/*
 * Copyright (c) 2003, 2004, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package com.sun.corba.se.impl.presentation.rmi ;

import java.io.Serializable ;
import java.io.Externalizable ;

import javax.rmi.PortableRemoteObject ;
import javax.rmi.CORBA.Util ;

import org.omg.CORBA.portable.IDLEntity ;

import org.omg.CORBA_2_3.portable.InputStream ;
import org.omg.CORBA_2_3.portable.OutputStream ;
import org.omg.CORBA.portable.ApplicationException ;

import java.lang.reflect.Method ;

import java.rmi.RemoteException ;

import com.sun.corba.se.spi.orb.ORB ;

import com.sun.corba.se.spi.presentation.rmi.DynamicMethodMarshaller ;

public class DynamicMethodMarshallerImpl implements DynamicMethodMarshaller
{
    Method method ;
    ExceptionHandler ehandler ;
    boolean hasArguments = true ;
    boolean hasVoidResult = true ;
    boolean needsArgumentCopy ;         // true if copyObjects call needs for args
    boolean needsResultCopy ;           // true if copyObject call needs for result
    ReaderWriter[] argRWs = null ;
    ReaderWriter resultRW = null ;

    private static boolean isAnyClass( Class cls )
    {
        return cls.equals( Object.class ) || cls.equals( Serializable.class ) ||
            cls.equals( Externalizable.class ) ;
    }

    // Assume that cls is not Remote, !isAnyClass(cls), and
    // !org.omg.CORBA.Object.class.isAssignableFrom( cls ).
    // Then return whether cls is an RMI-IIOP abstract interface.
    private static boolean isAbstractInterface( Class cls )
    {
        // Either cls is an interface that extends IDLEntity, or else
        // cls does not extend java.rmi.Remote and all of its methods
        // throw RemoteException.
        if (IDLEntity.class.isAssignableFrom( cls ))
            return cls.isInterface() ;
        else
            return cls.isInterface() && allMethodsThrowRemoteException( cls ) ;
    }

    private static boolean allMethodsThrowRemoteException( Class cls )
    {
        Method[] methods = cls.getMethods() ;

        // Check that all methods (other than those declared in java.lang.Object)
        // throw an exception that is a subclass of RemoteException.
        for (int ctr=0; ctr<methods.length; ctr++) {
            Method method = methods[ctr] ;
            if (method.getDeclaringClass() != Object.class)
                if (!throwsRemote( method ))
                    return false ;
        }

        return true ;
    }

    private static boolean throwsRemote( Method method )
    {
        Class[] exceptionTypes = method.getExceptionTypes() ;

        // Check that some exceptionType is a subclass of RemoteException
        for (int ctr=0; ctr<exceptionTypes.length; ctr++) {
            Class exceptionType = exceptionTypes[ctr] ;
            if (java.rmi.RemoteException.class.isAssignableFrom( exceptionType ))
                return true ;
        }

        return false ;
    }

    public interface ReaderWriter
    {
        Object read( InputStream is ) ;

        void write( OutputStream os, Object value ) ;
    }

    abstract static class ReaderWriterBase implements ReaderWriter
    {
        String name ;

        public ReaderWriterBase( String name )
        {
            this.name = name ;
        }

        public String toString()
        {
            return "ReaderWriter[" + name + "]" ;
        }
    }

    private static ReaderWriter booleanRW = new ReaderWriterBase( "boolean" )
    {
        public Object read( InputStream is )
        {
            return is.read_boolean() ;
        }

        public void write( OutputStream os, Object value )
        {
            Boolean val = (Boolean)value ;
            os.write_boolean( val.booleanValue() ) ;
        }
    } ;

    private static ReaderWriter byteRW = new ReaderWriterBase( "byte" )
    {
        public Object read( InputStream is )
        {
            byte value = is.read_octet() ;
            return new Byte( value ) ;
        }

        public void write( OutputStream os, Object value )
        {
            Byte val = (Byte)value ;
            os.write_octet( val.byteValue() ) ;
        }
    } ;

