// JQuery URL Parser
// Written by Mark Perkins, mark@allmarkedup.com
// License: http://unlicense.org/ (i.e. do what you want with it!)

jQuery.url = function() {
    var segments = {};
    
    var parsed = {};
    
    /**
     * Options object. Only the URI and strictMode values can be changed via the setters below.
     */
    var options = {
	url : window.location, // default URI is the page in which the script is running
	strictMode: false, // 'loose' parsing by default
	key: ["source","protocol","authority","userInfo","user","password","host","port","relative","path","directory","file","query","anchor"], // keys available to query 
	q: {
	    name: "queryKey",
	    parser: /(?:^|&)([^&=]*)=?([^&]*)/g
	},
	parser: {
	    strict: /^(?:([^:\/?#]+):)?(?:\/\/((?:(([^:@]*):?([^:@]*))?@)?([^:\/?#]*)(?::(\d*))?))?((((?:[^?#\/]*\/)*)([^?#]*))(?:\?([^#]*))?(?:#(.*))?)/,  //less intuitive, more accurate to the specs
	    loose:  /^(?:(?![^:@]+:[^:@\/]*@)([^:\/?#.]+):)?(?:\/\/)?((?:(([^:@]*):?([^:@]*))?@)?([^:\/?#]*)(?::(\d*))?)(((\/(?:[^?#](?![^?#\/]*\.[^?#\/.]+(?:[?#]|$)))*\/?)?([^?#\/]*))(?:\?([^#]*))?(?:#(.*))?)/ // more intuitive, fails on relative paths and deviates from specs
	}
    };
    
    /**
     * Deals with the parsing of the URI according to the regex above.
     * Written by Steven Levithan - see credits at top.
     */		
    var parseUri = function() {
	str = decodeURI( options.url );
	
	var m = options.parser[ options.strictMode ? "strict" : "loose" ].exec( str );
	var uri = {};
	var i = 14;

	while (i--) {
	    uri[options.key[i]] = m[i] || "";
	}

	uri[options.q.name] = {};
	uri[options.key[12]].replace( options.q.parser, function ( $0, $1, $2 ) {
	    if ($1) {
		uri[options.q.name][$1] = $2;
	    }
	});

	return uri;
    };

    /**
     * Returns the value of the passed in key from the parsed URI.
     * 
     * @param string key The key whose value is required
     */		
    var key = function( key ) {
	if (jQuery.isEmptyObject(parsed)) {
	    setUp(); // if the URI has not been parsed yet then do this first...	
	} 
	if (key == "base") {
	    if (parsed.port !== null && parsed.port !== "") {
		return parsed.protocol+"://"+parsed.host+":"+parsed.port+"/";	
	    } else {
		return parsed.protocol+"://"+parsed.host+"/";
	    }
	}
	return (parsed[key] === "") ? null : parsed[key];
    };
    
    /**
     * Returns the value of the required query string parameter.
     * 
     * @param string item The parameter whose value is required
     */		
    var param = function(item) {
	if (jQuery.isEmptyObject(parsed) ) {
	    setUp(); // if the URI has not been parsed yet then do this first...	
	}
	return ( parsed.queryKey[item] === null ) ? null : parsed.queryKey[item];
    };

    /**
     * 'Constructor' (not really!) function.
     *  Called whenever the URI changes to kick off re-parsing of the URI and splitting it up into segments. 
     */	
    var setUp = function() {
	parsed = parseUri();
	getSegments();	
    };
    
    /**
     * Splits up the body of the URI into segments (i.e. sections delimited by '/')
     */
    var getSegments = function() {
	var p = parsed.path;
	segments = []; // clear out segments array
	segments = parsed.path.length == 1 ? {} : ( p.charAt( p.length - 1 ) == "/" ? p.substring( 1, p.length - 1 ) : path = p.substring( 1 ) ).split("/");
    };
    
    return {
	/**
	 * Sets the parsing mode - either strict or loose. Set to loose by default.
	 *
	 * @param string mode The mode to set the parser to. Anything apart from a value of 'strict' will set it to loose!
	 */
	setMode: function( mode ) {
	    options.strictMode = mode == "strict" ? true : false;
	    return this;
	},
	
	/**
	 * Sets URI to parse if you don't want to to parse the current page's URI.
	 * Calling the function with no value for newUri resets it to the current page's URI.
	 *
	 * @param string newUri The URI to parse.
	 */		
	setUrl: function( newUri ) {
	    options.url = newUri === undefined ? window.location : newUri;
	    setUp();
	    return this;
	},		
	
	/**
	 * Returns the value of the specified URI segment. Segments are numbered from 1 to the number of segments.
	 * For example the URI http://test.com/about/company/ segment(1) would return 'about'.
	 *
	 * If no integer is passed into the function it returns the number of segments in the URI.
	 *
	 * @param int pos The position of the segment to return. Can be empty.
	 */	
	segment: function( pos ) {
	    if ( jQuery.isEmptyObject(parsed) )
	    {
		setUp(); // if the URI has not been parsed yet then do this first...	
	    } 
	    if ( pos === undefined )
	    {
		return segments.length;
	    }
	    return ( segments[pos] === "" || segments[pos] === undefined ) ? null : segments[pos];
	},
	
	attr: key, // provides public access to private 'key' function - see above
	
	param: param // provides public access to private 'param' function - see above
	
    };
    
}();