/*

 * 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

 * particular file as subject to the "Classpath" exception as provided

 *

 * 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.

 *

 */

package com.sun.corba.se.spi.orb ;

import java.util.StringTokenizer ;

import java.lang.reflect.Array ;

import java.net.URL ;

import java.net.MalformedURLException ;

import com.sun.corba.se.spi.logging.CORBALogDomains ;

import com.sun.corba.se.impl.logging.ORBUtilSystemException ;

import com.sun.corba.se.impl.orbutil.ORBClassLoader ;

import com.sun.corba.se.impl.orbutil.ObjectUtility ;

/** This is a static factory class for commonly used operations

* for property parsing.  The following operations are supported:

* <ul>

* <li>maskErrorAction( Operation op ) executes op and returns the result.  If op throws an

* exception, the result is null.

* <li>indexAction( int arg ) returns the [arg] element of value, which must be an Object[]</li>

* <li>identityAction() return the value</li>

* <li>booleanAction() return a Boolean representing true or false values of the String value</li>

* <li>integerAction() returns an Integer for the String value, which must be a decimal integer</li>

* <li>stringAction() returns the String value</li>

* <li>classAction() returns a class for the String value, as loaded by the ORB classloader</li>

* <li>setFlagAction() always return Boolean.TRUE</li>

* <li>URLAction() returns a java.net.URL for the String value, which must be a valid URL</li>

* <li>integerRangeAction( int min, int max ) returns an Integer for the String value, which must be a

* decimal integer in the range min to max inclusive</li>

* <li>listAction( String sep, Operation ) tokenizes the String value with sep as separator, then

* applies the Operation to each token, and returns an array of the result</li>

* <li>sequenceAction( String, Operation[] ) tokenizes the String value with sep as separator, then

* applies each Operation in the Operation array to successive tokens, and returns an array of the results</li>

* <li>compose( Operation op1, Operation op2 ) is the operation that applies op2 to the result of applying

* op1 to the value</li>

* <li>mapAction( Operation ) applies the Operation to each element of an array of objects, and returns

* an array of the results</li>

* <li>mapSequenceAction( Operation[] ) applies the corresponding element of the Operation array to an

* element of the Object[] value, and returns an array of the results</li>

* <li>convertIntegerToShort coerces an Integer into a Short.</li>

* </ul>

* Other operations can be directly defined, and combined using these basic operations.

*/

public abstract class OperationFactory {

    private OperationFactory() {}

    private static String getString( Object obj )

    {

        if (obj instanceof String)

            return (String)obj ;

        else

            throw new Error( "String expected" ) ;

    }

    private static Object[] getObjectArray( Object obj )

    {

        if (obj instanceof Object[])

            return (Object[])obj ;

        else

            throw new Error( "Object[] expected" ) ;

    }

    private static StringPair getStringPair( Object obj )

    {

        if (obj instanceof StringPair)

            return (StringPair)obj ;

        else

            throw new Error( "StringPair expected" ) ;

    }

    private static abstract class OperationBase implements Operation{

        public boolean equals( Object obj )

        {

            if (this==obj)

                return true ;

            if (!(obj instanceof OperationBase))

                return false ;

            OperationBase other = (OperationBase)obj ;

            return toString().equals( other.toString() ) ;

        }

        public int hashCode()

        {

            return toString().hashCode() ;

        }

    }

    private static class MaskErrorAction extends OperationBase

    {

        private Operation op ;

        public MaskErrorAction( Operation op )

        {

            this.op = op ;

        }

        public Object operate( Object arg )

        {

            try {

                return op.operate( arg ) ;

            } catch (java.lang.Exception exc) {

                return null ;

            }

        }

        public String toString()

        {

            return "maskErrorAction(" + op + ")" ;

        }

    }

    public static Operation maskErrorAction( Operation op )

    {

        return new MaskErrorAction( op ) ;

    }

    private static class IndexAction extends OperationBase

    {

        private int index ;

        public IndexAction( int index )

        {

            this.index = index ;

        }

        public Object operate( Object value )

        {

            return getObjectArray( value )[ index ] ;

        }

        public String toString()

