<?php
/**
* @version		$Id: browser.php 8288 2007-08-01 08:40:54Z eddieajau $
* @package		Joomla.Framework
* @subpackage	Environment
* @copyright	Copyright (C) 2005 - 2007 Open Source Matters. All rights reserved.
* @license		GNU/GPL, see LICENSE.php
* Joomla! is free software. This version may have been modified pursuant
* to the GNU General Public License, and as distributed it includes or
* is derivative of works licensed under the GNU General Public License or
* other free or open source software licenses.
* See COPYRIGHT.php for copyright notices and details.
*/

// Check to ensure this file is within the rest of the framework
defined('JPATH_BASE') or die();

/**
 * Browser class, provides capability information about the current web client.
 *
 * Browser identification is performed by examining the HTTP_USER_AGENT
 * environment variable provided by the web server.
 *
 * This class has many influences from the lib/Browser.php code in
 * version 3 of Horde.
 *
 * @author  Chuck Hagenbuch <chuck@horde.org>
 * @author  Jon Parise <jon@horde.org>
 * @author	Johan Janssens <johan.janssens@joomla.org>
 *
 * @package		Joomla.Framework
 * @subpackage	Environment
 * @since		1.5
 */

class JBrowser extends JObject
{
	/**
	 * Major version number.
	 *
	 * @var integer
	 */
	var $_majorVersion = 0;

	/**
	 * Minor version number.
	 *
	 * @var integer
	 */
	var $_minorVersion = 0;

	/**
	 * Browser name.
	 *
	 * @var string
	 */
	var $_browser = '';

	/**
	 * Full user agent string.
	 *
	 * @var string
	 */
	var $_agent = '';

	/**
	 * Lower-case user agent string.
	 *
	 * @var string
	 */
	var $_lowerAgent = '';

	/**
	 * HTTP_ACCEPT string
	 *
	 * @var string
	 */
	var $_accept = '';

	 /**
	 * Platform the browser is running on.
	 *
	 * @var string
	 */
	var $_platform = '';

	/**
	 * Known robots.
	 *
	 * @var array
	 */
	var $_robots = array(
		/* The most common ones. */
		'Googlebot',
		'msnbot',
		'Slurp',
		'Yahoo',
		/* The rest alphabetically. */
		'Arachnoidea',
		'ArchitextSpider',
		'Ask Jeeves',
		'B-l-i-t-z-Bot',
		'Baiduspider',
		'BecomeBot',
		'cfetch',
		'ConveraCrawler',
		'ExtractorPro',
		'FAST-WebCrawler',
		'FDSE robot',
		'fido',
		'geckobot',
		'Gigabot',
		'Girafabot',
		'grub-client',
		'Gulliver',
		'HTTrack',
		'ia_archiver',
		'InfoSeek',
		'kinjabot',
		'KIT-Fireball',
		'larbin',
		'LEIA',
		'lmspider',
		'Lycos_Spider',
		'Mediapartners-Google',
		'MuscatFerret',
		'NaverBot',
		'OmniExplorer_Bot',
		'polybot',
		'Pompos',
		'Scooter',
		'Teoma',
		'TheSuBot',
		'TurnitinBot',
		'Ultraseek',
		'ViolaBot',
		'webbandit',
		'www.almaden.ibm.com/cs/crawler',
		'ZyBorg',
	);

	/**
	 * Is this a mobile browser?
	 *
	 * @var boolean
	 */
	var $_mobile = false;

	/**
	 * Features.
	 *
	 * @var array
	 */
	var $_features = array(
		'html'			=> true,
		'hdml'			=> false,
		'wml'			=> false,
		'images'	 	=> true,
		'iframes'		=> false,
		'frames'	 	=> true,
		'tables'	 	=> true,
		'java'			=> true,
		'javascript'	=> true,
		'dom'			=> false,
		'utf'			=> false,
		'rte'			=> false,
		'homepage'		=> false,
		'accesskey'		=> false,
		'optgroup'		=> false,
		'xmlhttpreq'	=> false,
		'cite'			=> false,
	);

