text: // Copyright 2006 The Closure Library Authors. All Rights Reserved.
  //
  // Licensed under the Apache License, Version 2.0 (the "License");
  // you may not use this file except in compliance with the License.
  // You may obtain a copy of the License at
  //
  //      http://www.apache.org/licenses/LICENSE-2.0
  //
  // Unless required by applicable law or agreed to in writing, software
  // distributed under the License is distributed on an "AS-IS" BASIS,
  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  // See the License for the specific language governing permissions and
  // limitations under the License.
  
  /**
   * @fileoverview Class for parsing and formatting URIs.
   *
   * Use goog.Uri(string) to parse a URI string.  Use goog.Uri.create(...) to
   * create a new instance of the goog.Uri object from Uri parts.
   *
   * e.g: <code>var myUri = new goog.Uri(window.location);</code>
   *
   * Implements RFC 3986 for parsing/formatting URIs.
   * http://gbiv.com/protocols/uri/rfc/rfc3986.html
   *
   * Some changes have been made to the interface (more like .NETs), though the
   * internal representation is now of un-encoded parts, this will change the
   * behavior slightly.
   *
   */
  
  goog.provide('goog.Uri');
  goog.provide('goog.Uri.QueryData');
  
  goog.require('goog.array');
  goog.require('goog.string');
  goog.require('goog.structs');
  goog.require('goog.structs.Map');
  goog.require('goog.uri.utils');
  goog.require('goog.uri.utils.ComponentIndex');
  
  
  
  /**
   * This class contains setters and getters for the parts of the URI.
   * The <code>getXyz</code>/<code>setXyz</code> methods return the decoded part
   * -- so<code>goog.Uri.parse('/foo%20bar').getPath()</code> will return the
   * decoded path, <code>/foo bar</code>.
   *
   * The constructor accepts an optional unparsed, raw URI string.  The parser
   * is relaxed, so special characters that aren't escaped but don't cause
   * ambiguities will not cause parse failures.
   *
   * All setters return <code>this</code> and so may be chained, a la
   * <code>goog.Uri.parse('/foo').setFragment('part').toString()</code>.
   *
   * @param {*=} opt_uri Optional string URI to parse
   *        (use goog.Uri.create() to create a URI from parts), or if
   *        a goog.Uri is passed, a clone is created.
   * @param {boolean=} opt_ignoreCase If true, #getParameterValue will ignore
   * the case of the parameter name.
   *
   * @constructor
   */
  goog.Uri = function(opt_uri, opt_ignoreCase) {
    // Parse in the uri string
    var m;
    if (opt_uri instanceof goog.Uri) {
      this.ignoreCase_ = goog.isDef(opt_ignoreCase) ?
          opt_ignoreCase : opt_uri.getIgnoreCase();
      this.setScheme(opt_uri.getScheme());
      this.setUserInfo(opt_uri.getUserInfo());
      this.setDomain(opt_uri.getDomain());
      this.setPort(opt_uri.getPort());
      this.setPath(opt_uri.getPath());
      this.setQueryData(opt_uri.getQueryData().clone());
      this.setFragment(opt_uri.getFragment());
    } else if (opt_uri && (m = goog.uri.utils.split(String(opt_uri)))) {
      this.ignoreCase_ = !!opt_ignoreCase;
  
      // Set the parts -- decoding as we do so.
      // COMPATABILITY NOTE - In IE, unmatched fields may be empty strings,
      // whereas in other browsers they will be undefined.
      this.setScheme(m[goog.uri.utils.ComponentIndex.SCHEME] || '', true);
      this.setUserInfo(m[goog.uri.utils.ComponentIndex.USER_INFO] || '', true);
      this.setDomain(m[goog.uri.utils.ComponentIndex.DOMAIN] || '', true);
      this.setPort(m[goog.uri.utils.ComponentIndex.PORT]);
      this.setPath(m[goog.uri.utils.ComponentIndex.PATH] || '', true);
      this.setQueryData(m[goog.uri.utils.ComponentIndex.QUERY_DATA] || '', true);
      this.setFragment(m[goog.uri.utils.ComponentIndex.FRAGMENT] || '', true);
  
    } else {
      this.ignoreCase_ = !!opt_ignoreCase;
      this.queryData_ = new goog.Uri.QueryData(null, null, this.ignoreCase_);
    }
  };
  
  
  /**
   * If true, we preserve the type of query parameters set programmatically.
   *
   * This means that if you set a parameter to a boolean, and then call
   * getParameterValue, you will get a boolean back.
   *
   * If false, we will coerce parameters to strings, just as they would
   * appear in real URIs.
   *
   * TODO(nicksantos): Remove this once people have time to fix all tests.
   *
   * @type {boolean}
   */
  goog.Uri.preserveParameterTypesCompatibilityFlag = false;
  
  
  /**
   * Parameter name added to stop caching.
   * @type {string}
   */
  goog.Uri.RANDOM_PARAM = goog.uri.utils.StandardQueryParam.RANDOM;
  
  
  /**
   * Scheme such as "http".
   * @type {string}
   * @private
   */
  goog.Uri.prototype.scheme_ = '';
  
  
  /**
   * User credentials in the form "username:password".
   * @type {string}
   * @private
   */
  goog.Uri.prototype.userInfo_ = '';
  
  
  /**
   * Domain part, e.g. "www.google.com".
   * @type {string}
   * @private
   */
  goog.Uri.prototype.domain_ = '';
  
  
  /**
   * Port, e.g. 8080.
   * @type {?number}
   * @private
   */
  goog.Uri.prototype.port_ = null;
  
  
  /**
   * Path, e.g. "/tests/img.png".
   * @type {string}
   * @private
   */
  goog.Uri.prototype.path_ = '';
  
