<?php

set_time_limit(0);

//允许下载的url

$allowed_url = [

    '',

    '',

    '']; // 允许的url

//$file_urls = post('file_urls');

$file_urls = '';//远程文件路径

$file_url_arr = explode(',', $file_urls);

$file_url_arr = array_unique($file_url_arr); // 过滤相同url

//foreach ($file_url_arr as $key => $val) {

//    $url_arr = parse_url($val);

//    if (!isset($url_arr['host']) || !in_array($url_arr['host'], $allowed_url)) {

//        unset($file_url_arr[$key]);

//    }

//}

if (empty($file_url_arr)) {

    $output = array(

        'status' => 2,

        'code' => 999,

        'error' => '未找到合法url',

    );

    exit(json_encode($output));

}

$download_dir = ROOT.'download'.DIRECTORY_SEPARATOR;

if(!file_exists($download_dir)) mkdir($download_dir, 0777, true);

$tmp_dir = $download_dir.time().rand(100, 999).DIRECTORY_SEPARATOR; // 文件临时存放目录

$downloader = new fileDownloader();

if($file_url_arr && !empty($file_url_arr)) $downloader->download($tmp_dir, $file_url_arr); // 下载文件

$file_lists = scandir($tmp_dir);

$file_lists = array_diff($file_lists, ['.', '..']);

$file_lists = array_values($file_lists); // 重置索引

if(empty($file_lists)){

    $output = array(

        'status' => 2,

        'code' => 999,

        'error' => '无下载文件',

    );

    exit(json_encode($output));

}

//if (count($file_lists) > 1) { // 如果是多个文件就压缩

//    $file_name = $downloader->compress($tmp_dir, $subject_title);

//} else {

    $file_name = $file_lists[0]; // 如果是单个文件就直接输出

//}

$file_headers = get_headers($file_urls, 1);

header("Cache-Control: public");

header("Content-Description: File Transfer");

//header('Content-disposition: attachment; filename='.basename($file_name)); //文件名

header('Content-Type: '.$file_headers['Content-Type']); //zip

header("Content-Transfer-Encoding: binary"); //二进制文件

header('Content-Length: '. filesize($tmp_dir.$file_name)); //文件大小

$user_agent = $_SERVER["HTTP_USER_AGENT"];

$encoded_name = rawurlencode($file_name);

if (preg_match("/Firefox/", $user_agent)) { //火狐浏览器

    header('Content-Disposition: attachment; filename*=utf-8\'\''.$encoded_name);

} else { // IE, 谷歌浏览器

    header('Content-Disposition: attachment; filename="' . $file_name . '"');

}

ob_clean();

flush();

@readfile($tmp_dir.$file_name);

$downloader->deleteDir($tmp_dir);

//文件下载类

class fileDownloader{

    // 下载文件

    // $dir 文件存放地址,绝对路径

    // $urls 文件下载地址

    public function download($dir, $urls = array()){

        if (!file_exists($dir)) {

            mkdir($dir, 0777, true);

        }

        if (empty($urls)) {

            return;

        }

        foreach ($urls as $val) {

            $file_name_arr = explode('/', $val); // 使用 / 分隔url

            $file_name = array_pop($file_name_arr); // 弹出数组的最后一个元素，作为文件名

            // 如果以linux作为主机，需要将utf文件名转换成GBK文件名

//                if (PHP_OS != 'WINNT') {

//                    $file_name = mb_convert_encoding($file_name, 'gbk', 'utf-8'); // 把文件名从utf-8转换为gbk

//                }

//            $file_name = mb_convert_encoding($file_name, 'gbk', 'utf-8'); // 把文件名从utf-8转换为gbk

            // 下载文件

            $ch = curl_init();

            curl_setopt($ch,CURLOPT_URL,$val);

            curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

            curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 0);

            $data = curl_exec($ch);

            error_log(var_export(curl_getinfo($ch), 1));

            curl_close($ch);

            if ($data) {

                // 保存文件

                file_put_contents($dir.$file_name, $data);

            }

        }

    }

    // 压缩文件

    // $dir 扫描目录

    // $filename 压缩文件名

    public function compress($dir, $filename = false){

        if (!file_exists($dir)) {

            return false;

        }

        $file_lists = scandir($dir); // 扫描文件夹

        $file_lists = array_diff($file_lists, ['.', '..']); //去除上级目录和当前目录

        if (empty($file_lists)) {

            return false;

        }

        if (!$filename) {

            $filename = time().rand(111, 999).'.zip';

        } else {

            $filename .= '.zip';

        }

        $fullname = $dir.$filename; // 带路径的压缩文件名

        if (!file_exists($fullname)) {

            $zip = new ZipArchive();

            if ($zip->open($fullname, ZipArchive::CREATE)==TRUE) {

                foreach($file_lists as $val){

                    if(file_exists($dir.$val)){

                        $zip->addFile($dir.$val, $val);

                    }

                }

                $zip->close();

            }

        }

        return $filename;

    }

    // 递归删除文件和文件夹

    // $path 要删除的文件路径

    public function deleteDir($path)

    {

        //如果是目录则继续

        if (is_dir($path)) {

            $file_lists = scandir($path);//扫描一个文件夹内的所有文件夹和文件并返回数组

            foreach ($file_lists as $val) {//排除目录中的.和..

                if ($val != "." && $val != "..") {//如果是目录则递归子目录，继续操作

                    if (is_dir($path . $val)) {//子目录中操作删除文件夹和文件

                        self::deleteDir($path . $val . '/');//目录清空后删除空文件夹

                        @rmdir($path . $val . '/');

                    } else {//如果是文件直接删除

                        unlink($path . $val);

                    }

                }

            }

            @rmdir($path);

        }

    }

}