/*

 */

/*

 * Copyright 2001-2004 The Apache Software Foundation.

 *

 * Licensed 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.

 */

package com.sun.org.apache.xalan.internal.xsltc.compiler;

import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen;

import com.sun.org.apache.bcel.internal.generic.INVOKEVIRTUAL;

import com.sun.org.apache.bcel.internal.generic.InstructionList;

import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ClassGenerator;

import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ErrorMsg;

import com.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodGenerator;

import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type;

import com.sun.org.apache.xalan.internal.xsltc.compiler.util.TypeCheckError;

import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Util;

import com.sun.org.apache.xml.internal.utils.XML11Char;

import java.util.Vector;

/**

 * @author Jacek Ambroziak

 * @author Santiago Pericas-Geertsen

 * @author Erwin Bolwidt <ejb@klomp.org>

 */

final class CallTemplate extends Instruction {

    /**

     * Name of template to call.

     */

    private QName _name;

    /**

     * The array of effective parameters in this CallTemplate. An object in

     * this array can be either a WithParam or a Param if no WithParam

     * exists for a particular parameter.

     */

    /**

     * The corresponding template which this CallTemplate calls.

     */

    private Template _calleeTemplate = null;

    public void display(int indent) {

        indent(indent);

        System.out.print("CallTemplate");

        Util.println(" name " + _name);

        displayContents(indent + IndentIncrement);

    }

    public boolean hasWithParams() {

        return elementCount() > 0;

    }

    public void parseContents(Parser parser) {

        final String name = getAttribute("name");

        if (name.length() > 0) {

            if (!XML11Char.isXML11ValidQName(name)) {

                ErrorMsg err = new ErrorMsg(ErrorMsg.INVALID_QNAME_ERR, name, this);

                parser.reportError(Constants.ERROR, err);

            }

            _name = parser.getQNameIgnoreDefaultNs(name);

        }

        else {

            reportError(this, parser, ErrorMsg.REQUIRED_ATTR_ERR, "name");

        }

        parseChildren(parser);

    }

    /**

     * Verify that a template with this name exists.

     */

    public Type typeCheck(SymbolTable stable) throws TypeCheckError {

        final Template template = stable.lookupTemplate(_name);

        if (template != null) {

            typeCheckContents(stable);

        }

        else {

            ErrorMsg err = new ErrorMsg(ErrorMsg.TEMPLATE_UNDEF_ERR,_name,this);

            throw new TypeCheckError(err);

        }

        return Type.Void;

    }

    public void translate(ClassGenerator classGen, MethodGenerator methodGen) {

        final Stylesheet stylesheet = classGen.getStylesheet();

        final ConstantPoolGen cpg = classGen.getConstantPool();

        final InstructionList il = methodGen.getInstructionList();

        // If there are Params in the stylesheet or WithParams in this call?

        if (stylesheet.hasLocalParams() || hasContents()) {

            _calleeTemplate = getCalleeTemplate();

            // Build the parameter list if the called template is simple named

            if (_calleeTemplate != null) {

                buildParameterList();

            }

            // This is only needed when the called template is not

            // a simple named template.

            else {

                // Push parameter frame

                final int push = cpg.addMethodref(TRANSLET_CLASS,

                                                  PUSH_PARAM_FRAME,

                                                  PUSH_PARAM_FRAME_SIG);

                il.append(classGen.loadTranslet());

                il.append(new INVOKEVIRTUAL(push));

                translateContents(classGen, methodGen);

            }

        }

        // Generate a valid Java method name

        final String className = stylesheet.getClassName();

        String methodName = Util.escape(_name.toString());

        // Load standard arguments

        il.append(classGen.loadTranslet());

        il.append(methodGen.loadDOM());

        il.append(methodGen.loadIterator());

        il.append(methodGen.loadHandler());

        il.append(methodGen.loadCurrentNode());

        // Initialize prefix of method signature

        StringBuffer methodSig = new StringBuffer("(" + DOM_INTF_SIG

            + NODE_ITERATOR_SIG + TRANSLET_OUTPUT_SIG + NODE_SIG);

        // If calling a simply named template, push actual arguments

        if (_calleeTemplate != null) {

            int numParams = _parameters.length;

            for (int i = 0; i < numParams; i++) {

                methodSig.append(OBJECT_SIG);   // append Object to signature

                // Push 'null' if Param to indicate no actual parameter specified

                if (node instanceof Param) {

                    il.append(ACONST_NULL);

                }

                else {  // translate WithParam

                    node.translate(classGen, methodGen);

                }

            }

        }

        // Complete signature and generate invokevirtual call

        methodSig.append(")V");

        il.append(new INVOKEVIRTUAL(cpg.addMethodref(className,

                                                     methodName,

                                                     methodSig.toString())));

        // Do not need to call Translet.popParamFrame() if we are

        // calling a simple named template.

        if (_calleeTemplate == null && (stylesheet.hasLocalParams() || hasContents())) {

            // Pop parameter frame

            final int pop = cpg.addMethodref(TRANSLET_CLASS,

                                             POP_PARAM_FRAME,

                                             POP_PARAM_FRAME_SIG);

            il.append(classGen.loadTranslet());

            il.append(new INVOKEVIRTUAL(pop));

        }

    }

    /**

     * Return the simple named template which this CallTemplate calls.

     * Return false if there is no matched template or the matched

     * template is not a simple named template.

     */

    public Template getCalleeTemplate() {

        Template foundTemplate

            = getXSLTC().getParser().getSymbolTable().lookupTemplate(_name);

        return foundTemplate.isSimpleNamedTemplate() ? foundTemplate : null;

    }

    /**

     * Build the list of effective parameters in this CallTemplate.

     * The parameters of the called template are put into the array first.

     * Then we visit the WithParam children of this CallTemplate and replace

     * the Param with a corresponding WithParam having the same name.

     */

    private void buildParameterList() {

        // Put the parameters from the called template into the array first.

        // This is to ensure the order of the parameters.

        int numParams = defaultParams.size();

        for (int i = 0; i < numParams; i++) {

            _parameters[i] = defaultParams.elementAt(i);

        }

        // Replace a Param with a WithParam if they have the same name.

        int count = elementCount();

        for (int i = 0; i < count; i++) {

            Object node = elementAt(i);

            // Ignore if not WithParam

            if (node instanceof WithParam) {

                WithParam withParam = (WithParam)node;

                QName name = withParam.getName();

                // Search for a Param with the same name

                for (int k = 0; k < numParams; k++) {

                        withParam.setDoParameterOptimization(true);

                        _parameters[k] = withParam;

                        break;

                    }

                        withParam.setDoParameterOptimization(true);

                        _parameters[k] = withParam;

                        break;

                    }

                }

            }

        }

     }

}