	/**
	 * Quirks
	 *
	 * @var array
	 */
	var $_quirks = array(
		'avoid_popup_windows'			=> false,
		'break_disposition_header'		=> false,
		'break_disposition_filename'	=> false,
		'broken_multipart_form'			=> false,
		'cache_same_url'				=> false,
		'cache_ssl_downloads'			=> false,
		'double_linebreak_textarea'		=> false,
		'empty_file_input_value'		=> false,
		'must_cache_forms'				=> false,
		'no_filename_spaces'			=> false,
		'no_hidden_overflow_tables'		=> false,
		'ow_gui_1.3'					=> false,
		'png_transparency'				=> false,
		'scrollbar_in_way'				=> false,
		'scroll_tds'					=> false,
		'windowed_controls'				=> false,
	);

	/**
	 * List of viewable image MIME subtypes.
	 * This list of viewable images works for IE and Netscape/Mozilla.
	 *
	 * @var array
	 */
	var $_images = array('jpeg', 'gif', 'png', 'pjpeg', 'x-png', 'bmp');


	/**
	 * Create a browser instance (Constructor).
	 *
	 * @param string $userAgent  The browser string to parse.
	 * @param string $accept	 The HTTP_ACCEPT settings to use.
	 */
	function __construct($userAgent = null, $accept = null)
	{
		$this->match($userAgent, $accept);
	}

	/**
	 * Returns a reference to the global Browser object, only creating it
	 * if it doesn't already exist.
	 *
	 * This method must be invoked as:
	 * 		<pre>  $browser = &JBrowser::getInstance([$userAgent[, $accept]]);</pre>
	 *
	 * @access public
	 * @param string $userAgent  The browser string to parse.
	 * @param string $accept	 The HTTP_ACCEPT settings to use.
	 * @return JBrowser  The Browser object.
	 */
	function &getInstance($userAgent = null, $accept = null)
	{
		static $instances;

		if (!isset($instances)) {
			$instances = array();
		}

		$signature = serialize(array($userAgent, $accept));

		if (empty($instances[$signature])) {
			$instances[$signature] = new JBrowser($userAgent, $accept);
		}

		return $instances[$signature];
	}

	/**
	 * Parses the user agent string and inititializes the object with
	 * all the known features and quirks for the given browser.
	 *
	 * @param string $userAgent  The browser string to parse.
	 * @param string $accept	 The HTTP_ACCEPT settings to use.
	 */
	function match($userAgent = null, $accept = null)
	{
		// Set our agent string.
		if (is_null($userAgent)) {
			if (isset($_SERVER['HTTP_USER_AGENT'])) {
				$this->_agent = trim($_SERVER['HTTP_USER_AGENT']);
			}
		} else {
			$this->_agent = $userAgent;
		}
		$this->_lowerAgent = strtolower($this->_agent);

		// Set our accept string.
		if (is_null($accept)) {
			if (isset($_SERVER['HTTP_ACCEPT'])) {
				$this->_accept = strtolower(trim($_SERVER['HTTP_ACCEPT']));
			}
		} else {
			$this->_accept = strtolower($accept);
		}

		// Check for UTF support.
		if (isset($_SERVER['HTTP_ACCEPT_CHARSET'])) {
			$this->setFeature('utf', strpos(strtolower($_SERVER['HTTP_ACCEPT_CHARSET']), 'utf') !== false);
		}

		if (!empty($this->_agent)) {
			$this->_setPlatform();

			if (strpos($this->_lowerAgent, 'mobileexplorer') !== false ||
				strpos($this->_lowerAgent, 'openwave') !== false ||
				strpos($this->_lowerAgent, 'opera mini') !== false ||
				strpos($this->_lowerAgent, 'operamini') !== false) {
				$this->setFeature('frames', false);
				$this->setFeature('javascript', false);
				$this->setQuirk('avoid_popup_windows');
				$this->_mobile = true;
			} elseif (preg_match('|Opera[/ ]([0-9.]+)|', $this->_agent, $version)) {
						$this->setBrowser('opera');
						list($this->_majorVersion, $this->_minorVersion) = explode('.', $version[1]);
						$this->setFeature('javascript', true);
						$this->setQuirk('no_filename_spaces');

