<?php

/**
 * Simple file upload layer. Handles file metadata and storage
 * FileHandler: part that handles a specific disk storage layout
 *
 * Version 2019-05-01
 * (c) Vitaliy Filippov 2018+
 */

class FileHandler
{
    public static $uploadCurl;

    public function __construct($config)
    {
        $this->config = $config + [
            'basedir' => '',
            'baseurl' => '',
            'mime_blacklist' => '#'.
                // HTML may contain cookie-stealing JavaScript and web bugs
                '^text/(html|(x-)?javascript)$|^application/x-shellscript$'.
                // PHP/Perl/Bash/etc scripts may execute arbitrary code on the server
                '|php|perl|python|bash|x-c?sh(e|$)'.
                // Client-side hazards on Internet Explorer
                '|^text/scriptlet$|^application/x-msdownload$'.
                // Windows metafile, client-side vulnerability on some systems
                '|^application/x-msmetafile$'.
                '#is',
            'thumb_path' => 'thumb/',
        ];
    }

    public function getPath($web_or_fs, $file)
    {
        $s = $file['sha1'];
        return $this->config[$web_or_fs ? 'baseurl' : 'basedir'] . '/' .
            substr($s, 0, 1) . '/' . substr($s, 0, 2) . '/' . $s . '.' . $file['format'];
    }

    public function getThumbPath($web_or_fs, $file, $type)
    {
        $s = $file['sha1'];
        $ext = $file['format'] == 'jpg' || $file['format'] == 'png' || $file['format'] == 'gif'
            ? $file['format'] : 'jpg';
        return $this->config[$web_or_fs ? 'baseurl' : 'basedir'] . '/' .
            $this->config['thumb_path'] . '/' . $type . '/' .substr($s, 0, 1) . '/' . substr($s, 0, 2) . '/' . $s . '.' . $ext;
    }

    public function upload($localFile, $allowedFormats = FileUtils::ANYTHING)
    {
        $tmp_name = $localFile->getLocalPath();
        $props = FileUtils::getProps($allowedFormats, $this->config['mime_blacklist'], $tmp_name, $localFile->getFileName());
        $fn = $this->getPath(false, $props);
        if (file_exists($fn) && filesize($fn) == $props['size'])
        {
            return $props;
        }
        FileUtils::mkpath(dirname($fn), true);
        $m = $localFile->shouldMove ? 'rename' : 'copy';
        if (!@$m($tmp_name, $fn))
        {
            $error = error_get_last();
            throw new Exception($error['message']);
        }
        chmod($fn, 0666 & ~umask());
        return $props;
    }

    public function uploadUrl($url, $flags = FileUtils::ONLY_IMAGES, $curl_options = [])
    {
        if (!$url)
        {
            return NULL;
        }
        $file = NULL;
        if (substr($url, 0, 2) == '//')
        {
            $url = "http:$url";
        }
        if (!self::$uploadCurl)
        {
            // Reuse handle to use keepalive when possible
            self::$uploadCurl = curl_init();
        }
        curl_setopt_array(self::$uploadCurl, [
            CURLOPT_URL => $url,
            CURLOPT_RETURNTRANSFER => true,
        ] + $curl_options);
        $s = curl_exec(self::$uploadCurl);
        if ($s)
        {
            $tmp = tempnam(sys_get_temp_dir(), 'upl');
            file_put_contents($tmp, $s);
            unset($s);
            $file = $this->upload(new LocalFile($tmp, true), $flags);
            @unlink($tmp);
        }
        else
        {
            // Log it as E_USER_NOTICE
            trigger_error(curl_error(self::$uploadCurl));
        }
        return $file;
    }

    public function deleteFile($e)
    {
        $disk_name = $this->getPath(false, $e);
        if (file_exists($disk_name))
        {
            // Remove old file
            unlink($disk_name);
        }
        $thumb_glob = $this->getThumbPath(false, $e, '*');
        foreach (glob($thumb_glob) as $thumb)
        {
            if (file_exists($thumb))
            {
                unlink($thumb);
            }
        }
    }

    /**
     * Get or generate a thumbnail and return its URL
     */
    public function getThumb($file, $width, $height, $force = false, $crop = false, $alignY = 0.5)
    {
        $type = FileUtils::getThumbType($file, $width, $height, $crop, $alignY);
        if (!$type)
        {
            return NULL;
        }
        $fn = $this->getThumbPath(false, $file, $type['type']);
        if (!file_exists($fn) || $force)
        {
            if (substr($file['mimetype'], 0, 6) === 'video/')
            {
                $sourcefn = $this->getThumbPath(false, $file, 'src');
            }
            else
            {
                $sourcefn = $this->getPath(false, $file);
            }
            if (!FileUtils::generateThumbnail($sourcefn, $fn, $file, $type['width'], $type['height'], $crop, $alignY))
            {
                return NULL;
            }
        }
        return $this->getThumbPath(true, $file, $type);
    }
}