  
  /**
   * Object representing query data.
   * @type {!goog.Uri.QueryData}
   * @private
   */
  goog.Uri.prototype.queryData_;
  
  
  /**
   * The fragment without the #.
   * @type {string}
   * @private
   */
  goog.Uri.prototype.fragment_ = '';
  
  
  /**
   * Whether or not this Uri should be treated as Read Only.
   * @type {boolean}
   * @private
   */
  goog.Uri.prototype.isReadOnly_ = false;
  
  
  /**
   * Whether or not to ignore case when comparing query params.
   * @type {boolean}
   * @private
   */
  goog.Uri.prototype.ignoreCase_ = false;
  
  
  /**
   * @return {string} The string form of the url.
   * @override
   */
  goog.Uri.prototype.toString = function() {
    var out = [];
  
    var scheme = this.getScheme();
    if (scheme) {
      out.push(goog.Uri.encodeSpecialChars_(
          scheme, goog.Uri.reDisallowedInSchemeOrUserInfo_), ':');
    }
  
    var domain = this.getDomain();
    if (domain) {
      out.push('//');
  
      var userInfo = this.getUserInfo();
      if (userInfo) {
        out.push(goog.Uri.encodeSpecialChars_(
            userInfo, goog.Uri.reDisallowedInSchemeOrUserInfo_), '@');
      }
  
      out.push(goog.string.urlEncode(domain));
  
      var port = this.getPort();
      if (port != null) {
        out.push(':', String(port));
      }
    }
  
    var path = this.getPath();
    if (path) {
      if (this.hasDomain() && path.charAt(0) != '/') {
        out.push('/');
      }
      out.push(goog.Uri.encodeSpecialChars_(
          path,
          path.charAt(0) == '/' ?
              goog.Uri.reDisallowedInAbsolutePath_ :
              goog.Uri.reDisallowedInRelativePath_));
    }
  
    var query = this.getEncodedQuery();
    if (query) {
      out.push('?', query);
    }
  
    var fragment = this.getFragment();
    if (fragment) {
      out.push('#', goog.Uri.encodeSpecialChars_(
          fragment, goog.Uri.reDisallowedInFragment_));
    }
    return out.join('');
  };
  
  
  /**
   * Resolves a relative url string to a this base uri.
   *
   * There are several kinds of relative urls:<br>
   * 1. foo - replaces the last part of the path, the whole query and fragment<br>
   * 2. /foo - replaces the the path, the query and fragment<br>
   * 3. //foo - replaces everything from the domain on.  foo is a domain name<br>
   * 4. ?foo - replace the query and fragment<br>
   * 5. #foo - replace the fragment only
   *
   * Additionally, if relative url has a non-empty path, all ".." and "."
   * segments will be resolved, as described in RFC 3986.
   *
   * @param {goog.Uri} relativeUri The relative url to resolve.
   * @return {!goog.Uri} The resolved URI.
   */
  goog.Uri.prototype.resolve = function(relativeUri) {
  
    var absoluteUri = this.clone();
  
    // we satisfy these conditions by looking for the first part of relativeUri
    // that is not blank and applying defaults to the rest
  
    var overridden = relativeUri.hasScheme();
  
    if (overridden) {
      absoluteUri.setScheme(relativeUri.getScheme());
    } else {
      overridden = relativeUri.hasUserInfo();
    }
  
    if (overridden) {
      absoluteUri.setUserInfo(relativeUri.getUserInfo());
    } else {
      overridden = relativeUri.hasDomain();
    }
  
    if (overridden) {
      absoluteUri.setDomain(relativeUri.getDomain());
    } else {
      overridden = relativeUri.hasPort();
    }
  
    var path = relativeUri.getPath();
    if (overridden) {
      absoluteUri.setPort(relativeUri.getPort());
    } else {
      overridden = relativeUri.hasPath();
      if (overridden) {
        // resolve path properly
        if (path.charAt(0) != '/') {
          // path is relative
          if (this.hasDomain() && !this.hasPath()) {
            // RFC 3986, section 5.2.3, case 1
            path = '/' + path;
          } else {
            // RFC 3986, section 5.2.3, case 2
            var lastSlashIndex = absoluteUri.getPath().lastIndexOf('/');
            if (lastSlashIndex != -1) {
              path = absoluteUri.getPath().substr(0, lastSlashIndex + 1) + path;
            }
          }
        }
        path = goog.Uri.removeDotSegments(path);
      }
    }
  
    if (overridden) {
      absoluteUri.setPath(path);
    } else {
      overridden = relativeUri.hasQuery();
    }
  
    if (overridden) {
      absoluteUri.setQueryData(relativeUri.getDecodedQuery());
    } else {
      overridden = relativeUri.hasFragment();
    }
  
    if (overridden) {
      absoluteUri.setFragment(relativeUri.getFragment());
    }
  
    return absoluteUri;
  };
  
  
  /**
   * Clones the URI instance.
   * @return {!goog.Uri} New instance of the URI objcet.
   */
  goog.Uri.prototype.clone = function() {
    return new goog.Uri(this);
  };
  
  
  /**
   * @return {string} The encoded scheme/protocol for the URI.
   */
  goog.Uri.prototype.getScheme = function() {
    return this.scheme_;
  };
  
  
  /**
   * Sets the scheme/protocol.
   * @param {string} newScheme New scheme value.
   * @param {boolean=} opt_decode Optional param for whether to decode new value.
   * @return {!goog.Uri} Reference to this URI object.
   */
  goog.Uri.prototype.setScheme = function(newScheme, opt_decode) {
    this.enforceReadOnly();
    this.scheme_ = opt_decode ? goog.Uri.decodeOrEmpty_(newScheme) : newScheme;
  