				if ($this->_majorVersion >= 7) {
					$this->setFeature('dom');
					$this->setFeature('iframes');
					$this->setFeature('accesskey');
					$this->setFeature('optgroup');
					$this->setQuirk('double_linebreak_textarea');
				}
			} elseif (strpos($this->_lowerAgent, 'elaine/') !== false ||
						strpos($this->_lowerAgent, 'palmsource') !== false ||
						strpos($this->_lowerAgent, 'digital paths') !== false) {
				$this->setBrowser('palm');
				$this->setFeature('images', false);
				$this->setFeature('frames', false);
				$this->setFeature('javascript', false);
				$this->setQuirk('avoid_popup_windows');
				$this->_mobile = true;
			} elseif ((preg_match('|MSIE ([0-9.]+)|', $this->_agent, $version)) ||
						(preg_match('|Internet Explorer/([0-9.]+)|', $this->_agent, $version))) {

				$this->setBrowser('msie');
				$this->setQuirk('cache_ssl_downloads');
				$this->setQuirk('cache_same_url');
				$this->setQuirk('break_disposition_filename');

				if (strpos($version[1], '.') !== false) {
					list($this->_majorVersion, $this->_minorVersion) = explode('.', $version[1]);
				} else {
					$this->_majorVersion = $version[1];
					$this->_minorVersion = 0;
				}

				/* IE (< 7) on Windows does not support alpha transparency in
				 * PNG images. */
				if (($this->_majorVersion < 7) &&
					preg_match('/windows/i', $this->_agent)) {
					$this->setQuirk('png_transparency');
				}

				/* Some Handhelds have their screen resolution in the
				 * user agent string, which we can use to look for
				 * mobile agents. */
				if (preg_match('/; (120x160|240x280|240x320|320x320)\)/', $this->_agent)) {
					$this->_mobile = true;
				}

				switch ($this->_majorVersion) {
				case 7:
					$this->setFeature('javascript', 1.4);
					$this->setFeature('dom');
					$this->setFeature('iframes');
					$this->setFeature('utf');
					$this->setFeature('rte');
					$this->setFeature('homepage');
					$this->setFeature('accesskey');
					$this->setFeature('optgroup');
					$this->setFeature('xmlhttpreq');
					$this->setQuirk('scrollbar_in_way');
					break;

				case 6:
					$this->setFeature('javascript', 1.4);
					$this->setFeature('dom');
					$this->setFeature('iframes');
					$this->setFeature('utf');
					$this->setFeature('rte');
					$this->setFeature('homepage');
					$this->setFeature('accesskey');
					$this->setFeature('optgroup');
					$this->setFeature('xmlhttpreq');
					$this->setQuirk('scrollbar_in_way');
					$this->setQuirk('broken_multipart_form');
					$this->setQuirk('windowed_controls');
					break;

				case 5:
					if ($this->getPlatform() == 'mac') {
						$this->setFeature('javascript', 1.2);
						$this->setFeature('optgroup');
					} else {
						// MSIE 5 for Windows.
						$this->setFeature('javascript', 1.4);
						$this->setFeature('dom');
						$this->setFeature('xmlhttpreq');
						if ($this->_minorVersion >= 5) {
							$this->setFeature('rte');
							$this->setQuirk('windowed_controls');
						}
					}
					$this->setFeature('iframes');
					$this->setFeature('utf');
					$this->setFeature('homepage');
					$this->setFeature('accesskey');
					if ($this->_minorVersion == 5) {
						$this->setQuirk('break_disposition_header');
						$this->setQuirk('broken_multipart_form');
					}
					break;

				case 4:
					$this->setFeature('javascript', 1.2);
					$this->setFeature('accesskey');
					if ($this->_minorVersion > 0) {
						$this->setFeature('utf');
					}
					break;

