001// ***************************************************************************************************************************
002// * Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements.  See the NOTICE file *
003// * distributed with this work for additional information regarding copyright ownership.  The ASF licenses this file        *
004// * to you under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance            *
005// * with the License.  You may obtain a copy of the License at                                                              *
006// *                                                                                                                         *
007// *  http://www.apache.org/licenses/LICENSE-2.0                                                                             *
008// *                                                                                                                         *
009// * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an  *
010// * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the License for the        *
011// * specific language governing permissions and limitations under the License.                                              *
012// ***************************************************************************************************************************
013package org.apache.juneau;
014
015import static org.apache.juneau.common.internal.StringUtils.*;
016import static org.apache.juneau.internal.CollectionUtils.*;
017import static org.apache.juneau.internal.ObjectUtils.*;
018
019import java.util.*;
020import java.util.function.*;
021
022import org.apache.http.*;
023import org.apache.http.message.*;
024import org.apache.juneau.annotation.*;
025
026/**
027 * Represents a single value in a comma-delimited header value that optionally contains a quality metric for
028 * comparison and extension parameters.
029 *
030 * <p>
031 * Similar in concept to {@link MediaRanges} except instead of media types (e.g. <js>"text/json"</js>),
032 * it's a simple type (e.g. <js>"iso-8601"</js>).
033 *
034 * <p>
035 * An example of a type range is a value in an <c>Accept-Encoding</c> header.
036 *
037 * <h5 class='section'>See Also:</h5><ul>
038 *    <li class='link'><a class="doclink" href="../../../index.html#juneau-rest-common">juneau-rest-common</a>
039 *    <li class='extlink'><a class="doclink" href="https://www.w3.org/Protocols/rfc2616/rfc2616.html">Hypertext Transfer Protocol -- HTTP/1.1</a>
040
041 * </ul>
042 */
043@BeanIgnore
044public class StringRange {
045
046   private final NameValuePair[] extensions;
047   private final Float qValue;
048   private final String name;
049   private final String string;
050
051   /**
052    * Constructor.
053    *
054    * @param value
055    *    The raw string range string.
056    *    <br>A value of <jk>null</jk> gets interpreted as matching anything (e.g. <js>"*"</js>).
057    */
058   public StringRange(String value) {
059      this(parse(value));
060   }
061
062   /**
063    * Constructor.
064    *
065    * @param e The parsed string range element.
066    */
067   public StringRange(HeaderElement e) {
068      Float qValue = 1f;
069
070      // The media type consists of everything up to the q parameter.
071      // The q parameter and stuff after is part of the range.
072      List<NameValuePair> extensions = list();
073      for (NameValuePair p : e.getParameters()) {
074         if (p.getName().equals("q")) {
075            qValue = Float.parseFloat(p.getValue());
076         } else {
077            extensions.add(new BasicNameValuePair(p.getName(), p.getValue()));
078         }
079      }
080
081      this.qValue = qValue;
082      this.extensions = extensions.toArray(new NameValuePair[extensions.size()]);
083      this.name = e.getName();
084
085      StringBuffer sb = new StringBuffer();
086      sb.append(name);
087
088      // '1' is equivalent to specifying no qValue. If there's no extensions, then we won't include a qValue.
089      if (Float.compare(qValue.floatValue(), 1f) == 0) {
090         if (this.extensions.length > 0) {
091            sb.append(";q=").append(qValue);
092            extensions.forEach(x -> sb.append(';').append(x.getName()).append('=').append(x.getValue()));
093         }
094      } else {
095         sb.append(";q=").append(qValue);
096         extensions.forEach(x -> sb.append(';').append(x.getName()).append('=').append(x.getValue()));
097      }
098      string = sb.toString();
099   }
100
101   /**
102    * Returns the name of this string range.
103    *
104    * <p>
105    * This is the primary value minus the quality or other parameters.
106    *
107    * @return The name of this string range.
108    */
109   public String getName() {
110      return name;
111   }
112
113   /**
114    * Returns the <js>'q'</js> (quality) value for this type, as described in Section 3.9 of RFC2616.
115    *
116    * <p>
117    * The quality value is a float between <c>0.0</c> (unacceptable) and <c>1.0</c> (most acceptable).
118    *
119    * <p>
120    * If 'q' value doesn't make sense for the context (e.g. this range was extracted from a <js>"content-*"</js>
121    * header, as opposed to <js>"accept-*"</js> header, its value will always be <js>"1"</js>.
122    *
123    * @return The 'q' value for this type, never <jk>null</jk>.
124    */
125   public Float getQValue() {
126      return qValue;
127   }
128
129   /**
130    * Returns the optional set of custom extensions defined for this type.
131    *
132    * <p>
133    * Values are lowercase and never <jk>null</jk>.
134    *
135    * @return The optional list of extensions, never <jk>null</jk>.
136    */
137   public List<NameValuePair> getExtensions() {
138      return ulist(extensions);
139   }
140
141   /**
142    * Performs an action on the optional set of custom extensions defined for this type.
143    *
144    * @param action The action to perform.
145    * @return This object.
146    */
147   public StringRange forEachExtension(Consumer<NameValuePair> action) {
148      for (NameValuePair p : extensions)
149         action.accept(p);
150      return this;
151   }
152
153   /**
154    * Returns <jk>true</jk> if the specified object is also a <c>StringRange</c>, and has the same qValue, type,
155    * parameters, and extensions.
156    *
157    * @return <jk>true</jk> if object is equivalent.
158    */
159   @Override /* Object */
160   public boolean equals(Object o) {
161      return (o instanceof StringRange) && eq(this, (StringRange)o, (x,y)->eq(x.string, y.string));
162   }
163
164   /**
165    * Returns a hash based on this instance's <c>media-type</c>.
166    *
167    * @return A hash based on this instance's <c>media-type</c>.
168    */
169   @Override /* Object */
170   public int hashCode() {
171      return string.hashCode();
172   }
173
174   /**
175    * Performs a match of this string range against the specified name.
176    *
177    * @param name The name being compared against.
178    * @return
179    *    0 = no match, 100 = perfect match, 50 = meta-match.
180    */
181   public int match(String name) {
182      if (qValue == 0)
183         return 0;
184      if (eq(this.name, name))
185         return 100;
186      if (eq(this.name, "*"))
187         return 50;
188      return 0;
189   }
190
191   private static HeaderElement parse(String value) {
192      HeaderElement[] elements = BasicHeaderValueParser.parseElements(emptyIfNull(trim(value)), null);
193      return (elements.length > 0 ? elements[0] : new BasicHeaderElement("*", ""));
194   }
195
196   @Override /* Object */
197   public String toString() {
198      return string;
199   }
200}