/*
 * 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.marshall.marshaller;

import java.io.*;
import java.lang.reflect.*;
import java.nio.charset.*;

import org.apache.juneau.marshall.*;
import org.apache.juneau.marshall.parser.*;
import org.apache.juneau.marshall.serializer.*;
import org.apache.juneau.marshall.stream.*;

/**
 * Top-level class for a pairing of a {@link Serializer} and {@link Parser} into a single class with convenience read/write methods.
 *
 * <p>
 *    The general idea is to combine a single serializer and parser inside a simplified API for reading and writing POJOs.
 *
 * <h5 class='figure'>Examples:</h5>
 * <p class='bjava'>
 *    <jc>// Using instance.</jc>
    *    Marshaller <jv>json</jv> = <jk>new</jk> Json();
 *    MyPojo <jv>myPojo</jv> = <jv>json</jv>.read(<jv>string</jv>, MyPojo.<jk>class</jk>);
 *    String <jv>string</jv> = <jv>json</jv>.write(<jv>myPojo</jv>);
 * </p>
 * <p class='bjava'>
 * <jc>// Using DEFAULT instance.</jc>
 *    MyPojo <jv>myPojo</jv> = Json.<jsf>DEFAULT</jsf>.read(<jv>string</jv>, MyPojo.<jk>class</jk>);
 *    String <jv>string</jv> = Json.<jsf>DEFAULT</jsf>.write(<jv>myPojo</jv>);
 * </p>
 *
 * <h5 class='section'>See Also:</h5><ul>
 *    <li class='link'><a class="doclink" href="https://juneau.apache.org/docs/topics/Marshallers">Marshallers</a>
 * </ul>
 */
@SuppressWarnings({
   "resource" // Cursor shortcut methods return Closeables owned by the caller; Eclipse JDT @Owning warning is by design.
})
public abstract class Marshaller {
   private final Serializer s;
   private final Parser p;

   /**
    * Constructor.
    *
    * @param s
    *    The serializer to use for serializing output.
    *    <br>Must not be <jk>null</jk>.
    * @param p
    *    The parser to use for parsing input.
    *    <br>Must not be <jk>null</jk>.
    */
   protected Marshaller(Serializer s, Parser p) {
      this.s = s;
      this.p = p;
   }

   /**
    * Returns the parser associated with this marshaller.
    *
    * @return The parser associated with this marshaller.
    */
   public Parser getParser() { return p; }

   /**
    * Returns the serializer associated with this marshaller.
    *
    * @return The serializer associated with this marshaller.
    */
   public Serializer getSerializer() { return s; }

