// ***************************************************************************************************************************
// * 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.dto.jsonschema;

import static org.apache.juneau.internal.StringUtils.*;

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

import org.apache.juneau.*;
import org.apache.juneau.annotation.*;
import org.apache.juneau.json.*;
import org.apache.juneau.parser.*;
import org.apache.juneau.serializer.*;
import org.apache.juneau.transform.*;

/**
 * Represents a top-level schema object bean in the JSON-Schema core specification.
 *
 * <h5 class='section'>See Also:</h5>
 * <ul class='doctree'>
 *    <li class='jp'>{@doc package-summary.html#TOC org.apache.juneau.dto.jsonschema}
 * </ul>
 */
@Bean(typeName="schema",
   properties="id,$schema,$ref, title,description,type,definitions,properties,"
      + "patternProperties,dependencies,items,multipleOf,maximum,exclusiveMaximum,"
      + "minimum,exclusiveMinimum,maxLength,minLength,pattern,additionalItems,"
      + "maxItems,minItems,uniqueItems,maxProperties,minProperties,required,"
      + "additionalProperties,enum,allOf,anyOf,oneOf,not"
)
public class JsonSchema {
   private String name;                                   // Property name.  Not serialized.
   private URI id;
   private URI schemaVersion;
   private String title;
   private String description;
   private JsonType typeJsonType;                         // JsonType representation of type
   private JsonTypeArray typeJsonTypeArray;               // JsonTypeArray representation of type
   private Map<String,JsonSchema> definitions;
   private Map<String,JsonSchema> properties;
   private Map<String,JsonSchema> patternProperties;
   private Map<String,JsonSchema> dependencies;
   private JsonSchema itemsSchema;                            // JsonSchema representation of items
   private JsonSchemaArray itemsSchemaArray;                  // JsonSchemaArray representation of items
   private Number multipleOf;
   private Number maximum;
   private Boolean exclusiveMaximum;
   private Number minimum;
   private Boolean exclusiveMinimum;
   private Integer maxLength;
   private Integer minLength;
   private String pattern;
   private Boolean additionalItemsBoolean;                // Boolean representation of additionalItems
   private JsonSchemaArray additionalItemsSchemaArray;        // JsonSchemaArray representation of additionalItems
   private Integer maxItems;
   private Integer minItems;
   private Boolean uniqueItems;
   private Integer maxProperties;
   private Integer minProperties;
   private List<String> required;
   private Boolean additionalPropertiesBoolean;           // Boolean representation of additionalProperties
   private JsonSchema additionalPropertiesSchema;             // JsonSchema representation of additionalProperties
   private List<String> _enum;
   private List<JsonSchema> allOf;
   private List<JsonSchema> anyOf;
   private List<JsonSchema> oneOf;
   private JsonSchema not;
   private URI ref;
   private JsonSchemaMap schemaMap;
   private JsonSchema master = this;

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


   //-----------------------------------------------------------------------------------------------------------------
   // Bean properties
   //-----------------------------------------------------------------------------------------------------------------

   /**
    * Bean property getter:  <property>name</property>.
    *
    * @return The value of the <property>name</property> property on this bean, or <jk>null</jk> if it is not set.
    */
   @BeanIgnore
   public String getName() {
      return name;
   }

   /**
    * Bean property setter:  <property>name</property>.
    *
    * @param name The new value for the <property>name</property> property on this bean.
    * @return This object (for method chaining).
    */
   @BeanIgnore
   public JsonSchema setName(String name) {
      this.name = name;
      return this;
   }

   /**
    * Bean property getter:  <property>id</property>.
    *
    * @return The value of the <property>id</property> property on this bean, or <jk>null</jk> if it is not set.
    */
   public URI getId() {
      return id;
   }

   /**
    * Bean property setter:  <property>id</property>.
    *
    * <p>
    * The value can be of any of the following types: {@link URI}, {@link URL}, {@link String}.
    * Strings must be valid URIs.
    *
    * <p>
    * URIs defined by {@link UriResolver} can be used for values.
    *
    * @param id The new value for the <property>id</property> property on this bean.
    * @return This object (for method chaining).
    */
   public JsonSchema setId(Object id) {
      this.id = toURI(id);
      return this;
   }

   /**
    * Bean property getter:  <property>$schema</property>.
    *
    * @return The value of the <property>$schema</property> property on this bean, or <jk>null</jk> if it is not set.
    */
   @BeanProperty("$schema")
   public URI getSchemaVersionUri() {
      return schemaVersion;
   }

   /**
    * Bean property setter:  <property>$schema</property>.
    *
    * <p>
    * The value can be of any of the following types: {@link URI}, {@link URL}, {@link String}.
    * Strings must be valid URIs.
    *
    * <p>
    * URIs defined by {@link UriResolver} can be used for values.
    *
    * @param schemaVersion The new value for the <property>schemaVersion</property> property on this bean.
    * @return This object (for method chaining).
    */
   @BeanProperty("$schema")
   public JsonSchema setSchemaVersionUri(Object schemaVersion) {
      this.schemaVersion = toURI(schemaVersion);
      return this;
   }

   /**
    * Bean property getter:  <property>title</property>.
    *
    * @return The value of the <property>title</property> property, or <jk>null</jk> if it is not set.
    */
   public String getTitle() {
      return title;
   }

   /**
    * Bean property setter:  <property>title</property>.
    *
    * @param title The new value for the <property>title</property> property on this bean.
    * @return This object (for method chaining).
    */
   public JsonSchema setTitle(String title) {
      this.title = title;
      return this;
   }

