/*
 * 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.commons.utils.AssertionUtils.*;
import static org.apache.juneau.commons.utils.CollectionUtils.*;
import static org.apache.juneau.commons.utils.Utils.*;
import static org.apache.juneau.internal.ConverterUtils.*;

import java.util.*;

import org.apache.juneau.commons.collections.*;

/**
 * TODO
 *
 * <p>
 * The ServerVariable Object represents a server variable for server URL template substitution. Server variables can be
 * used to define different server environments (e.g., development, staging, production) with different base URLs,
 * ports, or other variable parts of the server URL.
 *
 * <h5 class='section'>OpenAPI Specification:</h5>
 * <p>
 * The ServerVariable Object is composed of the following fields:
 * <ul class='spaced-list'>
 *    <li><c>enum</c> (array of any) - An enumeration of string values to be used if the substitution options are from a limited set
 *    <li><c>default</c> (string, REQUIRED) - The default value to use for substitution, which SHALL be sent if an alternate value is not supplied
 *    <li><c>description</c> (string) - An optional description for the server variable. CommonMark syntax MAY be used for rich text representation
 * </ul>
 *
 * <h5 class='section'>Example:</h5>
 * <p class='bcode'>
 *    <jc>// Construct using SwaggerBuilder.</jc>
 *    ServerVariable <jv>x</jv> = <jsm>serverVariable</jsm>()
 *       .setDefault(<js>"api"</js>)
 *       .setEnum(<js>"api"</js>, <js>"staging"</js>, <js>"dev"</js>)
 *       .setDescription(<js>"Environment to use"</js>);
 *
 *    <jc>// Serialize using JsonSerializer.</jc>
 *    String <jv>json</jv> = Json.<jsm>from</jsm>(<jv>x</jv>);
 *
 *    <jc>// Or just use toString() which does the same as above.</jc>
 *    <jv>json</jv> = <jv>x</jv>.toString();
 * </p>
 * <p class='bcode'>
 *    <jc>// Output</jc>
 *    {
 *       <js>"default"</js>: <js>"api"</js>,
 *       <js>"enum"</js>: [<js>"api"</js>, <js>"staging"</js>, <js>"dev"</js>],
 *       <js>"description"</js>: <js>"Environment to use"</js>
 *    }
 * </p>
 *
 * <h5 class='section'>See Also:</h5><ul>
 *    <li class='link'><a class="doclink" href="https://spec.openapis.org/oas/v3.0.0#server-variable-object">OpenAPI Specification &gt; Server Variable Object</a>
 *    <li class='link'><a class="doclink" href="https://swagger.io/docs/specification/api-host-and-base-path/">OpenAPI API Host and Base Path</a>
 *    <li class='link'><a class="doclink" href="https://juneau.apache.org/docs/topics/JuneauBeanOpenApi3">juneau-bean-openapi-v3</a>
 * </ul>
 */
public class ServerVariable extends OpenApiElement {

   private List<Object> enum_ = list();
   private String default_;
   private String description;

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

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

      if (nn(copyFrom.enum_))
         this.enum_.addAll(copyOf(copyFrom.enum_));
      this.default_ = copyFrom.default_;
      this.description = copyFrom.description;
   }

   /**
    * Adds one or more values to the <property>enum</property> property.
    *
    * @param values
    *    The values to add to this property.
    *    <br>Valid types:
    *    <ul>
    *       <li><code>Object</code>
    *       <li><code>Collection&lt;Object&gt;</code>
    *       <li><code>String</code> - JSON array representation of <code>Collection&lt;Object&gt;</code>
    *          <h5 class='figure'>Example:</h5>
    *          <p class='bcode'>
    *    enum_(<js>"['foo','bar']"</js>);
    *          </p>
    *       <li><code>String</code> - Individual values
    *          <h5 class='figure'>Example:</h5>
    *          <p class='bcode'>
    *    enum_(<js>"foo"</js>, <js>"bar"</js>);
    *          </p>
    *    </ul>
    *    <br>Ignored if <jk>null</jk>.
    * @return This object
    */
   public ServerVariable addEnum(Object...values) {
      if (nn(values))
         for (var v : values)
            if (nn(v))
               enum_.add(v);
      return this;
   }

