/*
 * Copyright (c) 2001-2008 Caucho Technology, Inc.  All rights reserved.
 *
 * The Apache Software License, Version 1.1
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:
 *       "This product includes software developed by the
 *        Caucho Technology (http://www.caucho.com/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "Burlap", "Resin", and "Caucho" must not be used to
 *    endorse or promote products derived from this software without prior
 *    written permission. For written permission, please contact
 *    info@caucho.com.
 *
 * 5. Products derived from this software may not be called "Resin"
 *    nor may "Resin" appear in their names without prior written
 *    permission of Caucho Technology.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL CAUCHO TECHNOLOGY OR ITS CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
 * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * @author Scott Ferguson
 */

package com.caucho.hessian.io;

import java.io.IOException;
import java.lang.ref.SoftReference;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.ArrayList;
import java.util.WeakHashMap;
import java.util.logging.Level;
import java.util.logging.Logger;

import com.caucho.hessian.HessianUnshared;

/**
 * Serializing an object for known object types.
 */
public class JavaSerializer extends AbstractSerializer
{
  private static final Logger log
    = Logger.getLogger(JavaSerializer.class.getName());

  private static final WeakHashMap<Class<?>,SoftReference<JavaSerializer>> _serializerMap
    = new WeakHashMap<Class<?>,SoftReference<JavaSerializer>>();

  private Field []_fields;
  private FieldSerializer []_fieldSerializers;

  private Object _writeReplaceFactory;
  private Method _writeReplace;
  
  public JavaSerializer(Class<?> cl)
  {
    introspect(cl);

    _writeReplace = getWriteReplace(cl);

    if (_writeReplace != null)
      _writeReplace.setAccessible(true);
  }

  public static Serializer create(Class<?> cl)
  {
    synchronized (_serializerMap) {
      SoftReference<JavaSerializer> baseRef
        = _serializerMap.get(cl);
      
      JavaSerializer base = baseRef != null ? baseRef.get() : null;

      if (base == null) {
        if (cl.isAnnotationPresent(HessianUnshared.class))
          base = new JavaUnsharedSerializer(cl);
        else
          base = new JavaSerializer(cl);
        
        baseRef = new SoftReference<JavaSerializer>(base);
        _serializerMap.put(cl, baseRef);
      }

      return base;
    }
  }

  protected void introspect(Class<?> cl)
  {
    if (_writeReplace != null)
      _writeReplace.setAccessible(true);

    ArrayList<Field> primitiveFields = new ArrayList<Field>();
    ArrayList<Field> compoundFields = new ArrayList<Field>();
    
    for (; cl != null; cl = cl.getSuperclass()) {
      Field []fields = cl.getDeclaredFields();
      for (int i = 0; i < fields.length; i++) {
        Field field = fields[i];

        if (Modifier.isTransient(field.getModifiers())
            || Modifier.isStatic(field.getModifiers()))
          continue;

        // XXX: could parameterize the handler to only deal with public
        field.setAccessible(true);

        if (field.getType().isPrimitive()
            || (field.getType().getName().startsWith("java.lang.")
                && ! field.getType().equals(Object.class)))
          primitiveFields.add(field);
        else
          compoundFields.add(field);
      }
    }

    ArrayList<Field> fields = new ArrayList<Field>();
    fields.addAll(primitiveFields);
    fields.addAll(compoundFields);

    _fields = new Field[fields.size()];
    fields.toArray(_fields);

    _fieldSerializers = new FieldSerializer[_fields.length];

    for (int i = 0; i < _fields.length; i++) {
      _fieldSerializers[i] = getFieldSerializer(_fields[i].getType());
    }
  }