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

   /**
    * Bean property setter:  <property>description</property>.
    *
    * @param description The new value for the <property>description</property> property on this bean.
    * @return This object (for method chaining).
    */
   public JsonSchema setDescription(String description) {
      this.description = description;
      return this;
   }

   /**
    * Bean property getter:  <property>type</property>.
    *
    * @return
    *    The value of the <property>type</property> property on this bean, or <jk>null</jk> if it is not set.
    *    Can be either a {@link JsonType} or {@link JsonTypeArray} depending on what value was used to set it.
    */
   @Swap(JsonTypeOrJsonTypeArraySwap.class)
   public Object getType() {
      if (typeJsonType != null)
         return typeJsonType;
      return typeJsonTypeArray;
   }

   /**
    * Bean property getter:  <property>type</property>.
    *
    * <p>
    * Convenience method for returning the <property>type</property> property when it is a {@link JsonType} value.
    *
    * @return
    *    The currently set value, or <jk>null</jk> if the property is not set, or is set as a {@link JsonTypeArray}.
    */
   @BeanIgnore
   public JsonType getTypeAsJsonType() {
      return typeJsonType;
   }

   /**
    * Bean property getter:  <property>type</property>.
    *
    * <p>
    * Convenience method for returning the <property>type</property> property when it is a {@link JsonTypeArray} value.
    *
    * @return The currently set value, or <jk>null</jk> if the property is not set, or is set as a {@link JsonType}.
    */
   @BeanIgnore
   public JsonTypeArray getTypeAsJsonTypeArray() {
      return typeJsonTypeArray;
   }

   /**
    * Bean property setter:  <property>type</property>.
    *
    * @param type
    *    The new value for the <property>type</property> property on this bean.
    *    This object must be of type {@link JsonType} or {@link JsonTypeArray}.
    * @return This object (for method chaining).
    * @throws BeanRuntimeException If invalid object type passed in.
    */
   public JsonSchema setType(Object type) {
      this.typeJsonType = null;
      this.typeJsonTypeArray = null;
      if (type != null) {
         if (type instanceof JsonType)
            this.typeJsonType = (JsonType)type;
         else if (type instanceof JsonTypeArray)
            this.typeJsonTypeArray = (JsonTypeArray)type;
         else
            throw new BeanRuntimeException(JsonSchemaProperty.class,
               "Invalid attribute type ''{0}'' passed in.  Must be one of the following:  SimpleType, SimpleTypeArray",
               type.getClass().getName());
      }
      return this;
   }

   /**
    * Bean property appender:  <property>type</property>.
    *
    * @param types The list of items to append to the <property>type</property> property on this bean.
    * @return This object (for method chaining).
    */
   public JsonSchema addTypes(JsonType...types) {
      if (this.typeJsonTypeArray == null)
         this.typeJsonTypeArray = new JsonTypeArray();
      this.typeJsonTypeArray.addAll(types);
      return this;
   }

   /**
    * Used during parsing to convert the <property>type</property> property to the correct class type.
    *
    * <ul class='spaced-list'>
    *    <li>
    *       If parsing a JSON-array, converts to a {@link JsonTypeArray}.
    *    <li>
    *       If parsing a JSON-object, converts to a {@link JsonType}.
    * </ul>
    *
    * <p>
    * Serialization method is a no-op.
    */
   public static class JsonTypeOrJsonTypeArraySwap extends PojoSwap<Object,Object> {

      @Override /* PojoSwap */
      public Object swap(BeanSession session, Object o) throws SerializeException {
         return o;
      }

      @Override /* PojoSwap */
      public Object unswap(BeanSession session, Object o, ClassMeta<?> hint) throws ParseException {
         ClassMeta<?> cm = (
            o instanceof Collection
            ? session.getClassMeta(JsonTypeArray.class)
            : session.getClassMeta(JsonType.class)
         );
         return session.convertToType(o, cm);
      }
   }

   /**
    * Bean property getter:  <property>definitions</property>.
    *
    * @return
    *    The value of the <property>definitions</property> property on this bean, or <jk>null</jk> if it is not set.
    */
   public Map<String,JsonSchema> getDefinitions() {
      return definitions;
   }

   /**
    * Bean property setter:  <property>definitions</property>.
    *
    * @param definitions The new value for the <property>definitions</property> property on this bean.
    * @return This object (for method chaining).
    */
   public JsonSchema setDefinitions(Map<String,JsonSchema> definitions) {
      this.definitions = definitions;
      if (definitions != null)
         setMasterOn(definitions.values());
      return this;
   }

   /**
    * Bean property appender:  <property>definitions</property>.
    *
    * @param name The key in the definitions map entry.
    * @param definition The value in the definitions map entry.
    * @return This object (for method chaining).
    */
   public JsonSchema addDefinition(String name, JsonSchema definition) {
      if (this.definitions == null)
         this.definitions = new LinkedHashMap<>();
      this.definitions.put(name, definition);
      setMasterOn(definition);
      return this;
   }

   /**
    * Bean property getter:  <property>properties</property>.
    *
    * @return The value of the <property>properties</property> property on this bean, or <jk>null</jk> if it is not set.
    */
   public Map<String,JsonSchema> getProperties() {
      return properties;
   }

   /**
    * Returns the property with the specified name.
    *
    * <p>
    * This is equivalent to calling <property>getProperty(name, <jk>false</jk>)</property>.
    *
    * @param name The property name.
    * @return The property with the specified name, or <jk>null</jk> if no property is specified.
    */
   public JsonSchema getProperty(String name) {
      return getProperty(name, false);
   }

