<?php
/**
 * Service: deliver CSS file(s)
 *
 * $Id$
 *
 * @author gERD Schaufelberger <gerd@php-tools.net>
 * @license PHP License
 * @package WB
 * @subpackage service
 */

WBClass::load('WBService');

/**
 * Service: deliver CSS file(s)
 *
 * Features:
 * - Deliver multiple files as one file
 * - Use cache
 * - minimize CSS (strip comments, remove blanks)
 *
 * @version 1.0.0
 * @package WB
 * @subpackage service
 */
class WBService_Css extends WBService
{
   /**
    * Display
    *
    * @param int $status
    * @param mixed $data to be send
    * @param string $checksum
    * @return bool true
    * @todo strip comments
    */
    public function run(&$status, &$data, &$checksum = null)
    {
        $this->res->addHeader('Content-Type', 'text/css; charset=utf-8;');

        // add caching header
        $useCache   =   WBParam::get('wb/cache/use', 1);
        if ($useCache) {
            $this->res->addHeader('Expires', gmdate('D, j M Y H:i:s', time() + 3600) . ' GMT');
        }

        $css    =   $this->conf->get('skin/css', 'main');
        if (!empty($this->path)) {
            $css    =   implode('/', $this->path);
        }

        // deliver a single file
        if (is_string($css)) {
            $css    =   array($css);
        }

        $file   =   WBClass::create('WBFile');
        /** @var $file WBFile */

        // cache multiple css files
        $cacheFile  =   'var/cache/css/' . md5(implode(',', $css));

        // use separate cache file for datauri
        if (WBParam::get('wb/html/datauri/use', false)) {
            $cacheFile .=   '-datauri';
        }
        if ($useCache && $file->exists($cacheFile)) {
            $status =   $this->deliverFile($file->realpath(), $data, $checksum);
            return true;
        }

        $file->touch($cacheFile);

        $cache  =   fopen($file->realpath(), 'w');
        fputs($cache, "@charset \"UTF-8\";\n");
        foreach ($css as $sheet) {
            $status     =   $this->resolveCssFile($sheet, $data, $checksum);
            fputs($cache, "/* css: $sheet */\n");
            if ($status != 200) {
                fclose($cache);
                if ($file->exists()) {
                    unlink($file->realpath());
                }
                return true;
            }
            fputs($cache, $this->loadCSSFile($data) . "\n");

            continue;

            // collect and strip file
            while (!feof($data)) {
                $line   =   trim(fgets($data, 8192));
                if (empty($line)) {
                    continue;
                }
                if (strncmp(strtolower($line), "@charset ", 9) == 0) {
                    continue;
                }
                fputs($cache, $line . "\n");
            }
        }

        fclose($cache);
        $status =   $this->deliverFile($file->realpath(), $data, $checksum);
        return true;
    }

    /**
     * load CSS file from resource
     *
     * Collect all data from CSS file, strip and add to buffer
     *
     * @param resource $data
     * @return string
     */
    private function loadCSSFile($data)
    {
        $minimize   =   false;
        if('minimize' == WBParam::get('wb/html/compress', 'minimize')) {
            $minimize   =   true;
        }
        $buffer =   array();

        // collect and strip file
        $inComment  =   false;
        while (!feof($data)) {
            $line   =   trim(fgets($data, 8192));
            if (empty($line)) {
                continue;
            }
            if (strncmp(strtolower($line), "@charset ", 9) == 0) {
                continue;
            }

            // import external files
            if (strncmp(strtolower($line), "@import ", 8) == 0) {
                $buffer[]   =   '/* IMPORT start */';
                $buffer[]   =   $this->resolveImport($line);
                $buffer[]   =   '/* IMPORT end */';
                continue;
            }

            $line   =   $this->resolveUrl($line);
            if (!$minimize) {
                $buffer[]   =   $line;
                continue;
            }

            // find end of multi-line comment
            if ($inComment) {
                $pos    =   strpos($line, '*/');
                if (false === $pos) {
                    continue;
                }
                $line   =   trim(substr($line, $pos + 2));
                $inComment  =   false;
                if (!empty($line)) {
                    $buffer[]   =   $line;
                }
                continue;
            }

