<?php
/**
 * Browser detection
 *
 * $Id$
 *
 * @author gERD Schaufelberger <gerd@php-tools.net>
 * @license PHP License
 * @package WB
 * @subpackage base
 */

WBClass::load('WBCache');

/**
 * Browser detection
 *
 * @version 0.3.0
 * @package WB
 * @subpackage base
 * 
 * @todo Well, maybe browscap.ini isn't a so good idea after all. It looks like the URLs are going to change
 */
class WBInfo_Browser extends WBStdClass
{
    /**
     * Path to cache file
     */
    const BROWSCAP_PATH = '/var/cache/browscap/browscap.ini';

    /**
     * Download URL
     */
    // const BROWSCAP_URL  = 'http://browsers.garykeith.com/stream.asp?BrowsCapINI';
    //const BROWSCAP_URL  =   'http://tempdownloads.browserscap.com/stream.asp?BrowsCapINI';
    const BROWSCAP_URL  =   'http://browscap.org/stream?q=PHP_BrowsCapINI'
    

    /**
     * Version identifier
     */
    const VER_TYPE_FULL     = 'version';
    const VER_TYPE_MAJOR    = 'majorver';
    const VER_TYPE_MINOR    = 'minorver';

    /**
     * list of browser capabilities
     * @var array
     */
    static private $browscap = array();

    /**
     * list of regular expressions to find user agent in browscap
     * @var array
     */
    static private $browsreg = array();

    /**
     * Capabilities of detected browser
     * @var array
     */
    private $cap    =   array();

    /**
     * Load browscap
     *
     * Parse INI file and build regular expressions to detect browsers by user agent.
     * Store everything in static class variables for later reuse.
     *
     * @todo add TTL to browscap.ini
     * @todo check RSS feed if download is needed
     * @todo add caching of some sort
     */
    private function initBrowsecap()
    {
        if (!empty(self::$browscap)) {
            return;
        }

        $ini    =   WBClass::create('WBFile');
        if (!$ini->exists(self::BROWSCAP_PATH)) {
            $this->downloadBrowscap($ini);
        }

        self::$browscap =   parse_ini_file($ini->realpath(), true, INI_SCANNER_RAW);

        $search =   array('(', ')', '@', '+', '*', '?');
        $repl   =   array('\\(', '\\)', '\\@', '\\+', '.*', '.');
        foreach (self::$browscap as $key => $v) {
            $quote  =   preg_quote($key, '@');
            $reg    =   '@^' . str_replace($search, $repl, $key) . '$@i';
            self::$browsreg[$key]   =   $reg;
        }
    }

    /**
     * Download browscap from web
     *
     * Download and store file. Use special user agent to avoid HTTP 403 - error.
     *
     * @param WBFile $des
     */
    private function downloadBrowscap($des)
    {
        $co =   array(
                    'user_agent'    =>  'Browser Capabilities Project - PHP Browscap/2012 02'
                    );
        WBClass::load('WBStream');
        $des->touch(self::BROWSCAP_PATH);
        $dfh    =   fopen($des->realpath(), 'w');
        $sfh    =   WBStream::open(self::BROWSCAP_URL, 'r', false, $co);
        while (!feof($sfh)) {
            fputs($dfh, fgets($sfh));
        }
        fclose($dfh);
        fclose($sfh);
    }

    /**
     * Identify browser using user agent
     *
     * @param string $userAgentString
     */
    public function detect($userAgentString = null)
    {
        $this->initBrowsecap();
        if (empty($userAgentString)) {
            $userAgentString    =   $_SERVER['HTTP_USER_AGENT'];
        }

        $this->userAgent    =   $userAgentString;

        // detect browser by regular expression
        $cap    =   array();
        foreach (self::$browsreg as $key => $reg) {
            if (!preg_match($reg, $userAgentString)) {
                continue;
            }
            $cap    =   self::$browscap[$key];
            break;
        }

        // merge with parents
        while (isset($cap['Parent']) && !empty($cap['Parent'])) {
            $p      =   $cap['Parent'];
            unset($cap['Parent']);
            $cap    =   array_merge(self::$browscap[$p], $cap);
        }

        // type conversion for booleans
        foreach ($cap as &$v) {
            if ('false' === $v) {
                $v  =   false;
            } else if ('true' === $v) {
                $v  =   true;
            }
        }
        // type conversion for majorver and minorver
        $cap['MajorVer']    =   intval($cap['MajorVer']);
        $cap['MinorVer']    =   intval($cap['MinorVer']);

        $this->cap  =   array_change_key_case($cap, CASE_LOWER);
    }

    /**
     * Get user agent string
     */
    public function getUserAgent()
    {
        return $this->userAgent;
    }

    /**
     * Get platform
     *
     * Get names platform like Linux, Windows, WinXP, Win7, ...
     * @return string
     */
    public function getPlatform()
    {
        $plat = $this->getAny('platform');
        if ('unknown' != $plat) {
            return $plat;
        }

        if ($this->cap['win16'] || $this->cap['win32'] || $this->cap['win64']) {
            return 'Windows';
        }
        return $plat;
    }

    /**
     * Get browser name
     *
     * Names like IE, Firefox, Opera
     * @return string
     */
    public function getName()
    {
        return $this->getAny('browser');
    }

    /**
     * Get browser version
     *
     * Return either complet version string or major/minor version
     *
     * @param string $type
     * @return string|int
     */
    public function getVersion($type = self::VER_TYPE_FULL)
    {
        return $this->getAny($type);
    }

    /**
     * Tell whether browser is marked as spider
     *
     * Browser is known as bot/spider/crawler etc.
     * @return bool
     */
    public function isCrawler()
    {
        return $this->cap['crawler'];
    }

    /**
     * Get any data from cap
     *
     * If value exists, return string, null otherwise
     *
     * @param string $key
     * @return string|null
     */
    private function getAny($key)
    {
        if (isset($this->cap[$key])) {
            return $this->cap[$key];
        }
        return null;
    }

}