				case 3:
					$this->setFeature('javascript', 1.5);
					$this->setQuirk('avoid_popup_windows');
					break;
				}
			} elseif (preg_match('|ANTFresco/([0-9]+)|', $this->_agent, $version)) {
				$this->setBrowser('fresco');
				$this->setFeature('javascript', 1.5);
				$this->setQuirk('avoid_popup_windows');
			} elseif (strpos($this->_lowerAgent, 'avantgo') !== false) {
				$this->setBrowser('avantgo');
				$this->_mobile = true;
			} elseif (preg_match('|Konqueror/([0-9]+)|', $this->_agent, $version) ||
						preg_match('|Safari/([0-9]+)\.?([0-9]+)?|', $this->_agent, $version)) {
				// Konqueror and Apple's Safari both use the KHTML
				// rendering engine.
				$this->setBrowser('konqueror');
				$this->setQuirk('empty_file_input_value');
				$this->setQuirk('no_hidden_overflow_tables');
				$this->_majorVersion = $version[1];
				if (isset($version[2])) {
					$this->_minorVersion = $version[2];
				}

				if (strpos($this->_agent, 'Safari') !== false &&
					$this->_majorVersion >= 60) {
					// Safari.
					$this->setFeature('utf');
					$this->setFeature('javascript', 1.4);
					$this->setFeature('dom');
					$this->setFeature('iframes');
					if ($this->_majorVersion > 125 ||
						($this->_majorVersion == 125 &&
						 $this->_minorVersion >= 1)) {
						$this->setFeature('accesskey');
						$this->setFeature('xmlhttpreq');
					}
				} else {
					// Konqueror.
					$this->setFeature('javascript', 1.5);
					switch ($this->_majorVersion) {
					case 3:
						$this->setFeature('dom');
						$this->setFeature('iframes');
						break;
					}
				}
			} elseif (preg_match('|Mozilla/([0-9.]+)|', $this->_agent, $version)) {
				$this->setBrowser('mozilla');
				$this->setQuirk('must_cache_forms');

				list($this->_majorVersion, $this->_minorVersion) = explode('.', $version[1]);
				switch ($this->_majorVersion) {
				case 5:
					if ($this->getPlatform() == 'win') {
						$this->setQuirk('break_disposition_filename');
					}
					$this->setFeature('javascript', 1.4);
					$this->setFeature('dom');
					$this->setFeature('accesskey');
					$this->setFeature('optgroup');
					$this->setFeature('xmlhttpreq');
					$this->setFeature('cite');
					if (preg_match('|rv:(.*)\)|', $this->_agent, $revision)) {
						if ($revision[1] >= 1) {
							$this->setFeature('iframes');
						}
						if ($revision[1] >= 1.3) {
							$this->setFeature('rte');
						}
					}
					break;

				case 4:
					$this->setFeature('javascript', 1.3);
					$this->setQuirk('buggy_compression');
					break;

				case 3:
				default:
					$this->setFeature('javascript', 1);
					$this->setQuirk('buggy_compression');
					break;
				}
			} elseif (preg_match('|Lynx/([0-9]+)|', $this->_agent, $version)) {
				$this->setBrowser('lynx');
				$this->setFeature('images', false);
				$this->setFeature('frames', false);
				$this->setFeature('javascript', false);
				$this->setQuirk('avoid_popup_windows');
			} elseif (preg_match('|Links \(([0-9]+)|', $this->_agent, $version)) {
				$this->setBrowser('links');
				$this->setFeature('images', false);
				$this->setFeature('frames', false);
				$this->setFeature('javascript', false);
				$this->setQuirk('avoid_popup_windows');
			} elseif (preg_match('|HotJava/([0-9]+)|', $this->_agent, $version)) {
				$this->setBrowser('hotjava');
				$this->setFeature('javascript', false);
			} elseif (strpos($this->_agent, 'UP/') !== false ||
						strpos($this->_agent, 'UP.B') !== false ||
						strpos($this->_agent, 'UP.L') !== false) {
				$this->setBrowser('up');
				$this->setFeature('html', false);
				$this->setFeature('javascript', false);
				$this->setFeature('hdml');
				$this->setFeature('wml');

