/*
 * 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.
 */
package org.apache.jasper.compiler;

import java.io.CharArrayWriter;
import java.io.FileNotFoundException;
import java.net.URL;
import java.util.Iterator;
import java.util.List;

import javax.servlet.jsp.tagext.TagAttributeInfo;
import javax.servlet.jsp.tagext.TagFileInfo;
import javax.servlet.jsp.tagext.TagInfo;
import javax.servlet.jsp.tagext.TagLibraryInfo;

import org.apache.jasper.Constants;
import org.apache.jasper.JasperException;
import org.apache.jasper.JspCompilationContext;
import org.xml.sax.Attributes;
import org.xml.sax.helpers.AttributesImpl;

/**
 * This class implements a parser for a JSP page (non-xml view).
 * JSP page grammar is included here for reference.  The token '#'
 * that appears in the production indicates the current input token
 * location in the production.
 * 
 * @author Kin-man Chung
 * @author Shawn Bayern
 * @author Mark Roth
 */

class Parser implements TagConstants {

    private ParserController parserController;
    private JspCompilationContext ctxt;
    private JspReader reader;
    private String currentFile;
    private Mark start;
    private ErrorDispatcher err;
    private int scriptlessCount;
    private boolean isTagFile;
    private boolean directivesOnly;
    private URL jarFileUrl;
    private PageInfo pageInfo;

    // Virtual body content types, to make parsing a little easier.
    // These are not accessible from outside the parser.
    private static final String JAVAX_BODY_CONTENT_PARAM = 
        "JAVAX_BODY_CONTENT_PARAM";
    private static final String JAVAX_BODY_CONTENT_PLUGIN = 
        "JAVAX_BODY_CONTENT_PLUGIN";
    private static final String JAVAX_BODY_CONTENT_TEMPLATE_TEXT = 
        "JAVAX_BODY_CONTENT_TEMPLATE_TEXT";

    /**
     * The constructor
     */
    private Parser(ParserController pc, JspReader reader, boolean isTagFile,
                   boolean directivesOnly, URL jarFileUrl) {
        this.parserController = pc;
        this.ctxt = pc.getJspCompilationContext();
        this.pageInfo = pc.getCompiler().getPageInfo();
        this.err = pc.getCompiler().getErrorDispatcher();
        this.reader = reader;
        this.currentFile = reader.mark().getFile();
        this.scriptlessCount = 0;
        this.isTagFile = isTagFile;
        this.directivesOnly = directivesOnly;
        this.jarFileUrl = jarFileUrl;
        start = reader.mark();
    }

    /**
     * The main entry for Parser
     * 
     * @param pc The ParseController, use for getting other objects in compiler
     *                 and for parsing included pages
     * @param reader To read the page
     * @param parent The parent node to this page, null for top level page
     * @return list of nodes representing the parsed page
     */
    public static Node.Nodes parse(ParserController pc,
                                   JspReader reader,
                                   Node parent,
                                   boolean isTagFile,
                                   boolean directivesOnly,
                                   URL jarFileUrl,
                                   String pageEnc,
                                   String jspConfigPageEnc,
                                   boolean isDefaultPageEncoding)
                throws JasperException {

        Parser parser = new Parser(pc, reader, isTagFile, directivesOnly,
                                   jarFileUrl);

        Node.Root root = new Node.Root(reader.mark(), parent, false);
        root.setPageEncoding(pageEnc);
        root.setJspConfigPageEncoding(jspConfigPageEnc);
        root.setIsDefaultPageEncoding(isDefaultPageEncoding);

        if (directivesOnly) {
            parser.parseTagFileDirectives(root);
            return new Node.Nodes(root);
        }

        // For the Top level page, add inlcude-prelude and include-coda
        PageInfo pageInfo = pc.getCompiler().getPageInfo();
        if (parent == null) {
            parser.addInclude(root, pageInfo.getIncludePrelude());
        }
        while (reader.hasMoreInput()) {
            parser.parseElements(root);
        }
        if (parent == null) {
            parser.addInclude(root, pageInfo.getIncludeCoda());
        }

        Node.Nodes page = new Node.Nodes(root);
        return page;
    }

    /**
     * Attributes ::= (S Attribute)* S?
     */
    Attributes parseAttributes() throws JasperException {
        AttributesImpl attrs = new AttributesImpl();

        reader.skipSpaces();
        while (parseAttribute(attrs))
            reader.skipSpaces();

        return attrs;
    }

    /**
     * Parse Attributes for a reader, provided for external use
     */
    public static Attributes parseAttributes(ParserController pc,
                                             JspReader reader)
                throws JasperException {
        Parser tmpParser = new Parser(pc, reader, false, false, null);
        return tmpParser.parseAttributes();
    }

    /**
     * Attribute ::= Name S? Eq S?
     *               (   '"<%=' RTAttributeValueDouble
     *                 | '"' AttributeValueDouble
     *                 | "'<%=" RTAttributeValueSingle
     *                 | "'" AttributeValueSingle
     *               }
     * Note: JSP and XML spec does not allow while spaces around Eq.  It is
     * added to be backward compatible with Tomcat, and with other xml parsers.
     */
    private boolean parseAttribute(AttributesImpl attrs)
                throws JasperException {

        // Get the qualified name
        String qName = parseName();
        if (qName == null)
            return false;

        // Determine prefix and local name components
        String localName = qName;
        String uri = "";
        int index = qName.indexOf(':');
        if (index != -1) {
            String prefix = qName.substring(0, index);
            uri = pageInfo.getURI(prefix);
            if (uri == null) {
                err.jspError(reader.mark(),
                             "jsp.error.attribute.invalidPrefix", prefix);
            }
            localName = qName.substring(index+1);
        }

         reader.skipSpaces();
        if (!reader.matches("="))
            err.jspError(reader.mark(), "jsp.error.attribute.noequal");

         reader.skipSpaces();
        char quote = (char) reader.nextChar();
        if (quote != '\'' && quote != '"')
            err.jspError(reader.mark(), "jsp.error.attribute.noquote");