   /**
    * Returns the property with the specified name.
    *
    * <p>
    * If <property>resolve</property> is <jk>true</jk>, the property object will automatically be  resolved by calling
    * {@link #resolve()}.
    * Therefore, <property>getProperty(name, <jk>true</jk>)</property> is equivalent to calling
    * <property>getProperty(name).resolve()</property>, except it's safe from a potential
    * <property>NullPointerException</property>.
    *
    * @param name The property name.
    * @param resolve If <jk>true</jk>, calls {@link #resolve()} on object before returning.
    * @return The property with the specified name, or <jk>null</jk> if no property is specified.
    */
   public JsonSchema getProperty(String name, boolean resolve) {
      if (properties == null)
         return null;
      JsonSchema s = properties.get(name);
      if (s == null)
         return null;
      if (resolve)
         s = s.resolve();
      return s;
   }

   /**
    * Bean property setter:  <property>properties</property>.
    *
    * @param properties The new value for the <property>properties</property> property on this bean.
    * @return This object (for method chaining).
    */
   public JsonSchema setProperties(Map<String,JsonSchema> properties) {
      this.properties = properties;
      if (properties != null)
         for (Map.Entry<String,JsonSchema> e : properties.entrySet()) {
            JsonSchema value = e.getValue();
            setMasterOn(value);
            value.setName(e.getKey());
         }
      return this;
   }

   /**
    * Bean property appender:  <property>properties</property>.
    *
    * <p>
    * Properties must have their <property>name</property> property set on them when using this method.
    *
    * @param properties The list of items to append to the <property>properties</property> property on this bean.
    * @return This object (for method chaining).
    * @throws BeanRuntimeException If property is found without a set <property>name</property> property.
    */
   public JsonSchema addProperties(JsonSchema...properties) {
      if (this.properties == null)
         this.properties = new LinkedHashMap<>();
      for (JsonSchema p : properties) {
         if (p.getName() == null)
            throw new BeanRuntimeException(JsonSchema.class,
               "Invalid property passed to JsonSchema.addProperties().  Property name was null.");
         setMasterOn(p);
         this.properties.put(p.getName(), p);
      }
      return this;
   }

   /**
    * Bean property getter:  <property>patternProperties</property>.
    *
    * @return
    *    The value of the <property>patternProperties</property> property on this bean, or <jk>null</jk> if it is
    *    not set.
    */
   public Map<String,JsonSchema> getPatternProperties() {
      return patternProperties;
   }

   /**
    * Bean property setter:  <property>patternProperties</property>.
    *
    * @param patternProperties The new value for the <property>patternProperties</property> property on this bean.
    * @return This object (for method chaining).
    */
   public JsonSchema setPatternProperties(Map<String,JsonSchema> patternProperties) {
      this.patternProperties = patternProperties;
      if (patternProperties != null)
         for (Map.Entry<String,JsonSchema> e : patternProperties.entrySet()) {
            JsonSchema s = e.getValue();
            setMasterOn(s);
            s.setName(e.getKey());
         }
      return this;
   }

   /**
    * Bean property appender:  <property>patternProperties</property>.
    *
    * <p>
    * Properties must have their <property>name</property> property set to the pattern string when using this method.
    *
    * @param properties The list of items to append to the <property>patternProperties</property> property on this bean.
    * @return This object (for method chaining).
    * @throws BeanRuntimeException If property is found without a set <property>name</property> property.
    */
   public JsonSchema addPatternProperties(JsonSchemaProperty...properties) {
      if (this.patternProperties == null)
         this.patternProperties = new LinkedHashMap<>();
      for (JsonSchema p : properties) {
         if (p.getName() == null)
            throw new BeanRuntimeException(JsonSchema.class,
               "Invalid property passed to JsonSchema.addProperties().  Property name was null.");
         setMasterOn(p);
         this.patternProperties.put(p.getName(), p);
      }
      return this;
   }

   /**
    * Bean property getter:  <property>dependencies</property>.
    *
    * @return
    *    The value of the <property>dependencies</property> property on this bean, or <jk>null</jk> if it is not set.
    */
   public Map<String,JsonSchema> getDependencies() {
      return dependencies;
   }

   /**
    * Bean property setter:  <property>dependencies</property>.
    *
    * @param dependencies The new value for the <property>dependencies</property> property on this bean.
    * @return This object (for method chaining).
    */
   public JsonSchema setDependencies(Map<String,JsonSchema> dependencies) {
      this.dependencies = dependencies;
      if (dependencies != null)
         setMasterOn(dependencies.values());
      return this;
   }

   /**
    * Bean property appender:  <property>dependencies</property>.
    *
    * @param name The key of the entry in the dependencies map.
    * @param dependency The value of the entry in the dependencies map.
    * @return This object (for method chaining).
    */
   public JsonSchema addDependency(String name, JsonSchema dependency) {
      if (this.dependencies == null)
         this.dependencies = new LinkedHashMap<>();
      this.dependencies.put(name, dependency);
      setMasterOn(dependency);
      return this;
   }

   /**
    * Bean property getter:  <property>items</property>.
    *
    * @return
    *    The value of the <property>items</property> property on this bean, or <jk>null</jk> if it is not set.
    *    Can be either a {@link JsonSchema} or {@link JsonSchemaArray} depending on what value was used to set it.
    */
   @Swap(JsonSchemaOrSchemaArraySwap.class)
   public Object getItems() {
      if (itemsSchema != null)
         return itemsSchema;
      return itemsSchemaArray;
   }

   /**
    * Bean property getter:  <property>items</property>.
    *
    * <p>
    * Convenience method for returning the <property>items</property> property when it is a {@link JsonSchema} value.
    *
    * @return The currently set value, or <jk>null</jk> if the property is not set, or is set as a {@link JsonSchemaArray}.
    */
   @BeanIgnore
   public JsonSchema getItemsAsSchema() {
      return itemsSchema;
   }