    // remove an : at the end of the scheme so somebody can pass in
    // window.location.protocol
    if (this.scheme_) {
      this.scheme_ = this.scheme_.replace(/:$/, '');
    }
    return this;
  };
  
  
  /**
   * @return {boolean} Whether the scheme has been set.
   */
  goog.Uri.prototype.hasScheme = function() {
    return !!this.scheme_;
  };
  
  
  /**
   * @return {string} The decoded user info.
   */
  goog.Uri.prototype.getUserInfo = function() {
    return this.userInfo_;
  };
  
  
  /**
   * Sets the userInfo.
   * @param {string} newUserInfo New userInfo value.
   * @param {boolean=} opt_decode Optional param for whether to decode new value.
   * @return {!goog.Uri} Reference to this URI object.
   */
  goog.Uri.prototype.setUserInfo = function(newUserInfo, opt_decode) {
    this.enforceReadOnly();
    this.userInfo_ = opt_decode ? goog.Uri.decodeOrEmpty_(newUserInfo) :
                     newUserInfo;
    return this;
  };
  
  
  /**
   * @return {boolean} Whether the user info has been set.
   */
  goog.Uri.prototype.hasUserInfo = function() {
    return !!this.userInfo_;
  };
  
  
  /**
   * @return {string} The decoded domain.
   */
  goog.Uri.prototype.getDomain = function() {
    return this.domain_;
  };
  
  
  /**
   * Sets the domain.
   * @param {string} newDomain New domain value.
   * @param {boolean=} opt_decode Optional param for whether to decode new value.
   * @return {!goog.Uri} Reference to this URI object.
   */
  goog.Uri.prototype.setDomain = function(newDomain, opt_decode) {
    this.enforceReadOnly();
    this.domain_ = opt_decode ? goog.Uri.decodeOrEmpty_(newDomain) : newDomain;
    return this;
  };
  
  
  /**
   * @return {boolean} Whether the domain has been set.
   */
  goog.Uri.prototype.hasDomain = function() {
    return !!this.domain_;
  };
  
  
  /**
   * @return {?number} The port number.
   */
  goog.Uri.prototype.getPort = function() {
    return this.port_;
  };
  
  
  /**
   * Sets the port number.
   * @param {*} newPort Port number. Will be explicitly casted to a number.
   * @return {!goog.Uri} Reference to this URI object.
   */
  goog.Uri.prototype.setPort = function(newPort) {
    this.enforceReadOnly();
  
    if (newPort) {
      newPort = Number(newPort);
      if (isNaN(newPort) || newPort < 0) {
        throw Error('Bad port number ' + newPort);
      }
      this.port_ = newPort;
    } else {
      this.port_ = null;
    }
  
    return this;
  };
  
  
  /**
   * @return {boolean} Whether the port has been set.
   */
  goog.Uri.prototype.hasPort = function() {
    return this.port_ != null;
  };
  
  
  /**
    * @return {string} The decoded path.
   */
  goog.Uri.prototype.getPath = function() {
    return this.path_;
  };
  
  
  /**
   * Sets the path.
   * @param {string} newPath New path value.
   * @param {boolean=} opt_decode Optional param for whether to decode new value.
   * @return {!goog.Uri} Reference to this URI object.
   */
  goog.Uri.prototype.setPath = function(newPath, opt_decode) {
    this.enforceReadOnly();
    this.path_ = opt_decode ? goog.Uri.decodeOrEmpty_(newPath) : newPath;
    return this;
  };
  
  
  /**
   * @return {boolean} Whether the path has been set.
   */
  goog.Uri.prototype.hasPath = function() {
    return !!this.path_;
  };
  
  
  /**
   * @return {boolean} Whether the query string has been set.
   */
  goog.Uri.prototype.hasQuery = function() {
    return this.queryData_.toString() !== '';
  };
  
  
  /**
   * Sets the query data.
   * @param {goog.Uri.QueryData|string|undefined} queryData QueryData object.
   * @param {boolean=} opt_decode Optional param for whether to decode new value.
   *     Applies only if queryData is a string.
   * @return {!goog.Uri} Reference to this URI object.
   */
  goog.Uri.prototype.setQueryData = function(queryData, opt_decode) {
    this.enforceReadOnly();
  
    if (queryData instanceof goog.Uri.QueryData) {
      this.queryData_ = queryData;
      this.queryData_.setIgnoreCase(this.ignoreCase_);
    } else {
      if (!opt_decode) {
        // QueryData accepts encoded query string, so encode it if
        // opt_decode flag is not true.
        queryData = goog.Uri.encodeSpecialChars_(queryData,
                                                 goog.Uri.reDisallowedInQuery_);
      }
      this.queryData_ = new goog.Uri.QueryData(queryData, null, this.ignoreCase_);
    }
  
    return this;
  };
  
  
  /**
   * Sets the URI query.
   * @param {string} newQuery New query value.
   * @param {boolean=} opt_decode Optional param for whether to decode new value.
   * @return {!goog.Uri} Reference to this URI object.
   */
  goog.Uri.prototype.setQuery = function(newQuery, opt_decode) {
    return this.setQueryData(newQuery, opt_decode);
  };
  
  
  /**
   * @return {string} The encoded URI query, not including the ?.
   */
  goog.Uri.prototype.getEncodedQuery = function() {
    return this.queryData_.toString();
  };
  
  
  /**
   * @return {string} The decoded URI query, not including the ?.
   */
  goog.Uri.prototype.getDecodedQuery = function() {
    return this.queryData_.toDecodedString();
  };
  
  
  /**
   * Returns the query data.
   * @return {goog.Uri.QueryData} QueryData object.
   */
  goog.Uri.prototype.getQueryData = function() {
    return this.queryData_;
  };
  