         String watchString = "";
        if (reader.matches("<%="))
            watchString = "%>";
        watchString = watchString + quote;
        
        String attrValue = parseAttributeValue(watchString);
        attrs.addAttribute(uri, localName, qName, "CDATA", attrValue);
        return true;
    }

    /**
     * Name ::= (Letter | '_' | ':') (Letter | Digit | '.' | '_' | '-' | ':')*
     */
    private String parseName() throws JasperException {
        char ch = (char)reader.peekChar();
        if (Character.isLetter(ch) || ch == '_' || ch == ':') {
            StringBuffer buf = new StringBuffer();
            buf.append(ch);
            reader.nextChar();
            ch = (char)reader.peekChar();
            while (Character.isLetter(ch) || Character.isDigit(ch) ||
                        ch == '.' || ch == '_' || ch == '-' || ch == ':') {
                buf.append(ch);
                reader.nextChar();
                ch = (char) reader.peekChar();
            }
            return buf.toString();
        }
        return null;
    }

    /**
     * AttributeValueDouble ::= (QuotedChar - '"')*
     *                                ('"' | <TRANSLATION_ERROR>)
     * RTAttributeValueDouble ::= ((QuotedChar - '"')* - ((QuotedChar-'"')'%>"')
     *                                  ('%>"' | TRANSLATION_ERROR)
     */
    private String parseAttributeValue(String watch) throws JasperException {
        Mark start = reader.mark();
        Mark stop = reader.skipUntilIgnoreEsc(watch);
        if (stop == null) {
            err.jspError(start, "jsp.error.attribute.unterminated", watch);
        }

        String ret = parseQuoted(reader.getText(start, stop));
        if (watch.length() == 1)        // quote
            return ret;

        // putback delimiter '<%=' and '%>', since they are needed if the
        // attribute does not allow RTexpression.
        return "<%=" + ret + "%>";
    }

    /**
     * QuotedChar ::=   '&apos;'
     *                      | '&quot;'
     *                | '\\'
     *                | '\"'
     *                | "\'"
     *                | '\>'
     *                | '\$'
     *                | Char
     */
    private String parseQuoted(String tx) {
        StringBuffer buf = new StringBuffer();
        int size = tx.length();
        int i = 0;
        while (i < size) {
            char ch = tx.charAt(i);
            if (ch == '&') {
                if (i+5 < size && tx.charAt(i+1) == 'a'
                        && tx.charAt(i+2) == 'p' && tx.charAt(i+3) == 'o'
                        && tx.charAt(i+4) == 's' && tx.charAt(i+5) == ';') {
                    buf.append('\'');
                    i += 6;
                } else if (i+5 < size && tx.charAt(i+1) == 'q'
                           && tx.charAt(i+2) == 'u' && tx.charAt(i+3) == 'o'
                           && tx.charAt(i+4) == 't' && tx.charAt(i+5) == ';') {
                    buf.append('"');
                    i += 6;
                } else {
                    buf.append(ch);
                    ++i;
                }
            } else if (ch == '\\' && i+1 < size) {
                ch = tx.charAt(i+1);
                if (ch == '\\' || ch == '\"' || ch == '\'' || ch == '>') {
                    buf.append(ch);
                    i += 2;
                } else if (ch == '$') {
                    // Replace "\$" with some special char.  XXX hack!
                    buf.append(Constants.HACK_CHAR);
                    i += 2;
                } else {
                    buf.append('\\');
                    ++i;
                }
            } else {
                buf.append(ch);
                ++i;
            }
        }
        return buf.toString();
    }

    private String parseScriptText(String tx) {
        CharArrayWriter cw = new CharArrayWriter();
        int size = tx.length();
        int i = 0;
        while (i < size) {
            char ch = tx.charAt(i);
            if (i+2 < size && ch == '%' && tx.charAt(i+1) == '\\'
                    && tx.charAt(i+2) == '>') {
                cw.write('%');
                cw.write('>');
                i += 3;
            } else {
                cw.write(ch);
                ++i;
            }
        }
        cw.close();
        return cw.toString();
    }

    /*
     * Invokes parserController to parse the included page
     */
    private void processIncludeDirective(String file, Node parent) 
                throws JasperException {
        if (file == null) {
            return;
        }

        try {
            parserController.parse(file, parent, jarFileUrl);
        } catch (FileNotFoundException ex) {
            err.jspError(start, "jsp.error.file.not.found", file);
        } catch (Exception ex) {
            err.jspError(start, ex.getMessage());
        }
    }

    /*
     * Parses a page directive with the following syntax:
     *   PageDirective ::= ( S Attribute)*
     */
    private void parsePageDirective(Node parent) throws JasperException {
        Attributes attrs = parseAttributes();
        Node.PageDirective n = new Node.PageDirective(attrs, start, parent);

        /*
         * A page directive may contain multiple 'import' attributes, each of
         * which consists of a comma-separated list of package names.
         * Store each list with the node, where it is parsed.
         */
        for (int i = 0; i < attrs.getLength(); i++) {
            if ("import".equals(attrs.getQName(i))) {
                n.addImport(attrs.getValue(i));
            }
        }
    }

    /*
     * Parses an include directive with the following syntax:
     *   IncludeDirective ::= ( S Attribute)*
     */
    private void parseIncludeDirective(Node parent) throws JasperException {
        Attributes attrs = parseAttributes();

        // Included file expanded here
        Node includeNode = new Node.IncludeDirective(attrs, start, parent);
        processIncludeDirective(attrs.getValue("file"), includeNode);
    }

