/*

 * reserved comment block

 * DO NOT REMOVE OR ALTER!

 */

/*

 * 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.

 */

/*

 * $Id: Parser.java,v 1.2.4.1 2005/09/13 12:14:32 pvedula Exp $

 */

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

import java.io.File;

import java.io.IOException;

import java.io.StringReader;

import java.util.Dictionary;

import java.util.Enumeration;

import java.util.Hashtable;

import java.util.Properties;

import java.util.Stack;

import java.util.StringTokenizer;

import java.util.Vector;

import com.sun.java_cup.internal.runtime.Symbol;

import javax.xml.XMLConstants;

import javax.xml.parsers.ParserConfigurationException;

import javax.xml.parsers.SAXParser;

import javax.xml.parsers.SAXParserFactory;

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

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

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.utils.FactoryImpl;

import com.sun.org.apache.xalan.internal.utils.ObjectFactory;

import org.xml.sax.Attributes;

import org.xml.sax.helpers.AttributesImpl;

import org.xml.sax.ContentHandler;

import org.xml.sax.InputSource;

import org.xml.sax.Locator;

import org.xml.sax.SAXException;

import org.xml.sax.SAXParseException;

import org.xml.sax.XMLReader;

/**

 * @author Jacek Ambroziak

 * @author Santiago Pericas-Geertsen

 * @author G. Todd Miller

 * @author Morten Jorgensen

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

 */

public class Parser implements Constants, ContentHandler {

    private static final String XSL = "xsl";            // standard prefix

    private static final String TRANSLET = "translet"; // extension prefix

    private Locator _locator = null;

    private XSLTC _xsltc;             // Reference to the compiler object.

    private XPathParser _xpathParser; // Reference to the XPath parser.

    private Vector _errors;           // Contains all compilation errors

    private Vector _warnings;         // Contains all compilation errors

    private Hashtable   _instructionClasses; // Maps instructions to classes

    private Hashtable   _instructionAttrs;;  // reqd and opt attrs

    private Hashtable   _qNames;

    private Hashtable   _namespaces;

    private QName       _useAttributeSets;

    private QName       _excludeResultPrefixes;

    private QName       _extensionElementPrefixes;

    private Hashtable   _variableScope;

    private Stylesheet  _currentStylesheet;

    private SymbolTable _symbolTable; // Maps QNames to syntax-tree nodes

    private Output      _output;

    private Template    _template;    // Reference to the template being parsed.

    private boolean     _rootNamespaceDef; // Used for validity check

    private SyntaxTreeNode _root;

    private String _target;

    private int _currentImportPrecedence;

    private boolean _useServicesMechanism = true;

    public Parser(XSLTC xsltc, boolean useServicesMechanism) {

        _xsltc = xsltc;

        _useServicesMechanism = useServicesMechanism;

    }

    public void init() {

        _qNames              = new Hashtable(512);

        _namespaces          = new Hashtable();

        _instructionClasses  = new Hashtable();

        _instructionAttrs    = new Hashtable();

        _variableScope       = new Hashtable();

        _template            = null;

        _errors              = new Vector();

        _warnings            = new Vector();

        _symbolTable         = new SymbolTable();

        _xpathParser         = new XPathParser(this);

        _currentStylesheet   = null;

        _output              = null;

        _root                = null;

        _rootNamespaceDef    = false;

        _currentImportPrecedence = 1;

        initStdClasses();

        initInstructionAttrs();

        initExtClasses();

        initSymbolTable();

        _useAttributeSets =

            getQName(XSLT_URI, XSL, "use-attribute-sets");

        _excludeResultPrefixes =

            getQName(XSLT_URI, XSL, "exclude-result-prefixes");

        _extensionElementPrefixes =

            getQName(XSLT_URI, XSL, "extension-element-prefixes");