  
  /**
   * @return {string} The encoded URI query, not including the ?.
   *
   * Warning: This method, unlike other getter methods, returns encoded
   * value, instead of decoded one.
   */
  goog.Uri.prototype.getQuery = function() {
    return this.getEncodedQuery();
  };
  
  
  /**
   * Sets the value of the named query parameters, clearing previous values for
   * that key.
   *
   * @param {string} key The parameter to set.
   * @param {*} value The new value.
   * @return {!goog.Uri} Reference to this URI object.
   */
  goog.Uri.prototype.setParameterValue = function(key, value) {
    this.enforceReadOnly();
    this.queryData_.set(key, value);
    return this;
  };
  
  
  /**
   * Sets the values of the named query parameters, clearing previous values for
   * that key.  Not new values will currently be moved to the end of the query
   * string.
   *
   * So, <code>goog.Uri.parse('foo?a=b&c=d&e=f').setParameterValues('c', ['new'])
   * </code> yields <tt>foo?a=b&e=f&c=new</tt>.</p>
   *
   * @param {string} key The parameter to set.
   * @param {*} values The new values. If values is a single
   *     string then it will be treated as the sole value.
   * @return {!goog.Uri} Reference to this URI object.
   */
  goog.Uri.prototype.setParameterValues = function(key, values) {
    this.enforceReadOnly();
  
    if (!goog.isArray(values)) {
      values = [String(values)];
    }
  
    // TODO(nicksantos): This cast shouldn't be necessary.
    this.queryData_.setValues(key, /** @type {Array} */ (values));
  
    return this;
  };
  
  
  /**
   * Returns the value<b>s</b> for a given cgi parameter as a list of decoded
   * query parameter values.
   * @param {string} name The parameter to get values for.
   * @return {Array} The values for a given cgi parameter as a list of
   *     decoded query parameter values.
   */
  goog.Uri.prototype.getParameterValues = function(name) {
    return this.queryData_.getValues(name);
  };
  
  
  /**
   * Returns the first value for a given cgi parameter or undefined if the given
   * parameter name does not appear in the query string.
   * @param {string} paramName Unescaped parameter name.
   * @return {string|undefined} The first value for a given cgi parameter or
   *     undefined if the given parameter name does not appear in the query
   *     string.
   */
  goog.Uri.prototype.getParameterValue = function(paramName) {
    // NOTE(nicksantos): This type-cast is a lie when
    // preserveParameterTypesCompatibilityFlag is set to true.
    // But this should only be set to true in tests.
    return /** @type {string|undefined} */ (this.queryData_.get(paramName));
  };
  
  
  /**
   * @return {string} The URI fragment, not including the #.
   */
  goog.Uri.prototype.getFragment = function() {
    return this.fragment_;
  };
  
  
  /**
   * Sets the URI fragment.
   * @param {string} newFragment New fragment value.
   * @param {boolean=} opt_decode Optional param for whether to decode new value.
   * @return {!goog.Uri} Reference to this URI object.
   */
  goog.Uri.prototype.setFragment = function(newFragment, opt_decode) {
    this.enforceReadOnly();
    this.fragment_ = opt_decode ? goog.Uri.decodeOrEmpty_(newFragment) :
                     newFragment;
    return this;
  };
  
  
  /**
   * @return {boolean} Whether the URI has a fragment set.
   */
  goog.Uri.prototype.hasFragment = function() {
    return !!this.fragment_;
  };
  
  
  /**
   * Returns true if this has the same domain as that of uri2.
   * @param {goog.Uri} uri2 The URI object to compare to.
   * @return {boolean} true if same domain; false otherwise.
   */
  goog.Uri.prototype.hasSameDomainAs = function(uri2) {
    return ((!this.hasDomain() && !uri2.hasDomain()) ||
            this.getDomain() == uri2.getDomain()) &&
        ((!this.hasPort() && !uri2.hasPort()) ||
            this.getPort() == uri2.getPort());
  };
  
  
  /**
   * Adds a random parameter to the Uri.
   * @return {!goog.Uri} Reference to this Uri object.
   */
  goog.Uri.prototype.makeUnique = function() {
    this.enforceReadOnly();
    this.setParameterValue(goog.Uri.RANDOM_PARAM, goog.string.getRandomString());
  
    return this;
  };
  
  
  /**
   * Removes the named query parameter.
   *
   * @param {string} key The parameter to remove.
   * @return {!goog.Uri} Reference to this URI object.
   */
  goog.Uri.prototype.removeParameter = function(key) {
    this.enforceReadOnly();
    this.queryData_.remove(key);
    return this;
  };
  
  
  /**
   * Sets whether Uri is read only. If this goog.Uri is read-only,
   * enforceReadOnly_ will be called at the start of any function that may modify
   * this Uri.
   * @param {boolean} isReadOnly whether this goog.Uri should be read only.
   * @return {!goog.Uri} Reference to this Uri object.
   */
  goog.Uri.prototype.setReadOnly = function(isReadOnly) {
    this.isReadOnly_ = isReadOnly;
    return this;
  };
  
  
  /**
   * @return {boolean} Whether the URI is read only.
   */
  goog.Uri.prototype.isReadOnly = function() {
    return this.isReadOnly_;
  };
  
  
  /**
   * Checks if this Uri has been marked as read only, and if so, throws an error.
   * This should be called whenever any modifying function is called.
   */
  goog.Uri.prototype.enforceReadOnly = function() {
    if (this.isReadOnly_) {
      throw Error('Tried to modify a read-only Uri');
    }
  };
  