    /**
     * Add a list of files.  This is used for implementing include-prelude
     * and include-coda of jsp-config element in web.xml
     */
    private void addInclude(Node parent, List files) throws JasperException {
        if( files != null ) {
            Iterator iter = files.iterator();
            while (iter.hasNext()) {
                String file = (String) iter.next();
                AttributesImpl attrs = new AttributesImpl();
                attrs.addAttribute("", "file", "file", "CDATA", file);

                // Create a dummy Include directive node
                Node includeNode = new Node.IncludeDirective(attrs, 
                    reader.mark(), parent);
                processIncludeDirective(file, includeNode);
            }
        }
    }

    /*
     * Parses a taglib directive with the following syntax:
     *   Directive ::= ( S Attribute)*
     */
    private void parseTaglibDirective(Node parent) throws JasperException {

        Attributes attrs = parseAttributes();
        String uri = attrs.getValue("uri");
        String prefix = attrs.getValue("prefix");
        if (prefix != null) {
            Mark prevMark = pageInfo.getNonCustomTagPrefix(prefix);
            if (prevMark != null) {
                err.jspError(reader.mark(), "jsp.error.prefix.use_before_dcl",
                    prefix, prevMark.getFile(), "" + prevMark.getLineNumber());
            }
            if (uri != null) {
                String uriPrev = pageInfo.getURI(prefix);
                if (uriPrev != null && !uriPrev.equals(uri)) {
                    err.jspError(reader.mark(), "jsp.error.prefix.refined",
                        prefix, uri, uriPrev);
                }
                if (pageInfo.getTaglib(uri) == null) {
            TagLibraryInfoImpl impl = null;
            if (ctxt.getOptions().isCaching()) {
                impl = (TagLibraryInfoImpl) ctxt.getOptions().getCache().get(uri);
            }
            if (impl == null) {
                String[] location = ctxt.getTldLocation(uri);
                impl = new TagLibraryInfoImpl(ctxt,
                        parserController,
                        prefix,
                        uri,
                        location,
                        err);
                if (ctxt.getOptions().isCaching()) {
                    ctxt.getOptions().getCache().put(uri, impl);
                }
            }
                    pageInfo.addTaglib(uri, impl);
                }
                pageInfo.addPrefixMapping(prefix, uri);
            } else {
                String tagdir = attrs.getValue("tagdir");
                if (tagdir != null) {
                    String urnTagdir = URN_JSPTAGDIR + tagdir;
                    if (pageInfo.getTaglib(urnTagdir) == null) {
                        pageInfo.addTaglib(urnTagdir,
                                           new ImplicitTagLibraryInfo(
                                                   ctxt,
                                                   parserController,
                                                   prefix, 
                                                   tagdir,
                                                   err));
                    }
                    pageInfo.addPrefixMapping(prefix, urnTagdir);
                }
            }
        }

        new Node.TaglibDirective(attrs, start, parent);
    }

    /*
     * Parses a directive with the following syntax:
     *   Directive ::= S? (   'page' PageDirective
     *                            | 'include' IncludeDirective
     *                            | 'taglib' TagLibDirective)
     *                       S? '%>'
     *
     *   TagDirective ::= S? ('tag' PageDirective
     *                            | 'include' IncludeDirective
     *                            | 'taglib' TagLibDirective)
     *                      | 'attribute AttributeDirective
     *                      | 'variable VariableDirective
     *                       S? '%>'
     */
    private void parseDirective(Node parent) throws JasperException {
        reader.skipSpaces();

        String directive = null;
        if (reader.matches("page")) {
            directive = "&lt;%@ page";
            if (isTagFile) {
                err.jspError(reader.mark(), "jsp.error.directive.istagfile",
                                            directive);
            }
            parsePageDirective(parent);
        } else if (reader.matches("include")) {
            directive = "&lt;%@ include";
            parseIncludeDirective(parent);
        } else if (reader.matches("taglib")) {
            if (directivesOnly) {
                // No need to get the tagLibInfo objects.  This alos suppresses
                // parsing of any tag files used in this tag file.
                return;
            }
            directive = "&lt;%@ taglib";
            parseTaglibDirective(parent);
        } else if (reader.matches("tag")) {
            directive = "&lt;%@ tag";
            if (!isTagFile) {
                err.jspError(reader.mark(), "jsp.error.directive.isnottagfile",
                                            directive);
            }
            parseTagDirective(parent);
        } else if (reader.matches("attribute")) {
            directive = "&lt;%@ attribute";
            if (!isTagFile) {
                err.jspError(reader.mark(), "jsp.error.directive.isnottagfile",
                                            directive);
            }
            parseAttributeDirective(parent);
        } else if (reader.matches("variable")) {
            directive = "&lt;%@ variable";
            if (!isTagFile) {
                err.jspError(reader.mark(), "jsp.error.directive.isnottagfile",
                                            directive);
            }
            parseVariableDirective(parent);
        } else {
            err.jspError(reader.mark(), "jsp.error.invalid.directive");
        }

        reader.skipSpaces();
        if (!reader.matches("%>")) {
            err.jspError(start, "jsp.error.unterminated", directive);
        }
    }
        
    /*
     * Parses a directive with the following syntax:
     *
     *   XMLJSPDirectiveBody ::= S? (   ( 'page' PageDirectiveAttrList
     *                                    S? ( '/>' | ( '>' S? ETag ) )
     *                               | ( 'include' IncludeDirectiveAttrList
     *                                    S? ( '/>' | ( '>' S? ETag ) )
     *                           | <TRANSLATION_ERROR>
     *
     *   XMLTagDefDirectiveBody ::= (   ( 'tag' TagDirectiveAttrList
     *                                    S? ( '/>' | ( '>' S? ETag ) )
     *                                | ( 'include' IncludeDirectiveAttrList
     *                                    S? ( '/>' | ( '>' S? ETag ) )
     *                                | ( 'attribute' AttributeDirectiveAttrList
     *                                    S? ( '/>' | ( '>' S? ETag ) )
     *                                | ( 'variable' VariableDirectiveAttrList
     *                                    S? ( '/>' | ( '>' S? ETag ) )
     *                              )
     *                            | <TRANSLATION_ERROR>
     */
    private void parseXMLDirective(Node parent) throws JasperException {
       reader.skipSpaces();