    private static ReaderWriter charRW = new ReaderWriterBase( "char" )
    {
        public Object read( InputStream is )
        {
            char value = is.read_wchar() ;
            return new Character( value ) ;
        }

        public void write( OutputStream os, Object value )
        {
            Character val = (Character)value ;
            os.write_wchar( val.charValue() ) ;
        }
    } ;

    private static ReaderWriter shortRW = new ReaderWriterBase( "short" )
    {
        public Object read( InputStream is )
        {
            short value = is.read_short() ;
            return new Short( value ) ;
        }

        public void write( OutputStream os, Object value )
        {
            Short val = (Short)value ;
            os.write_short( val.shortValue() ) ;
        }
    } ;

    private static ReaderWriter intRW = new ReaderWriterBase( "int" )
    {
        public Object read( InputStream is )
        {
            int value = is.read_long() ;
            return new Integer( value ) ;
        }

        public void write( OutputStream os, Object value )
        {
            Integer val = (Integer)value ;
            os.write_long( val.intValue() ) ;
        }
    } ;

    private static ReaderWriter longRW = new ReaderWriterBase( "long" )
    {
        public Object read( InputStream is )
        {
            long value = is.read_longlong() ;
            return new Long( value ) ;
        }

        public void write( OutputStream os, Object value )
        {
            Long val = (Long)value ;
            os.write_longlong( val.longValue() ) ;
        }
    } ;

    private static ReaderWriter floatRW = new ReaderWriterBase( "float" )
    {
        public Object read( InputStream is )
        {
            float value = is.read_float() ;
            return new Float( value ) ;
        }

        public void write( OutputStream os, Object value )
        {
            Float val = (Float)value ;
            os.write_float( val.floatValue() ) ;
        }
    } ;

    private static ReaderWriter doubleRW = new ReaderWriterBase( "double" )
    {
        public Object read( InputStream is )
        {
            double value = is.read_double() ;
            return new Double( value ) ;
        }

        public void write( OutputStream os, Object value )
        {
            Double val = (Double)value ;
            os.write_double( val.doubleValue() ) ;
        }
    } ;

    private static ReaderWriter corbaObjectRW = new ReaderWriterBase(
        "org.omg.CORBA.Object" )
    {
        public Object read( InputStream is )
        {
            return is.read_Object() ;
        }

        public void write( OutputStream os, Object value )
        {
            os.write_Object( (org.omg.CORBA.Object)value ) ;
        }
    } ;

    private static ReaderWriter anyRW = new ReaderWriterBase( "any" )
    {
        public Object read( InputStream is )
        {
            return Util.readAny(is) ;
        }

        public void write( OutputStream os, Object value )
        {
            Util.writeAny( os, value ) ;
        }
    } ;

    private static ReaderWriter abstractInterfaceRW = new ReaderWriterBase(
        "abstract_interface"  )
    {
        public Object read( InputStream is )
        {
            return is.read_abstract_interface() ;
        }

        public void write( OutputStream os, Object value )
        {
            Util.writeAbstractObject( os, value ) ;
        }
    } ;


    public static ReaderWriter makeReaderWriter( final Class cls )
    {
        if (cls.equals( boolean.class ))
            return booleanRW ;
        else if (cls.equals( byte.class ))
            return byteRW ;
        else if (cls.equals( char.class ))
            return charRW ;
        else if (cls.equals( short.class ))
            return shortRW ;
        else if (cls.equals( int.class ))
            return intRW ;
        else if (cls.equals( long.class ))
            return longRW ;
        else if (cls.equals( float.class ))
            return floatRW ;
        else if (cls.equals( double.class ))
            return doubleRW ;
        else if (java.rmi.Remote.class.isAssignableFrom( cls ))
            return new ReaderWriterBase( "remote(" + cls.getName() + ")" )
            {
                public Object read( InputStream is )
                {
                    return PortableRemoteObject.narrow( is.read_Object(),
                        cls ) ;
                }