   /**
    * Bean property getter:  <property>items</property>.
    *
    * <p>
    * Convenience method for returning the <property>items</property> property when it is a {@link JsonSchemaArray} value.
    *
    * @return The currently set value, or <jk>null</jk> if the property is not set, or is set as a {@link JsonSchema}.
    */
   @BeanIgnore
   public JsonSchemaArray getItemsAsSchemaArray() {
      return itemsSchemaArray;
   }

   /**
    * Used during parsing to convert the <property>items</property> property to the correct class type.
    *
    * <ul class='spaced-list'>
    *    <li>
    *       If parsing a JSON-array, converts to a {@link JsonSchemaArray}.
    *    <li>
    *       If parsing a JSON-object, converts to a {@link JsonSchema}.
    * </ul>
    *
    * <p>
    * Serialization method is a no-op.
    */
   public static class JsonSchemaOrSchemaArraySwap extends PojoSwap<Object,Object> {

      @Override /* PojoSwap */
      public Object swap(BeanSession session, Object o) throws SerializeException {
         return o;
      }

      @Override /* PojoSwap */
      public Object unswap(BeanSession session, Object o, ClassMeta<?> hint) throws ParseException {
         ClassMeta<?> cm = (
            o instanceof Collection
            ? session.getClassMeta(JsonSchemaArray.class)
            : session.getClassMeta(JsonSchema.class)
         );
         return session.convertToType(o, cm);
      }
   }

   /**
    * Bean property setter:  <property>items</property>.
    *
    * @param
    *    items The new value for the <property>items</property> property on this bean.
    *    This object must be of type {@link JsonSchema} or {@link JsonSchemaArray}.
    * @return This object (for method chaining).
    * @throws BeanRuntimeException If invalid object type passed in.
    */
   public JsonSchema setItems(Object items) {
      this.itemsSchema = null;
      this.itemsSchemaArray = null;
      if (items != null) {
         if (items instanceof JsonSchema) {
            this.itemsSchema = (JsonSchema)items;
            setMasterOn(this.itemsSchema);
         } else if (items instanceof JsonSchemaArray) {
            this.itemsSchemaArray = (JsonSchemaArray)items;
            setMasterOn(this.itemsSchemaArray);
         } else
            throw new BeanRuntimeException(JsonSchemaProperty.class,
               "Invalid attribute type ''{0}'' passed in.  Must be one of the following:  JsonSchema, JsonSchemaArray",
               items.getClass().getName());
      }
      return this;
   }

   /**
    * Bean property appender:  <property>items</property>.
    *
    * @param items The list of items to append to the <property>items</property> property on this bean.
    * @return This object (for method chaining).
    */
   public JsonSchema addItems(JsonSchema...items) {
      if (this.itemsSchemaArray == null)
         this.itemsSchemaArray = new JsonSchemaArray();
      this.itemsSchemaArray.addAll(items);
      setMasterOn(items);
      return this;
   }

   /**
    * Bean property getter:  <property>multipleOf</property>.
    *
    * @return The value of the <property>multipleOf</property> property on this bean, or <jk>null</jk> if it is not set.
    */
   public Number getMultipleOf() {
      return multipleOf;
   }

   /**
    * Bean property setter:  <property>multipleOf</property>.
    *
    * @param multipleOf The new value for the <property>multipleOf</property> property on this bean.
    * @return This object (for method chaining).
    */
   public JsonSchema setMultipleOf(Number multipleOf) {
      this.multipleOf = multipleOf;
      return this;
   }

   /**
    * Bean property getter:  <property>maximum</property>.
    *
    * @return The value of the <property>maximum</property> property on this bean, or <jk>null</jk> if it is not set.
    */
   public Number getMaximum() {
      return maximum;
   }

   /**
    * Bean property setter:  <property>maximum</property>.
    *
    * @param maximum The new value for the <property>maximum</property> property on this bean.
    * @return This object (for method chaining).
    */
   public JsonSchema setMaximum(Number maximum) {
      this.maximum = maximum;
      return this;
   }

   /**
    * Bean property getter:  <property>exclusiveMaximum</property>.
    *
    * @return
    *    The value of the <property>exclusiveMaximum</property> property on this bean, or <jk>null</jk> if it is
    *    not set.
    */
   public Boolean isExclusiveMaximum() {
      return exclusiveMaximum;
   }

   /**
    * Bean property setter:  <property>exclusiveMaximum</property>.
    *
    * @param exclusiveMaximum The new value for the <property>exclusiveMaximum</property> property on this bean.
    * @return This object (for method chaining).
    */
   public JsonSchema setExclusiveMaximum(Boolean exclusiveMaximum) {
      this.exclusiveMaximum = exclusiveMaximum;
      return this;
   }

   /**
    * Bean property getter:  <property>minimum</property>.
    *
    * @return The value of the <property>minimum</property> property on this bean, or <jk>null</jk> if it is not set.
    */
   public Number getMinimum() {
      return minimum;
   }

   /**
    * Bean property setter:  <property>minimum</property>.
    *
    * @param minimum The new value for the <property>minimum</property> property on this bean.
    * @return This object (for method chaining).
    */
   public JsonSchema setMinimum(Number minimum) {
      this.minimum = minimum;
      return this;
   }

   /**
    * Bean property getter:  <property>exclusiveMinimum</property>.
    *
    * @return
    *    The value of the <property>exclusiveMinimum</property> property on this bean, or <jk>null</jk> if it is
    *    not set.
    */
   public Boolean isExclusiveMinimum() {
      return exclusiveMinimum;
   }

