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

import java.io.IOException;

/**
 * Deserializing an object.
 */
public class AbstractDeserializer implements Deserializer {
    public static final NullDeserializer NULL = new NullDeserializer();

    public Class<?> getType() {
        return Object.class;
    }

    public boolean isReadResolve() {
        return false;
    }

    public Object readObject(AbstractHessianInput in)
            throws IOException {
        Object obj = in.readObject();

        String className = getClass().getName();

        if (obj != null)
            throw error(className + ": unexpected object " + obj.getClass().getName());
        else
            throw error(className + ": unexpected null value");
    }

    public Object readList(AbstractHessianInput in, int length)
            throws IOException {
        throw new UnsupportedOperationException(String.valueOf(this));
    }

    public Object readLengthList(AbstractHessianInput in, int length)
            throws IOException {
        throw new UnsupportedOperationException(String.valueOf(this));
    }

    public Object readMap(AbstractHessianInput in)
            throws IOException {
        Object obj = in.readObject();

        String className = getClass().getName();

        if (obj != null)
            throw error(className + ": unexpected object " + obj.getClass().getName());
        else
            throw error(className + ": unexpected null value");
    }

    /**
     * Creates the field array for a class. The default
     * implementation returns a String[] array.
     *
     * @param len number of items in the array
     * @return the new empty array
     */
    public Object[] createFields(int len) {
        return new String[len];
    }

    /**
     * Creates a field value class. The default
     * implementation returns the String.
     *
     * @param len number of items in the array
     * @return the new empty array
     */
    public Object createField(String name) {
        return name;
    }

    @Override
    public Object readObject(AbstractHessianInput in,
                             String[] fieldNames)
            throws IOException {
        return readObject(in, (Object[]) fieldNames);
    }

    /**
     * Reads an object instance from the input stream
     */
    @Override
    public Object readObject(AbstractHessianInput in,
                             Object[] fields)
            throws IOException {
        throw new UnsupportedOperationException(toString());
    }

    protected HessianProtocolException error(String msg) {
        return new HessianProtocolException(msg);
    }

    protected String codeName(int ch) {
        if (ch < 0)
            return "end of file";
        else
            return "0x" + Integer.toHexString(ch & 0xff);
    }

    /**
     * The NullDeserializer exists as a marker for the factory classes so
     * they save a null result.
     */
    static final class NullDeserializer extends AbstractDeserializer {
    }
}