        String eTag = null;
       if (reader.matches("page")) {
            eTag = "jsp:directive.page";
           if (isTagFile) {
               err.jspError(reader.mark(), "jsp.error.directive.istagfile",
                                           "&lt;" + eTag);
           }
           parsePageDirective(parent);
       } else if (reader.matches("include")) {
            eTag = "jsp:directive.include";
           parseIncludeDirective(parent);
       } else if (reader.matches("tag")) {
            eTag = "jsp:directive.tag";
           if (!isTagFile) {
               err.jspError(reader.mark(), "jsp.error.directive.isnottagfile",
                                           "&lt;" + eTag);
           }
           parseTagDirective(parent);
       } else if (reader.matches("attribute")) {
            eTag = "jsp:directive.attribute";
           if (!isTagFile) {
               err.jspError(reader.mark(), "jsp.error.directive.isnottagfile",
                                           "&lt;" + eTag);
           }
           parseAttributeDirective(parent);
       } else if (reader.matches("variable")) {
            eTag = "jsp:directive.variable";
           if (!isTagFile) {
               err.jspError(reader.mark(), "jsp.error.directive.isnottagfile",
                                           "&lt;" + eTag);
           }
           parseVariableDirective(parent);
       } else {
           err.jspError(reader.mark(), "jsp.error.invalid.directive");
       }

       reader.skipSpaces();
        if( reader.matches( ">" ) ) {
            reader.skipSpaces();
            if( !reader.matchesETag( eTag ) ) {
                err.jspError(start, "jsp.error.unterminated", "&lt;" + eTag );
            }
        }
        else if( !reader.matches( "/>" ) ) {
            err.jspError(start, "jsp.error.unterminated", "&lt;" + eTag );
        }
    }

    /*
     * Parses a tag directive with the following syntax:
     *   PageDirective ::= ( S Attribute)*
     */
    private void parseTagDirective(Node parent) throws JasperException {
        Attributes attrs = parseAttributes();
        Node.TagDirective n = new Node.TagDirective(attrs, start, parent);

        /*
         * A page directive may contain multiple 'import' attributes, each of
         * which consists of a comma-separated list of package names.
         * Store each list with the node, where it is parsed.
         */
        for (int i = 0; i < attrs.getLength(); i++) {
            if ("import".equals(attrs.getQName(i))) {
                n.addImport(attrs.getValue(i));
            }
        }
    }

    /*
     * Parses a attribute directive with the following syntax:
     *   AttributeDirective ::= ( S Attribute)*
     */
    private void parseAttributeDirective(Node parent) throws JasperException {
        Attributes attrs = parseAttributes();
        Node.AttributeDirective n =
                new Node.AttributeDirective(attrs, start, parent);
    }

    /*
     * Parses a variable directive with the following syntax:
     *   PageDirective ::= ( S Attribute)*
     */
    private void parseVariableDirective(Node parent) throws JasperException {
        Attributes attrs = parseAttributes();
        Node.VariableDirective n =
                new Node.VariableDirective(attrs, start, parent);
    }

    /*
     * JSPCommentBody ::= (Char* - (Char* '--%>')) '--%>'
     */
    private void parseComment(Node parent) throws JasperException {        
        start = reader.mark();
        Mark stop = reader.skipUntil("--%>");
        if (stop == null) {
            err.jspError(start, "jsp.error.unterminated", "&lt;%--");
        }

        new Node.Comment(reader.getText(start, stop), start, parent);
    }

    /*
     * DeclarationBody ::= (Char* - (char* '%>')) '%>'
     */
    private void parseDeclaration(Node parent) throws JasperException {
        start = reader.mark();
        Mark stop = reader.skipUntil("%>");
        if (stop == null) {
            err.jspError(start, "jsp.error.unterminated", "&lt;%!");
        }

        new Node.Declaration(parseScriptText(reader.getText(start, stop)),
                             start, parent);
    }

    /*
     * XMLDeclarationBody ::=   ( S? '/>' )
     *                        | ( S? '>' (Char* - (char* '<')) CDSect?)* ETag
     *                        | <TRANSLATION_ERROR>
     * CDSect ::= CDStart CData CDEnd
     * CDStart ::= '<![CDATA['
     * CData ::= (Char* - (Char* ']]>' Char*))
     * CDEnd ::= ']]>'
     */
    private void parseXMLDeclaration(Node parent) throws JasperException {
        reader.skipSpaces();
        if( !reader.matches( "/>" ) ) {
            if( !reader.matches( ">" ) ) {
                err.jspError(start, "jsp.error.unterminated",
                        "&lt;jsp:declaration&gt;");
            }
            Mark stop;
            String text;
            while (true) {
                start = reader.mark();
                stop = reader.skipUntil("<");
                if (stop == null) {
                    err.jspError(start, "jsp.error.unterminated",
                        "&lt;jsp:declaration&gt;");
                }
                text = parseScriptText(reader.getText(start, stop));
                new Node.Declaration(text, start, parent);
                if (reader.matches("![CDATA[")) {
                    start = reader.mark();
                    stop = reader.skipUntil("]]>");
                    if (stop == null) {
                        err.jspError(start, "jsp.error.unterminated", "CDATA");
                    }
                    text = parseScriptText(reader.getText(start, stop));
                    new Node.Declaration(text, start, parent);
                }
                else {
                    break;
                }
            }
                
            if (!reader.matchesETagWithoutLessThan( "jsp:declaration" ) ) {
                err.jspError(start, "jsp.error.unterminated",
                        "&lt;jsp:declaration&gt;");
            }
        }
    }