   /**
    * Bean property setter:  <property>exclusiveMinimum</property>.
    *
    * @param exclusiveMinimum The new value for the <property>exclusiveMinimum</property> property on this bean.
    * @return This object (for method chaining).
    */
   public JsonSchema setExclusiveMinimum(Boolean exclusiveMinimum) {
      this.exclusiveMinimum = exclusiveMinimum;
      return this;
   }

   /**
    * Bean property getter:  <property>maxLength</property>.
    *
    * @return The value of the <property>maxLength</property> property on this bean, or <jk>null</jk> if it is not set.
    */
   public Integer getMaxLength() {
      return maxLength;
   }

   /**
    * Bean property setter:  <property>maxLength</property>.
    *
    * @param maxLength The new value for the <property>maxLength</property> property on this bean.
    * @return This object (for method chaining).
    */
   public JsonSchema setMaxLength(Integer maxLength) {
      this.maxLength = maxLength;
      return this;
   }

   /**
    * Bean property getter:  <property>minLength</property>.
    *
    * @return The value of the <property>minLength</property> property on this bean, or <jk>null</jk> if it is not set.
    */
   public Integer getMinLength() {
      return minLength;
   }

   /**
    * Bean property setter:  <property>minLength</property>.
    *
    * @param minLength The new value for the <property>minLength</property> property on this bean.
    * @return This object (for method chaining).
    */
   public JsonSchema setMinLength(Integer minLength) {
      this.minLength = minLength;
      return this;
   }

   /**
    * Bean property getter:  <property>pattern</property>.
    *
    * @return The value of the <property>pattern</property> property on this bean, or <jk>null</jk> if it is not set.
    */
   public String getPattern() {
      return pattern;
   }

   /**
    * Bean property setter:  <property>pattern</property>.
    *
    * @param pattern The new value for the <property>pattern</property> property on this bean.
    * @return This object (for method chaining).
    */
   public JsonSchema setPattern(String pattern) {
      this.pattern = pattern;
      return this;
   }

   /**
    * Bean property getter:  <property>additionalItems</property>.
    *
    * @return
    *    The value of the <property>additionalItems</property> property on this bean, or <jk>null</jk> if it is
    *    not set.
    *    Can be either a {@link Boolean} or {@link JsonSchemaArray} depending on what value was used to set it.
    */
   @Swap(BooleanOrSchemaArraySwap.class)
   public Object getAdditionalItems() {
      if (additionalItemsBoolean != null)
         return additionalItemsBoolean;
      return additionalItemsSchemaArray;
   }

   /**
    * Bean property getter:  <property>additionalItems</property>.
    *
    * <p>
    * Convenience method for returning the <property>additionalItems</property> property when it is a {@link Boolean}
    * value.
    *
    * @return The currently set value, or <jk>null</jk> if the property is not set, or is set as a {@link JsonSchemaArray}.
    */
   @BeanIgnore
   public Boolean getAdditionalItemsAsBoolean() {
      return additionalItemsBoolean;
   }

   /**
    * Bean property getter:  <property>additionalItems</property>.
    *
    * <p>
    * Convenience method for returning the <property>additionalItems</property> property when it is a
    * {@link JsonSchemaArray} value.
    *
    * @return The currently set value, or <jk>null</jk> if the property is not set, or is set as a {@link Boolean}.
    */
   @BeanIgnore
   public List<JsonSchema> getAdditionalItemsAsSchemaArray() {
      return additionalItemsSchemaArray;
   }

   /**
    * Bean property setter:  <property>additionalItems</property>.
    *
    * @param additionalItems
    *    The new value for the <property>additionalItems</property> property on this bean.
    *    This object must be of type {@link Boolean} or {@link JsonSchemaArray}.
    * @return This object (for method chaining).
    * @throws BeanRuntimeException If invalid object type passed in.
    */
   public JsonSchema setAdditionalItems(Object additionalItems) {
      this.additionalItemsBoolean = null;
      this.additionalItemsSchemaArray = null;
      if (additionalItems != null) {
         if (additionalItems instanceof Boolean)
            this.additionalItemsBoolean = (Boolean)additionalItems;
         else if (additionalItems instanceof JsonSchemaArray) {
            this.additionalItemsSchemaArray = (JsonSchemaArray)additionalItems;
            setMasterOn(this.additionalItemsSchemaArray);
         } else
            throw new BeanRuntimeException(JsonSchemaProperty.class,
               "Invalid attribute type ''{0}'' passed in.  Must be one of the following:  Boolean, JsonSchemaArray",
               additionalItems.getClass().getName());
      }
      return this;
   }

   /**
    * Bean property appender:  <property>additionalItems</property>.
    *
    * @param additionalItems
    *    The list of items to append to the <property>additionalItems</property> property on this bean.
    * @return This object (for method chaining).
    */
   public JsonSchema addAdditionalItems(JsonSchema...additionalItems) {
      if (this.additionalItemsSchemaArray == null)
         this.additionalItemsSchemaArray = new JsonSchemaArray();
      this.additionalItemsSchemaArray.addAll(additionalItems);
      setMasterOn(additionalItems);
      return this;
   }

   /**
    * Used during parsing to convert the <property>additionalItems</property> property to the correct class type.
    *
    * <ul class='spaced-list'>
    *    <li>
    *       If parsing a JSON-array, converts to a {@link JsonSchemaArray}.
    *    <li>
    *       If parsing a JSON-boolean, converts to a {@link Boolean}.
    * </ul>
    *
    * <p>
    * Serialization method is a no-op.
    */
   public static class BooleanOrSchemaArraySwap extends PojoSwap<Object,Object> {

      @Override /* PojoSwap */
      public Object swap(BeanSession session, Object o) throws SerializeException {
         return o;
      }