  
  /**
   * Sets whether to ignore case.
   * NOTE: If there are already key/value pairs in the QueryData, and
   * ignoreCase_ is set to false, the keys will all be lower-cased.
   * @param {boolean} ignoreCase whether this goog.Uri should ignore case.
   * @return {!goog.Uri} Reference to this Uri object.
   */
  goog.Uri.prototype.setIgnoreCase = function(ignoreCase) {
    this.ignoreCase_ = ignoreCase;
    if (this.queryData_) {
      this.queryData_.setIgnoreCase(ignoreCase);
    }
    return this;
  };
  
  
  /**
   * @return {boolean} Whether to ignore case.
   */
  goog.Uri.prototype.getIgnoreCase = function() {
    return this.ignoreCase_;
  };
  
  
  //==============================================================================
  // Static members
  //==============================================================================
  
  
  /**
   * Creates a uri from the string form.  Basically an alias of new goog.Uri().
   * If a Uri object is passed to parse then it will return a clone of the object.
   *
   * @param {*} uri Raw URI string or instance of Uri
   *     object.
   * @param {boolean=} opt_ignoreCase Whether to ignore the case of parameter
   * names in #getParameterValue.
   * @return {!goog.Uri} The new URI object.
   */
  goog.Uri.parse = function(uri, opt_ignoreCase) {
    return uri instanceof goog.Uri ?
           uri.clone() : new goog.Uri(uri, opt_ignoreCase);
  };
  
  
  /**
   * Creates a new goog.Uri object from unencoded parts.
   *
   * @param {?string=} opt_scheme Scheme/protocol or full URI to parse.
   * @param {?string=} opt_userInfo username:password.
   * @param {?string=} opt_domain www.google.com.
   * @param {?number=} opt_port 9830.
   * @param {?string=} opt_path /some/path/to/a/file.html.
   * @param {string|goog.Uri.QueryData=} opt_query a=1&b=2.
   * @param {?string=} opt_fragment The fragment without the #.
   * @param {boolean=} opt_ignoreCase Whether to ignore parameter name case in
   *     #getParameterValue.
   *
   * @return {!goog.Uri} The new URI object.
   */
  goog.Uri.create = function(opt_scheme, opt_userInfo, opt_domain, opt_port,
                             opt_path, opt_query, opt_fragment, opt_ignoreCase) {
  
    var uri = new goog.Uri(null, opt_ignoreCase);
  
    // Only set the parts if they are defined and not empty strings.
    opt_scheme && uri.setScheme(opt_scheme);
    opt_userInfo && uri.setUserInfo(opt_userInfo);
    opt_domain && uri.setDomain(opt_domain);
    opt_port && uri.setPort(opt_port);
    opt_path && uri.setPath(opt_path);
    opt_query && uri.setQueryData(opt_query);
    opt_fragment && uri.setFragment(opt_fragment);
  
    return uri;
  };
  
  
  /**
   * Resolves a relative Uri against a base Uri, accepting both strings and
   * Uri objects.
   *
   * @param {*} base Base Uri.
   * @param {*} rel Relative Uri.
   * @return {!goog.Uri} Resolved uri.
   */
  goog.Uri.resolve = function(base, rel) {
    if (!(base instanceof goog.Uri)) {
      base = goog.Uri.parse(base);
    }
  
    if (!(rel instanceof goog.Uri)) {
      rel = goog.Uri.parse(rel);
    }
  
    return base.resolve(rel);
  };
  
  
  /**
   * Removes dot segments in given path component, as described in
   * RFC 3986, section 5.2.4.
   *
   * @param {string} path A non-empty path component.
   * @return {string} Path component with removed dot segments.
   */
  goog.Uri.removeDotSegments = function(path) {
    if (path == '..' || path == '.') {
      return '';
  
    } else if (!goog.string.contains(path, './') &&
               !goog.string.contains(path, '/.')) {
      // This optimization detects uris which do not contain dot-segments,
      // and as a consequence do not require any processing.
      return path;
  
    } else {
      var leadingSlash = goog.string.startsWith(path, '/');
      var segments = path.split('/');
      var out = [];
  
      for (var pos = 0; pos < segments.length; ) {
        var segment = segments[pos++];
  
        if (segment == '.') {
          if (leadingSlash && pos == segments.length) {
            out.push('');
          }
        } else if (segment == '..') {
          if (out.length > 1 || out.length == 1 && out[0] != '') {
            out.pop();
          }
          if (leadingSlash && pos == segments.length) {
            out.push('');
          }
        } else {
          out.push(segment);
          leadingSlash = true;
        }
      }
  
      return out.join('/');
    }
  };
  
  
  /**
   * Decodes a value or returns the empty string if it isn't defined or empty.
   * @param {string|undefined} val Value to decode.
   * @return {string} Decoded value.
   * @private
   */
  goog.Uri.decodeOrEmpty_ = function(val) {
    // Don't use UrlDecode() here because val is not a query parameter.
    return val ? decodeURIComponent(val) : '';
  };
  
  
  /**
   * If unescapedPart is non null, then escapes any characters in it that aren't
   * valid characters in a url and also escapes any special characters that
   * appear in extra.
   *
   * @param {*} unescapedPart The string to encode.
   * @param {RegExp} extra A character set of characters in [\01-\177].
   * @return {?string} null iff unescapedPart == null.
   * @private
   */
  goog.Uri.encodeSpecialChars_ = function(unescapedPart, extra) {
    if (goog.isString(unescapedPart)) {
      return encodeURI(unescapedPart).replace(extra, goog.Uri.encodeChar_);
    }
    return null;
  };
  
  
  /**
   * Converts a character in [\01-\177] to its unicode character equivalent.
   * @param {string} ch One character string.
   * @return {string} Encoded string.
   * @private
   */
  goog.Uri.encodeChar_ = function(ch) {
    var n = ch.charCodeAt(0);
    return '%' + ((n >> 4) & 0xf).toString(16) + (n & 0xf).toString(16);
  };
  