   /**
    * Same as {@link #read(Object, Type, Type...)} except optimized for a non-parameterized class.
    *
    * <p>
    * This is the preferred parse method for simple types since you don't need to cast the results.
    *
    * <h5 class='section'>Examples:</h5>
    * <p class='bjava'>
    *    Marshaller <jv>marshaller</jv>  = Json.<jsf>DEFAULT</jsf>;
    *
    *    <jc>// Parse into a string.</jc>
    *    String <jv>string</jv> = <jv>marshaller</jv> .read(<jv>json</jv>, String.<jk>class</jk>);
    *
    *    <jc>// Parse into a bean.</jc>
    *    MyBean <jv>bean</jv> = <jv>marshaller</jv> .read(<jv>json</jv>, MyBean.<jk>class</jk>);
    *
    *    <jc>// Parse into a bean array.</jc>
    *    MyBean[] <jv>beanArray</jv> = <jv>marshaller</jv> .read(<jv>json</jv>, MyBean[].<jk>class</jk>);
    *
    *    <jc>// Parse into a linked-list of objects.</jc>
    *    List <jv>list</jv> = <jv>marshaller</jv> .read(<jv>json</jv>, LinkedList.<jk>class</jk>);
    *
    *    <jc>// Parse into a map of object keys/values.</jc>
    *    Map <jv>map</jv> = <jv>marshaller</jv> .read(<jv>json</jv>, TreeMap.<jk>class</jk>);
    * </p>
    *
    * @param <T> The class type of the object being created.
    * @param input
    *    The input.
    *    <br>Character-based parsers can handle the following input class types:
    *    <ul>
    *       <li><jk>null</jk>
    *       <li>{@link Reader}
    *       <li>{@link CharSequence}
    *       <li>{@link InputStream} containing UTF-8 encoded text (or charset defined by
    *          {@link org.apache.juneau.marshall.parser.ReaderParser.Builder#streamCharset(Charset) ReaderParser.Builder#streamCharset(Charset)} property value).
    *       <li><code><jk>byte</jk>[]</code> containing UTF-8 encoded text (or charset defined by
    *          {@link org.apache.juneau.marshall.parser.ReaderParser.Builder#streamCharset(Charset) ReaderParser.Builder#streamCharset(Charset)} property value).
    *       <li>{@link File} containing system encoded text.
    *    </ul>
    *    <br>Stream-based parsers can handle the following input class types:
    *    <ul>
    *       <li><jk>null</jk>
    *       <li>{@link InputStream}
    *       <li><code><jk>byte</jk>[]</code>
    *       <li>{@link File}
    *       <li>{@link CharSequence} containing encoded bytes according to the {@link org.apache.juneau.marshall.parser.InputStreamParser.Builder#binaryFormat(BinaryFormat) InputStreamParser.Builder#binaryFormat(BinaryFormat)} setting.
    *    </ul>
    * @param type The object type to create.
    * @return The parsed object.
    * @throws ParseException Malformed input encountered.
    * @throws IOException Thrown by underlying stream.
    */
   public final <T> T read(Object input, Class<T> type) throws ParseException, IOException {
      return p.read(input, type);
   }

   /**
    * Parses input into the specified object 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'>
    *    Marshaller <jv>marshaller</jv> = Json.<jsf>DEFAULT</jsf>;
    *
    *    <jc>// Parse into a linked-list of strings.</jc>
    *    List <jv>list1</jv> = <jv>marshaller</jv> .read(<jv>json</jv>, LinkedList.<jk>class</jk>, String.<jk>class</jk>);
    *
    *    <jc>// Parse into a linked-list of beans.</jc>
    *    List <jv>list2</jv> = <jv>marshaller</jv> .read(<jv>json</jv>, LinkedList.<jk>class</jk>, MyBean.<jk>class</jk>);
    *
    *    <jc>// Parse into a linked-list of linked-lists of strings.</jc>
    *    List <jv>list3</jv> = <jv>marshaller</jv> .read(<jv>json</jv>, LinkedList.<jk>class</jk>, LinkedList.<jk>class</jk>, String.<jk>class</jk>);
    *
    *    <jc>// Parse into a map of string keys/values.</jc>
    *    Map <jv>map1</jv> = <jv>marshaller</jv> .read(<jv>json</jv>, TreeMap.<jk>class</jk>, String.<jk>class</jk>, String.<jk>class</jk>);
    *
    *    <jc>// Parse into a map containing string keys and values of lists containing beans.</jc>
    *    Map <jv>map2</jv> = <jv>marshaller</jv> .read(<jv>json</jv>, 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.
    *
    * <h5 class='section'>Notes:</h5><ul>
    *    <li class='note'>
    *       Use the {@link #read(Object, Class)} method instead if you don't need a parameterized map/collection.
    * </ul>
    *
    * @param <T> The class type of the object to create.
    * @param input
    *    The input.
    *    <br>Character-based parsers can handle the following input class types:
    *    <ul>
    *       <li><jk>null</jk>
    *       <li>{@link Reader}
    *       <li>{@link CharSequence}
    *       <li>{@link InputStream} containing UTF-8 encoded text (or charset defined by
    *          {@link org.apache.juneau.marshall.parser.ReaderParser.Builder#streamCharset(Charset) ReaderParser.Builder#streamCharset(Charset)} property value).
    *       <li><code><jk>byte</jk>[]</code> containing UTF-8 encoded text (or charset defined by
    *          {@link org.apache.juneau.marshall.parser.ReaderParser.Builder#streamCharset(Charset) ReaderParser.Builder#streamCharset(Charset)} property value).
    *       <li>{@link File} containing system encoded text.
    *    </ul>
    *    <br>Stream-based parsers can handle the following input class types:
    *    <ul>
    *       <li><jk>null</jk>
    *       <li>{@link InputStream}
    *       <li><code><jk>byte</jk>[]</code>
    *       <li>{@link File}
    *       <li>{@link CharSequence} containing encoded bytes according to the {@link org.apache.juneau.marshall.parser.InputStreamParser.Builder#binaryFormat(BinaryFormat) InputStreamParser.Builder#binaryFormat(BinaryFormat)} setting.
    *    </ul>
    * @param type
    *    The object type to create.
    *    <br>Can be any of the following: {@link ClassMeta}, {@link Class}, {@link ParameterizedType}, {@link GenericArrayType}
    * @param args
    *    The type arguments of the class if it's a collection or map.
    *    <br>Can be any of the following: {@link ClassMeta}, {@link Class}, {@link ParameterizedType}, {@link GenericArrayType}
    *    <br>Ignored if the main type is not a map or collection.
    * @return The parsed object.
    * @throws ParseException Malformed input encountered.
    * @throws IOException Thrown by underlying stream.
    * @see MarshallingSession#getClassMeta(Type,Type...) for argument syntax for maps and collections.
    */
   public final <T> T read(Object input, Type type, Type...args) throws ParseException, IOException {
      return p.read(input, type, args);
   }