      @Override /* PojoSwap */
      public Object unswap(BeanSession session, Object o, ClassMeta<?> hint) throws ParseException {
         ClassMeta<?> cm = (
            o instanceof Collection
            ? session.getClassMeta(JsonSchemaArray.class)
            : session.getClassMeta(Boolean.class)
         );
         return session.convertToType(o, cm);
      }
   }

   /**
    * Bean property getter:  <property>maxItems</property>.
    *
    * @return The value of the <property>maxItems</property> property on this bean, or <jk>null</jk> if it is not set.
    */
   public Integer getMaxItems() {
      return maxItems;
   }

   /**
    * Bean property setter:  <property>maxItems</property>.
    *
    * @param maxItems The new value for the <property>maxItems</property> property on this bean.
    * @return This object (for method chaining).
    */
   public JsonSchema setMaxItems(Integer maxItems) {
      this.maxItems = maxItems;
      return this;
   }

   /**
    * Bean property getter:  <property>minItems</property>.
    *
    * @return The value of the <property>minItems</property> property on this bean, or <jk>null</jk> if it is not set.
    */
   public Integer getMinItems() {
      return minItems;
   }

   /**
    * Bean property setter:  <property>minItems</property>.
    *
    * @param minItems The new value for the <property>minItems</property> property on this bean.
    * @return This object (for method chaining).
    */
   public JsonSchema setMinItems(Integer minItems) {
      this.minItems = minItems;
      return this;
   }

   /**
    * Bean property getter:  <property>uniqueItems</property>.
    *
    * @return
    *    The value of the <property>uniqueItems</property> property on this bean, or <jk>null</jk> if it is not set.
    */
   public Boolean getUniqueItems() {
      return uniqueItems;
   }

   /**
    * Bean property setter:  <property>uniqueItems</property>.
    *
    * @param uniqueItems The new value for the <property>uniqueItems</property> property on this bean.
    * @return This object (for method chaining).
    */
   public JsonSchema setUniqueItems(Boolean uniqueItems) {
      this.uniqueItems = uniqueItems;
      return this;
   }

   /**
    * Bean property getter:  <property>maxProperties</property>.
    *
    * @return
    *    The value of the <property>maxProperties</property> property on this bean, or <jk>null</jk> if it is not set.
    */
   public Integer getMaxProperties() {
      return maxProperties;
   }

   /**
    * Bean property setter:  <property>maxProperties</property>.
    *
    * @param maxProperties The new value for the <property>maxProperties</property> property on this bean.
    * @return This object (for method chaining).
    */
   public JsonSchema setMaxProperties(Integer maxProperties) {
      this.maxProperties = maxProperties;
      return this;
   }

   /**
    * Bean property getter:  <property>minProperties</property>.
    *
    * @return
    *    The value of the <property>minProperties</property> property on this bean, or <jk>null</jk> if it is not set.
    */
   public Integer getMinProperties() {
      return minProperties;
   }

   /**
    * Bean property setter:  <property>minProperties</property>.
    *
    * @param minProperties The new value for the <property>minProperties</property> property on this bean.
    * @return This object (for method chaining).
    */
   public JsonSchema setMinProperties(Integer minProperties) {
      this.minProperties = minProperties;
      return this;
   }

   /**
    * Bean property getter:  <property>required</property>.
    *
    * @return The value of the <property>required</property> property on this bean, or <jk>null</jk> if it is not set.
    */
   public List<String> getRequired() {
      return required;
   }

   /**
    * Bean property setter:  <property>required</property>.
    *
    * @param required The new value for the <property>required</property> property on this bean.
    * @return This object (for method chaining).
    */
   public JsonSchema setRequired(List<String> required) {
      this.required = required;
      return this;
   }

   /**
    * Bean property appender:  <property>required</property>.
    *
    * @param required The list of items to append to the <property>required</property> property on this bean.
    * @return This object (for method chaining).
    */
   public JsonSchema addRequired(List<String> required) {
      if (this.required == null)
         this.required = new LinkedList<>();
      for (String r : required)
         this.required.add(r);
      return this;
   }

   /**
    * Bean property appender:  <property>required</property>.
    *
    * @param required The list of items to append to the <property>required</property> property on this bean.
    * @return This object (for method chaining).
    */
   public JsonSchema addRequired(String...required) {
      if (this.required == null)
         this.required = new LinkedList<>();
      for (String r : required)
         this.required.add(r);
      return this;
   }

   /**
    * Bean property appender:  <property>required</property>.
    *
    * @param properties The list of items to append to the <property>required</property> property on this bean.
    * @return This object (for method chaining).
    */
   public JsonSchema addRequired(JsonSchemaProperty...properties) {
      if (this.required == null)
         this.required = new LinkedList<>();
      for (JsonSchemaProperty p : properties)
         this.required.add(p.getName());
      return this;
   }

   /**
    * Bean property getter:  <property>additionalProperties</property>.
    *
    * @return
    *    The value of the <property>additionalProperties</property> property on this bean, or <jk>null</jk> if it
    *    is not set.
    *    Can be either a {@link Boolean} or {@link JsonSchemaArray} depending on what value was used to set it.
    */
   @Swap(BooleanOrSchemaSwap.class)
   public Object getAdditionalProperties() {
      if (additionalPropertiesBoolean != null)
         return additionalItemsBoolean;
      return additionalPropertiesSchema;
   }

   /**
    * Bean property getter:  <property>additionalProperties</property>.
    *
    * <p>
    * Convenience method for returning the <property>additionalProperties</property> property when it is a
    * {@link Boolean} value.
    *
    * @return The currently set value, or <jk>null</jk> if the property is not set, or is set as a {@link JsonSchema}.
    */
   @BeanIgnore
   public Boolean getAdditionalPropertiesAsBoolean() {
      return additionalPropertiesBoolean;
   }

