/*
 * 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.alibaba.com.caucho.hessian.io;

import java.io.IOException;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;

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

    private static Object[] NULL_ARGS = new Object[0];

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

    private Object _writeReplaceFactory;
    private Method _writeReplace;

    public JavaSerializer(Class cl, ClassLoader loader) {
        introspectWriteReplace(cl, loader);

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

        List primitiveFields = new ArrayList();
        List compoundFields = new ArrayList();

        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);
            }
        }

        List fields = new ArrayList();
        fields.addAll(primitiveFields);
        fields.addAll(compoundFields);
        Collections.reverse(fields);

        _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;
    }

    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;
    }

    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, 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);

                //Some class would return itself for wrapReplace, which would cause infinite recursion
                //In this case, we could write the object just like normal cases
                if (repl != obj) {
                    out.removeRef(obj);

                    out.writeObject(repl);

                    out.replaceRef(repl, obj);

                    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);
        }
    }

    private 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());
        }
    }

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

            _fieldSerializers[i].serialize(out, obj, field);
        }
    }

    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 Java field: " + field,
                        e);
            } catch (IOException e) {
                throw new IOExceptionWrapper(e.getMessage() + "\n Java field: " + field,
                        e);
            }
        }
    }

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

        @Override
        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();

        @Override
        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();

        @Override
        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();

        @Override
        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();

        @Override
        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();

        @Override
        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());
        }
    }
}