  
  /**
   * Regular expression for characters that are disallowed in the scheme or
   * userInfo part of the URI.
   * @type {RegExp}
   * @private
   */
  goog.Uri.reDisallowedInSchemeOrUserInfo_ = /[#\/\?@]/g;
  
  
  /**
   * Regular expression for characters that are disallowed in a relative path.
   * @type {RegExp}
   * @private
   */
  goog.Uri.reDisallowedInRelativePath_ = /[\#\?:]/g;
  
  
  /**
   * Regular expression for characters that are disallowed in an absolute path.
   * @type {RegExp}
   * @private
   */
  goog.Uri.reDisallowedInAbsolutePath_ = /[\#\?]/g;
  
  
  /**
   * Regular expression for characters that are disallowed in the query.
   * @type {RegExp}
   * @private
   */
  goog.Uri.reDisallowedInQuery_ = /[\#\?@]/g;
  
  
  /**
   * Regular expression for characters that are disallowed in the fragment.
   * @type {RegExp}
   * @private
   */
  goog.Uri.reDisallowedInFragment_ = /#/g;
  
  
  /**
   * Checks whether two URIs have the same domain.
   * @param {string} uri1String First URI string.
   * @param {string} uri2String Second URI string.
   * @return {boolean} true if the two URIs have the same domain; false otherwise.
   */
  goog.Uri.haveSameDomain = function(uri1String, uri2String) {
    // Differs from goog.uri.utils.haveSameDomain, since this ignores scheme.
    // TODO(gboyer): Have this just call goog.uri.util.haveSameDomain.
    var pieces1 = goog.uri.utils.split(uri1String);
    var pieces2 = goog.uri.utils.split(uri2String);
    return pieces1[goog.uri.utils.ComponentIndex.DOMAIN] ==
               pieces2[goog.uri.utils.ComponentIndex.DOMAIN] &&
           pieces1[goog.uri.utils.ComponentIndex.PORT] ==
               pieces2[goog.uri.utils.ComponentIndex.PORT];
  };
  
  
  
  /**
   * Class used to represent URI query parameters.  It is essentially a hash of
   * name-value pairs, though a name can be present more than once.
   *
   * Has the same interface as the collections in goog.structs.
   *
   * @param {?string=} opt_query Optional encoded query string to parse into
   *     the object.
   * @param {goog.Uri=} opt_uri Optional uri object that should have its
   *     cache invalidated when this object updates. Deprecated -- this
   *     is no longer required.
   * @param {boolean=} opt_ignoreCase If true, ignore the case of the parameter
   *     name in #get.
   * @constructor
   */
  goog.Uri.QueryData = function(opt_query, opt_uri, opt_ignoreCase) {
    /**
     * Encoded query string, or null if it requires computing from the key map.
     * @type {?string}
     * @private
     */
    this.encodedQuery_ = opt_query || null;
  
    /**
     * If true, ignore the case of the parameter name in #get.
     * @type {boolean}
     * @private
     */
    this.ignoreCase_ = !!opt_ignoreCase;
  };
  
  
  /**
   * If the underlying key map is not yet initialized, it parses the
   * query string and fills the map with parsed data.
   * @private
   */
  goog.Uri.QueryData.prototype.ensureKeyMapInitialized_ = function() {
    if (!this.keyMap_) {
      this.keyMap_ = new goog.structs.Map();
      this.count_ = 0;
  
      if (this.encodedQuery_) {
        var pairs = this.encodedQuery_.split('&');
        for (var i = 0; i < pairs.length; i++) {
          var indexOfEquals = pairs[i].indexOf('=');
          var name = null;
          var value = null;
          if (indexOfEquals >= 0) {
            name = pairs[i].substring(0, indexOfEquals);
            value = pairs[i].substring(indexOfEquals + 1);
          } else {
            name = pairs[i];
          }
          name = goog.string.urlDecode(name);
          name = this.getKeyName_(name);
          this.add(name, value ? goog.string.urlDecode(value) : '');
        }
      }
    }
  };
  
  
  /**
   * Creates a new query data instance from a map of names and values.
   *
   * @param {!goog.structs.Map|!Object} map Map of string parameter
   *     names to parameter value. If parameter value is an array, it is
   *     treated as if the key maps to each individual value in the
   *     array.
   * @param {goog.Uri=} opt_uri URI object that should have its cache
   *     invalidated when this object updates.
   * @param {boolean=} opt_ignoreCase If true, ignore the case of the parameter
   *     name in #get.
   * @return {!goog.Uri.QueryData} The populated query data instance.
   */
  goog.Uri.QueryData.createFromMap = function(map, opt_uri, opt_ignoreCase) {
    var keys = goog.structs.getKeys(map);
    if (typeof keys == 'undefined') {
      throw Error('Keys are undefined');
    }
  
    var queryData = new goog.Uri.QueryData(null, null, opt_ignoreCase);
    var values = goog.structs.getValues(map);
    for (var i = 0; i < keys.length; i++) {
      var key = keys[i];
      var value = values[i];
      if (!goog.isArray(value)) {
        queryData.add(key, value);
      } else {
        queryData.setValues(key, value);
      }
    }
    return queryData;
  };
  
  
  /**
   * Creates a new query data instance from parallel arrays of parameter names
   * and values. Allows for duplicate parameter names. Throws an error if the
   * lengths of the arrays differ.
   *
   * @param {Array.<string>} keys Parameter names.
   * @param {Array} values Parameter values.
   * @param {goog.Uri=} opt_uri URI object that should have its cache
   *     invalidated when this object updates.
   * @param {boolean=} opt_ignoreCase If true, ignore the case of the parameter
   *     name in #get.
   * @return {!goog.Uri.QueryData} The populated query data instance.
   */
  goog.Uri.QueryData.createFromKeysValues = function(
      keys, values, opt_uri, opt_ignoreCase) {
    if (keys.length != values.length) {
      throw Error('Mismatched lengths for keys/values');
    }
    var queryData = new goog.Uri.QueryData(null, null, opt_ignoreCase);
    for (var i = 0; i < keys.length; i++) {
      queryData.add(keys[i], values[i]);
    }
    return queryData;
  };
  