    }

    public void setOutput(Output output) {

        if (_output != null) {

            if (_output.getImportPrecedence() <= output.getImportPrecedence()) {

                String cdata = _output.getCdata();

                output.mergeOutput(_output);

                _output.disable();

                _output = output;

            }

            else {

                output.disable();

            }

        }

        else {

            _output = output;

        }

    }

    public Output getOutput() {

        return _output;

    }

    public Properties getOutputProperties() {

        return getTopLevelStylesheet().getOutputProperties();

    }

    public void addVariable(Variable var) {

        addVariableOrParam(var);

    }

    public void addParameter(Param param) {

        addVariableOrParam(param);

    }

    private void addVariableOrParam(VariableBase var) {

        Object existing = _variableScope.get(var.getName());

        if (existing != null) {

            if (existing instanceof Stack) {

                Stack stack = (Stack)existing;

                stack.push(var);

            }

            else if (existing instanceof VariableBase) {

                Stack stack = new Stack();

                stack.push(existing);

                stack.push(var);

                _variableScope.put(var.getName(), stack);

            }

        }

        else {

            _variableScope.put(var.getName(), var);

        }

    }

    public void removeVariable(QName name) {

        Object existing = _variableScope.get(name);

        if (existing instanceof Stack) {

            Stack stack = (Stack)existing;

            if (!stack.isEmpty()) stack.pop();

            if (!stack.isEmpty()) return;

        }

        _variableScope.remove(name);

    }

    public VariableBase lookupVariable(QName name) {

        Object existing = _variableScope.get(name);

        if (existing instanceof VariableBase) {

            return((VariableBase)existing);

        }

        else if (existing instanceof Stack) {

            Stack stack = (Stack)existing;

            return((VariableBase)stack.peek());

        }

        return(null);

    }

    public void setXSLTC(XSLTC xsltc) {

        _xsltc = xsltc;

    }

    public XSLTC getXSLTC() {

        return _xsltc;

    }

    public int getCurrentImportPrecedence() {

        return _currentImportPrecedence;

    }

    public int getNextImportPrecedence() {

        return ++_currentImportPrecedence;

    }

    public void setCurrentStylesheet(Stylesheet stylesheet) {

        _currentStylesheet = stylesheet;

    }

    public Stylesheet getCurrentStylesheet() {

        return _currentStylesheet;

    }

    public Stylesheet getTopLevelStylesheet() {

        return _xsltc.getStylesheet();

    }

    public QName getQNameSafe(final String stringRep) {

        // parse and retrieve namespace

        final int colon = stringRep.lastIndexOf(':');

        if (colon != -1) {

            final String prefix = stringRep.substring(0, colon);

            final String localname = stringRep.substring(colon + 1);

            String namespace = null;

            // Get the namespace uri from the symbol table

            if (prefix.equals(XMLNS_PREFIX) == false) {

                namespace = _symbolTable.lookupNamespace(prefix);

                if (namespace == null) namespace = EMPTYSTRING;

            }

            return getQName(namespace, prefix, localname);

        }

        else {

            final String uri = stringRep.equals(XMLNS_PREFIX) ? null

                : _symbolTable.lookupNamespace(EMPTYSTRING);

            return getQName(uri, null, stringRep);

        }

    }

    public QName getQName(final String stringRep) {

        return getQName(stringRep, true, false);

    }

    public QName getQNameIgnoreDefaultNs(final String stringRep) {

        return getQName(stringRep, true, true);

    }

    public QName getQName(final String stringRep, boolean reportError) {

        return getQName(stringRep, reportError, false);

    }

    private QName getQName(final String stringRep, boolean reportError,

        boolean ignoreDefaultNs)

    {

        // parse and retrieve namespace

        final int colon = stringRep.lastIndexOf(':');

        if (colon != -1) {

            final String prefix = stringRep.substring(0, colon);

            final String localname = stringRep.substring(colon + 1);

            String namespace = null;

