/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the  "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id$
 */

package org.apache.xalan.xsltc.compiler;

import org.apache.bcel.generic.ALOAD;
import org.apache.bcel.generic.ASTORE;
import org.apache.bcel.generic.ConstantPoolGen;
import org.apache.bcel.generic.GETFIELD;
import org.apache.bcel.generic.INVOKEINTERFACE;
import org.apache.bcel.generic.INVOKESTATIC;
import org.apache.bcel.generic.INVOKEVIRTUAL;
import org.apache.bcel.generic.InstructionList;
import org.apache.bcel.generic.LocalVariableGen;
import org.apache.xalan.xsltc.compiler.util.ClassGenerator;
import org.apache.xalan.xsltc.compiler.util.ErrorMsg;
import org.apache.xalan.xsltc.compiler.util.MethodGenerator;
import org.apache.xalan.xsltc.compiler.util.Type;
import org.apache.xalan.xsltc.compiler.util.TypeCheckError;
import org.apache.xalan.xsltc.compiler.util.Util;
import org.apache.xml.utils.XML11Char;

/**
 * @author Jacek Ambroziak
 * @author Santiago Pericas-Geertsen
 */
final class ProcessingInstruction extends Instruction {

    private AttributeValue _name; // name treated as AVT (7.1.3)
    private boolean _isLiteral = false;  // specified name is not AVT  
    
    public void parseContents(Parser parser) {
	final String name  = getAttribute("name");
    
        if (name.length() > 0) {
            _isLiteral = Util.isLiteral(name);
            if (_isLiteral) {
                if (!XML11Char.isXML11ValidNCName(name)) {
                    ErrorMsg err = new ErrorMsg(ErrorMsg.INVALID_NCNAME_ERR, name, this);
                    parser.reportError(Constants.ERROR, err);           
                }
            }   
            _name = AttributeValue.create(this, name, parser);
        }
        else
            reportError(this, parser, ErrorMsg.REQUIRED_ATTR_ERR, "name");
            
	if (name.equals("xml")) {
	    reportError(this, parser, ErrorMsg.ILLEGAL_PI_ERR, "xml");
	}
	parseChildren(parser);
    }

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

    public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
	final ConstantPoolGen cpg = classGen.getConstantPool();
	final InstructionList il = methodGen.getInstructionList();
    
        if (!_isLiteral) {
            // if the ncname is an AVT, then the ncname has to be checked at runtime if it is a valid ncname
            LocalVariableGen nameValue =
                    methodGen.addLocalVariable2("nameValue",
                                                Util.getJCRefType(STRING_SIG),
                                                null);
            
            // store the name into a variable first so _name.translate only needs to be called once  
            _name.translate(classGen, methodGen);
            nameValue.setStart(il.append(new ASTORE(nameValue.getIndex())));
            il.append(new ALOAD(nameValue.getIndex()));
            
            // call checkNCName if the name is an AVT
            final int check = cpg.addMethodref(BASIS_LIBRARY_CLASS, "checkNCName",
                                "("
                                +STRING_SIG
                                +")V");                 
                                il.append(new INVOKESTATIC(check));
            
            // Save the current handler base on the stack
            il.append(methodGen.loadHandler());
            il.append(DUP);     // first arg to "attributes" call            
            
            // load name value again    
            nameValue.setEnd(il.append(new ALOAD(nameValue.getIndex())));            
        } else {    
            // Save the current handler base on the stack
            il.append(methodGen.loadHandler());
            il.append(DUP);     // first arg to "attributes" call
            
            // Push attribute name
            _name.translate(classGen, methodGen);// 2nd arg
        
        }
        
	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,
						     "getValueOfPI",
						     "()" + STRING_SIG)));
	// call "processingInstruction"
	final int processingInstruction =
	    cpg.addInterfaceMethodref(TRANSLET_OUTPUT_INTERFACE,
				      "processingInstruction", 
				      "(" + STRING_SIG + STRING_SIG + ")V");
	il.append(new INVOKEINTERFACE(processingInstruction, 3));
	// Restore old handler base from stack
	il.append(methodGen.storeHandler());
    }
}