  /**
   * Returns the writeReplace method
   */
  protected static Method getWriteReplace(Class<?> cl)
  {
    for (; cl != null; cl = cl.getSuperclass()) {
      Method []methods = cl.getDeclaredMethods();
      
      for (int i = 0; i < methods.length; i++) {
        Method method = methods[i];

        if (method.getName().equals("writeReplace")
            && method.getParameterTypes().length == 0)
          return method;
      }
    }

    return null;
  }

  /**
   * Returns the writeReplace method
   */
  protected Method getWriteReplace(Class<?> cl, Class<?> param)
  {
    for (; cl != null; cl = cl.getSuperclass()) {
      for (Method method : cl.getDeclaredMethods()) {
        if (method.getName().equals("writeReplace")
            && method.getParameterTypes().length == 1
            && param.equals(method.getParameterTypes()[0]))
          return method;
      }
    }

    return null;
  }
  
  @Override
  public void writeObject(Object obj, AbstractHessianOutput out)
    throws IOException
  {
    if (out.addRef(obj)) {
      return;
    }
    
    Class<?> cl = obj.getClass();

    try {
      if (_writeReplace != null) {
        Object repl;

        if (_writeReplaceFactory != null)
          repl = _writeReplace.invoke(_writeReplaceFactory, obj);
        else
          repl = _writeReplace.invoke(obj);

        // out.removeRef(obj);

        /*
        out.writeObject(repl);

        out.replaceRef(repl, obj);
        */

        //hessian/3a5a
        int ref = out.writeObjectBegin(cl.getName());

        if (ref < -1) {
          writeObject10(repl, out);
        } else {
          if (ref == -1) {
            writeDefinition20(out);
            out.writeObjectBegin(cl.getName());
          }

          writeInstance(repl, out);
        }

        return;
      }
    } catch (RuntimeException e) {
      throw e;
    } catch (Exception e) {
      // log.log(Level.FINE, e.toString(), e);
      throw new RuntimeException(e);
    }

    int ref = out.writeObjectBegin(cl.getName());

    if (ref < -1) {
      writeObject10(obj, out);
    }
    else {
      if (ref == -1) {
        writeDefinition20(out);
        out.writeObjectBegin(cl.getName());
      }

      writeInstance(obj, out);
    }
  }
  
  protected void writeObject10(Object obj, AbstractHessianOutput out)
    throws IOException
  {
    for (int i = 0; i < _fields.length; i++) {
      Field field = _fields[i];

      out.writeString(field.getName());

      _fieldSerializers[i].serialize(out, obj, field);
    }
      
    out.writeMapEnd();
  }
  
  private void writeDefinition20(AbstractHessianOutput out)
    throws IOException
  {
    out.writeClassFieldLength(_fields.length);

    for (int i = 0; i < _fields.length; i++) {
      Field field = _fields[i];
      
      out.writeString(field.getName());
    }
  }
  
  @Override
  public void writeInstance(Object obj, AbstractHessianOutput out)
    throws IOException
  {
    try {
      for (int i = 0; i < _fields.length; i++) {
        Field field = _fields[i];

        _fieldSerializers[i].serialize(out, obj, field);
      }
    } catch (RuntimeException e) {
      throw new RuntimeException(e.getMessage() + "\n class: "
                                 + obj.getClass().getName()
                                 + " (object=" + obj + ")",
                                 e);
    } catch (IOException e) {
      throw new IOExceptionWrapper(e.getMessage() + "\n class: "
                                   + obj.getClass().getName()
                                   + " (object=" + obj + ")",
                                   e);
    }
  }

  private static FieldSerializer getFieldSerializer(Class<?> type)
  {
    if (int.class.equals(type)
        || byte.class.equals(type)
        || short.class.equals(type)
        || int.class.equals(type)) {
      return IntFieldSerializer.SER;
    }
    else if (long.class.equals(type)) {
      return LongFieldSerializer.SER;
    }
    else if (double.class.equals(type) ||
        float.class.equals(type)) {
      return DoubleFieldSerializer.SER;
    }
    else if (boolean.class.equals(type)) {
      return BooleanFieldSerializer.SER;
    }
    else if (String.class.equals(type)) {
      return StringFieldSerializer.SER;
    }
    else if (java.util.Date.class.equals(type)
             || java.sql.Date.class.equals(type)
             || java.sql.Timestamp.class.equals(type)
             || java.sql.Time.class.equals(type)) {
      return DateFieldSerializer.SER;
    }
    else
      return FieldSerializer.SER;
  }

