/*
 * 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.collections;

import static org.apache.juneau.commons.utils.PredicateUtils.*;
import static org.apache.juneau.commons.utils.StringUtils.*;
import static org.apache.juneau.commons.utils.ThrowableUtils.*;
import static org.apache.juneau.commons.utils.Utils.*;

import java.io.*;
import java.lang.reflect.*;
import java.util.*;
import java.util.function.*;

import org.apache.juneau.*;
import org.apache.juneau.commons.utils.*;
import org.apache.juneau.json.*;
import org.apache.juneau.marshaller.*;
import org.apache.juneau.objecttools.*;
import org.apache.juneau.parser.*;
import org.apache.juneau.serializer.*;

/**
 * Java implementation of a JSON array.
 *
 * <p>
 * An extension of {@link LinkedList}, so all methods available to in that class are also available to this class.
 *
 * <p>
 * Note that the use of this class is optional for generating JSON.  The serializers will accept any objects that implement the
 * {@link Collection} interface.  But this class provides some useful additional functionality when working with JSON
 * models constructed from Java Collections Framework objects.  For example, a constructor is provided for converting a
 * JSON array string directly into a {@link List}.  It also contains accessor methods for to avoid common typecasting
 * when accessing elements in a list.
 *
 * <h5 class='section'>Example:</h5>
 * <p class='bjava'>
 *    <jc>// Construct an empty List</jc>
 *    JsonList <jv>list</jv> = JsonList.<jsm>of</jsm>();
 *
 *    <jc>// Construct a list of objects using various methods</jc>
 *    <jv>list</jv> = JsonList.<jsm>of</jsm>().a(<js>"foo"</js>).a(123).a(<jk>true</jk>);
 *    <jv>list</jv> = JsonList.<jsm>of</jsm>().a(<js>"foo"</js>, 123, <jk>true</jk>);  <jc>// Equivalent</jc>
 *    <jv>list</jv> = JsonList.<jsm>of</jsm>(<js>"foo"</js>, 123, <jk>true</jk>);  <jc>// Equivalent</jc>
 *
 *    <jc>// Construct a list of integers from JSON</jc>
 *    <jv>list</jv> = JsonList.<jsm>ofJson</jsm>(<js>"[1,2,3]"</js>);
 *
 *    <jc>// Construct a list of generic JsonMap objects from JSON</jc>
 *    <jv>list</jv> = JsonList.<jsm>ofJson</jsm>(<js>"[{foo:'bar'},{baz:'bing'}]"</js>);
 *
 *    <jc>// Construct a list of integers from XML</jc>
 *    String <jv>xml</jv> = <js>"&lt;array&gt;&lt;number&gt;1&lt;/number&gt;&lt;number&gt;2&lt;/number&gt;&lt;number&gt;3&lt;/number&gt;&lt;/array&gt;"</js>;
 *    <jv>list</jv> = JsonList.<jsm>of</jsm>(<jv>xml</jv>, XmlParser.<jsf>DEFAULT</jsf>);
 *    <jv>list</jv> = (List)XmlParser.<jsf>DEFAULT</jsf>.parse(<jv>xml</jv>);  <jc>// Equivalent</jc>
 *    <jv>list</jv> = (List)XmlParser.<jsf>DEFAULT</jsf>.parse(Object.<jk>class</jk>, <jv>xml</jv>);  <jc>// Equivalent</jc>
 *    <jv>list</jv> = XmlParser.<jsf>DEFAULT</jsf>.parse(List.<jk>class</jk>, <jv>xml</jv>);  <jc>// Equivalent</jc>
 *    <jv>list</jv> = XmlParser.<jsf>DEFAULT</jsf>.parse(JsonList.<jk>class</jk>, <jv>xml</jv>);  <jc>// Equivalent</jc>
 *
 *    <jc>// Construct JSON from JsonList</jc>
 *    <jv>list</jv> = JsonList.<jsm>ofJson</jsm>(<js>"[{foo:'bar'},{baz:'bing'}]"</js>);
 *    String <jv>json</jv> = <jv>list</jv>.toString();  <jc>// Produces "[{foo:'bar'},{baz:'bing'}]"</jc>
 *    <jv>json</jv> = <jv>list</jv>.toString(JsonSerializer.<jsf>DEFAULT</jsf>);  <jc>// Equivalent</jc>
 *    <jv>json</jv> = JsonSerializer.<jsf>DEFAULT</jsf>.serialize(<jv>list</jv>);  <jc>// Equivalent</jc>
 *
 *    <jc>// Get one of the entries in the list as an Integer</jc>
 *    <jv>list</jv> = JsonList.<jsm>ofJson</jsm>(<js>"[1,2,3]"</js>);
 *    Integer <jv>integer</jv> = <jv>list</jv>.getInt(1);
 *    <jv>list</jv> = <jv>list</jv>.get(Integer.<jk>class</jk>, 1);  <jc>// Equivalent</jc>
 *
 *    <jc>// Get one of the entries in the list as an Float</jc>
 *    <jv>list</jv> = JsonList.<jsm>ofJson</jsm>(<js>"[1,2,3]"</js>);
 *    Float <jv>_float</jv> = <jv>list</jv>.getFloat(1); <jc>// Returns 2f </jc>
 *    <jv>_float</jv> = <jv>list</jv>.get(Float.<jk>class</jk>, 1);  <jc>// Equivalent</jc>
 *
 *    <jc>// Same as above, except converted to a String</jc>
 *    <jv>list</jv> = JsonList.<jsm>ofJson</jsm>(<js>"[1,2,3]"</js>);
 *    String <jv>string</jv> = <jv>list</jv>.getString(1); <jc>// Returns "2" </jc>
 *    <jv>string</jv> = <jv>list</jv>.get(String.<jk>class</jk>, 1);  <jc>// Equivalent</jc>
 *
 *    <jc>// Get one of the entries in the list as a bean (converted to a bean if it isn't already one)</jc>
 *    <jv>list</jv> = JsonList.<jsm>ofJson</jsm>(<js>"[{name:'John Smith',age:45}]"</js>);
 *    Person <jv>person</jv> = <jv>list</jv>.get(Person.<jk>class</jk>, 0);
 *
 *    <jc>// Iterate over a list of beans using the elements() method</jc>
 *    <jv>list</jv> = JsonList.<jsm>ofJson</jsm>(<js>"[{name:'John Smith',age:45}]"</js>);
 *    <jk>for</jk> (Person <jv>person</jv> : <jv>list</jv>.elements(Person.<jk>class</jk>) {
 *       <jc>// Do something with p</jc>
 *    }
 * </p>
 *
 * <h5 class='section'>Notes:</h5><ul>
 *    <li class='warn'>This class is not thread safe.
 * </ul>
 *
 *
 * @serial exclude
 */
public class JsonList extends LinkedList<Object> {
   private static class UnmodifiableJsonList extends JsonList {
      private static final long serialVersionUID = 1L;