  
  /**
   * The map containing name/value or name/array-of-values pairs.
   * May be null if it requires parsing from the query string.
   *
   * We need to use a Map because we cannot guarantee that the key names will
   * not be problematic for IE.
   *
   * @type {goog.structs.Map}
   * @private
   */
  goog.Uri.QueryData.prototype.keyMap_ = null;
  
  
  /**
   * The number of params, or null if it requires computing.
   * @type {?number}
   * @private
   */
  goog.Uri.QueryData.prototype.count_ = null;
  
  
  /**
   * @return {?number} The number of parameters.
   */
  goog.Uri.QueryData.prototype.getCount = function() {
    this.ensureKeyMapInitialized_();
    return this.count_;
  };
  
  
  /**
   * Adds a key value pair.
   * @param {string} key Name.
   * @param {*} value Value.
   * @return {!goog.Uri.QueryData} Instance of this object.
   */
  goog.Uri.QueryData.prototype.add = function(key, value) {
    this.ensureKeyMapInitialized_();
    this.invalidateCache_();
  
    key = this.getKeyName_(key);
    var values = this.keyMap_.get(key);
    if (!values) {
      this.keyMap_.set(key, (values = []));
    }
    values.push(value);
    this.count_++;
    return this;
  };
  
  
  /**
   * Removes all the params with the given key.
   * @param {string} key Name.
   * @return {boolean} Whether any parameter was removed.
   */
  goog.Uri.QueryData.prototype.remove = function(key) {
    this.ensureKeyMapInitialized_();
  
    key = this.getKeyName_(key);
    if (this.keyMap_.containsKey(key)) {
      this.invalidateCache_();
  
      // Decrement parameter count.
      this.count_ -= this.keyMap_.get(key).length;
      return this.keyMap_.remove(key);
    }
    return false;
  };
  
  
  /**
   * Clears the parameters.
   */
  goog.Uri.QueryData.prototype.clear = function() {
    this.invalidateCache_();
    this.keyMap_ = null;
    this.count_ = 0;
  };
  
  
  /**
   * @return {boolean} Whether we have any parameters.
   */
  goog.Uri.QueryData.prototype.isEmpty = function() {
    this.ensureKeyMapInitialized_();
    return this.count_ == 0;
  };
  
  
  /**
   * Whether there is a parameter with the given name
   * @param {string} key The parameter name to check for.
   * @return {boolean} Whether there is a parameter with the given name.
   */
  goog.Uri.QueryData.prototype.containsKey = function(key) {
    this.ensureKeyMapInitialized_();
    key = this.getKeyName_(key);
    return this.keyMap_.containsKey(key);
  };
  
  
  /**
   * Whether there is a parameter with the given value.
   * @param {*} value The value to check for.
   * @return {boolean} Whether there is a parameter with the given value.
   */
  goog.Uri.QueryData.prototype.containsValue = function(value) {
    // NOTE(arv): This solution goes through all the params even if it was the
    // first param. We can get around this by not reusing code or by switching to
    // iterators.
    var vals = this.getValues();
    return goog.array.contains(vals, value);
  };
  
  
  /**
   * Returns all the keys of the parameters. If a key is used multiple times
   * it will be included multiple times in the returned array
   * @return {!Array} All the keys of the parameters.
   */
  goog.Uri.QueryData.prototype.getKeys = function() {
    this.ensureKeyMapInitialized_();
    // We need to get the values to know how many keys to add.
    var vals = /** @type {Array.<Array|*>} */ (this.keyMap_.getValues());
    var keys = this.keyMap_.getKeys();
    var rv = [];
    for (var i = 0; i < keys.length; i++) {
      var val = vals[i];
      for (var j = 0; j < val.length; j++) {
        rv.push(keys[i]);
      }
    }
    return rv;
  };
  
  
  /**
   * Returns all the values of the parameters with the given name. If the query
   * data has no such key this will return an empty array. If no key is given
   * all values wil be returned.
   * @param {string=} opt_key The name of the parameter to get the values for.
   * @return {!Array} All the values of the parameters with the given name.
   */
  goog.Uri.QueryData.prototype.getValues = function(opt_key) {
    this.ensureKeyMapInitialized_();
    var rv = [];
    if (opt_key) {
      if (this.containsKey(opt_key)) {
        rv = goog.array.concat(rv, this.keyMap_.get(this.getKeyName_(opt_key)));
      }
    } else {
      // Return all values.
      var values = /** @type {Array.<Array|*>} */ (this.keyMap_.getValues());
      for (var i = 0; i < values.length; i++) {
        rv = goog.array.concat(rv, values[i]);
      }
    }
    return rv;
  };
  
  
  /**
   * Sets a key value pair and removes all other keys with the same value.
   *
   * @param {string} key Name.
   * @param {*} value Value.
   * @return {!goog.Uri.QueryData} Instance of this object.
   */
  goog.Uri.QueryData.prototype.set = function(key, value) {
    this.ensureKeyMapInitialized_();
    this.invalidateCache_();
  
    // TODO(user): This could be better written as
    // this.remove(key), this.add(key, value), but that would reorder
    // the key (since the key is first removed and then added at the
    // end) and we would have to fix unit tests that depend on key
    // ordering.
    key = this.getKeyName_(key);
    if (this.containsKey(key)) {
      this.count_ -= this.keyMap_.get(key).length;
    }
    this.keyMap_.set(key, [value]);
    this.count_++;
    return this;
  };
  