                public void write( OutputStream os, Object value )
                {
                    Util.writeRemoteObject( os, value ) ;
                }
            } ;
        else if (cls.equals(org.omg.CORBA.Object.class))
            return corbaObjectRW ;
        else if (org.omg.CORBA.Object.class.isAssignableFrom( cls ))
            return new ReaderWriterBase( "org.omg.CORBA.Object(" +
                cls.getName() + ")" )
            {
                public Object read( InputStream is )
                {
                    return is.read_Object(cls) ;
                }

                public void write( OutputStream os, Object value )
                {
                    os.write_Object( (org.omg.CORBA.Object)value ) ;
                }
            } ;
        else if (isAnyClass(cls))
            return anyRW ;
        else if (isAbstractInterface(cls))
            return abstractInterfaceRW ;

        // For anything else, just read it as a value type.
        return new ReaderWriterBase( "value(" + cls.getName() + ")" )
        {
            public Object read( InputStream is )
            {
                return is.read_value(cls) ;
            }

            public void write( OutputStream os, Object value )
            {
                os.write_value( (Serializable)value, cls ) ;
            }
        } ;
    }

    public DynamicMethodMarshallerImpl( Method method )
    {
        this.method = method ;
        ehandler = new ExceptionHandlerImpl( method.getExceptionTypes() ) ;
        needsArgumentCopy = false ;

        Class[] argTypes = method.getParameterTypes() ;
        hasArguments = argTypes.length > 0 ;
        if (hasArguments) {
            argRWs = new ReaderWriter[ argTypes.length ] ;
            for (int ctr=0; ctr<argTypes.length; ctr++ ) {
                // This could be further optimized to avoid
                // copying if argTypes contains at most one
                // immutable object type.
                if (!argTypes[ctr].isPrimitive())
                    needsArgumentCopy = true ;
                argRWs[ctr] = makeReaderWriter( argTypes[ctr] ) ;
            }
        }

        Class resultType = method.getReturnType() ;
        needsResultCopy = false ;
        hasVoidResult = resultType.equals( void.class ) ;
        if (!hasVoidResult) {
            needsResultCopy = !resultType.isPrimitive() ;
            resultRW = makeReaderWriter( resultType ) ;
        }
    }

    public Method getMethod()
    {
        return method ;
    }

    public Object[] copyArguments( Object[] args,
        ORB orb ) throws RemoteException
    {
        if (needsArgumentCopy)
            return Util.copyObjects( args, orb ) ;
        else
            return args ;
    }

    public Object[] readArguments( InputStream is )
    {
        Object[] result = null ;

        if (hasArguments) {
            result = new Object[ argRWs.length ] ;
            for (int ctr=0; ctr<argRWs.length; ctr++ )
                result[ctr] = argRWs[ctr].read( is ) ;
        }

        return result ;
    }

    public void writeArguments( OutputStream os, Object[] args )
    {
        if (hasArguments) {
            if (args.length != argRWs.length)
                throw new IllegalArgumentException( "Expected " + argRWs.length +
                    " arguments, but got " + args.length + " arguments." ) ;

            for (int ctr=0; ctr<argRWs.length; ctr++ )
                argRWs[ctr].write( os, args[ctr] ) ;
        }
    }

    public Object copyResult( Object result, ORB orb ) throws RemoteException
    {
        if (needsResultCopy)
            return Util.copyObject( result, orb ) ;
        else
            return result ;
    }

    public Object readResult( InputStream is )
    {
        if (hasVoidResult)
            return null ;
        else
            return resultRW.read( is ) ;
    }

    public void writeResult( OutputStream os, Object result )
    {
        if (!hasVoidResult)
            resultRW.write( os, result ) ;
    }

    public boolean isDeclaredException( Throwable thr )
    {
        return ehandler.isDeclaredException( thr.getClass() ) ;
    }

    public void writeException( OutputStream os, Exception ex )
    {
        ehandler.writeException( os, ex ) ;
    }

    public Exception readException( ApplicationException ae )
    {
        return ehandler.readException( ae ) ;
    }
}