      @SuppressWarnings("synthetic-access")
      UnmodifiableJsonList(JsonList contents) {
         if (nn(contents))
            contents.forEach(super::add);
      }

      @Override /* Overridden from List */
      public void add(int location, Object object) {
         throw unsupportedOpReadOnly();
      }

      @Override
      public boolean isUnmodifiable() { return true; }

      @Override /* Overridden from List */
      public Object remove(int location) {
         throw unsupportedOpReadOnly();
      }

      @Override /* Overridden from List */
      public Object set(int location, Object object) {
         throw unsupportedOpReadOnly();
      }
   }

   private static final long serialVersionUID = 1L;
   /**
    * An empty read-only JsonList.
    *
    * @serial exclude
    */
   public static final JsonList EMPTY_LIST = new JsonList() {
      private static final long serialVersionUID = 1L;

      @Override /* Overridden from List */
      public void add(int location, Object object) {
         throw unsupportedOpReadOnly();
      }

      @Override /* Overridden from List */
      public ListIterator<Object> listIterator(int location) {
         return Collections.emptyList().listIterator(location);
      }

      @Override /* Overridden from List */
      public Object remove(int location) {
         throw unsupportedOpReadOnly();
      }

      @Override /* Overridden from List */
      public Object set(int location, Object object) {
         throw unsupportedOpReadOnly();
      }

      @Override /* Overridden from List */
      public List<Object> subList(int start, int end) {
         return Collections.emptyList().subList(start, end);
      }
   };

   /**
    * Construct an empty list.
    *
    * @return An empty list.
    */
   public static JsonList create() {
      return new JsonList();
   }

   /**
    * Construct a list initialized with the specified list.
    *
    * @param values
    *    The list to copy.
    *    <br>Can be <jk>null</jk>.
    * @return A new list or <jk>null</jk> if the list was <jk>null</jk>.
    */
   public static JsonList of(Collection<?> values) {
      return values == null ? null : new JsonList(values);
   }

