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	/*
	* Copyright (c) 2015, 2017, Oracle and/or its affiliates. All rights reserved.
	*/
	/*
	* 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: Key.java,v 1.6 2006/04/25 02:25:08 jeffsuttor Exp $
	*/

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

	import com.sun.org.apache.bcel.internal.generic.BranchHandle;
	import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen;
	import com.sun.org.apache.bcel.internal.generic.GOTO;
	import com.sun.org.apache.bcel.internal.generic.IFEQ;
	import com.sun.org.apache.bcel.internal.generic.IFGE;
	import com.sun.org.apache.bcel.internal.generic.IFGT;
	import com.sun.org.apache.bcel.internal.generic.ILOAD;
	import com.sun.org.apache.bcel.internal.generic.INVOKEINTERFACE;
	import com.sun.org.apache.bcel.internal.generic.INVOKEVIRTUAL;
	import com.sun.org.apache.bcel.internal.generic.ISTORE;
	import com.sun.org.apache.bcel.internal.generic.InstructionHandle;
	import com.sun.org.apache.bcel.internal.generic.InstructionList;
	import com.sun.org.apache.bcel.internal.generic.LocalVariableGen;
	import com.sun.org.apache.bcel.internal.generic.PUSH;
	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.NodeSetType;
	import com.sun.org.apache.xalan.internal.xsltc.compiler.util.StringType;
	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.dtm.Axis;
	import com.sun.org.apache.xml.internal.utils.XML11Char;

	/**
	* @author Morten Jorgensen
	* @author Santiago Pericas-Geertsen
	* @LastModified: Oct 2017
	*/
	final class Key extends TopLevelElement {

	/**
	* The name of this key as defined in xsl:key.
	*/
	private QName _name;

	/**
	* The pattern to match starting at the root node.
	*/
	private Pattern _match;

	/**
	* The expression that generates the values for this key.
	*/
	private Expression _use;

	/**
	* The type of the _use expression.
	*/
	private Type _useType;

	/**
	* Parse the <xsl:key> element and attributes
	* @param parser A reference to the stylesheet parser
	*/
	public void parseContents(Parser parser) {

	// Get the required attributes and parser XPath expressions
	final String name = getAttribute("name");
	if (!XML11Char.isXML11ValidQName(name)){
	ErrorMsg err = new ErrorMsg(ErrorMsg.INVALID_QNAME_ERR, name, this);
	parser.reportError(Constants.ERROR, err);
	}

	// Parse key name and add to symbol table
	_name = parser.getQNameIgnoreDefaultNs(name);
	getSymbolTable().addKey(_name, this);

	_match = parser.parsePattern(this, "match", null);
	_use = parser.parseExpression(this, "use", null);

	// Make sure required attribute(s) have been set
	if (_name == null) {
	reportError(this, parser, ErrorMsg.REQUIRED_ATTR_ERR, "name");
	return;
	}
	if (_match.isDummy()) {
	reportError(this, parser, ErrorMsg.REQUIRED_ATTR_ERR, "match");
	return;
	}
	if (_use.isDummy()) {
	reportError(this, parser, ErrorMsg.REQUIRED_ATTR_ERR, "use");
	return;
	}
	}

	/**
	* Returns a String-representation of this key's name
	* @return The key's name (from the <xsl:key> elements 'name' attribute).
	*/
	public String getName() {
	return _name.toString();
	}

	public Type typeCheck(SymbolTable stable) throws TypeCheckError {
	// Type check match pattern
	_match.typeCheck(stable);

	// Cast node values to string values (except for nodesets)
	_useType = _use.typeCheck(stable);
	if (_useType instanceof StringType == false &&
	_useType instanceof NodeSetType == false)
	{
	_use = new CastExpr(_use, Type.String);
	}

	return Type.Void;
	}

	/**
	* This method is called if the "use" attribute of the key contains a
	* node set. In this case we must traverse all nodes in the set and
	* create one entry in this key's index for each node in the set.
	*/
	public void traverseNodeSet(ClassGenerator classGen,
	MethodGenerator methodGen,
	int buildKeyIndex) {
	final ConstantPoolGen cpg = classGen.getConstantPool();
	final InstructionList il = methodGen.getInstructionList();

	// DOM.getStringValueX(nodeIndex) => String
	final int getNodeValue = cpg.addInterfaceMethodref(DOM_INTF,
	GET_NODE_VALUE,
	"(I)"+STRING_SIG);

	final int getNodeIdent = cpg.addInterfaceMethodref(DOM_INTF,
	"getNodeIdent",
	"(I)"+NODE_SIG);

	// AbstractTranslet.SetKeyIndexDom(name, Dom) => void
	final int keyDom = cpg.addMethodref(TRANSLET_CLASS,
	"setKeyIndexDom",
	"("+STRING_SIG+DOM_INTF_SIG+")V");


	// This variable holds the id of the node we found with the "match"
	// attribute of xsl:key. This is the id we store, with the value we
	// get from the nodes we find here, in the index for this key.
	final LocalVariableGen parentNode =
	methodGen.addLocalVariable("parentNode",
	Util.getJCRefType("I"),
	null, null);