   /**
    * Bean property getter:  <property>additionalProperties</property>.
    *
    * <p>
    * Convenience method for returning the <property>additionalProperties</property> property when it is a
    * {@link JsonSchema} value.
    *
    * @return The currently set value, or <jk>null</jk> if the property is not set, or is set as a {@link Boolean}.
    */
   @BeanIgnore
   public JsonSchema getAdditionalPropertiesAsSchema() {
      return additionalPropertiesSchema;
   }

   /**
    * Bean property setter:  <property>additionalProperties</property>.
    *
    * @param additionalProperties
    *    The new value for the <property>additionalProperties</property> property on this bean.
    *    This object must be of type {@link Boolean} or {@link JsonSchema}.
    * @return This object (for method chaining).
    * @throws BeanRuntimeException If invalid object type passed in.
    */
   @BeanProperty(beanDictionary={JsonSchema.class})
   public JsonSchema setAdditionalProperties(Object additionalProperties) {
      this.additionalPropertiesBoolean = null;
      this.additionalPropertiesSchema = null;
      if (additionalProperties != null) {
         if (additionalProperties instanceof Boolean)
            this.additionalPropertiesBoolean = (Boolean)additionalProperties;
         else if (additionalProperties instanceof JsonSchema) {
            this.additionalPropertiesSchema = (JsonSchema)additionalProperties;
            setMasterOn(this.additionalPropertiesSchema);
         } else
            throw new BeanRuntimeException(JsonSchemaProperty.class,
               "Invalid attribute type ''{0}'' passed in.  Must be one of the following:  Boolean, JsonSchema",
               additionalProperties.getClass().getName());
      }
      return this;
   }

   /**
    * Used during parsing to convert the <property>additionalProperties</property> property to the correct class type.
    *
    * <ul class='spaced-list'>
    *    <li>
    *       If parsing a JSON-object, converts to a {@link JsonSchema}.
    *    <li>
    *       If parsing a JSON-boolean, converts to a {@link Boolean}.
    * </ul>
    *
    * <p>
    * Serialization method is a no-op.
    */
   public static class BooleanOrSchemaSwap extends PojoSwap<Object,Object> {

      @Override /* PojoSwap */
      public Object swap(BeanSession session, Object o) throws SerializeException {
         return o;
      }

      @Override /* PojoSwap */
      public Object unswap(BeanSession session, Object o, ClassMeta<?> hint) throws ParseException {
         ClassMeta<?> cm = (
            o instanceof Boolean
            ? session.getClassMeta(Boolean.class)
            : session.getClassMeta(JsonSchema.class)
         );
         return session.convertToType(o, cm);
      }
   }

   /**
    * Bean property getter:  <property>enum</property>.
    *
    * @return The value of the <property>enum</property> property on this bean, or <jk>null</jk> if it is not set.
    */
   public List<String> getEnum() {
      return _enum;
   }

   /**
    * Bean property setter:  <property>enum</property>.
    *
    * @param _enum The new value for the <property>enum</property> property on this bean.
    * @return This object (for method chaining).
    */
   public JsonSchema setEnum(List<String> _enum) {
      this._enum = _enum;
      return this;
   }

   /**
    * Bean property appender:  <property>enum</property>.
    *
    * @param _enum The list of items to append to the <property>enum</property> property on this bean.
    * @return This object (for method chaining).
    */
   public JsonSchema addEnum(String..._enum) {
      if (this._enum == null)
         this._enum = new LinkedList<>();
      for (String e : _enum)
         this._enum.add(e);
      return this;
   }

   /**
    * Bean property getter:  <property>allOf</property>.
    *
    * @return The value of the <property>allOf</property> property on this bean, or <jk>null</jk> if it is not set.
    */
   public List<JsonSchema> getAllOf() {
      return allOf;
   }

   /**
    * Bean property setter:  <property>allOf</property>.
    *
    * @param allOf The new value for the <property>allOf</property> property on this bean.
    * @return This object (for method chaining).
    */
   public JsonSchema setAllOf(List<JsonSchema> allOf) {
      this.allOf = allOf;
      setMasterOn(allOf);
      return this;
   }

   /**
    * Bean property appender:  <property>allOf</property>.
    *
    * @param allOf The list of items to append to the <property>allOf</property> property on this bean.
    * @return This object (for method chaining).
    */
   public JsonSchema addAllOf(JsonSchema...allOf) {
      if (this.allOf == null)
         this.allOf = new LinkedList<>();
      setMasterOn(allOf);
      for (JsonSchema s : allOf)
         this.allOf.add(s);
      return this;
   }

   /**
    * Bean property getter:  <property>anyOf</property>.
    *
    * @return The value of the <property>anyOf</property> property on this bean, or <jk>null</jk> if it is not set.
    */
   public List<JsonSchema> getAnyOf() {
      return anyOf;
   }

   /**
    * Bean property setter:  <property>anyOf</property>.
    *
    * @param anyOf The new value of the <property>anyOf</property> property on this bean.
    * @return This object (for method chaining).
    */
   public JsonSchema setAnyOf(List<JsonSchema> anyOf) {
      this.anyOf = anyOf;
      setMasterOn(anyOf);
      return this;
   }

   /**
    * Bean property appender:  <property>anyOf</property>.
    *
    * @param anyOf The list of items to append to the <property>anyOf</property> property on this bean.
    * @return This object (for method chaining).
    */
   public JsonSchema addAnyOf(JsonSchema...anyOf) {
      if (this.anyOf == null)
         this.anyOf = new LinkedList<>();
      setMasterOn(anyOf);
      for (JsonSchema s : anyOf)
         this.anyOf.add(s);
      return this;
   }