            // Get the namespace uri from the symbol table

            if (prefix.equals(XMLNS_PREFIX) == false) {

                namespace = _symbolTable.lookupNamespace(prefix);

                if (namespace == null && reportError) {

                    final int line = getLineNumber();

                    ErrorMsg err = new ErrorMsg(ErrorMsg.NAMESPACE_UNDEF_ERR,

                                                line, prefix);

                    reportError(ERROR, err);

                }

            }

            return getQName(namespace, prefix, localname);

        }

        else {

            if (stringRep.equals(XMLNS_PREFIX)) {

                ignoreDefaultNs = true;

            }

            final String defURI = ignoreDefaultNs ? null

                                  : _symbolTable.lookupNamespace(EMPTYSTRING);

            return getQName(defURI, null, stringRep);

        }

    }

    public QName getQName(String namespace, String prefix, String localname) {

        if (namespace == null || namespace.equals(EMPTYSTRING)) {

            QName name = (QName)_qNames.get(localname);

            if (name == null) {

                name = new QName(null, prefix, localname);

                _qNames.put(localname, name);

            }

            return name;

        }

        else {

            Dictionary space = (Dictionary)_namespaces.get(namespace);

            String lexicalQName =

                       (prefix == null || prefix.length() == 0)

                            ? localname

                            : (prefix + ':' + localname);

            if (space == null) {

                final QName name = new QName(namespace, prefix, localname);

                _namespaces.put(namespace, space = new Hashtable());

                space.put(lexicalQName, name);

                return name;

            }

            else {

                QName name = (QName)space.get(lexicalQName);

                if (name == null) {

                    name = new QName(namespace, prefix, localname);

                    space.put(lexicalQName, name);

                }

                return name;

            }

        }

    }

    public QName getQName(String scope, String name) {

        return getQName(scope + name);

    }

    public QName getQName(QName scope, QName name) {

        return getQName(scope.toString() + name.toString());

    }

    public QName getUseAttributeSets() {

        return _useAttributeSets;

    }

    public QName getExtensionElementPrefixes() {

        return _extensionElementPrefixes;

    }

    public QName getExcludeResultPrefixes() {

        return _excludeResultPrefixes;

    }

    /**

     * Create an instance of the <code>Stylesheet</code> class,

     * and then parse, typecheck and compile the instance.

     * Must be called after <code>parse()</code>.

     */

    public Stylesheet makeStylesheet(SyntaxTreeNode element)

        throws CompilerException {

        try {

            Stylesheet stylesheet;

            if (element instanceof Stylesheet) {

                stylesheet = (Stylesheet)element;

            }

            else {

                stylesheet = new Stylesheet();

                stylesheet.setSimplified();

                stylesheet.addElement(element);

                stylesheet.setAttributes((AttributesImpl) element.getAttributes());

                // Map the default NS if not already defined

                if (element.lookupNamespace(EMPTYSTRING) == null) {

                    element.addPrefixMapping(EMPTYSTRING, EMPTYSTRING);

                }

            }

            stylesheet.setParser(this);

            return stylesheet;

        }

        catch (ClassCastException e) {

            ErrorMsg err = new ErrorMsg(ErrorMsg.NOT_STYLESHEET_ERR, element);

            throw new CompilerException(err.toString());

        }

    }

    /**

     * Instanciates a SAX2 parser and generate the AST from the input.