	// Get the 'parameter' from the stack and store it in a local var.
	parentNode.setStart(il.append(new ISTORE(parentNode.getIndex())));

	// Save current node and current iterator on the stack
	il.append(methodGen.loadCurrentNode());
	il.append(methodGen.loadIterator());

	// Overwrite current iterator with one that gives us only what we want
	_use.translate(classGen, methodGen);
	_use.startIterator(classGen, methodGen);
	il.append(methodGen.storeIterator());

	final BranchHandle nextNode = il.append(new GOTO(null));
	final InstructionHandle loop = il.append(NOP);

	// Prepare to call buildKeyIndex(String name, int node, String value);
	il.append(classGen.loadTranslet());
	il.append(new PUSH(cpg, _name.toString()));
	parentNode.setEnd(il.append(new ILOAD(parentNode.getIndex())));

	// Now get the node value and push it on the parameter stack
	il.append(methodGen.loadDOM());
	il.append(methodGen.loadCurrentNode());
	il.append(new INVOKEINTERFACE(getNodeValue, 2));

	// Finally do the call to add an entry in the index for this key.
	il.append(new INVOKEVIRTUAL(buildKeyIndex));

	il.append(classGen.loadTranslet());
	il.append(new PUSH(cpg, getName()));
	il.append(methodGen.loadDOM());
	il.append(new INVOKEVIRTUAL(keyDom));

	nextNode.setTarget(il.append(methodGen.loadIterator()));
	il.append(methodGen.nextNode());

	il.append(DUP);
	il.append(methodGen.storeCurrentNode());
	il.append(new IFGE(loop)); // Go on to next matching node....

	// Restore current node and current iterator from the stack
	il.append(methodGen.storeIterator());
	il.append(methodGen.storeCurrentNode());
	}

	/**
	* Gather all nodes that match the expression in the attribute "match"
	* and add one (or more) entries in this key's index.
	*/
	public void translate(ClassGenerator classGen, MethodGenerator methodGen) {

	final ConstantPoolGen cpg = classGen.getConstantPool();
	final InstructionList il = methodGen.getInstructionList();
	final int current = methodGen.getLocalIndex("current");

	// AbstractTranslet.buildKeyIndex(name,node_id,value) => void
	final int key = cpg.addMethodref(TRANSLET_CLASS,
	"buildKeyIndex",
	"("+STRING_SIG+"I"+STRING_SIG+")V");

	// AbstractTranslet.SetKeyIndexDom(name, Dom) => void
	final int keyDom = cpg.addMethodref(TRANSLET_CLASS,
	"setKeyIndexDom",
	"("+STRING_SIG+DOM_INTF_SIG+")V");

	final int getNodeIdent = cpg.addInterfaceMethodref(DOM_INTF,
	"getNodeIdent",
	"(I)"+NODE_SIG);

	// DOM.getAxisIterator(root) => NodeIterator
	final int git = cpg.addInterfaceMethodref(DOM_INTF,
	"getAxisIterator",
	"(I)"+NODE_ITERATOR_SIG);

	il.append(methodGen.loadCurrentNode());
	il.append(methodGen.loadIterator());

	// Get an iterator for all nodes in the DOM
	il.append(methodGen.loadDOM());
	il.append(new PUSH(cpg,Axis.DESCENDANT));
	il.append(new INVOKEINTERFACE(git, 2));

	// Reset the iterator to start with the root node
	il.append(methodGen.loadCurrentNode());
	il.append(methodGen.setStartNode());
	il.append(methodGen.storeIterator());

	// Loop for traversing all nodes in the DOM
	final BranchHandle nextNode = il.append(new GOTO(null));
	final InstructionHandle loop = il.append(NOP);

	// Check if the current node matches the pattern in "match"
	il.append(methodGen.loadCurrentNode());
	_match.translate(classGen, methodGen);
	_match.synthesize(classGen, methodGen); // Leaves 0 or 1 on stack
	final BranchHandle skipNode = il.append(new IFEQ(null));

	// If this is a node-set we must go through each node in the set
	if (_useType instanceof NodeSetType) {
	// Pass current node as parameter (we're indexing on that node)
	il.append(methodGen.loadCurrentNode());
	traverseNodeSet(classGen, methodGen, key);
	}
	else {
	il.append(classGen.loadTranslet());
	il.append(DUP);
	il.append(new PUSH(cpg, _name.toString()));
	il.append(DUP_X1);
	il.append(methodGen.loadCurrentNode());
	_use.translate(classGen, methodGen);
	il.append(new INVOKEVIRTUAL(key));

	il.append(methodGen.loadDOM());
	il.append(new INVOKEVIRTUAL(keyDom));
	}

	// Get the next node from the iterator and do loop again...
	final InstructionHandle skip = il.append(NOP);

	il.append(methodGen.loadIterator());
	il.append(methodGen.nextNode());
	il.append(DUP);
	il.append(methodGen.storeCurrentNode());
	il.append(new IFGT(loop));

	// Restore current node and current iterator from the stack
	il.append(methodGen.storeIterator());
	il.append(methodGen.storeCurrentNode());

	nextNode.setTarget(skip);
	skipNode.setTarget(skip);
	}
	}

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