/* ===========================================================================
 *
 * 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 Stephen Levithian.
 * 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

    ignoreCase: true, //ignore case for query string 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: /(?:^|&)([^&=]*)=?([^&]*)/gi
    },

    parser: {
      strict: /^(?:([^:\/?#]+):)?(?:\/\/((?:(([^:@]*):?([^:@]*))?@)?([^:\/?#]*)(?::(\d*))?))?((((?:[^?#\/]*\/)*)([^?#]*))(?:\?([^#]*))?(?:#(.*))?)/i, // more intuitive, fails on relative paths and deviates from specs
      loose: /^(?:(?![^:@]+:[^:@\/]*@)([^:\/?#.]+):)?(?:\/\/)?((?:(([^:@]*):?([^:@]*))?@)?([^:\/?#]*)(?::(\d*))?)(((\/(?:[^?#](?![^?#\/]*\.[^?#\/.]+(?:[?#]|$)))*\/?)?([^?#\/]*))(?:\?([^#]*))?(?:#(.*))?)/i //less intuitive, more accurate to the 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...
    }
    if (options.ignoreCase) {
      for (var key in parsed.queryKey) {
        if (item.toLowerCase() == key.toLowerCase())
          return parsed.queryKey[key];
      }
      return null;
    }
    else {
      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

  };

} ();