/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.
 */
package org.apache.juneau.bean.openapi3;

import static org.apache.juneau.common.utils.StringUtils.*;
import static org.apache.juneau.common.utils.Utils.*;
import static org.apache.juneau.internal.CollectionUtils.*;
import static org.apache.juneau.internal.ConverterUtils.*;

import java.net.*;
import java.util.*;

import org.apache.juneau.*;
import org.apache.juneau.common.utils.*;
import org.apache.juneau.internal.*;

/**
 * Allows referencing an external resource for extended documentation.
 *
 * <p>
 * The External Documentation Object allows referencing an external resource for extended documentation. This can be 
 * used to provide additional documentation that is not part of the main OpenAPI specification, such as detailed 
 * guides, tutorials, or API documentation hosted elsewhere.
 *
 * <h5 class='section'>OpenAPI Specification:</h5>
 * <p>
 * The External Documentation Object is composed of the following fields:
 * <ul class='spaced-list'>
 *    <li><c>description</c> (string) - A short description of the target documentation (CommonMark syntax may be used)
 *    <li><c>url</c> (string, REQUIRED) - The URL for the target documentation
 * </ul>
 *
 * <h5 class='section'>Example:</h5>
 * <p class='bjava'>
 *    <jc>// Create external documentation reference</jc>
 *    ExternalDocumentation <jv>docs</jv> = <jk>new</jk> ExternalDocumentation()
 *       .setDescription(<js>"Find more info here"</js>)
 *       .setUrl(<js>"https://example.com"</js>);
 * </p>
 *
 * <h5 class='section'>See Also:</h5><ul>
 *    <li class='link'><a class="doclink" href="https://spec.openapis.org/oas/v3.0.0#external-documentation-object">OpenAPI Specification &gt; External Documentation Object</a>
 *    <li class='link'><a class="doclink" href="https://swagger.io/docs/specification/external-documentation/">OpenAPI External Documentation</a>
 *    <li class='link'><a class="doclink" href="https://juneau.apache.org/docs/topics/JuneauBeanOpenApi3">juneau-bean-openapi-v3</a>
 * </ul>
 */
public class ExternalDocumentation extends OpenApiElement {

   private String description;
   private URI url;

   /**
    * Default constructor.
    */
   public ExternalDocumentation() {}

   /**
    * Copy constructor.
    *
    * @param copyFrom The object to copy.
    */
   public ExternalDocumentation(ExternalDocumentation copyFrom) {
      super(copyFrom);

      this.description = copyFrom.description;
      this.url = copyFrom.url;
   }

   /**
    * Make a deep copy of this object.
    *
    * @return A deep copy of this object.
    */
   public ExternalDocumentation copy() {
      return new ExternalDocumentation(this);
   }

   /**
    * Bean property getter:  <property>description</property>.
    *
    * <p>
    * A short description of the target documentation.
    *
    * @return The property value, or <jk>null</jk> if it is not set.
    */
   public String getDescription() {
      return description;
   }

   /**
    * Bean property setter:  <property>description</property>.
    *
    * <p>
    * A short description of the target documentation.
    *
    * @param value
    *    The new value for this property.
    *    <br>Can be <jk>null</jk> to unset the property.
    * @return This object
    */
   public ExternalDocumentation setDescription(String value) {
      description = value;
      return this;
   }

   /**
    * Bean property getter:  <property>url</property>.
    *
    * <p>
    * The URL for the target documentation.
    *
    * @return The property value, or <jk>null</jk> if it is not set.
    */
   public URI getUrl() {
      return url;
   }

   /**
    * Bean property setter:  <property>url</property>.
    *
    * <p>
    * The URL for the target documentation.
    *
    * @param value
    *    The new value for this property.
    *    <br>Property value is required.
    *    <br>URIs defined by {@link UriResolver} can be used for values.
    *    <br>Can be <jk>null</jk> to unset the property.
    * @return This object
    */
   public ExternalDocumentation setUrl(URI value) {
      url = value;
      return this;
   }

   @Override /* Overridden from OpenApiElement */
   public <T> T get(String property, Class<T> type) {
      assertArgNotNull("property", property);
      return switch (property) {
         case "description" -> toType(getDescription(), type);
         case "url" -> toType(getUrl(), type);
         default -> super.get(property, type);
      };
   }

   @Override /* Overridden from OpenApiElement */
   public ExternalDocumentation set(String property, Object value) {
      assertArgNotNull("property", property);
      return switch (property) {
         case "description" -> setDescription(Utils.s(value));
         case "url" -> setUrl(toURI(value));
         default -> {
            super.set(property, value);
            yield this;
         }
      };
   }

   @Override /* Overridden from OpenApiElement */
   public Set<String> keySet() {
      var s = setBuilder(String.class)
         .addIf(description != null, "description")
         .addIf(url != null, "url")
         .build();
      return new MultiSet<>(s, super.keySet());
   }

   @Override /* Overridden from OpenApiElement */
   public ExternalDocumentation strict() {
      super.strict();
      return this;
   }

   @Override /* Overridden from OpenApiElement */
   public ExternalDocumentation strict(Object value) {
      super.strict(value);
      return this;
   }

}