   /**
    * Bean property getter:  <property>oneOf</property>.
    *
    * @return The value of the <property>oneOf</property> property on this bean, or <jk>null</jk> if it is not set.
    */
   public List<JsonSchema> getOneOf() {
      return oneOf;
   }

   /**
    * Bean property setter:  <property>oneOf</property>.
    *
    * @param oneOf The new value for the <property>oneOf</property> property on this bean.
    * @return This object (for method chaining).
    */
   public JsonSchema setOneOf(List<JsonSchema> oneOf) {
      this.oneOf = oneOf;
      setMasterOn(oneOf);
      return this;
   }

   /**
    * Bean property appender:  <property>oneOf</property>.
    *
    * @param oneOf The list of items to append to the <property>oneOf</property> property on this bean.
    * @return This object (for method chaining).
    */
   public JsonSchema addOneOf(JsonSchema...oneOf) {
      if (this.oneOf == null)
         this.oneOf = new LinkedList<>();
      setMasterOn(oneOf);
      for (JsonSchema s : oneOf)
         this.oneOf.add(s);
      return this;
   }

   /**
    * Bean property getter:  <property>not</property>.
    *
    * @return The value of the <property>not</property> property on this bean, or <jk>null</jk> if it is not set.
    */
   public JsonSchema getNot() {
      return not;
   }

   /**
    * Bean property setter:  <property>not</property>.
    *
    * @param not The new value for the <property>not</property> property on this bean.
    * @return This object (for method chaining).
    */
   public JsonSchema setNot(JsonSchema not) {
      this.not = not;
      setMasterOn(not);
      return this;
   }

   /**
    * Bean property getter:  <property>$ref</property>.
    *
    * @return The value of the <property>$ref</property> property on this bean, or <jk>null</jk> if it is not set.
    */
   @BeanProperty("$ref")
   public URI getRef() {
      return ref;
   }

   /**
    * Bean property setter:  <property>$ref</property>.
    *
    * <p>
    * The value can be of any of the following types: {@link URI}, {@link URL}, {@link String}.
    * Strings must be valid URIs.
    *
    * <p>
    * URIs defined by {@link UriResolver} can be used for values.
    *
    * @param ref The new value for the <property>$ref</property> property on this bean.
    * @return This object (for method chaining).
    */
   @BeanProperty("$ref")
   public JsonSchema setRef(Object ref) {
      this.ref = toURI(ref);
      return this;
   }

   private void setMasterOn(JsonSchema s) {
      if (s != null)
         s.setMaster(this);
   }

   private void setMasterOn(JsonSchema[] ss) {
      if (ss != null)
         for (JsonSchema s : ss)
            setMasterOn(s);
   }

   private void setMasterOn(Collection<JsonSchema> ss) {
      if (ss != null)
         for (JsonSchema s : ss)
            setMasterOn(s);
   }

   private void setMasterOn(JsonSchemaArray ss) {
      if (ss != null)
         for (JsonSchema s : ss)
            setMasterOn(s);
   }

   /**
    * Sets the master schema for this schema and all child schema objects.
    *
    * <p>
    * All child elements in a schema should point to a single "master" schema in order to locate registered JsonSchemaMap
    * objects for resolving external schemas.
    *
    * @param master The master schema to associate on this and all children.  Can be <jk>null</jk>.
    */
   protected void setMaster(JsonSchema master) {
      this.master = master;
      if (definitions != null)
         for (JsonSchema s : definitions.values())
            s.setMaster(master);
      if (properties != null)
         for (JsonSchema s : properties.values())
            s.setMaster(master);
      if (patternProperties != null)
         for (JsonSchema s : patternProperties.values())
            s.setMaster(master);
      if (dependencies != null)
         for (JsonSchema s : dependencies.values())
            s.setMaster(master);
      if (itemsSchema != null)
         itemsSchema.setMaster(master);
      if (itemsSchemaArray != null)
         for (JsonSchema s : itemsSchemaArray)
            s.setMaster(master);
      if (additionalItemsSchemaArray != null)
         for (JsonSchema s : additionalItemsSchemaArray)
            s.setMaster(master);
      if (additionalPropertiesSchema != null)
         additionalPropertiesSchema.setMaster(master);
      if (allOf != null)
         for (JsonSchema s : allOf)
            s.setMaster(master);
      if (anyOf != null)
         for (JsonSchema s : anyOf)
            s.setMaster(master);
      if (oneOf != null)
         for (JsonSchema s : oneOf)
            s.setMaster(master);
      if (not != null)
         not.setMaster(master);
   }

   /**
    * Resolve schema if reference.
    *
    * <p>
    * If this schema is a reference to another schema (has its <property>$ref</property> property set), this
    * method will retrieve the referenced schema from the schema map registered with this schema.
    *
    * <p>
    * If this schema is not a reference, or no schema map is registered with this schema, this method is a no-op and
    * simply returns this object.
    *
    * @return The referenced schema, or <jk>null</jk>.
    */
   public JsonSchema resolve() {
      if (ref == null || master.schemaMap == null)
         return this;
      return master.schemaMap.get(ref);
   }

   /**
    * Associates a schema map with this schema for resolving other schemas identified through <property>$ref</property>
    * properties.
    *
    * @param schemaMap The schema map to associate with this schema.  Can be <jk>null</jk>.
    * @return This object (for method chaining).
    */
   public JsonSchema setSchemaMap(JsonSchemaMap schemaMap) {
      this.schemaMap = schemaMap;
      return this;
   }

   @Override /* Object */
   public String toString() {
      return JsonSerializer.DEFAULT.toString(this);
   }
}