   /**
    * Construct a list initialized with the specified values.
    *
    * @param values The values to add to this list.
    * @return A new list, never <jk>null</jk>.
    */
   public static JsonList of(Object...values) {
      return new JsonList(values);
   }

   /**
    * Convenience method for creating a list of array objects.
    *
    * @param values The initial values.
    * @return A new list.
    */
   public static JsonList ofArrays(Object[]...values) {
      var l = new JsonList();
      for (var v : values)
         l.add(v);
      return l;
   }

   /**
    * Convenience method for creating a list of collection objects.
    *
    * @param values The initial values.
    * @return A new list.
    */
   public static JsonList ofCollections(Collection<?>...values) {
      var l = new JsonList();
      for (var v : values)
         l.add(v);
      return l;
   }

   /**
    * Construct a list initialized with the specified JSON string.
    *
    * @param json
    *    The JSON text to parse.
    *    <br>Can be normal or simplified JSON.
    * @return A new list or <jk>null</jk> if the string was null.
    * @throws ParseException Malformed input encountered.
    */
   public static JsonList ofJson(CharSequence json) throws ParseException {
      return json == null ? null : new JsonList(json);
   }

   /**
    * Construct a list initialized with the specified reader containing JSON.
    *
    * @param json
    *    The reader containing JSON text to parse.
    *    <br>Can contain normal or simplified JSON.
    * @return A new list or <jk>null</jk> if the input was <jk>null</jk>.
    * @throws ParseException Malformed input encountered.
    */
   public static JsonList ofJson(Reader json) throws ParseException {
      return json == null ? null : new JsonList(json);
   }

   /**
    * Parses a string that can consist of either a JSON array or comma-delimited list.
    *
    * <p>
    * The type of string is auto-detected.
    *
    * @param s The string to parse.
    * @return The parsed string.
    * @throws ParseException Malformed input encountered.
    */
   public static JsonList ofJsonOrCdl(String s) throws ParseException {
      if (Utils.e(s))  // NOAI
         return null;
      if (! isProbablyJsonArray(s, true))
         return new JsonList((Object[])splita(s.trim(), ','));
      return new JsonList(s);
   }

   /**
    * Construct a list initialized with the specified string.
    *
    * @param in
    *    The input being parsed.
    *    <br>Can be <jk>null</jk>.
    * @param p
    *    The parser to use to parse the input.
    *    <br>If <jk>null</jk>, uses {@link JsonParser}.
    * @return A new list or <jk>null</jk> if the input was <jk>null</jk>.
    * @throws ParseException Malformed input encountered.
    */
   public static JsonList ofText(CharSequence in, Parser p) throws ParseException {
      return in == null ? null : new JsonList(in, p);
   }

   /**
    * Construct a list initialized with the specified string.
    *
    * @param in
    *    The reader containing the input being parsed.
    *    <br>Can contain normal or simplified JSON.
    * @param p
    *    The parser to use to parse the input.
    *    <br>If <jk>null</jk>, uses {@link JsonParser}.
    * @return A new list or <jk>null</jk> if the input was <jk>null</jk>.
    * @throws ParseException Malformed input encountered.
    */
   public static JsonList ofText(Reader in, Parser p) throws ParseException {
      return in == null ? null : new JsonList(in);
   }

   transient BeanSession session = null;

   private transient ObjectRest objectRest;

   /**
    * Construct an empty list.
    */
   public JsonList() {}

   /**
    * Construct an empty list with the specified bean context.
    *
    * @param session The bean session to use for creating beans.
    */
   public JsonList(BeanSession session) {
      this.session = session;
   }

   /**
    * Construct a list initialized with the specified JSON.
    *
    * @param json
    *    The JSON text to parse.
    *    <br>Can be normal or simplified JSON.
    * @throws ParseException Malformed input encountered.
    */
   public JsonList(CharSequence json) throws ParseException {
      this(json, JsonParser.DEFAULT);
   }

   /**
    * Construct a list initialized with the specified string.
    *
    * @param in
    *    The input being parsed.
    *    <br>Can be <jk>null</jk>.
    * @param p
    *    The parser to use to parse the input.
    *    <br>If <jk>null</jk>, uses {@link JsonParser}.
    * @throws ParseException Malformed input encountered.
    */
   public JsonList(CharSequence in, Parser p) throws ParseException {
      this(p == null ? BeanContext.DEFAULT_SESSION : p.getBeanContext().getSession());
      if (p == null)
         p = JsonParser.DEFAULT;
      if (nn(in))
         p.parseIntoCollection(in, this, bs().object());
   }