  
  /**
   * Returns the first value associated with the key. If the query data has no
   * such key this will return undefined or the optional default.
   * @param {string} key The name of the parameter to get the value for.
   * @param {*=} opt_default The default value to return if the query data
   *     has no such key.
   * @return {*} The first string value associated with the key, or opt_default
   *     if there's no value.
   */
  goog.Uri.QueryData.prototype.get = function(key, opt_default) {
    var values = key ? this.getValues(key) : [];
    if (goog.Uri.preserveParameterTypesCompatibilityFlag) {
      return values.length > 0 ? values[0] : opt_default;
    } else {
      return values.length > 0 ? String(values[0]) : opt_default;
    }
  };
  
  
  /**
   * Sets the values for a key. If the key already exists, this will
   * override all of the existing values that correspond to the key.
   * @param {string} key The key to set values for.
   * @param {Array} values The values to set.
   */
  goog.Uri.QueryData.prototype.setValues = function(key, values) {
    this.remove(key);
  
    if (values.length > 0) {
      this.invalidateCache_();
      this.keyMap_.set(this.getKeyName_(key), goog.array.clone(values));
      this.count_ += values.length;
    }
  };
  
  
  /**
   * @return {string} Encoded query string.
   * @override
   */
  goog.Uri.QueryData.prototype.toString = function() {
    if (this.encodedQuery_) {
      return this.encodedQuery_;
    }
  
    if (!this.keyMap_) {
      return '';
    }
  
    var sb = [];
  
    // In the past, we use this.getKeys() and this.getVals(), but that
    // generates a lot of allocations as compared to simply iterating
    // over the keys.
    var keys = this.keyMap_.getKeys();
    for (var i = 0; i < keys.length; i++) {
      var key = keys[i];
      var encodedKey = goog.string.urlEncode(key);
      var val = this.getValues(key);
      for (var j = 0; j < val.length; j++) {
        var param = encodedKey;
        // Ensure that null and undefined are encoded into the url as
        // literal strings.
        if (val[j] !== '') {
          param += '=' + goog.string.urlEncode(val[j]);
        }
        sb.push(param);
      }
    }
  
    return this.encodedQuery_ = sb.join('&');
  };
  
  
  /**
   * @return {string} Decoded query string.
   */
  goog.Uri.QueryData.prototype.toDecodedString = function() {
    return goog.Uri.decodeOrEmpty_(this.toString());
  };
  
  
  /**
   * Invalidate the cache.
   * @private
   */
  goog.Uri.QueryData.prototype.invalidateCache_ = function() {
    this.encodedQuery_ = null;
  };
  
  
  /**
   * Removes all keys that are not in the provided list. (Modifies this object.)
   * @param {Array.<string>} keys The desired keys.
   * @return {!goog.Uri.QueryData} a reference to this object.
   */
  goog.Uri.QueryData.prototype.filterKeys = function(keys) {
    this.ensureKeyMapInitialized_();
    goog.structs.forEach(this.keyMap_,
        /** @this {goog.Uri.QueryData} */
        function(value, key, map) {
          if (!goog.array.contains(keys, key)) {
            this.remove(key);
          }
        }, this);
    return this;
  };
  
  
  /**
   * Clone the query data instance.
   * @return {!goog.Uri.QueryData} New instance of the QueryData object.
   */
  goog.Uri.QueryData.prototype.clone = function() {
    var rv = new goog.Uri.QueryData();
    rv.encodedQuery_ = this.encodedQuery_;
    if (this.keyMap_) {
      rv.keyMap_ = this.keyMap_.clone();
      rv.count_ = this.count_;
    }
    return rv;
  };
  
  
  /**
   * Helper function to get the key name from a JavaScript object. Converts
   * the object to a string, and to lower case if necessary.
   * @private
   * @param {*} arg The object to get a key name from.
   * @return {string} valid key name which can be looked up in #keyMap_.
   */
  goog.Uri.QueryData.prototype.getKeyName_ = function(arg) {
    var keyName = String(arg);
    if (this.ignoreCase_) {
      keyName = keyName.toLowerCase();
    }
    return keyName;
  };
  
  
  /**
   * Ignore case in parameter names.
   * NOTE: If there are already key/value pairs in the QueryData, and
   * ignoreCase_ is set to false, the keys will all be lower-cased.
   * @param {boolean} ignoreCase whether this goog.Uri should ignore case.
   */
  goog.Uri.QueryData.prototype.setIgnoreCase = function(ignoreCase) {
    var resetKeys = ignoreCase && !this.ignoreCase_;
    if (resetKeys) {
      this.ensureKeyMapInitialized_();
      this.invalidateCache_();
      goog.structs.forEach(this.keyMap_,
          /** @this {goog.Uri.QueryData} */
          function(value, key) {
            var lowerCase = key.toLowerCase();
            if (key != lowerCase) {
              this.remove(key);
              this.setValues(lowerCase, value);
            }
          }, this);
    }
    this.ignoreCase_ = ignoreCase;
  };
  
  
  /**
   * Extends a query data object with another query data or map like object. This
   * operates 'in-place', it does not create a new QueryData object.
   *
   * @param {...(goog.Uri.QueryData|goog.structs.Map|Object)} var_args The object
   *     from which key value pairs will be copied.
   */
  goog.Uri.QueryData.prototype.extend = function(var_args) {
    for (var i = 0; i < arguments.length; i++) {
      var data = arguments[i];
      goog.structs.forEach(data,
          /** @this {goog.Uri.QueryData} */
          function(value, key) {
            this.add(key, value);
          }, this);
    }
  };
  