    /*
     * ExpressionBody ::= (Char* - (char* '%>')) '%>'
     */
    private void parseExpression(Node parent) throws JasperException {
        start = reader.mark();
        Mark stop = reader.skipUntil("%>");
        if (stop == null) {
            err.jspError(start, "jsp.error.unterminated", "&lt;%=");
        }

        new Node.Expression(parseScriptText(reader.getText(start, stop)),
                            start, parent);
    }

    /*
     * XMLExpressionBody ::=   ( S? '/>' )
     *                       | ( S? '>' (Char* - (char* '<')) CDSect?)* ETag )
     *                       | <TRANSLATION_ERROR>
     */
    private void parseXMLExpression(Node parent) throws JasperException {
        reader.skipSpaces();
        if( !reader.matches( "/>" ) ) {
            if( !reader.matches( ">" ) ) {
                err.jspError(start, "jsp.error.unterminated",
                    "&lt;jsp:expression&gt;");
            }
            Mark stop;
            String text;
            while (true) {
                start = reader.mark();
                stop = reader.skipUntil("<");
                if (stop == null) {
                    err.jspError(start, "jsp.error.unterminated",
                        "&lt;jsp:expression&gt;");
                }
                text = parseScriptText(reader.getText(start, stop));
                new Node.Expression(text, start, parent);
                if (reader.matches("![CDATA[")) {
                    start = reader.mark();
                    stop = reader.skipUntil("]]>");
                    if (stop == null) {
                        err.jspError(start, "jsp.error.unterminated", "CDATA");
                    }
                    text = parseScriptText(reader.getText(start, stop));
                    new Node.Expression(text, start, parent);
                }
                else {
                    break;
                }
            }
            if (!reader.matchesETagWithoutLessThan( "jsp:expression" )) {
                err.jspError(start, "jsp.error.unterminated",
                    "&lt;jsp:expression&gt;");
            }
        }
    }

    /*
     * ELExpressionBody
     * (following "${" to first unquoted "}")
     * // XXX add formal production and confirm implementation against it,
     * //     once it's decided
     */
    private void parseELExpression(Node parent) throws JasperException {
        start = reader.mark();
        Mark last = null;
        boolean singleQuoted = false, doubleQuoted = false;
        int currentChar;
        do {
            // XXX could move this logic to JspReader
            last = reader.mark();               // XXX somewhat wasteful
            currentChar = reader.nextChar();
            if (currentChar == '\\' && (singleQuoted || doubleQuoted)) {
                // skip character following '\' within quotes
                reader.nextChar();
                currentChar = reader.nextChar();
            }
            if (currentChar == -1)
                err.jspError(start, "jsp.error.unterminated", "${");
            if (currentChar == '"')
                doubleQuoted = !doubleQuoted;
            if (currentChar == '\'')
                singleQuoted = !singleQuoted;
        } while (currentChar != '}' || (singleQuoted || doubleQuoted));

        new Node.ELExpression(reader.getText(start, last), start, parent);
    }

    /*
     * ScriptletBody ::= (Char* - (char* '%>')) '%>'
     */
    private void parseScriptlet(Node parent) throws JasperException {
        start = reader.mark();
        Mark stop = reader.skipUntil("%>");
        if (stop == null) {
            err.jspError(start, "jsp.error.unterminated", "&lt;%");
        }

        new Node.Scriptlet(parseScriptText(reader.getText(start, stop)),
                           start, parent);
    }

    /*
     * XMLScriptletBody ::=   ( S? '/>' )
     *                      | ( S? '>' (Char* - (char* '<')) CDSect?)* ETag )
     *                      | <TRANSLATION_ERROR>
     */
    private void parseXMLScriptlet(Node parent) throws JasperException {
        reader.skipSpaces();
        if( !reader.matches( "/>" ) ) {
            if( !reader.matches( ">" ) ) {
                err.jspError(start, "jsp.error.unterminated",
                    "&lt;jsp:scriptlet&gt;");
            }
            Mark stop;
            String text;
            while (true) {
                start = reader.mark();
                stop = reader.skipUntil("<");
                if (stop == null) {
                    err.jspError(start, "jsp.error.unterminated",
                        "&lt;jsp:scriptlet&gt;");
                }
                text = parseScriptText(reader.getText(start, stop));
                new Node.Scriptlet(text, start, parent);
                if (reader.matches("![CDATA[")) {
                    start = reader.mark();
                    stop = reader.skipUntil("]]>");
                    if (stop == null) {
                        err.jspError(start, "jsp.error.unterminated", "CDATA");
                    }
                    text = parseScriptText(reader.getText(start, stop));
                    new Node.Scriptlet(text, start, parent);
                }
                else {
                    break;
                }
            }

            if (!reader.matchesETagWithoutLessThan( "jsp:scriptlet" )) {
                err.jspError(start, "jsp.error.unterminated",
                    "&lt;jsp:scriptlet&gt;");
            }
        }
    }
        
    /**
     * Param ::= '<jsp:param' S Attributes S? EmptyBody S?
     */
    private void parseParam(Node parent) throws JasperException {
        if (!reader.matches("<jsp:param")) {
            err.jspError(reader.mark(), "jsp.error.paramexpected");
        }
        Attributes attrs = parseAttributes();
        reader.skipSpaces();
        