				if (strpos($this->_agent, 'GUI') !== false &&
					strpos($this->_agent, 'UP.Link') !== false) {
					/* The device accepts Openwave GUI extensions for
					 * WML 1.3. Non-UP.Link gateways sometimes have
					 * problems, so exclude them. */
					$this->setQuirk('ow_gui_1.3');
				}
				$this->_mobile = true;
			} elseif (strpos($this->_agent, 'Xiino/') !== false) {
				$this->setBrowser('xiino');
				$this->setFeature('hdml');
				$this->setFeature('wml');
				$this->_mobile = true;
			} elseif (strpos($this->_agent, 'Palmscape/') !== false) {
				$this->setBrowser('palmscape');
				$this->setFeature('javascript', false);
				$this->setFeature('hdml');
				$this->setFeature('wml');
				$this->_mobile = true;
			} elseif (strpos($this->_agent, 'Nokia') !== false) {
				$this->setBrowser('nokia');
				$this->setFeature('html', false);
				$this->setFeature('wml');
				$this->setFeature('xhtml');
				$this->_mobile = true;
			} elseif (strpos($this->_agent, 'Ericsson') !== false) {
				$this->setBrowser('ericsson');
				$this->setFeature('html', false);
				$this->setFeature('wml');
				$this->_mobile = true;
			} elseif (strpos($this->_lowerAgent, 'wap') !== false) {
				$this->setBrowser('wap');
				$this->setFeature('html', false);
				$this->setFeature('javascript', false);
				$this->setFeature('hdml');
				$this->setFeature('wml');
				$this->_mobile = true;
			} elseif (strpos($this->_lowerAgent, 'docomo') !== false ||
						strpos($this->_lowerAgent, 'portalmmm') !== false) {
				$this->setBrowser('imode');
				$this->setFeature('images', false);
				$this->_mobile = true;
		} elseif (strpos($this->_agent, 'BlackBerry') !== false) {
				$this->setBrowser('blackberry');
				$this->setFeature('html', false);
				$this->setFeature('javascript', false);
				$this->setFeature('hdml');
				$this->setFeature('wml');
				$this->_mobile = true;
			} elseif (strpos($this->_agent, 'MOT-') !== false) {
				$this->setBrowser('motorola');
				$this->setFeature('html', false);
				$this->setFeature('javascript', false);
				$this->setFeature('hdml');
				$this->setFeature('wml');
				$this->_mobile = true;
			} elseif (strpos($this->_lowerAgent, 'j-') !== false) {
				$this->setBrowser('mml');
				$this->_mobile = true;
			}
		}
	}

	 /**
	 * Match the platform of the browser.
	 *
	 * This is a pretty simplistic implementation, but it's intended
	 * to let us tell what line breaks to send, so it's good enough
	 * for its purpose.
	 */
	function _setPlatform()
	{
		if (strpos($this->_lowerAgent, 'wind') !== false) {
			$this->_platform = 'win';
		} elseif (strpos($this->_lowerAgent, 'mac') !== false) {
			$this->_platform = 'mac';
		} else {
			$this->_platform = 'unix';
		}
	}

	/**
	 * Return the currently matched platform.
	 *
	 * @return string  The user's platform.
	 */
	function getPlatform()	 {
		return $this->_platform;
	}

	/**
	 * Sets the current browser.
	 *
	 * @param string $browser  The browser to set as current.
	 */
	function setBrowser($browser) {
		$this->_browser = $browser;
	}

	/**
	 * Retrieve the current browser.
	 *
	 * @return string  The current browser.
	 */
	function getBrowser()	 {
		return $this->_browser;
	}

	/**
	 * Retrieve the current browser's major version.
	 *
	 * @return integer  The current browser's major version.
	 */
	function getMajor()	 {
		return $this->_majorVersion;
	}

	/**
	 * Retrieve the current browser's minor version.
	 * @return integer  The current browser's minor version.
	 */
	function getMinor()	 {
		return $this->_minorVersion;
	}

	/**
	 * Retrieve the current browser's version.
	 * @return string  The current browser's version.
	 */
	function getVersion()	 {
		return $this->_majorVersion . '.' . $this->_minorVersion;
	}

	/**
	 * Return the full browser agent string.
	 *
	 * @return string  The browser agent string.
	 */
	function getAgentString()	 {
		return $this->_agent;
	}