   /**
    * Construct a list initialized with the specified list.
    *
    * @param copyFrom
    *    The list to copy.
    *    <br>Can be <jk>null</jk>.
    */
   public JsonList(Collection<?> copyFrom) {
      super(copyFrom);
   }

   /**
    * Construct a list initialized with the contents.
    *
    * @param entries The entries to add to this list.
    */
   public JsonList(Object...entries) {
      Collections.addAll(this, entries);
   }

   /**
    * Construct a list initialized with the specified reader containing JSON.
    *
    * @param json
    *    The reader containing JSON text to parse.
    *    <br>Can contain normal or simplified JSON.
    * @throws ParseException Malformed input encountered.
    */
   public JsonList(Reader json) throws ParseException {
      parse(json, JsonParser.DEFAULT);
   }

   /**
    * Construct a list initialized with the specified string.
    *
    * @param in
    *    The reader containing the input being parsed.
    *    <br>Can contain normal or simplified JSON.
    * @param p
    *    The parser to use to parse the input.
    *    <br>If <jk>null</jk>, uses {@link JsonParser}.
    * @throws ParseException Malformed input encountered.
    */
   public JsonList(Reader in, Parser p) throws ParseException {
      this(p == null ? BeanContext.DEFAULT_SESSION : p.getBeanContext().getSession());
      parse(in, p);
   }

   /**
    * Adds all the values in the specified collection to this list.
    *
    * @param values The values to add to this list.
    * @return This object.
    */
   public JsonList append(Collection<?> values) {
      if (nn(values))
         addAll(values);
      return this;
   }

   /**
    * Adds the value to this list.
    *
    * @param value The value to add to this list.
    * @return This object.
    */
   public JsonList append(Object value) {
      add(value);
      return this;
   }

   /**
    * Adds all the values in the specified array to this list.
    *
    * @param values The values to add to this list.
    * @return This object.
    */
   public JsonList append(Object...values) {
      Collections.addAll(this, values);
      return this;
   }

   /**
    * Adds an entry to this list if the boolean flag is <jk>true</jk>.
    *
    * @param flag The boolean flag.
    * @param value The value to add.
    * @return This object.
    */
   public JsonList appendIf(boolean flag, Object value) {
      if (flag)
         append(value);
      return this;
   }

   /**
    * Add if predicate matches.
    *
    * @param <T> The type being tested.
    * @param test The predicate to match against.
    * @param value The value to add if the predicate matches.
    * @return This object.
    */
   public <T> JsonList appendIf(Predicate<T> test, T value) {
      return appendIf(test(test, value), value);
   }

   /**
    * Adds all the entries in the specified collection to this list in reverse order.
    *
    * @param values The collection to add to this list.
    * @return This object.
    */
   public JsonList appendReverse(List<?> values) {
      for (ListIterator<?> i = values.listIterator(values.size()); i.hasPrevious();)
         add(i.previous());
      return this;
   }

   /**
    * Adds the contents of the array to the list in reverse order.
    *
    * <p>
    * i.e. add values from the array from end-to-start order to the end of the list.
    *
    * @param values The collection to add to this list.
    * @return This object.
    */
   public JsonList appendReverse(Object...values) {
      for (var i = values.length - 1; i >= 0; i--)
         add(values[i]);
      return this;
   }

   /**
    * A synonym for {@link #toString()}
    *
    * @return This object as a JSON string.
    */
   public String asJson() {
      return toString();
   }

   /**
    * Serialize this array to Simplified JSON.
    *
    * @return This object as a serialized string.
    */
   public String asString() {
      return Json5Serializer.DEFAULT.toString(this);
   }

   /**
    * Serialize this array to a string using the specified serializer.
    *
    * @param serializer The serializer to use to convert this object to a string.
    * @return This object as a serialized string.
    */
   public String asString(WriterSerializer serializer) {
      return serializer.toString(this);
   }

   /**
    * Converts this object into the specified class type.
    *
    * <p>
    * This method performs a round-trip serialization and deserialization to convert the list into the target type.
    *
    * <h5 class='section'>Notes:</h5><ul>
    *    <li class='warn'>The current implementation uses a serialization round-trip which may be inefficient for
    *       frequent conversions of large objects. Consider caching results or using direct object conversion where possible.
    * </ul>
    *
    * @param cm The class type to convert this object to.
    * @return A converted object.
    */
   public Object cast(ClassMeta<?> cm) {
      try {
         return JsonParser.DEFAULT.parse(Json5Serializer.DEFAULT.serialize(this), cm);
      } catch (ParseException | SerializeException e) {
         throw toRex(e);
      }
   }

