/*
 * @(#)$Id$
 *
 * The Apache Software License, Version 1.1
 *
 *
 * Copyright (c) 2001-2003 The Apache Software Foundation.  All rights
 * reserved.
 *
 * 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 acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Xalan" and "Apache Software Foundation" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache",
 *    nor may "Apache" appear in their name, without prior written
 *    permission of the Apache Software Foundation.
 *
 * 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 THE APACHE SOFTWARE FOUNDATION 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.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation and was
 * originally based on software copyright (c) 2001, Sun
 * Microsystems., http://www.sun.com.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 * @author Jacek Ambroziak
 * @author Santiago Pericas-Geertsen
 * @author Morten Jorgensen
 *
 */

package org.apache.xalan.xsltc.compiler;

import org.apache.bcel.generic.ConstantPoolGen;
import org.apache.bcel.generic.GETFIELD;
import org.apache.bcel.generic.INVOKEINTERFACE;
import org.apache.bcel.generic.INVOKEVIRTUAL;
import org.apache.bcel.generic.PUSH;
import org.apache.bcel.generic.InstructionList;
import org.apache.xalan.xsltc.compiler.util.ClassGenerator;
import org.apache.xalan.xsltc.compiler.util.MethodGenerator;
import org.apache.xalan.xsltc.compiler.util.Type;
import org.apache.xalan.xsltc.compiler.util.TypeCheckError;

final class Comment extends Instruction {

    public void parseContents(Parser parser) {
	parseChildren(parser);
    }

    public Type typeCheck(SymbolTable stable) throws TypeCheckError {
	typeCheckContents(stable);
	return Type.String;
    }

    public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
	final ConstantPoolGen cpg = classGen.getConstantPool();
	final InstructionList il = methodGen.getInstructionList();

        // Shortcut for literal strings
        Text rawText = null;
        if (elementCount() == 1) {
            Object content = elementAt(0);
            if (content instanceof Text) {
                rawText = (Text) content;
            }
        }

        // If the content is literal text, call comment(char[],int,int) or
        // comment(String), as appropriate.  Otherwise, use a
        // StringValueHandler to gather the textual content of the xsl:comment
        // and call comment(String) with the result.
        if (rawText != null) {
            il.append(methodGen.loadHandler());

            if (rawText.canLoadAsArrayOffsetLength()) {
                rawText.loadAsArrayOffsetLength(classGen, methodGen);
                final int comment =
                        cpg.addInterfaceMethodref(TRANSLET_OUTPUT_INTERFACE,
                                                  "comment",
                                                  "([CII)V");
                il.append(new INVOKEINTERFACE(comment, 4));
            } else {
                il.append(new PUSH(cpg, rawText.getText()));
                final int comment =
                        cpg.addInterfaceMethodref(TRANSLET_OUTPUT_INTERFACE,
                                                  "comment",
                                                  "(" + STRING_SIG + ")V");
                il.append(new INVOKEINTERFACE(comment, 2));
            }
        } else {
            // Save the current handler base on the stack
            il.append(methodGen.loadHandler());
            il.append(DUP);             // first arg to "comment" call

            // Get the translet's StringValueHandler
            il.append(classGen.loadTranslet());
            il.append(new GETFIELD(cpg.addFieldref(TRANSLET_CLASS,
                                                   "stringValueHandler",
                                                   STRING_VALUE_HANDLER_SIG)));
            il.append(DUP);
            il.append(methodGen.storeHandler());

            // translate contents with substituted handler
            translateContents(classGen, methodGen);

            // get String out of the handler
            il.append(new INVOKEVIRTUAL(cpg.addMethodref(STRING_VALUE_HANDLER,
                                                         "getValue",
                                                         "()" + STRING_SIG)));
            // call "comment"
            final int comment =
                        cpg.addInterfaceMethodref(TRANSLET_OUTPUT_INTERFACE,
                                                  "comment",
                                                  "(" + STRING_SIG + ")V");
            il.append(new INVOKEINTERFACE(comment, 2));
            // Restore old handler base from stack
            il.append(methodGen.storeHandler());
        }
    }
}