   /**
    * Serializes a POJO to the specified output stream or writer.
    *
    * <p>
    * Equivalent to calling <c>serializer.createSession().write(o, output);</c>
    *
    * @param object The object to serialize.
    * @param output
    *    The output object.
    *    <br>Character-based serializers can handle the following output class types:
    *    <ul>
    *       <li>{@link Writer}
    *       <li>{@link OutputStream} - Output will be written as UTF-8 encoded stream.
    *       <li>{@link File} - Output will be written as system-default encoded stream.
    *       <li>{@link StringBuilder} - Output will be written to the specified string builder.
    *    </ul>
    *    <br>Stream-based serializers can handle the following output class types:
    *    <ul>
    *       <li>{@link OutputStream}
    *       <li>{@link File}
    *    </ul>
    * @throws SerializeException If a problem occurred trying to convert the output.
    * @throws IOException Thrown by underlying stream.
    */
   public final void write(Object object, Object output) throws SerializeException, IOException {
      s.write(object, output);
   }

   /**
    * Opens a low-level {@link TokenReader} cursor over the specified input.
    *
    * <p>
    * Shortcut for <c>((TokenReadable)getParser()).readTokens(<jv>input</jv>)</c>.  See
    * {@link TokenReader} for the cursor contract.
    *
    * <h5 class='section'>Notes:</h5><ul>
    *    <li class='note'>This capability depends on the underlying parser.  Formats whose parser
    *       does not implement {@link TokenReadable} (the structural-token role) yield a
    *       {@link ClassCastException}.
    * </ul>
    *
    * @param input The input.  Accepts {@link Reader}, {@link CharSequence}, {@link InputStream},
    *    <code><jk>byte</jk>[]</code>, or {@link File}.
    * @return A new {@link TokenReader} cursor.
    * @throws IOException If a problem occurred opening the underlying input.
    */
   public TokenReader readTokens(Object input) throws IOException {
      return ((TokenReadable) getParser()).readTokens(input);
   }

   /**
    * Opens a low-level push generator that emits structural events one at a time.
    *
    * <p>
    * Shortcut for <c>((TokenWritable)getSerializer()).writeTokens(<jv>output</jv>)</c>.  See
    * {@link TokenWriter} for the generator contract.
    *
    * <h5 class='section'>Notes:</h5><ul>
    *    <li class='note'>This capability depends on the underlying serializer.  Formats whose
    *       serializer does not implement {@link TokenWritable} (the structural-token role) yield a
    *       {@link ClassCastException}.
    * </ul>
    *
    * @param output The output.  Accepts {@link Writer}, {@link OutputStream}, {@link File}, or
    *    {@link StringBuilder}.
    * @return A new {@link TokenWriter}.
    * @throws IOException If the output type is not supported or could not be opened.
    */
   public TokenWriter writeTokens(Object output) throws IOException {
      return ((TokenWritable) getSerializer()).writeTokens(output);
   }

