/*
    * 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
    *
    *      https://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.commons.beanutils2;
  
  import java.util.Map;
  import java.util.Objects;
  
  /**
   * <p>
   * Provides a <em>light weight</em> {@code DynaBean</code> facade to a <code>Map}
   *  with <em>lazy</em> map/list processing.</p>
   *
   * <p>Its a <em>light weight</em> {@code DynaBean} implementation because there is no
   *    actual {@code DynaClass</code> associated with this <code>DynaBean} - in fact
   *    it implements the {@code DynaClass} interface itself providing <em>pseudo</em> DynaClass
   *    behavior from the actual values stored in the {@code Map}.</p>
   *
   * <p>As well providing rhe standard {@code DynaBean</code> access to the <code>Map}'s properties
   *    this class also provides the usual <em>Lazy</em> behavior:</p>
   *    <ul>
   *       <li>Properties don't need to be pre-defined in a {@code DynaClass}</li>
   *       <li>Indexed properties ({@code Lists</code> or <code>Arrays}) are automatically instantiated
   *           and <em>grown</em> so that they are large enough to cater for the index being set.</li>
   *       <li>Mapped properties are automatically instantiated.</li>
   *    </ul>
   *
   * <p><strong><u><em>Restricted</em> DynaClass</u></strong></p>
   *    <p>This class implements the {@code MutableDynaClass} interface.
   *       {@code MutableDynaClass</code> have a facility to <em>restrict</em> the <code>DynaClass} so that its properties cannot be modified. If the
   * {@code MutableDynaClass} is restricted then calling any of the {@code set()} methods for a property which doesn't exist will result in a
   * {@code IllegalArgumentException} being thrown.
   * </p>
   */
  public class LazyDynaMap extends LazyDynaBean implements MutableDynaClass {
  
      private static final long serialVersionUID = 1L;
  
      /**
       * The name of this DynaClass (analogous to the {@code getName()</code> method of <code>java.lang.Class}).
       */
      protected String name;
  
      /**
       * Controls whether changes to this DynaClass's properties are allowed.
       */
      protected boolean restricted;
  
      /**
       * <p>
       * Controls whether the {@code getDynaProperty()} method returns null if a property doesn't exist - or creates a new one.
       * </p>
       *
       * <p>
       * Default is {@code false}.
       */
      protected boolean returnNull;
  
      /**
       * Constructs a new instance.
       */
      public LazyDynaMap() {
          this(null, (Map<String, Object>) null);
      }
  
      /**
       * Constructs a new {@code LazyDynaMap} based on an exisiting DynaClass
       *
       * @param dynaClass DynaClass to copy the name and properties from
       */
      public LazyDynaMap(final DynaClass dynaClass) {
          this(dynaClass.getName(), dynaClass.getDynaProperties());
      }
  
      /**
       * Constructs a new {@code LazyDynaMap} with the specified properties.
       *
       * @param properties Property descriptors for the supported properties
       */
      public LazyDynaMap(final DynaProperty[] properties) {
          this(null, properties);
      }
  
      /**
       * Constructs a new {@code LazyDynaMap</code> with the specified <code>Map}.
       *
      * @param values The Map backing this {@code LazyDynaMap}
      */
     public LazyDynaMap(final Map<String, Object> values) {
         this(null, values);
     }
 
     /**
      * Constructs a new {@code LazyDynaMap} with the specified name.
      *
      * @param name Name of this DynaBean class
      */
     public LazyDynaMap(final String name) {
         this(name, (Map<String, Object>) null);
     }
 
     /**
      * Constructs a new {@code LazyDynaMap} with the specified name and properties.
      *
      * @param name       Name of this DynaBean class
      * @param properties Property descriptors for the supported properties
      */
     public LazyDynaMap(final String name, final DynaProperty[] properties) {
         this(name, (Map<String, Object>) null);
         if (properties != null) {
             for (final DynaProperty property : properties) {
                 add(property);
             }
         }
     }
 
     /**
      * Constructs a new {@code LazyDynaMap</code> with the specified name and  <code>Map}.
      *
      * @param name   Name of this DynaBean class
      * @param values The Map backing this {@code LazyDynaMap}
      */
     public LazyDynaMap(final String name, final Map<String, Object> values) {
         this.name = name == null ? "LazyDynaMap" : name;
         this.values = values == null ? newMap() : values;
         this.dynaClass = this;
     }
 
     /**
      * Add a new dynamic property.
      *
      * @param property Property the new dynamic property to add.
      * @throws IllegalArgumentException if name is null
      */
     protected void add(final DynaProperty property) {
         add(property.getName(), property.getType());
     }
 
