/*
 * User-agent detection
 */
( function( $ ) {
$.client = new ( function() {

	/* Private Members */

	var profile;

	/* Public Functions */

	/**
	 * Returns an object containing information about the browser
	 *
	 * The resulting client object will be in the following format:
	 * 	{
	 * 		'name': 'firefox',
	 * 		'layout': 'gecko',
	 * 		'layoutVersion': '20101026',
	 * 		'platform': 'linux'
	 * 		'version': '3.5.1',
	 * 		'versionBase': '3',
	 * 		'versionNumber': 3.5,
	 * 	}
	 */
	this.profile = function() {
		// Use the cached version if possible
		if ( typeof profile === 'undefined' ) {

			/* Configuration */

			// Name of browsers or layout engines we don't recognize
			var uk = 'unknown';
			// Generic version digit
			var x = 'x';
			// Strings found in user agent strings that need to be conformed
			var wildUserAgents = [ 'Opera', 'Navigator', 'Minefield', 'KHTML', 'Chrome', 'PLAYSTATION 3'];
			// Translations for conforming user agent strings
			var userAgentTranslations = [
			    // Tons of browsers lie about being something they are not
				[/(Firefox|MSIE|KHTML,\slike\sGecko|Konqueror)/, ''],
				// Chrome lives in the shadow of Safari still
				['Chrome Safari', 'Chrome'],
				// KHTML is the layout engine not the browser - LIES!
				['KHTML', 'Konqueror'],
				// Firefox nightly builds
				['Minefield', 'Firefox'],
				// This helps keep differnt versions consistent
				['Navigator', 'Netscape'],
				// This prevents version extraction issues, otherwise translation would happen later
				['PLAYSTATION 3', 'PS3'],
			];
			// Strings which precede a version number in a user agent string - combined and used as match 1 in
			// version detectection
			var versionPrefixes = [
				'camino', 'chrome', 'firefox', 'netscape', 'netscape6', 'opera', 'version', 'konqueror', 'lynx',
				'msie', 'safari', 'ps3'
			];
			// Used as matches 2, 3 and 4 in version extraction - 3 is used as actual version number
			var versionSuffix = '(\\/|\\;?\\s|)([a-z0-9\\.\\+]*?)(\\;|dev|rel|\\)|\\s|$)';
			// Names of known browsers
			var names = [
			 	'camino', 'chrome', 'firefox', 'netscape', 'konqueror', 'lynx', 'msie', 'opera', 'safari', 'ipod',
			 	'iphone', 'blackberry', 'ps3'
			];
			// Tanslations for conforming browser names
			var nameTranslations = [];
			// Names of known layout engines
			var layouts = ['gecko', 'konqueror', 'msie', 'opera', 'webkit'];
			// Translations for conforming layout names
			var layoutTranslations = [['konqueror', 'khtml'], ['msie', 'trident'], ['opera', 'presto']];
			// Names of supported layout engines for version number
			var layoutVersions = ['applewebkit', 'gecko'];
			// Names of known operating systems
			var platforms = ['win', 'mac', 'linux', 'sunos', 'solaris', 'iphone'];
			// Translations for conforming operating system names
			var platformTranslations = [['sunos', 'solaris']];

			/* Methods */

			// Performs multiple replacements on a string
			function translate( source, translations ) {
				for ( var i = 0; i < translations.length; i++ ) {
					source = source.replace( translations[i][0], translations[i][1] );
				}
				return source;
			};

			/* Pre-processing  */

			var userAgent = navigator.userAgent, match, name = uk, layout = uk, layoutversion = uk, platform = uk, version = x;
			if ( match = new RegExp( '(' + wildUserAgents.join( '|' ) + ')' ).exec( userAgent ) ) {
				// Takes a userAgent string and translates given text into something we can more easily work with
				userAgent = translate( userAgent, userAgentTranslations );
			}
			// Everything will be in lowercase from now on
			userAgent = userAgent.toLowerCase();

