnd.openxmlformats-officedocument.presentationml.slideshow' => '.ppsx',
 'application/vnd.ms-powerpoint.addin.macroEnabled.12' => '.ppam',
 ];

 /**
 * File header signatures.
 *
 * @var array
 */
 protected static $signatures = [
 'ffd8ff' => '.jpg',
 '424d' => '.bmp',
 '47494638' => '.gif',
 '2f55736572732f6f7665' => '.png',
 '89504e47' => '.png',
 '494433' => '.mp3',
 'fffb' => '.mp3',
 'fff3' => '.mp3',
 '3026b2758e66cf11' => '.wma',
 '52494646' => '.wav',
 '57415645' => '.wav',
 '41564920' => '.avi',
 '000001ba' => '.mpg',
 '000001b3' => '.mpg',
 '2321414d52' => '.amr',
 '25504446' => '.pdf',
 ];

 /**
 * Return steam extension.
 *
 * @param string $stream
 *
 * @return string|false
 */
 public static function getStreamExt($stream)
 {
 $ext = self::getExtBySignature($stream);

 try {
 if (empty($ext) && is_readable($stream)) {
 $stream = file_get_contents($stream);
 }
 } catch (\Exception $e) {
 }

 $fileInfo = new finfo(FILEINFO_MIME);

 $mime = strstr($fileInfo->buffer($stream), ';', true);

 return isset(self::$extensionMap[$mime]) ? self::$extensionMap[$mime] : $ext;
 }

 /**
 * Get file extension by file header signature.
 *
 * @param string $stream
 *
 * @return string
 */
 public static function getExtBySignature($stream)
 {
 $prefix = strval(bin2hex(mb_strcut($stream, 0, 10)));

 foreach (self::$signatures as $signature => $extension) {
 if (0 === strpos($prefix, strval($signature))) {
 return $extension;
 }
 }

 return '';
 }
}