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

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

   /**
    * Bean property getter:  <property>default</property>.
    *
    * <p>
    * Declares the value of the item that the server will use if none is provided.
    *
    * <h5 class='section'>Notes:</h5>
    * <ul class='spaced-list'>
    *    <li>
    *       <js>"default"</js> has no meaning for required items.
    *    <li>
    *       Unlike JSON Schema this value MUST conform to the defined <code>type</code> for the data type.
    * </ul>
    *
    * @return The property value, or <jk>null</jk> if it is not set.
    */
   public String getDefault() { return default_; }

   /**
    * Bean property getter:  <property>description</property>.
    *
    * <p>
    * Declares the value of the item that the server will use if none is provided.
    *
    * <h5 class='section'>Notes:</h5>
    * <ul class='spaced-list'>
    *    <li>
    *       <js>"description"</js> has no meaning for required items.
    *    <li>
    *       Unlike JSON Schema this value MUST conform to the defined <code>type</code> for the data type.
    * </ul>
    *
    * @return The property value, or <jk>null</jk> if it is not set.
    */
   public String getDescription() { return description; }

   /**
    * Bean property getter:  <property>enum</property>.
    *
    * @return The property value, or <jk>null</jk> if it is not set.
    */
   public List<Object> getEnum() { return nullIfEmpty(enum_); }

   @Override /* Overridden from OpenApiElement */
   public Set<String> keySet() {
      // @formatter:off
      var s = setb(String.class)
         .addIf(nn(default_),"default" )
         .addIf(nn(description), "description")
         .addIf(ne(enum_), "enum")
         .build();
      // @formatter:on
      return new MultiSet<>(s, super.keySet());
   }

   @Override /* Overridden from OpenApiElement */
   public ServerVariable set(String property, Object value) {
      assertArgNotNull("property", property);
      return switch (property) {
         case "default" -> setDefault(s(value));
         case "description" -> setDescription(s(value));
         case "enum" -> setEnum(listb(Object.class).addAny(value).sparse().build());
         default -> {
            super.set(property, value);
            yield this;
         }
      };
   }

   /**
    * Bean property setter:  <property>default</property>.
    *
    * <p>
    * Declares the value of the item that the server will use if none is provided.
    *
    * <h5 class='section'>Notes:</h5>
    * <ul class='spaced-list'>
    *    <li>
    *       <js>"default"</js> has no meaning for required items.
    *    <li>
    *       Unlike JSON Schema this value MUST conform to the defined <code>type</code> for the data type.
    * </ul>
    *
    * @param value
    *    The new value for this property.
    *    <br>Can be <jk>null</jk> to unset the property.
    * @return This object
    */
   public ServerVariable setDefault(String value) {
      default_ = value;
      return this;
   }

   /**
    * Bean property setter:  <property>description</property>.
    *
    * <p>
    * Declares the value of the item that the server will use if none is provided.
    *
    * <h5 class='section'>Notes:</h5>
    * <ul class='spaced-list'>
    *    <li>
    *       <js>"description"</js> has no meaning for required items.
    *    <li>
    *       Unlike JSON Schema this value MUST conform to the defined <code>type</code> for the data type.
    * </ul>
    *
    * @param value
    *    The new value for this property.
    *    <br>Can be <jk>null</jk> to unset the property.
    * @return This object
    */
   public ServerVariable setDescription(String value) {
      description = value;
      return this;
   }

   /**
    * Bean property setter:  <property>enum</property>.
    *
    * @param value
    *    The new value for this property.
    *    <br>Can be <jk>null</jk> to unset the property.
    * @return This object
    */
   public ServerVariable setEnum(Collection<Object> value) {
      enum_.clear();
      if (nn(value))
         enum_.addAll(value);
      return this;
   }

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

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