	/**
	 * Returns the server protocol in use on the current server.
	 *
	 * @return string  The HTTP server protocol version.
	 */
	function getHTTPProtocol()
	{
		if (isset($_SERVER['SERVER_PROTOCOL'])) {
			if (($pos = strrpos($_SERVER['SERVER_PROTOCOL'], '/'))) {
				return substr($_SERVER['SERVER_PROTOCOL'], $pos + 1);
			}
		}
		return null;
	}

	/**
	 * Set unique behavior for the current browser.
	 *
	 * @param string $quirk  The behavior to set.
	 * @param string $value  Special behavior parameter.
	 */
	function setQuirk($quirk, $value = true) {
		$this->_quirks[$quirk] = $value;
	}

	/**
	 * Check unique behavior for the current browser.
	 *
	 * @param string $quirk  The behavior to check.
	 * @return boolean  Does the browser have the behavior set?
	 */
	function hasQuirk($quirk) {
		return !empty($this->_quirks[$quirk]);
	}

	 /**
	 * Retrieve unique behavior for the current browser.
	 *
	 * @param string $quirk  The behavior to retrieve.
	 * @return string  The value for the requested behavior.
	 */
	function getQuirk($quirk)
	{
		return isset($this->_quirks[$quirk])
				? $this->_quirks[$quirk]
				: null;
	}

	/**
	 * Set capabilities for the current browser.
	 *
	 * @param string $feature  The capability to set.
	 * @param string $value	Special capability parameter.
	 */
	function setFeature($feature, $value = true) {
		$this->_features[$feature] = $value;
	}


	/**
	 * Check the current browser capabilities.
	 * @param string $feature  The capability to check.
	 * @return boolean  Does the browser have the capability set?
	 */
	function hasFeature($feature)	 {
		return !empty($this->_features[$feature]);
	}

	/**
	 * Retrieve the current browser capability.
	 *
	 * @param string $feature  The capability to retrieve.
	 * @return string  The value of the requested capability.
	 */
	function getFeature($feature)	 {
		 return isset($this->_features[$feature])
				? $this->_features[$feature]
				: null;
	}

	/**
	 * Determines if a browser can display a given MIME type.
	 *
	 * @param string $mimetype  The MIME type to check.
	 * @return boolean  True if the browser can display the MIME type.
	 */
	function isViewable($mimetype)
	{
		$mimetype = strtolower($mimetype);
		list($type, $subtype) = explode('/', $mimetype);

		if (!empty($this->_accept)) {
			$wildcard_match = false;

			if (strpos($this->_accept, $mimetype) !== false) {
				return true;
			}

			if (strpos($this->_accept, '*/*') !== false) {
				$wildcard_match = true;
				if ($type != 'image') {
					return true;
				}
			 }

			/* image/jpeg and image/pjpeg *appear* to be the same
			* entity, but Mozilla doesn't seem to want to accept the
			* latter.  For our purposes, we will treat them the
			* same.
			*/
				if ($this->isBrowser('mozilla') &&
				($mimetype == 'image/pjpeg') &&
				(strpos($this->_accept, 'image/jpeg') !== false)) {
					return true;
				}

			if (!$wildcard_match) {
				return false;
			}
		}

		if (!$this->hasFeature('images') || ($type != 'image')) {
			return false;
		}

		return (in_array($subtype, $this->_images));
	}

	/**
	 * Determine if the given browser is the same as the current.
	 *
	 * @param string $browser  The browser to check.
	 * @return boolean  Is the given browser the same as the current?
	 */
	function isBrowser($browser)
	{
		return ($this->_browser === $browser);
	}

	/**
	 * Determines if the browser is a robot or not.
	 *
	 * @return boolean  True if browser is a known robot.
	 */
	function isRobot()
	{
		 foreach ($this->_robots as $robot) {
			 if (strpos($this->_agent, $robot) !== false) {
				 return true;
			}
		}
		return false;
	}

	/**
	 * Determine if we are using a secure (SSL) connection.
	 *
	 * @return boolean  True if using SSL, false if not.
	 */
	function isSSLConnection()
	{
		return ((isset($_SERVER['HTTPS']) &&
			($_SERVER['HTTPS'] == 'on')) ||
			getenv('SSL_PROTOCOL_VERSION'));
	}
}