     /**
      * Add a new dynamic property with no restrictions on data type, readability, or writeability.
      *
      * @param name Name of the new dynamic property
      * @throws IllegalArgumentException if name is null
      */
     @Override
     public void add(final String name) {
         add(name, null);
     }
 
     /**
      * Add a new dynamic property with the specified data type, but with no restrictions on readability or writeability.
      *
      * @param name Name of the new dynamic property
      * @param type Data type of the new dynamic property (null for no restrictions)
      * @throws IllegalArgumentException if name is null
      * @throws IllegalStateException    if this DynaClass is currently restricted, so no new properties can be added
      */
     @Override
     public void add(final String name, final Class<?> type) {
         Objects.requireNonNull(name, "name");
         if (isRestricted()) {
             throw new IllegalStateException("DynaClass is currently restricted. No new properties can be added.");
         }
         // Check if the property already exists
         values.computeIfAbsent(name, k -> type == null ? null : createProperty(name, type));
     }
 
     /**
      * <p>
      * Add a new dynamic property with the specified data type, readability, and writeability.
      * </p>
      *
      * <p>
      * <strong>N.B.</strong>Support for readable/writable properties has not been implemented and this method always throws a
      * {@code UnsupportedOperationException}.
      * </p>
      *
      * <p>
      * I'm not sure the intention of the original authors for this method, but it seems to me that readable/writable should be attributes of the
      * {@code DynaProperty} class (which they are not) and is the reason this method has not been implemented.
      * </p>
      *
      * @param name     Name of the new dynamic property
      * @param type     Data type of the new dynamic property (null for no restrictions)
      * @param readable Set to {@code true} if this property value should be readable
      * @param writable Set to {@code true} if this property value should be writable
      * @throws UnsupportedOperationException anytime this method is called
      */
     @Override
     public void add(final String name, final Class<?> type, final boolean readable, final boolean writable) {
         throw new java.lang.UnsupportedOperationException("readable/writable properties not supported");
     }
 
     /**
      * <p>
      * Return an array of {@code PropertyDescriptor} for the properties currently defined in this DynaClass. If no properties are defined, a zero-length array
      * will be returned.
      * </p>
      *
      * <p>
      * <strong>FIXME</strong> - Should we really be implementing {@code getBeanInfo()} instead, which returns property descriptors and a bunch of other stuff?
      * </p>
      *
      * @return the set of properties for this DynaClass
      */
     @Override
     public DynaProperty[] getDynaProperties() {
         int i = 0;
         final DynaProperty[] properties = new DynaProperty[values.size()];
         for (final Map.Entry<String, Object> e : values.entrySet()) {
             final String name = e.getKey();
             final Object value = values.get(name);
             properties[i++] = new DynaProperty(name, value == null ? null : value.getClass());
         }
 
         return properties;
     }
 
     /**
      * <p>
      * Return a property descriptor for the specified property.
      * </p>
      *
      * <p>
      * If the property is not found and the {@code returnNull} indicator is {@code true</code>, this method always returns <code>null}.
      * </p>
      *
      * <p>
      * If the property is not found and the {@code returnNull} indicator is {@code false} a new property descriptor is created and returned (although its not
      * actually added to the DynaClass's properties). This is the default behavior.
      * </p>
      *
      * <p>
      * The reason for not returning a {@code null} property descriptor is that {@code BeanUtils} uses this method to check if a property exists before trying to
      * set it - since these <em>Map</em> implementations automatically add any new properties when they are set, returning {@code null} from this method would
      * defeat their purpose.
      * </p>
      *
      * @param name Name of the dynamic property for which a descriptor is requested
      * @return The descriptor for the specified property
      * @throws IllegalArgumentException if no property name is specified
      */
     @Override
     public DynaProperty getDynaProperty(final String name) {
         Objects.requireNonNull(name, "name");
         final Object value = values.get(name);
         // If it doesn't exist and returnNull is false
         // create a new DynaProperty
         if (value == null && isReturnNull()) {
             return null;
         }
         if (value == null) {
             return new DynaProperty(name);
         }
         return new DynaProperty(name, value.getClass());
     }
 
     /**
      * Gets the underlying Map backing this {@code DynaBean}
      *
      * @return the underlying Map
      * @since 1.8.0
      */
     @Override
     public Map<String, Object> getMap() {
         return values;
     }
 