        Node paramActionNode = new Node.ParamAction( attrs, start, parent );
        
        parseEmptyBody( paramActionNode, "jsp:param" );
        
        reader.skipSpaces();
    }

    /*
     * For Include:
     * StdActionContent ::= Attributes ParamBody
     *
     * ParamBody ::=   EmptyBody
     *               | ( '>' S? ( '<jsp:attribute' NamedAttributes )?
     *                   '<jsp:body'
     *                   (JspBodyParam | <TRANSLATION_ERROR> )
     *                   S? ETag
     *                 )
     *               | ( '>' S? Param* ETag )
     *
     * EmptyBody ::=   '/>'
     *               | ( '>' ETag )
     *               | ( '>' S? '<jsp:attribute' NamedAttributes ETag )
     *
     * JspBodyParam ::= S? '>' Param* '</jsp:body>'
     */
    private void parseInclude(Node parent) throws JasperException {
        Attributes attrs = parseAttributes();
        reader.skipSpaces();

        Node includeNode = new Node.IncludeAction( attrs, start, parent );
        
        parseOptionalBody(includeNode, "jsp:include", 
                          JAVAX_BODY_CONTENT_PARAM);
    }

    /*
     * For Forward:
     * StdActionContent ::= Attributes ParamBody
     */
    private void parseForward(Node parent) throws JasperException {
        Attributes attrs = parseAttributes();
        reader.skipSpaces();

        Node forwardNode = new Node.ForwardAction( attrs, start, parent );
        
        parseOptionalBody(forwardNode, "jsp:forward",
                          JAVAX_BODY_CONTENT_PARAM);
    }

    private void parseInvoke(Node parent) throws JasperException {
        Attributes attrs = parseAttributes();
        reader.skipSpaces();

        Node invokeNode = new Node.InvokeAction(attrs, start, parent);
        
        parseEmptyBody(invokeNode, "jsp:invoke");
    }

    private void parseDoBody(Node parent) throws JasperException {
        Attributes attrs = parseAttributes();
        reader.skipSpaces();

        Node doBodyNode = new Node.DoBodyAction(attrs, start, parent);
        
        parseEmptyBody(doBodyNode, "jsp:doBody");
    }

    private void parseElement(Node parent) throws JasperException {
        Attributes attrs = parseAttributes();
        reader.skipSpaces();

        Node elementNode = new Node.JspElement(attrs, start, parent);
        
        parseOptionalBody( elementNode, "jsp:element", 
            TagInfo.BODY_CONTENT_JSP );
    }

    /*
     * For GetProperty:
     * StdActionContent ::= Attributes EmptyBody
     */
    private void parseGetProperty(Node parent) throws JasperException {
        Attributes attrs = parseAttributes();
        reader.skipSpaces();

        Node getPropertyNode = new Node.GetProperty( attrs, start, parent );
        
        parseOptionalBody(getPropertyNode, "jsp:getProperty",
                          TagInfo.BODY_CONTENT_EMPTY);
    }

    /*
     * For SetProperty:
     * StdActionContent ::= Attributes EmptyBody
     */
    private void parseSetProperty(Node parent) throws JasperException {
        Attributes attrs = parseAttributes();
        reader.skipSpaces();

        Node setPropertyNode = new Node.SetProperty( attrs, start, parent );
        
        parseOptionalBody(setPropertyNode, "jsp:setProperty",
                          TagInfo.BODY_CONTENT_EMPTY);
    }

    /*
     * EmptyBody ::=   '/>'
     *               | ( '>' ETag )
     *               | ( '>' S? '<jsp:attribute' NamedAttributes ETag )
     */
    private void parseEmptyBody( Node parent, String tag ) 
        throws JasperException
    {
        if( reader.matches("/>") ) {
            // Done
        }
        else if( reader.matches( ">" ) ) {
            if( reader.matchesETag( tag ) ) {
                // Done
            }
            else if( reader.matchesOptionalSpacesFollowedBy(
                "<jsp:attribute" ) )
            {
                // Parse the one or more named attribute nodes
                parseNamedAttributes( parent );
                if( !reader.matchesETag( tag ) ) {
                    // Body not allowed
                    err.jspError(reader.mark(),
                        "jsp.error.jspbody.emptybody.only",
                        "&lt;" + tag );
                }
            }
            else {
                err.jspError(reader.mark(), "jsp.error.jspbody.emptybody.only",
                    "&lt;" + tag );
            }
        }
        else {
            err.jspError(reader.mark(), "jsp.error.unterminated",
                "&lt;" + tag );
        }
    }

    /*
     * For UseBean:
     * StdActionContent ::= Attributes OptionalBody
     */
    private void parseUseBean(Node parent) throws JasperException {
        Attributes attrs = parseAttributes();
        reader.skipSpaces();
        
        Node useBeanNode = new Node.UseBean( attrs, start, parent );
        
        parseOptionalBody( useBeanNode, "jsp:useBean", 
            TagInfo.BODY_CONTENT_JSP );
    }

    /*
     * Parses OptionalBody, but also reused to parse bodies for plugin
     * and param since the syntax is identical (the only thing that
     * differs substantially is how to process the body, and thus
     * we accept the body type as a parameter).
     *
     * OptionalBody ::= EmptyBody | ActionBody
     *
     * ScriptlessOptionalBody ::= EmptyBody | ScriptlessActionBody
     *
     * TagDependentOptionalBody ::= EmptyBody | TagDependentActionBody
     *
     * EmptyBody ::=   '/>'
     *               | ( '>' ETag )
     *               | ( '>' S? '<jsp:attribute' NamedAttributes ETag )
     *
     * ActionBody ::=   JspAttributeAndBody
     *                | ( '>' Body ETag )
     *
     * ScriptlessActionBody ::=   JspAttributeAndBody 
     *                          | ( '>' ScriptlessBody ETag )
     * 
     * TagDependentActionBody ::=   JspAttributeAndBody
     *                            | ( '>' TagDependentBody ETag )
     *
     */
    private void parseOptionalBody( Node parent, String tag, String bodyType ) 
        throws JasperException 
    {
        if (reader.matches("/>")) {
            // EmptyBody
            return;
        }

        if (!reader.matches(">")) {
            err.jspError(reader.mark(), "jsp.error.unterminated",
                         "&lt;" + tag );
        }
        
        if( reader.matchesETag( tag ) ) {
            // EmptyBody
            return;
        }
        
        if( !parseJspAttributeAndBody( parent, tag, bodyType ) ) {
            // Must be ( '>' # Body ETag )
            parseBody(parent, tag, bodyType );
        }
    }
    