   /**
    * Similar to {@link #remove(int) remove(int)},but the key is a slash-delimited path used to traverse entries in
    * this POJO.
    *
    * <p>
    * For example, the following code is equivalent:
    * </p>
    * <p class='bjava'>
    *    JsonList <jv>list</jv> = JsonList.<jsm>ofJson</jsm>(<js>"..."</js>);
    *
    *    <jc>// Long way</jc>
    *    <jv>list</jv>.getMap(0).getList(<js>"bar"</js>).delete(0);
    *
    *    <jc>// Using this method</jc>
    *    <jv>list</jv>.deleteAt(<js>"0/bar/0"</js>);
    * </p>
    *
    * <p>
    * This method uses the {@link ObjectRest} class to perform the lookup, so the map can contain any of the various
    * class types that the {@link ObjectRest} class supports (e.g. beans, collections, arrays).
    *
    * @param path The path to the entry.
    * @return The previous value, or <jk>null</jk> if the entry doesn't exist.
    */
   public Object deleteAt(String path) {
      return getObjectRest().delete(path);
   }

   /**
    * Creates an {@link Iterable} with elements of the specified child type.
    *
    * <p>
    * Attempts to convert the child objects to the correct type if they aren't already the correct type.
    *
    * <p>
    * The <c>next()</c> method on the returned iterator may throw a {@link InvalidDataConversionException} if
    * the next element cannot be converted to the specified type.
    *
    * <p>
    * See {@link BeanSession#convertToType(Object, ClassMeta)} for a description of valid conversions.
    *
    * <h5 class='section'>Example:</h5>
    * <p class='bjava'>
    *    <jc>// Iterate over a list of JsonMaps.</jc>
    *    JsonList <jv>list</jv> = JsonList.<jsm>ofJson</jsm>(<js>"[{foo:'bar'},{baz:123}]"</js>);
    *    <jk>for</jk> (JsonMap <jv>map</jv> : <jv>list</jv>.elements(JsonMap.<jk>class</jk>)) {
    *       <jc>// Do something with map.</jc>
    *    }
    *
    *    <jc>// Iterate over a list of ints.</jc>
    *    JsonList <jv>list</jv> = JsonList.<jsm>ofJson</jsm>(<js>"[1,2,3]"</js>);
    *    <jk>for</jk> (Integer <jv>i</jv> : <jv>list</jv>.elements(Integer.<jk>class</jk>)) {
    *       <jc>// Do something with i.</jc>
    *    }
    *
    *    <jc>// Iterate over a list of beans.</jc>
    *    <jc>// Automatically converts to beans.</jc>
    *    JsonList <jv>list</jv> = JsonList.<jsm>ofJson</jsm>(<js>"[{name:'John Smith',age:45}]"</js>);
    *    <jk>for</jk> (Person <jv>p</jv> : <jv>list</jv>.elements(Person.<jk>class</jk>)) {
    *       <jc>// Do something with p.</jc>
    *    }
    * </p>
    *
    * @param <E> The child object type.
    * @param childType The child object type.
    * @return A new <c>Iterable</c> object over this list.
    */
   public <E> Iterable<E> elements(Class<E> childType) {
      final Iterator<?> iterator = iterator();
      return () -> new Iterator<>() {

         @Override /* Overridden from Iterator */
         public boolean hasNext() {
            return iterator.hasNext();
         }

         @Override /* Overridden from Iterator */
         public E next() {
            return bs().convertToType(iterator.next(), childType);
         }

         @Override /* Overridden from Iterator */
         public void remove() {
            iterator.remove();
         }

