/* ===========================================================================
*
* JQuery URL Parser
* Version 1.0
* Parses URLs and provides easy access to information within them.
*
* Author: Mark Perkins
* Author email: mark@allmarkedup.com
*
* For full documentation and more go to http://projects.allmarkedup.com/jquery_url_parser/
*
* ---------------------------------------------------------------------------
*
* CREDITS:
*
* Parser based on the Regex-based URI parser by Steven Levithan.
* For more information (including a detailed explaination of the differences
* between the 'loose' and 'strict' pasing modes) visit http://blog.stevenlevithan.com/archives/parseuri
*
* ---------------------------------------------------------------------------
*
* LICENCE:
*
* Released under a MIT Licence. See licence.txt that should have been supplied with this file,
* or visit http://projects.allmarkedup.com/jquery_url_parser/licence.txt
*
* ---------------------------------------------------------------------------
* 
* EXAMPLES OF USE:
*
* Get the domain name (host) from the current page URL
* jQuery.url.attr("host")
*
* Get the query string value for 'item' for the current page
* jQuery.url.param("item") // null if it doesn't exist
*
* Get the second segment of the URI of the current page
* jQuery.url.segment(2) // null if it doesn't exist
*
* Get the protocol of a manually passed in URL
* jQuery.url.setUrl("http://allmarkedup.com/").attr("protocol") // returns 'http'
*
*/

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 (!parsed.length) {
         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 (!parsed.length) {
         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) {
         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 (!parsed.length) {
            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

   };

} ();