    /**
     * Attempts to parse 'JspAttributeAndBody' production.  Returns true if
     * it matched, or false if not.  Assumes EmptyBody is okay as well.
     *
     * JspAttributeAndBody ::=
     *                  ( '>' # S? ( '<jsp:attribute' NamedAttributes )?
     *                    '<jsp:body'
     *                    ( JspBodyBody | <TRANSLATION_ERROR> )
     *                    S? ETag
     *                  )
     */
    private boolean parseJspAttributeAndBody( Node parent, String tag, 
        String bodyType ) 
        throws JasperException
    {
        boolean result = false;
        
        if( reader.matchesOptionalSpacesFollowedBy( "<jsp:attribute" ) ) {
            // May be an EmptyBody, depending on whether
            // There's a "<jsp:body" before the ETag
            
            // First, parse <jsp:attribute> elements:
            parseNamedAttributes( parent );
            
            result = true;
        }
        
        if( reader.matchesOptionalSpacesFollowedBy( "<jsp:body" ) ) {
            // ActionBody
            parseJspBody( parent, bodyType );
            reader.skipSpaces();
            if( !reader.matchesETag( tag ) ) {
                err.jspError(reader.mark(), "jsp.error.unterminated", 
                    "&lt;" + tag );
            }
            
            result = true;
        }
        else if( result && !reader.matchesETag( tag ) ) {
            // If we have <jsp:attribute> but something other than
            // <jsp:body> or the end tag, translation error.
            err.jspError(reader.mark(), "jsp.error.jspbody.required", 
                "&lt;" + tag );
        }
        
        return result;
    }

    /*
     * Params ::=  `>' S?
     *              (   ( `<jsp:body>'
     *                    ( ( S? Param+ S? `</jsp:body>' )
     *                      | <TRANSLATION_ERROR>
     *                    )
     *                  )
     *                | Param+
     *              )
     *              '</jsp:params>'
     */
    private void parseJspParams(Node parent) throws JasperException {
        Node jspParamsNode = new Node.ParamsAction(start, parent);
        parseOptionalBody(jspParamsNode, "jsp:params",
                          JAVAX_BODY_CONTENT_PARAM );
    }

    /*
     * Fallback ::=   '/>'
     *               | ( `>' S? `<jsp:body>'
     *                   (   ( S?
     *                         ( Char* - ( Char* `</jsp:body>' ) )
     *                         `</jsp:body>' S?
     *                       )
     *                     | <TRANSLATION_ERROR>
     *                   )
     *                   `</jsp:fallback>'
     *                 )
     *               | ( '>'
     *                   ( Char* - ( Char* '</jsp:fallback>' ) )
     *                   '</jsp:fallback>'
     *                 )
     */
    private void parseFallBack(Node parent) throws JasperException {
        Node fallBackNode = new Node.FallBackAction(start, parent);
        parseOptionalBody(fallBackNode, "jsp:fallback", 
                          JAVAX_BODY_CONTENT_TEMPLATE_TEXT);
    }

    /*
     * For Plugin:
     * StdActionContent ::= Attributes PluginBody
     *
     * PluginBody ::=   EmptyBody 
     *                | ( '>' S? ( '<jsp:attribute' NamedAttributes )?
     *                    '<jsp:body'
     *                    ( JspBodyPluginTags | <TRANSLATION_ERROR> )
     *                    S? ETag
     *                  )
     *                | ( '>' S? PluginTags ETag )
     *
     * EmptyBody ::=   '/>'
     *               | ( '>' ETag )
     *               | ( '>' S? '<jsp:attribute' NamedAttributes ETag )
     *
     */
    private void parsePlugin(Node parent) throws JasperException {
        Attributes attrs = parseAttributes();
        reader.skipSpaces();
        
        Node pluginNode = new Node.PlugIn(attrs, start, parent);
        
        parseOptionalBody( pluginNode, "jsp:plugin", 
            JAVAX_BODY_CONTENT_PLUGIN );
    }

    /*
     * PluginTags ::= ( '<jsp:params' Params S? )?
     *                ( '<jsp:fallback' Fallback? S? )?
     */
    private void parsePluginTags( Node parent ) throws JasperException {
        reader.skipSpaces();
        
        if( reader.matches( "<jsp:params" ) ) {
            parseJspParams( parent );
            reader.skipSpaces();
        }
        
        if( reader.matches( "<jsp:fallback" ) ) {
            parseFallBack( parent );
            reader.skipSpaces();
        }
    }
        
    /*
     * StandardAction ::=   'include'       StdActionContent
     *                    | 'forward'       StdActionContent
     *                    | 'invoke'        StdActionContent
     *                    | 'doBody'        StdActionContent
     *                    | 'getProperty'   StdActionContent
     *                    | 'setProperty'   StdActionContent
     *                    | 'useBean'       StdActionContent
     *                    | 'plugin'        StdActionContent
     *                    | 'element'       StdActionContent
     */
    private void parseStandardAction(Node parent) throws JasperException {
        Mark start = reader.mark();