  static class FieldSerializer {
    static final FieldSerializer SER = new FieldSerializer();
    
    void serialize(AbstractHessianOutput out, Object obj, Field field)
      throws IOException
    {
      Object value = null;

      try {
        value = field.get(obj);
      } catch (IllegalAccessException e) {
        log.log(Level.FINE, e.toString(), e);
      }

      try {
        out.writeObject(value);
      } catch (RuntimeException e) {
        throw new RuntimeException(e.getMessage() + "\n field: "
                                   + field.getDeclaringClass().getName()
                                   + '.' + field.getName(),
                                   e);
      } catch (IOException e) {
        throw new IOExceptionWrapper(e.getMessage() + "\n field: "
                                     + field.getDeclaringClass().getName()
                                     + '.' + field.getName(),
                                     e);
      }
    }
  }

  static class BooleanFieldSerializer extends FieldSerializer {
    static final FieldSerializer SER = new BooleanFieldSerializer();
    
    void serialize(AbstractHessianOutput out, Object obj, Field field)
      throws IOException
    {
      boolean value = false;

      try {
        value = field.getBoolean(obj);
      } catch (IllegalAccessException e) {
        log.log(Level.FINE, e.toString(), e);
      }

      out.writeBoolean(value);
    }
  }

  static class IntFieldSerializer extends FieldSerializer {
    static final FieldSerializer SER = new IntFieldSerializer();
    
    void serialize(AbstractHessianOutput out, Object obj, Field field)
      throws IOException
    {
      int value = 0;

      try {
        value = field.getInt(obj);
      } catch (IllegalAccessException e) {
        log.log(Level.FINE, e.toString(), e);
      }

      out.writeInt(value);
    }
  }

  static class LongFieldSerializer extends FieldSerializer {
    static final FieldSerializer SER = new LongFieldSerializer();
    
    void serialize(AbstractHessianOutput out, Object obj, Field field)
      throws IOException
    {
      long value = 0;

      try {
        value = field.getLong(obj);
      } catch (IllegalAccessException e) {
        log.log(Level.FINE, e.toString(), e);
      }

      out.writeLong(value);
    }
  }

  static class DoubleFieldSerializer extends FieldSerializer {
    static final FieldSerializer SER = new DoubleFieldSerializer();
    
    void serialize(AbstractHessianOutput out, Object obj, Field field)
      throws IOException
    {
      double value = 0;

      try {
        value = field.getDouble(obj);
      } catch (IllegalAccessException e) {
        log.log(Level.FINE, e.toString(), e);
      }

      out.writeDouble(value);
    }
  }

  static class StringFieldSerializer extends FieldSerializer {
    static final FieldSerializer SER = new StringFieldSerializer();
    
    void serialize(AbstractHessianOutput out, Object obj, Field field)
      throws IOException
    {
      String value = null;

      try {
        value = (String) field.get(obj);
      } catch (IllegalAccessException e) {
        log.log(Level.FINE, e.toString(), e);
      }

      out.writeString(value);
    }
  }

  static class DateFieldSerializer extends FieldSerializer {
    static final FieldSerializer SER = new DateFieldSerializer();

    void serialize(AbstractHessianOutput out, Object obj, Field field)
      throws IOException
    {
      java.util.Date value = null;

      try {
        value = (java.util.Date) field.get(obj);
      } catch (IllegalAccessException e) {
        log.log(Level.FINE, e.toString(), e);
      }

      if (value == null)
        out.writeNull();
      else
        out.writeUTCDate(value.getTime());
    }
  }
}
