<?php

class File {
    public $url;

    function __construct($url) {
        $this->url = $url;
    }

    function get_headers($follow=true) {
        $ch = curl_init();
        curl_setopt($ch, CURLOPT_URL, $this->url);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($ch, CURLOPT_FOLLOWLOCATION, $follow);
        curl_setopt($ch, CURLOPT_HEADER, true);
        curl_setopt($ch, CURLOPT_NOBODY, true);
        curl_setopt($ch, CURLOPT_TIMEOUT, 10);
        
        $output = curl_exec($ch);

        curl_close($ch);

        $headers = [];
        $output = rtrim($output);
        $data = explode("\n", $output);
        $headers['status'] = $data[0];
        array_shift($data);

        foreach($data as $part) {
            $middle = explode(":",$part,2);
            if ( !isset($middle[1]) ) { $middle[1] = null; }
            $headers[trim($middle[0])] = trim($middle[1]);
        }

        return $headers;
    }

    function get_status($follow=true, $throw=true) {
        if ($status=$this->get_headers($follow)["status"] >= 400) {
            throw new Exception("Error downloading " . $this->url . " - Status: " . $status);
        }
        return $status;
    }

    function get_filename($follow=true) {
        $content = $this->get_headers($follow);
        $content = array_change_key_case($content, CASE_LOWER);
    
        if ($content['content-disposition']) {
            $tmp_name = explode('=', $content['content-disposition']);
            if ($tmp_name[1]) $realfilename = trim($tmp_name[1],'";\'');
        };
        
        if (!$realfilename)  {
            $stripped_url = preg_replace('/\\?.*/', '', $this->url);
            $stripped_url = preg_replace('/\\/$/', '', $stripped_url);
            $realfilename = basename($stripped_url);
        }
    
        return $realfilename;
    }

    function fetch_file($write=false, $path=null, $follow=true) {
        $ch = curl_init();
        curl_setopt($ch, CURLOPT_URL, $this->url);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($ch, CURLOPT_FOLLOWLOCATION, $follow);
        curl_setopt($ch, CURLOPT_HEADER, false);
        curl_setopt($ch, CURLOPT_NOBODY, false);
        curl_setopt($ch, CURLOPT_TIMEOUT, 10);

        $output = curl_exec($ch);
        
        if(curl_errno($ch)) throw new Exception('Error downloading file. ' . curl_error($ch));

        curl_close($ch);
        
        if ($write) {
            if (!$path) $path = tempnam(sys_get_temp_dir(), "EXPMAIL_");
            if (!file_put_contents($path, $output)) throw new Exception('Error saving file to ' . $path);
        }

        return ($write ? $path : $output);
    }
}