            // find comment start
            $pos    =   strpos($line, '/*');
            if (false !== $pos) {
                $start      =   substr($line, 0, $pos);
                $line       =   substr($line, $pos + 2);
                $end        =   '';
                $inComment  =   true;

                // some comments end in the same line
                $pos    =   strpos($line, '*/');
                if (false !== $pos) {
                    $end   =   trim(substr($line, $pos + 2));
                    $inComment  =   false;
                }
                $line   =   $start . ' ' . $end;
            }

            $line   =   trim($line);
            if (!empty($line)) {
                $buffer[]   =   $line;
            }
        }

        return implode("\n", $buffer);
    }

    /**
     * Resolve @import in CSS file
     *
     * Include import CSS files to reduce number of requests. This applies for
     * local files only.
     *
     * @param string $line css line
     * @return string
     */
    private function resolveImport($line)
    {
        $regex  =   '|@import\s+url\(\s*([\'"]?)([^\^\'^")]*)([\'"]?)\s*\);|i';
        if (!preg_match($regex, $line, $match)) {
            return '/* import failed - bad line format */';
        }

        $css    =   $match[2];
        if (0 == strncmp('http://', $css, 7) || 0 == strncmp('https://', $css, 8)) {
            return sprintf('@import url("%s");', $css);
        }

        $this->resolveCssFile($css, $data, $checksum);
        return "/* css: $css */\n" . $this->loadCSSFile($data);
    }

    /**
     * Resolve URL
     *
     * Resolve url() and insert inline date instead, but ignore remote content
     * Actually remote content has URLs with "http://" or "https://" in it.
     *
     * @param string $line
     * @return string
     */
    private function resolveUrl($line)
    {
        if (!WBParam::get('wb/html/datauri/use', false)) {
            return $line;
        }

        // extract url parameters
        if (!preg_match('/^(.*)(\s*)url\(\s*(.+)\s*\)\s*(.*)$/', $line, $match)) {
            return $line;
        }

        // ignore remote files like
        if (strstr($match[3], 'http://') || strstr($match[3], 'https://')) {
            return $line;
        }

        $file   =   WBClass::create('WBFile');
        if (!$file->exists(str_replace('[[DOCROOT]]', 'htdoc', $match[3]))) {
            return $line;
        }
        $mime   =   $file->getMimeType();
        $data   =   base64_encode(file_get_contents($file->realpath()));
        $line   =   sprintf('%s%surl(data:%s/%s;base64,%s) %s',$match[1], $match[2], $mime[0], $mime[1], $data, $match[4]);
        return $line . "\n";
    }

    /**
     * find single CSS file
     *
     * @param string $css
     * @param resource $data
     * @param string $checksum
     * @return int $status
     */
    protected function resolveCssFile($css, &$data, &$checksum)
    {
        // remove optional ".css"
        if (strpos($css, '.')) {
            $tmp    =   explode('.', $css);
            if (end($tmp) == 'css') {
                array_pop($tmp);
                $css    =   implode('.', $tmp);
            }
        }

        $base   =   realpath(WBParam::get('wb/dir/base') . '/resource/css');
        $file   =   realpath($base . '/' . $css . '.css');

        // check for file
        if (empty($file)) {
            $data   =   <<<EOT
/*
 * Style sheet not found!
 *
 * Maybe there is a spell error in "$css.css".
 */
EOT;
            return 404;
        }

        // avoid escape from base dir jail
        if (strncmp($base, $file, strlen($base)) != 0) {
            $data   =   <<<EOT
/*
 * Style sheet not found!
 *
 * "$css.css" may not contain any "/../"
 */
EOT;
            return 403;
        }

        return $this->deliverFile($file, $data, $checksum);
    }

    /**
     * deliver real file
     *
     * @param string $file
     * @param resource $data
     * @param string $checksum
     * @return status
     */
    protected function deliverFile($file, &$data, &$checksum)
    {
        $data       =   fopen($file, 'r');
        $checksum   =   md5_file($file);
        return 200;
    }
}
?>