        {

            return "indexAction(" + index + ")" ;

        }

    }

    public static Operation indexAction( int index )

    {

        return new IndexAction( index ) ;

    }

    private static class SuffixAction extends OperationBase

    {

        public Object operate( Object value )

        {

            return getStringPair( value ).getFirst() ;

        }

        public String toString() { return "suffixAction" ; }

    }

    private static Operation suffixActionImpl = new SuffixAction() ;

    private static class ValueAction extends OperationBase

    {

        public Object operate( Object value )

        {

            return getStringPair( value ).getSecond() ;

        }

        public String toString() { return "valueAction" ; }

    }

    private static Operation valueActionImpl = new ValueAction() ;

    private static class IdentityAction extends OperationBase

    {

        public Object operate( Object value )

        {

            return value ;

        }

        public String toString() { return "identityAction" ; }

    }

    private static Operation identityActionImpl = new IdentityAction() ;

    private static class BooleanAction extends OperationBase

    {

        public Object operate( Object value )

        {

            return new Boolean( getString( value ) ) ;

        }

        public String toString() { return "booleanAction" ; }

    }

    private static Operation booleanActionImpl = new BooleanAction() ;

    private static class IntegerAction extends OperationBase

    {

        public Object operate( Object value )

        {

            return new Integer( getString( value ) ) ;

        }

        public String toString() { return "integerAction" ; }

    }

    private static Operation integerActionImpl = new IntegerAction() ;

    private static class StringAction extends OperationBase

    {

        public Object operate( Object value )

        {

            return value ;

        }

        public String toString() { return "stringAction" ; }

    }

    private static Operation stringActionImpl = new StringAction() ;

    private static class ClassAction extends OperationBase

    {

        public Object operate( Object value )

        {

            String className = getString( value ) ;

            try {

                Class result = ORBClassLoader.loadClass( className ) ;

                return result ;

            } catch (Exception exc) {

                ORBUtilSystemException wrapper = ORBUtilSystemException.get(

                    CORBALogDomains.ORB_LIFECYCLE ) ;

                throw wrapper.couldNotLoadClass( exc, className ) ;

            }

        }

        public String toString() { return "classAction" ; }

    }

    private static Operation classActionImpl = new ClassAction() ;

    private static class SetFlagAction extends OperationBase

    {

        public Object operate( Object value )

        {

            return Boolean.TRUE ;

        }

        public String toString() { return "setFlagAction" ; }

    }

    private static Operation setFlagActionImpl = new SetFlagAction() ;

    private static class URLAction extends OperationBase

    {

        public Object operate( Object value )

        {

            String val = (String)value ;

            try {

                return new URL( val ) ;

            } catch (MalformedURLException exc) {

                ORBUtilSystemException wrapper = ORBUtilSystemException.get(

                    CORBALogDomains.ORB_LIFECYCLE ) ;

                throw wrapper.badUrl( exc, val ) ;

            }

        }

        public String toString() { return "URLAction" ; }

    }

    private static Operation URLActionImpl = new URLAction() ;

    public static Operation identityAction()

    {

        return identityActionImpl ;

    }

    public static Operation suffixAction()

    {

        return suffixActionImpl ;

    }

    public static Operation valueAction()

    {

        return valueActionImpl ;

    }

    public static Operation booleanAction()

    {

        return booleanActionImpl ;

    }

    public static Operation integerAction()

    {

        return integerActionImpl ;

    }

    public static Operation stringAction()

    {

        return stringActionImpl ;

    }

    public static Operation classAction()

    {

        return classActionImpl ;

    }

    public static Operation setFlagAction()

    {

        return setFlagActionImpl ;

    }

    public static Operation URLAction()

    {

        return URLActionImpl ;

    }

    private static class IntegerRangeAction extends OperationBase

    {

        private int min ;

        private int max ;

        IntegerRangeAction( int min, int max )

        {

            this.min = min ;

            this.max = max ;

        }

        public Object operate( Object value )

        {

            int result = Integer.parseInt( getString( value ) ) ;

            if ((result >= min) && (result <= max))

                return new Integer( result ) ;

            else

                throw new IllegalArgumentException(

                    "Property value " + result + " is not in the range " +

                    min + " to " + max ) ;

