/*
 * $ URIs @VERSION
 * 
 * Copyright (c) 2008,2009 Jeni Tennison
 * Licensed under the MIT (MIT-LICENSE.txt)
 *
 */
/**
 * @fileOverview $ URIs
 * @author <a href="mailto:jeni@jenitennison.com">Jeni Tennison</a>
 * @copyright (c) 2008,2009 Jeni Tennison
 * @license MIT license (MIT-LICENSE.txt)
 * @version 1.0
 */
/**
 * @class
 * @name jQuery
 * @exports $ as jQuery
 * @description rdfQuery is a <a href="http://jquery.com/">jQuery</a> plugin. The only fields and methods listed here are those that come as part of the rdfQuery library.
 */
(function ($) {

  var
    mem = {},
    uriRegex = /^(([a-z][\-a-z0-9+\.]*):)?(\/\/([^\/?#]+))?([^?#]*)?(\?([^#]*))?(#(.*))?$/i,
    docURI,

    parseURI = function (u) {
      var m = u.match(uriRegex);
      if (m === null) {
        throw "Malformed URI: " + u;
      }
      return {
        scheme: m[1] ? m[2].toLowerCase() : undefined,
        authority: m[3] ? m[4] : undefined,
        path: m[5] || '',
        query: m[6] ? m[7] : undefined,
        fragment: m[8] ? m[9] : undefined
      };
    },

    removeDotSegments = function (u) {
      var r = '', m = [];
      if (/\./.test(u)) {
        while (u !== undefined && u !== '') {
          if (u === '.' || u === '..') {
            u = '';
          } else if (/^\.\.\//.test(u)) { // starts with ../
            u = u.substring(3);
          } else if (/^\.\//.test(u)) { // starts with ./
            u = u.substring(2);
          } else if (/^\/\.(\/|$)/.test(u)) { // starts with /./ or consists of /.
            u = '/' + u.substring(3);
          } else if (/^\/\.\.(\/|$)/.test(u)) { // starts with /../ or consists of /..
            u = '/' + u.substring(4);
            r = r.replace(/\/?[^\/]+$/, '');
          } else {
            m = u.match(/^(\/?[^\/]*)(\/.*)?$/);
            u = m[2];
            r = r + m[1];
          }
        }
        return r;
      } else {
        return u;
      }
    },

    merge = function (b, r) {
      if (b.authority !== '' && (b.path === undefined || b.path === '')) {
        return '/' + r;
      } else {
        return b.path.replace(/[^\/]+$/, '') + r;
      }
    };

  /**
   * Creates a new jQuery.uri object. This should be invoked as a method rather than constructed using new.
   * @class Represents a URI
   * @param {String} [relative='']
   * @param {String|jQuery.uri} [base] Defaults to the base URI of the page
   * @returns {jQuery.uri} The new jQuery.uri object.
   * @example uri = jQuery.uri('/my/file.html');
   */
  $.uri = function (relative, base) {
    var uri;
    relative = relative || '';
    if (mem[relative]) {
      return mem[relative];
    }
    base = base || $.uri.base();
    if (typeof base === 'string') {
      base = $.uri.absolute(base);
    }
    uri = new $.uri.fn.init(relative, base);
    if (mem[uri]) {
      return mem[uri];
    } else {
      mem[uri] = uri;
      return uri;
    }
  };

  $.uri.fn = $.uri.prototype = {
    /**
     * The scheme used in the URI
     * @type String
     */
    scheme: undefined,
    /**
     * The authority used in the URI
     * @type String
     */
    authority: undefined,
    /**
     * The path used in the URI
     * @type String
     */
    path: undefined,
    /**
     * The query part of the URI
     * @type String
     */
    query: undefined,
    /**
     * The fragment part of the URI
     * @type String
     */
    fragment: undefined,
    
    init: function (relative, base) {
      var r = {};
      base = base || {};
      $.extend(this, parseURI(relative));
      if (this.scheme === undefined) {
        this.scheme = base.scheme;
        if (this.authority !== undefined) {
          this.path = removeDotSegments(this.path);
        } else {
          this.authority = base.authority;
          if (this.path === '') {
            this.path = base.path;
            if (this.query === undefined) {
              this.query = base.query;
            }
          } else {
            if (!/^\//.test(this.path)) {
              this.path = merge(base, this.path);
            }
            this.path = removeDotSegments(this.path);
          }
        }
      }
      if (this.scheme === undefined) {
        throw "Malformed URI: URI is not an absolute URI and no base supplied: " + relative;
      }
      return this;
    },
  