			/* Extraction */

			if ( match = new RegExp( '(' + names.join( '|' ) + ')' ).exec( userAgent ) ) {
				name = translate( match[1], nameTranslations );
			}
			if ( match = new RegExp( '(' + layouts.join( '|' ) + ')' ).exec( userAgent ) ) {
				layout = translate( match[1], layoutTranslations );
			}
			if ( match = new RegExp( '(' + layoutVersions.join( '|' ) + ')\\\/(\\d+)').exec( navigator.userAgent.toLowerCase() ) ) {
				layoutversion = parseInt(match[2]);
			}
			if ( match = new RegExp( '(' + platforms.join( '|' ) + ')' ).exec( navigator.platform.toLowerCase() ) ) {
				platform = translate( match[1], platformTranslations );
			}
			if ( match = new RegExp( '(' + versionPrefixes.join( '|' ) + ')' + versionSuffix ).exec( userAgent ) ) {
				version = match[3];
			}

			/* Edge Cases -- did I mention about how user agent string lie? */

			// Decode Safari's crazy 400+ version numbers
			if ( name.match( /safari/ ) && version > 400 ) {
				version = '2.0';
			}
			// Expose Opera 10's lies about being Opera 9.8
			if ( name === 'opera' && version >= 9.8) {
				version = userAgent.match( /version\/([0-9\.]*)/i )[1] || 10;
			}

			/* Caching */

			profile = {
				'name': name,
				'layout': layout,
				'layoutVersion': layoutversion,
				'platform': platform,
				'version': version,
				'versionBase': ( version !== x ? new String( version ).substr( 0, 1 ) : x ),
				'versionNumber': ( parseFloat( version, 10 ) || 0.0 )
			};
		}
		return profile;
	};

	/**
	 * Checks the current browser against a support map object to determine if the browser has been black-listed or
	 * not. If the browser was not configured specifically it is assumed to work. It is assumed that the body
	 * element is classified as either "ltr" or "rtl". If neither is set, "ltr" is assumed.
	 *
	 * A browser map is in the following format:
	 *	{
	 * 		'ltr': {
	 * 			// Multiple rules with configurable operators
	 * 			'msie': [['>=', 7], ['!=', 9]],
	 *			// Blocked entirely
	 * 			'iphone': false
	 * 		},
	 * 		'rtl': {
	 * 			// Test against a string
	 * 			'msie': [['!==', '8.1.2.3']],
	 * 			// RTL rules do not fall through to LTR rules, you must explicity set each of them
	 * 			'iphone': false
	 * 		}
	 *	}
	 *
	 * @param map Object of browser support map
	 *
	 * @return Boolean true if browser known or assumed to be supported, false if blacklisted
	 */
	this.test = function( map ) {
		var profile = jQuery.client.profile();
		var dir = jQuery( 'body' ).is( '.rtl' ) ? 'rtl' : 'ltr';
		// Check over each browser condition to determine if we are running in a compatible client
		if ( typeof map[dir] !== 'object' || typeof map[dir][profile.name] === 'undefined' ) {
			// Unknown, so we assume it's working
			return true;
		}
		var name = map[dir][profile.name];
		for ( var condition in name ) {
			var op = name[condition][0];
			var val = name[condition][1];
			if ( val === false ) {
				return false;
			} else if ( typeof val == 'string' ) {
				if ( !( eval( 'profile.version' + op + '"' + val + '"' ) ) ) {
					return false;
				}
			} else if ( typeof val == 'number' ) {
				if ( !( eval( 'profile.versionNumber' + op + val ) ) ) {
					return false;
				}
			}
		}
		return true;
	}
} )();

$( document ).ready( function() {
	var profile = $.client.profile();
	$( 'html' )
		.addClass( 'client-' + profile.name )
		.addClass( 'client-' + profile.name + '-' + profile.versionBase )
		.addClass( 'client-' + profile.layout )
		.addClass( 'client-' + profile.platform );
} );

} )( jQuery );