     */

    public void createAST(Stylesheet stylesheet) {

        try {

            if (stylesheet != null) {

                stylesheet.parseContents(this);

                final int precedence = stylesheet.getImportPrecedence();

                final Enumeration elements = stylesheet.elements();

                while (elements.hasMoreElements()) {

                    Object child = elements.nextElement();

                    if (child instanceof Text) {

                        final int l = getLineNumber();

                        ErrorMsg err =

                            new ErrorMsg(ErrorMsg.ILLEGAL_TEXT_NODE_ERR,l,null);

                        reportError(ERROR, err);

                    }

                }

                if (!errorsFound()) {

                    stylesheet.typeCheck(_symbolTable);

                }

            }

        }

        catch (TypeCheckError e) {

        }

    }

    /**

     * Parses a stylesheet and builds the internal abstract syntax tree

     * @param reader A SAX2 SAXReader (parser)

     * @param input A SAX2 InputSource can be passed to a SAX reader

     * @return The root of the abstract syntax tree

     */

    public SyntaxTreeNode parse(XMLReader reader, InputSource input) {

        try {

            // Parse the input document and build the abstract syntax tree

            reader.setContentHandler(this);

            reader.parse(input);

            // Find the start of the stylesheet within the tree

            return (SyntaxTreeNode)getStylesheet(_root);

        }

        catch (IOException e) {

            if (_xsltc.debug()) e.printStackTrace();

        }

        catch (SAXException e) {

            Throwable ex = e.getException();

            if (_xsltc.debug()) {

                e.printStackTrace();

                if (ex != null) ex.printStackTrace();

            }

        }

        catch (CompilerException e) {

            if (_xsltc.debug()) e.printStackTrace();

        }

        catch (Exception e) {

            if (_xsltc.debug()) e.printStackTrace();

        }

        return null;

    }

    /**

     * Parses a stylesheet and builds the internal abstract syntax tree

     * @param input A SAX2 InputSource can be passed to a SAX reader

     * @return The root of the abstract syntax tree

     */

    public SyntaxTreeNode parse(InputSource input) {

        try {

            // Create a SAX parser and get the XMLReader object it uses

            final SAXParserFactory factory = FactoryImpl.getSAXFactory(_useServicesMechanism);

            if (_xsltc.isSecureProcessing()) {

                try {

                    factory.setFeature(XMLConstants.FEATURE_SECURE_PROCESSING, true);

                }

                catch (SAXException e) {}

            }

            try {

                factory.setFeature(Constants.NAMESPACE_FEATURE,true);

            }

            catch (Exception e) {

                factory.setNamespaceAware(true);

            }

            final SAXParser parser = factory.newSAXParser();

            final XMLReader reader = parser.getXMLReader();

            return(parse(reader, input));

        }

        catch (ParserConfigurationException e) {

            ErrorMsg err = new ErrorMsg(ErrorMsg.SAX_PARSER_CONFIG_ERR);

            reportError(ERROR, err);

        }

        catch (SAXParseException e){

            reportError(ERROR, new ErrorMsg(e.getMessage(),e.getLineNumber()));

        }

        catch (SAXException e) {

            reportError(ERROR, new ErrorMsg(e.getMessage()));

        }

        return null;

    }

    public SyntaxTreeNode getDocumentRoot() {

        return _root;

    }

    private String _PImedia = null;

    private String _PItitle = null;

    private String _PIcharset = null;

    /**

     * Set the parameters to use to locate the correct <?xml-stylesheet ...?>

     * processing instruction in the case where the input document is an

     * XML document with one or more references to a stylesheet.

     * @param media The media attribute to be matched. May be null, in which

     * case the prefered templates will be used (i.e. alternate = no).

     * @param title The value of the title attribute to match. May be null.

     * @param charset The value of the charset attribute to match. May be null.

     */

    protected void setPIParameters(String media, String title, String charset) {

        _PImedia = media;

        _PItitle = title;

        _PIcharset = charset;

    }

    /**

     * Extracts the DOM for the stylesheet. In the case of an embedded

     * stylesheet, it extracts the DOM subtree corresponding to the

     * embedded stylesheet that has an 'id' attribute whose value is the

     * same as the value declared in the <?xml-stylesheet...?> processing

     * instruction (P.I.). In the xml-stylesheet P.I. the value is labeled

     * as the 'href' data of the P.I. The extracted DOM representing the

     * stylesheet is returned as an Element object.

     */