/*
 * Copyright (c) 2001-2004 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.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.Locale;
import java.util.logging.*;

/**
 * Serializing an object for known object types.
 */
public class BeanSerializer extends AbstractSerializer {
  private static final Logger log
    = Logger.getLogger(BeanSerializer.class.getName());
  
  private static final Object []NULL_ARGS = new Object[0];
  private Method []_methods;
  private String []_names;

  private Object _writeReplaceFactory;
  private Method _writeReplace;
  
  public BeanSerializer(Class<?> cl, ClassLoader loader)
  {
    introspectWriteReplace(cl, loader);

    ArrayList<Method> primitiveMethods = new ArrayList<Method>();
    ArrayList compoundMethods = new ArrayList();
    
    for (; cl != null; cl = cl.getSuperclass()) {
      Method []methods = cl.getDeclaredMethods();
      
      for (int i = 0; i < methods.length; i++) {
        Method method = methods[i];

        if (Modifier.isStatic(method.getModifiers()))
          continue;

        if (method.getParameterTypes().length != 0)
          continue;

        String name = method.getName();

        if (! name.startsWith("get"))
          continue;

        Class type = method.getReturnType();

        if (type.equals(void.class))
          continue;

        if (findSetter(methods, name, type) == null)
          continue;

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

        if (type.isPrimitive()
            || type.getName().startsWith("java.lang.")
            && ! type.equals(Object.class))
          primitiveMethods.add(method);
        else
          compoundMethods.add(method);
      }
    }

    ArrayList methodList = new ArrayList();
    methodList.addAll(primitiveMethods);
    methodList.addAll(compoundMethods);

    Collections.sort(methodList, new MethodNameCmp());

    _methods = new Method[methodList.size()];
    methodList.toArray(_methods);

    _names = new String[_methods.length];
    
    for (int i = 0; i < _methods.length; i++) {
      String name = _methods[i].getName();

      name = name.substring(3);

      int j = 0;
      for (; j < name.length() && Character.isUpperCase(name.charAt(j)); j++) {
      }

      if (j == 1)
        name = name.substring(0, j).toLowerCase(Locale.ENGLISH) + name.substring(j);
      else if (j > 1)
        name = name.substring(0, j - 1).toLowerCase(Locale.ENGLISH) + name.substring(j - 1);

      _names[i] = name;
    }
  }

  private void introspectWriteReplace(Class cl, ClassLoader loader)
  {
    try {
      String className = cl.getName() + "HessianSerializer";

      Class serializerClass = Class.forName(className, false, loader);

      Object serializerObject = serializerClass.newInstance();

      Method writeReplace = getWriteReplace(serializerClass, cl);

      if (writeReplace != null) {
        _writeReplaceFactory = serializerObject;
        _writeReplace = writeReplace;

        return;
      }
    } catch (ClassNotFoundException e) {
    } catch (Exception e) {
      log.log(Level.FINER, e.toString(), e);
    }
      
    _writeReplace = getWriteReplace(cl);
  }

  /**
   * Returns the writeReplace method
   */
  protected 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;
  }
  
  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);

        return;
      }
    } catch (Exception e) {
      log.log(Level.FINER, e.toString(), e);
    }

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

    if (ref < -1) {
      // Hessian 1.1 uses a map
      
      for (int i = 0; i < _methods.length; i++) {
        Method method = _methods[i];
        Object value = null;

        try {
          value = _methods[i].invoke(obj, (Object []) null);
        } catch (Exception e) {
          log.log(Level.FINE, e.toString(), e);
        }

        out.writeString(_names[i]);

        out.writeObject(value);
      }
      
      out.writeMapEnd();
    }
    else {
      if (ref == -1) {
        out.writeInt(_names.length);

        for (int i = 0; i < _names.length; i++)
          out.writeString(_names[i]);

        out.writeObjectBegin(cl.getName());
      }

      for (int i = 0; i < _methods.length; i++) {
        Method method = _methods[i];
        Object value = null;

        try {
          value = _methods[i].invoke(obj, (Object []) null);
        } catch (Exception e) {
          log.log(Level.FINER, e.toString(), e);
        }

        out.writeObject(value);
      }
    }
  }

  /**
   * Finds any matching setter.
   */
  private Method findSetter(Method []methods, String getterName, Class arg)
  {
    String setterName = "set" + getterName.substring(3);
    
    for (int i = 0; i < methods.length; i++) {
      Method method = methods[i];

      if (! method.getName().equals(setterName))
        continue;
      
      if (! method.getReturnType().equals(void.class))
        continue;

      Class []params = method.getParameterTypes();

      if (params.length == 1 && params[0].equals(arg))
        return method;
    }

    return null;
  }

  static class MethodNameCmp implements Comparator<Method> {
    public int compare(Method a, Method b)
    {
      return a.getName().compareTo(b.getName());
    }
  }
}