    /**
     * Resolves a relative URI relative to this URI
     * @param {String} relative
     * @returns jQuery.uri
     */
    resolve: function (relative) {
      return $.uri(relative, this);
    },
    
    /**
     * Creates a relative URI giving the path from this URI to the absolute URI passed as a parameter
     * @param {String|jQuery.uri} absolute
     * @returns String
     */
    relative: function (absolute) {
      var aPath, bPath, i = 0, j, resultPath = [], result = '';
      if (typeof absolute === 'string') {
        absolute = $.uri(absolute, {});
      }
      if (absolute.scheme !== this.scheme || 
          absolute.authority !== this.authority) {
        return absolute.toString();
      }
      if (absolute.path !== this.path) {
        aPath = absolute.path.split('/');
        bPath = this.path.split('/');
        if (aPath[1] !== bPath[1]) {
          result = absolute.path;
        } else {
          while (aPath[i] === bPath[i]) {
            i += 1;
          }
          j = i;
          for (; i < bPath.length - 1; i += 1) {
            resultPath.push('..');
          }
          for (; j < aPath.length; j += 1) {
            resultPath.push(aPath[j]);
          }
          result = resultPath.join('/');
        }
        result = absolute.query === undefined ? result : result + '?' + absolute.query;
        result = absolute.fragment === undefined ? result : result + '#' + absolute.fragment;
        return result;
      }
      if (absolute.query !== undefined && absolute.query !== this.query) {
        return '?' + absolute.query + (absolute.fragment === undefined ? '' : '#' + absolute.fragment);
      }
      if (absolute.fragment !== undefined && absolute.fragment !== this.fragment) {
        return '#' + absolute.fragment;
      }
      return '';
    },
  
    /**
     * Returns the URI as an absolute string
     * @returns String
     */
    toString: function () {
      var result = '';
      if (this._string) {
        return this._string;
      } else {
        result = this.scheme === undefined ? result : (result + this.scheme + ':');
        result = this.authority === undefined ? result : (result + '//' + this.authority);
        result = result + this.path;
        result = this.query === undefined ? result : (result + '?' + this.query);
        result = this.fragment === undefined ? result : (result + '#' + this.fragment);
        this._string = result;
        return result;
      }
    }
  
  };

  $.uri.fn.init.prototype = $.uri.fn;

  /**
   * Creates a {@link jQuery.uri} from a known-to-be-absolute URI
   * @param {String}
   * @returns {jQuery.uri}
   */
  $.uri.absolute = function (uri) {
    return $.uri(uri, {});
  };

  /**
   * Creates a {@link jQuery.uri} from a relative URI and an optional base URI
   * @returns {jQuery.uri}
   * @see jQuery.uri
   */
  $.uri.resolve = function (relative, base) {
    return $.uri(relative, base);
  };
  
  /**
   * Creates a string giving the relative path from a base URI to an absolute URI
   * @param {String} absolute
   * @param {String} base
   * @returns {String}
   */
  $.uri.relative = function (absolute, base) {
    return $.uri(base, {}).relative(absolute);
  };
  
  /**
   * Returns the base URI of the page
   * @returns {jQuery.uri}
   */
  $.uri.base = function () {
    return $(document).base();
  };
  
  /**
   * Returns the base URI in scope for the first selected element
   * @methodOf jQuery#
   * @name jQuery#base
   * @returns {jQuery.uri}
   * @example baseURI = $('img').base();
   */
  $.fn.base = function () {
    var base = $(this).parents().andSelf().find('base').attr('href'),
      doc = $(this)[0].ownerDocument || document,
      docURI = $.uri.absolute(doc.location === null ? document.location.href : doc.location.href);
    return base === undefined ? docURI : $.uri(base, docURI);
  };

})(jQuery);