      };
   }

   /**
    * Get the entry at the specified index, converted to the specified type.
    *
    * <p>
    * This is the preferred get method for simple types.
    *
    * <h5 class='section'>Examples:</h5>
    * <p class='bjava'>
    *    JsonList <jv>list</jv> = JsonList.<jsm>ofJson</jsm>(<js>"..."</js>);
    *
    *    <jc>// Value converted to a string.</jc>
    *    String <jv>string</jv> = <jv>list</jv>.get(1, String.<jk>class</jk>);
    *
    *    <jc>// Value converted to a bean.</jc>
    *    MyBean <jv>bean</jv> = <jv>list</jv>.get(2, MyBean.<jk>class</jk>);
    *
    *    <jc>// Value converted to a bean array.</jc>
    *    MyBean[] <jv>beanArray</jv> = <jv>list</jv>.get(3, MyBean[].<jk>class</jk>);
    *
    *    <jc>// Value converted to a linked-list of objects.</jc>
    *    List <jv>list2</jv> = <jv>list</jv>.get(4, LinkedList.<jk>class</jk>);
    *
    *    <jc>// Value converted to a map of object keys/values.</jc>
    *    Map <jv>map</jv> = <jv>list</jv>.get(5, TreeMap.<jk>class</jk>);
    * </p>
    *
    * <p>
    * See {@link BeanSession#convertToType(Object, ClassMeta)} for the list of valid data conversions.
    *
    * @param index The index into this list.
    * @param type The type of object to convert the entry to.
    * @param <T> The type of object to convert the entry to.
    * @return The converted entry.
    */
   public <T> T get(int index, Class<T> type) {
      return bs().convertToType(get(index), type);
   }

   /**
    * Get the entry at the specified index, converted to the specified type.
    *
    * <p>
    * The type can be a simple type (e.g. beans, strings, numbers) or parameterized type (collections/maps).
    *
    * <h5 class='section'>Examples:</h5>
    * <p class='bjava'>
    *    JsonList <jv>list</jv> = JsonList.<jsm>ofJson</jsm>(<js>"..."</js>);
    *
    *    <jc>// Value converted to a linked-list of strings.</jc>
    *    List&lt;String&gt; <jv>list1</jv> = <jv>list</jv>.get(1, LinkedList.<jk>class</jk>, String.<jk>class</jk>);
    *
    *    <jc>// Value converted to a linked-list of beans.</jc>
    *    List&lt;MyBean&gt; <jv>list2</jv> = <jv>list</jv>.get(2, LinkedList.<jk>class</jk>, MyBean.<jk>class</jk>);
    *
    *    <jc>// Value converted to a linked-list of linked-lists of strings.</jc>
    *    List&lt;List&lt;String&gt;&gt; <jv>list3</jv> = <jv>list</jv>.get(3, LinkedList.<jk>class</jk>, LinkedList.<jk>class</jk>, String.<jk>class</jk>);
    *
    *    <jc>// Value converted to a map of string keys/values.</jc>
    *    Map&lt;String,String&gt; <jv>map1</jv> = <jv>list</jv>.get(4, TreeMap.<jk>class</jk>, String.<jk>class</jk>, String.<jk>class</jk>);
    *
    *    <jc>// Value converted to a map containing string keys and values of lists containing beans.</jc>
    *    Map&lt;String,List&lt;MyBean&gt;&gt; <jv>map2</jv> = <jv>list</jv>.get(5, TreeMap.<jk>class</jk>, String.<jk>class</jk>, List.<jk>class</jk>, MyBean.<jk>class</jk>);
    * </p>
    *
    * <p>
    * <c>Collection</c> classes are assumed to be followed by zero or one objects indicating the element type.
    *
    * <p>
    * <c>Map</c> classes are assumed to be followed by zero or two meta objects indicating the key and value types.
    *
    * <p>
    * The array can be arbitrarily long to indicate arbitrarily complex data structures.
    *
    * <p>
    * See {@link BeanSession#convertToType(Object, ClassMeta)} for the list of valid data conversions.
    *
    * @param index The index into this list.
    * @param type The type of object to convert the entry to.
    * @param args The type arguments of the type to convert the entry to.
    * @param <T> The type of object to convert the entry to.
    * @return The converted entry.
    */
   public <T> T get(int index, Type type, Type...args) {
      return bs().convertToType(get(index), type, args);
   }

   /**
    * Same as {@link #get(int,Class) get(int,Class)}, but the key is a slash-delimited path used to traverse entries in
    * this POJO.
    *
    * <p>
    * For example, the following code is equivalent:
    * </p>
    * <p class='bjava'>
    *    JsonList <jv>list</jv> = JsonList.<jsm>ofJson</jsm>(<js>"..."</js>);
    *
    *    <jc>// Long way</jc>
    *    <jk>long</jk> <jv>long1</jv> = <jv>list</jv>.getMap(<js>"0"</js>).getLong(<js>"baz"</js>);
    *
    *    <jc>// Using this method</jc>
    *    <jk>long</jk> <jv>long2</jv> = <jv>list</jv>.getAt(<js>"0/baz"</js>, <jk>long</jk>.<jk>class</jk>);
    * </p>
    *
    * <p>
    * This method uses the {@link ObjectRest} class to perform the lookup, so the map can contain any of the various
    * class types that the {@link ObjectRest} class supports (e.g. beans, collections, arrays).
    *
    * @param path The path to the entry.
    * @param type The class type.
    *
    * @param <T> The class type.
    * @return The value, or <jk>null</jk> if the entry doesn't exist.
    */
   public <T> T getAt(String path, Class<T> type) {
      return getObjectRest().get(path, type);
   }