        }

        public String toString() {

            return "integerRangeAction(" + min + "," + max + ")" ;

        }

    }

    public static Operation integerRangeAction( int min, int max )

    {

        return new IntegerRangeAction( min, max ) ;

    }

    private static class ListAction extends OperationBase {

        private String sep ;

        private Operation act ;

        ListAction( String sep, Operation act )

        {

            this.sep = sep ;

            this.act = act ;

        }

        // Note that this method carefully constructs an array of the type

        // of the first result, rather than just using Object[], which is

        // not convertible into the correct type.  Also note that no tokens

        // results in a null result.

        public Object operate( Object value )

        {

            StringTokenizer st = new StringTokenizer( getString( value ),

                sep ) ;

            int length = st.countTokens() ;

            Object result = null ;

            int ctr = 0 ;

            while (st.hasMoreTokens()) {

                String next = st.nextToken() ;

                Object val = act.operate( next ) ;

                if (result == null)

                    result = Array.newInstance( val.getClass(), length ) ;

                Array.set( result, ctr++, val ) ;

            }

            return result ;

        }

        public String toString() {

            return "listAction(separator=\"" + sep +

                "\",action=" + act + ")" ;

        }

    }

    public static Operation listAction( String sep, Operation act )

    {

        return new ListAction( sep, act ) ;

    }

    private static class SequenceAction extends OperationBase

    {

        private String sep ;

        private Operation[] actions ;

        SequenceAction( String sep, Operation[] actions )

        {

            this.sep = sep ;

            this.actions = actions ;

        }

        public Object operate( Object value )

        {

            StringTokenizer st = new StringTokenizer( getString( value ),

                sep ) ;

            int numTokens = st.countTokens() ;

            if (numTokens != actions.length)

                throw new Error(

                    "Number of tokens and number of actions do not match" ) ;

            int ctr = 0 ;

            Object[] result = new Object[ numTokens ] ;

            while (st.hasMoreTokens()) {

                Operation act = actions[ctr] ;

                String next = st.nextToken() ;

                result[ctr++] = act.operate( next ) ;

            }

            return result ;

        }

        public String toString() {

            return "sequenceAction(separator=\"" + sep +

                "\",actions=" +

                ObjectUtility.compactObjectToString(actions) + ")" ;

        }

    }

    public static Operation sequenceAction( String sep,

        Operation[] actions )

    {

        return new SequenceAction( sep, actions ) ;

    }

    private static class ComposeAction extends OperationBase

    {

        private Operation op1 ;

        private Operation op2 ;

        ComposeAction( Operation op1, Operation op2 )

        {

            this.op1 = op1 ;

            this.op2 = op2 ;

        }

        public Object operate( Object value )

        {

            return op2.operate( op1.operate( value ) ) ;

        }

        public String toString() {

            return "composition(" + op1 + "," + op2 + ")" ;

        }

    }

    public static Operation compose( Operation op1, Operation op2 )

    {

        return new ComposeAction( op1, op2 ) ;

    }

    private static class MapAction extends OperationBase

    {

        Operation op ;

        MapAction( Operation op )

        {

            this.op = op ;

        }

        public Object operate( Object value )

        {

            Object[] values = (Object[])value ;

            Object[] result = new Object[ values.length ] ;

            for (int ctr=0; ctr<values.length; ctr++ )

                result[ctr] = op.operate( values[ctr] ) ;

            return result ;

        }

        public String toString() {

            return "mapAction(" + op + ")" ;

        }

    }

    public static Operation mapAction( Operation op )

    {

        return new MapAction( op ) ;

    }

    private static class MapSequenceAction extends OperationBase

    {

        private Operation[] op ;

        public MapSequenceAction( Operation[] op )

        {

            this.op = op ;

        }

        // XXX Does this correctly handle array types?  It seems

        // that hetereogeneous arrays work this way, while

        // homogeneous arrays need to use Array.newInstance tricks.

        public Object operate( Object value )

        {

            Object[] values = (Object[])value ;

            Object[] result = new Object[ values.length ] ;