     /**
      * Gets the name of this DynaClass (analogous to the {@code getName()</code> method of <code>java.lang.Class})
      *
      * @return the name of the DynaClass
      */
     @Override
     public String getName() {
         return this.name;
     }
 
     /**
      * <p>
      * Indicate whether a property actually exists.
      * </p>
      *
      * <p>
      * <strong>N.B.</strong> Using {@code getDynaProperty(name) == null} doesn't work in this implementation because that method might return a DynaProperty if
      * it doesn't exist (depending on the {@code returnNull} indicator).
      * </p>
      *
      * @param name Name of the dynamic property
      * @return {@code true} if the property exists, otherwise {@code false}
      * @throws IllegalArgumentException if no property name is specified
      */
     @Override
     protected boolean isDynaProperty(final String name) {
         return values.containsKey(Objects.requireNonNull(name, "name"));
     }
 
     /**
      * <p>
      * Is this DynaClass currently restricted.
      * </p>
      * <p>
      * If restricted, no changes to the existing registration of property names, data types, readability, or writeability are allowed.
      * </p>
      *
      * @return {@code true} if this Mutable {@link DynaClass} is restricted, otherwise {@code false}
      */
     @Override
     public boolean isRestricted() {
         return restricted;
     }
 
     /**
      * Should this DynaClass return a {@code null} from the {@code getDynaProperty(name)} method if the property doesn't exist.
      *
      * @return {@code true</code> if a <code>null} {@link DynaProperty} should be returned if the property doesn't exist, otherwise {@code false} if a new
      *         {@link DynaProperty} should be created.
      */
     public boolean isReturnNull() {
         return returnNull;
     }
 
     /**
      * Instantiate and return a new DynaBean instance, associated with this DynaClass.
      *
      * @return A new {@code DynaBean} instance
      */
     @Override
     public DynaBean newInstance() {
         // Create a new instance of the Map
         Map<String, Object> newMap = null;
         try {
             final
             // The new map is used as properties map
             Map<String, Object> temp = getMap().getClass().newInstance();
             newMap = temp;
         } catch (final Exception ex) {
             newMap = newMap();
         }
 
         // Crate new LazyDynaMap and initialize properties
         final LazyDynaMap lazyMap = new LazyDynaMap(newMap);
         final DynaProperty[] properties = getDynaProperties();
         if (properties != null) {
             for (final DynaProperty property : properties) {
                 lazyMap.add(property);
             }
         }
         return lazyMap;
     }
 
     /**
      * Remove the specified dynamic property, and any associated data type, readability, and writeability, from this dynamic class. <strong>NOTE</strong> - This
      * does <strong>NOT</strong> cause any corresponding property values to be removed from DynaBean instances associated with this DynaClass.
      *
      * @param name Name of the dynamic property to remove
      * @throws IllegalArgumentException if name is null
      * @throws IllegalStateException    if this DynaClass is currently restricted, so no properties can be removed
      */
     @Override
     public void remove(final String name) {
         Objects.requireNonNull(name, "name");
         if (isRestricted()) {
             throw new IllegalStateException("DynaClass is currently restricted. No properties can be removed.");
         }
         values.remove(name);
     }
 
     /**
      * Sets the value of a simple property with the specified name.
      *
      * @param name  Name of the property whose value is to be set
      * @param value Value to which this property is to be set
      */
     @Override
     public void set(final String name, final Object value) {
         if (isRestricted() && !values.containsKey(name)) {
             throw new IllegalArgumentException("Invalid property name '" + name + "' (DynaClass is restricted)");
         }
         values.put(name, value);
     }
 
     /**
      * Sets the Map backing this {@code DynaBean}
      *
      * @param values The new Map of values
      */
     public void setMap(final Map<String, Object> values) {
         this.values = values;
     }
 
     /**
      * <p>
      * Set whether this DynaClass is currently restricted.
      * </p>
      * <p>
      * If restricted, no changes to the existing registration of property names, data types, readability, or writeability are allowed.
      * </p>
      *
      * @param restricted The new restricted state
      */
     @Override
     public void setRestricted(final boolean restricted) {
         this.restricted = restricted;
     }
 
     /**
      * Sets whether this DynaClass should return a {@code null} from the {@code getDynaProperty(name)} method if the property doesn't exist.
      *
      * @param returnNull {@code true</code> if a <code>null} {@link DynaProperty} should be returned if the property doesn't exist, otherwise {@code false} if a
      *                   new {@link DynaProperty} should be created.
      */
     public void setReturnNull(final boolean returnNull) {
         this.returnNull = returnNull;
     }
 
 }