   /**
    * Same as {@link #getAt(String,Class)}, but allows for conversion to complex maps and collections.
    *
    * @param path The path to the entry.
    * @param type The class type.
    * @param args The class parameter types.
    *
    * @param <T> The class type.
    * @return The value, or <jk>null</jk> if the entry doesn't exist.
    */
   public <T> T getAt(String path, Type type, Type...args) {
      return getObjectRest().get(path, type, args);
   }

   /**
    * Returns the {@link BeanSession} currently associated with this list.
    *
    * @return The {@link BeanSession} currently associated with this list.
    */
   public BeanSession getBeanSession() { return session; }

   /**
    * Shortcut for calling <code>get(index, Boolean.<jk>class</jk>)</code>.
    *
    * @param index The index.
    * @return The converted value.
    * @throws InvalidDataConversionException If value cannot be converted.
    */
   public Boolean getBoolean(int index) {
      return get(index, Boolean.class);
   }

   /**
    * Returns the {@link ClassMeta} of the class of the object at the specified index.
    *
    * @param index An index into this list, zero-based.
    * @return The data type of the object at the specified index, or <jk>null</jk> if the value is null.
    */
   public ClassMeta<?> getClassMeta(int index) {
      return bs().getClassMetaForObject(get(index));
   }

   /**
    * Shortcut for calling <code>get(index, Integer.<jk>class</jk>)</code>.
    *
    * @param index The index.
    * @return The converted value.
    * @throws InvalidDataConversionException If value cannot be converted.
    */
   public Integer getInt(int index) {
      return get(index, Integer.class);
   }

   /**
    * Shortcut for calling <code>get(index, JsonList.<jk>class</jk>)</code>.
    *
    * @param index The index.
    * @return The converted value.
    * @throws InvalidDataConversionException If value cannot be converted.
    */
   public JsonList getList(int index) {
      return get(index, JsonList.class);
   }

   /**
    * Same as {@link #getList(int)} except converts the elements to the specified types.
    *
    * @param <E> The element type.
    * @param index The index.
    * @param elementType The element type class.
    * @return The converted value.
    * @throws InvalidDataConversionException If value cannot be converted.
    */
   public <E> List<E> getList(int index, Class<E> elementType) {
      return bs().convertToType(get(index), List.class, elementType);
   }

   /**
    * Shortcut for calling <code>get(index, Long.<jk>class</jk>)</code>.
    *
    * @param index The index.
    * @return The converted value.
    * @throws InvalidDataConversionException If value cannot be converted.
    */
   public Long getLong(int index) {
      return get(index, Long.class);
   }

   /**
    * Shortcut for calling <code>get(index, JsonMap.<jk>class</jk>)</code>.
    *
    * @param index The index.
    * @return The converted value.
    * @throws InvalidDataConversionException If value cannot be converted.
    */
   public JsonMap getMap(int index) {
      return get(index, JsonMap.class);
   }

   /**
    * Same as {@link #getMap(int)} except converts the keys and values to the specified types.
    *
    * @param <K> The key type class.
    * @param <V> The value type class.
    * @param index The index.
    * @param keyType The key type class.
    * @param valType The value type class.
    * @return The converted value.
    * @throws InvalidDataConversionException If value cannot be converted.
    */
   public <K,V> Map<K,V> getMap(int index, Class<K> keyType, Class<V> valType) {
      return bs().convertToType(get(index), Map.class, keyType, valType);
   }

   /**
    * Shortcut for calling <code>get(index, String.<jk>class</jk>)</code>.
    *
    * @param index The index.
    * @return The converted value.
    */
   public String getString(int index) {
      return get(index, String.class);
   }

   /**
    * Returns <jk>true</jk> if this list is unmodifiable.
    *
    * @return <jk>true</jk> if this list is unmodifiable.
    */
   public boolean isUnmodifiable() { return false; }