   /**
    * Opens a low-level {@link RecordReader} cursor that yields each top-level value as a record.
    *
    * <p>
    * Shortcut for <c>((RecordReadable)getParser()).readRecords(<jv>input</jv>)</c>.  See
    * {@link RecordReader} for the cursor contract.
    *
    * <h5 class='section'>Notes:</h5><ul>
    *    <li class='note'>This capability depends on the underlying parser.  Formats whose parser
    *       does not implement {@link RecordReadable} yield a {@link ClassCastException}.
    * </ul>
    *
    * @param input The input.  Accepts {@link Reader}, {@link CharSequence}, {@link InputStream},
    *    <code><jk>byte</jk>[]</code>, or {@link File}.
    * @return A new {@link RecordReader} cursor.
    * @throws IOException If a problem occurred opening the underlying input.
    */
   public RecordReader readRecords(Object input) throws IOException {
      return ((RecordReadable) getParser()).readRecords(input);
   }

   /**
    * Opens a low-level {@link RecordWriter} cursor that emits each whole value as a record.
    *
    * <p>
    * Shortcut for <c>((RecordWritable)getSerializer()).writeRecords(<jv>output</jv>)</c>.  See
    * {@link RecordWriter} for the cursor contract.
    *
    * <h5 class='section'>Notes:</h5><ul>
    *    <li class='note'>This capability depends on the underlying serializer.  Formats whose
    *       serializer does not implement {@link RecordWritable} yield a {@link ClassCastException}.
    * </ul>
    *
    * @param output The output.  Accepts {@link Writer}, {@link OutputStream}, {@link File}, or
    *    {@link StringBuilder}.
    * @return A new {@link RecordWriter} cursor.
    * @throws IOException If a problem occurred opening the underlying output.
    */
   public RecordWriter writeRecords(Object output) throws IOException {
      return ((RecordWritable) getSerializer()).writeRecords(output);
   }

   /**
    * Opens a {@link RecordReader} that yields each element of a top-level wire array as a
    * separate record.
    *
    * <p>
    * Shortcut for <c>((ArrayRecordReadable)getParser()).readArrayRecords(<jv>input</jv>)</c>.
    *
    * <h5 class='section'>Notes:</h5><ul>
    *    <li class='note'>This capability depends on the underlying parser.  Formats whose parser
    *       does not implement {@link ArrayRecordReadable} yield a {@link ClassCastException}.
    * </ul>
    *
    * @param input The input.  Accepts {@link Reader}, {@link CharSequence}, {@link InputStream},
    *    <code><jk>byte</jk>[]</code>, or {@link File}.
    * @return A new element-streamed {@link RecordReader} cursor.
    * @throws IOException If a problem occurred opening the underlying input.
    */
   public RecordReader readArrayRecords(Object input) throws IOException {
      return ((ArrayRecordReadable) getParser()).readArrayRecords(input);
   }

   /**
    * Opens a {@link RecordWriter} that wraps each written value as one element of a top-level
    * wire array.
    *
    * <p>
    * Shortcut for <c>((ArrayRecordWritable)getSerializer()).writeArrayRecords(<jv>output</jv>)</c>.
    *
    * <h5 class='section'>Notes:</h5><ul>
    *    <li class='note'>This capability depends on the underlying serializer.  Formats whose
    *       serializer does not implement {@link ArrayRecordWritable} yield a
    *       {@link ClassCastException}.
    * </ul>
    *
    * @param output The output.  Accepts {@link Writer}, {@link OutputStream}, {@link File}, or
    *    {@link StringBuilder}.
    * @return A new element-streamed {@link RecordWriter} cursor.
    * @throws IOException If a problem occurred opening the underlying output.
    */
   public RecordWriter writeArrayRecords(Object output) throws IOException {
      return ((ArrayRecordWritable) getSerializer()).writeArrayRecords(output);
   }
}