   /**
    * Returns a modifiable copy of this list if it's unmodifiable.
    *
    * @return A modifiable copy of this list if it's unmodifiable, or this list if it is already modifiable.
    */
   public JsonList modifiable() {
      if (isUnmodifiable())
         return new JsonList(this);
      return this;
   }

   /**
    * Similar to {@link #putAt(String,Object) putAt(String,Object)}, but used to append to collections and arrays.
    *
    * <p>
    * For example, the following code is equivalent:
    * </p>
    * <p class='bjava'>
    *    JsonList <jv>list</jv> = JsonList.<jsm>ofJson</jsm>(<js>"..."</js>);
    *
    *    <jc>// Long way</jc>
    *    <jv>list</jv>.getMap(0).getList(<js>"bar"</js>).append(123);
    *
    *    <jc>// Using this method</jc>
    *    <jv>list</jv>.postAt(<js>"0/bar"</js>, 123);
    * </p>
    *
    * <p>
    * This method uses the {@link ObjectRest} class to perform the lookup, so the map can contain any of the various
    * class types that the {@link ObjectRest} class supports (e.g. beans, collections, arrays).
    *
    * @param path The path to the entry.
    * @param o The new value.
    * @return The previous value, or <jk>null</jk> if the entry doesn't exist.
    */
   public Object postAt(String path, Object o) {
      return getObjectRest().post(path, o);
   }

   /**
    * Same as {@link #set(int,Object) set(int,Object)}, but the key is a slash-delimited path used to traverse entries
    * in this POJO.
    *
    * <p>
    * For example, the following code is equivalent:
    * </p>
    * <p class='bjava'>
    *    JsonList <jv>list</jv> = JsonList.<jsm>ofJson</jsm>(<js>"..."</js>);
    *
    *    <jc>// Long way</jc>
    *    <jv>list</jv>.getMap(<js>"0"</js>).put(<js>"baz"</js>, 123);
    *
    *    <jc>// Using this method</jc>
    *    <jv>list</jv>.putAt(<js>"0/baz"</js>, 123);
    * </p>
    *
    * <p>
    * This method uses the {@link ObjectRest} class to perform the lookup, so the map can contain any of the various
    * class types that the {@link ObjectRest} class supports (e.g. beans, collections, arrays).
    *
    * @param path The path to the entry.
    * @param o The new value.
    * @return The previous value, or <jk>null</jk> if the entry doesn't exist.
    */
   public Object putAt(String path, Object o) {
      return getObjectRest().put(path, o);
   }

   /**
    * Override the default bean session used for converting POJOs.
    *
    * <p>
    * Default is {@link BeanContext#DEFAULT}, which is sufficient in most cases.
    *
    * <p>
    * Useful if you're serializing/parsing beans with transforms defined.
    *
    * @param session The new bean session.
    * @return This object.
    */
   public JsonList session(BeanSession session) {
      this.session = session;
      return this;
   }

   /**
    * Sets the {@link BeanSession} currently associated with this list.
    *
    * @param value The {@link BeanSession} currently associated with this list.
    * @return This object.
    */
   public JsonList setBeanSession(BeanSession value) {
      session = value;
      return this;
   }

   @Override /* Overridden from Object */
   public String toString() {
      return Json5.of(this);
   }

   /**
    * Returns an unmodifiable copy of this list if it's modifiable.
    *
    * @return An unmodifiable copy of this list if it's modifiable, or this list if it is already unmodifiable.
    */
   public JsonList unmodifiable() {
      if (this instanceof UnmodifiableJsonList this2)
         return this2;
      return new UnmodifiableJsonList(this);
   }

   /**
    * Convenience method for serializing this JsonList to the specified Writer using the JsonSerializer.DEFAULT
    * serializer.
    *
    * @param w The writer to send the serialized contents of this object.
    * @return This object.
    * @throws IOException If a problem occurred trying to write to the writer.
    * @throws SerializeException If a problem occurred trying to convert the output.
    */
   public JsonList writeTo(Writer w) throws IOException, SerializeException {
      JsonSerializer.DEFAULT.serialize(this, w);
      return this;
   }

   private ObjectRest getObjectRest() {
      if (objectRest == null)
         objectRest = new ObjectRest(this);
      return objectRest;
   }

   private void parse(Reader r, Parser p) throws ParseException {
      if (p == null)
         p = JsonParser.DEFAULT;
      p.parseIntoCollection(r, this, bs().object());
   }

   BeanSession bs() {
      if (session == null)
         session = BeanContext.DEFAULT_SESSION;
      return session;
   }
}