        if (reader.matches(INCLUDE_ACTION)) {
            parseInclude(parent);
        } else if (reader.matches(FORWARD_ACTION)) {
            parseForward(parent);
        } else if (reader.matches(INVOKE_ACTION)) {
            if (!isTagFile) {
                err.jspError(reader.mark(), "jsp.error.action.isnottagfile",
                             "&lt;jsp:invoke");
            }
            parseInvoke(parent);
        } else if (reader.matches(DOBODY_ACTION)) {
            if (!isTagFile) {
                err.jspError(reader.mark(), "jsp.error.action.isnottagfile",
                             "&lt;jsp:doBody");
            }
            parseDoBody(parent);
        } else if (reader.matches(GET_PROPERTY_ACTION)) {
            parseGetProperty(parent);
        } else if (reader.matches(SET_PROPERTY_ACTION)) {
            parseSetProperty(parent);
        } else if (reader.matches(USE_BEAN_ACTION)) {
            parseUseBean(parent);
        } else if (reader.matches(PLUGIN_ACTION)) {
            parsePlugin(parent);
        } else if (reader.matches(ELEMENT_ACTION)) {
            parseElement(parent);
        } else if (reader.matches(ATTRIBUTE_ACTION)) {
            err.jspError(start, "jsp.error.namedAttribute.invalidUse");
        } else if (reader.matches(BODY_ACTION)) {
            err.jspError(start, "jsp.error.jspbody.invalidUse");
        } else if (reader.matches(FALLBACK_ACTION)) {
            err.jspError(start, "jsp.error.fallback.invalidUse");
        } else if (reader.matches(PARAMS_ACTION)) {
            err.jspError(start, "jsp.error.params.invalidUse");
        } else if (reader.matches(PARAM_ACTION)) {
            err.jspError(start, "jsp.error.param.invalidUse");
        } else if (reader.matches(OUTPUT_ACTION)) {
            err.jspError(start, "jsp.error.jspoutput.invalidUse");
        } else {
            err.jspError(start, "jsp.error.badStandardAction");
        }
    }

    /*
     * # '<' CustomAction CustomActionBody
     *
     * CustomAction ::= TagPrefix ':' CustomActionName
     *
     * TagPrefix ::= Name
     *
     * CustomActionName ::= Name
     *
     * CustomActionBody ::=   ( Attributes CustomActionEnd )
     *                      | <TRANSLATION_ERROR>
     *
     * Attributes ::= ( S Attribute )* S?
     *
     * CustomActionEnd ::=   CustomActionTagDependent
     *                     | CustomActionJSPContent
     *                     | CustomActionScriptlessContent
     *
     * CustomActionTagDependent ::= TagDependentOptionalBody
     *
     * CustomActionJSPContent ::= OptionalBody
     *
     * CustomActionScriptlessContent ::= ScriptlessOptionalBody
     */
    private boolean parseCustomTag(Node parent) throws JasperException {

        if (reader.peekChar() != '<') {
            return false;
        }

        // Parse 'CustomAction' production (tag prefix and custom action name)
        reader.nextChar();        // skip '<'
        String tagName = reader.parseToken(false);
        int i = tagName.indexOf(':');
        if (i == -1) {
            reader.reset(start);
            return false;
        }

        String prefix = tagName.substring(0, i);
        String shortTagName = tagName.substring(i+1);

        // Check if this is a user-defined tag.
        String uri = pageInfo.getURI(prefix);
        if (uri == null) {
            reader.reset(start);
            // Remember the prefix for later error checking
            pageInfo.putNonCustomTagPrefix(prefix, reader.mark());
            return false;
        }

        TagLibraryInfo tagLibInfo = pageInfo.getTaglib(uri);
        TagInfo tagInfo = tagLibInfo.getTag(shortTagName);
        TagFileInfo tagFileInfo = tagLibInfo.getTagFile(shortTagName);
        if (tagInfo == null && tagFileInfo == null) {
            err.jspError(start, "jsp.error.bad_tag", shortTagName, prefix);
        }
        Class tagHandlerClass = null;
        if (tagInfo != null) {
            // Must be a classic tag, load it here.
            // tag files will be loaded later, in TagFileProcessor
            String handlerClassName = tagInfo.getTagClassName();
            try {
                tagHandlerClass =
                    ctxt.getClassLoader().loadClass(handlerClassName);
            } catch (Exception e) {
                err.jspError(start, "jsp.error.loadclass.taghandler",
                             handlerClassName, tagName);
            }
        }

        // Parse 'CustomActionBody' production:
        // At this point we are committed - if anything fails, we produce
        // a translation error.

        // Parse 'Attributes' production:
        Attributes attrs = parseAttributes();
        reader.skipSpaces();
        
        // Parse 'CustomActionEnd' production:
        if (reader.matches("/>")) {
            if (tagInfo != null) {
                new Node.CustomTag(tagName, prefix, shortTagName, uri, attrs,
                                   start, parent, tagInfo, tagHandlerClass);
            } else {
                new Node.CustomTag(tagName, prefix, shortTagName, uri, attrs,
                                   start, parent, tagFileInfo);
            }
            return true;
        }
        
        // Now we parse one of 'CustomActionTagDependent', 
        // 'CustomActionJSPContent', or 'CustomActionScriptlessContent'.
        // depending on body-content in TLD.

        // Looking for a body, it still can be empty; but if there is a
        // a tag body, its syntax would be dependent on the type of
        // body content declared in the TLD.
        String bc;
        if (tagInfo != null) {
            bc = tagInfo.getBodyContent();
        } else {
            bc = tagFileInfo.getTagInfo().getBodyContent();
        }

        Node tagNode = null;
        if (tagInfo != null) {
            tagNode = new Node.CustomTag(tagName, prefix, shortTagName, uri,
                                         attrs, start, parent, tagInfo,
                                         tagHandlerClass);
        } else {
            tagNode = new Node.CustomTag(tagName, prefix, shortTagName, uri,
                                         attrs, start, parent, tagFileInfo);
        }

        parseOptionalBody( tagNode, tagName, bc );

        return true;
    }

    /*
     * Parse for a template text string until '<' or "${" is encountered, 
     * recognizing escape sequences "\%" and "\$".
     */
    private void parseTemplateText(Node parent) throws JasperException {

        if (!reader.hasMoreInput())
            return;

        CharArrayWriter ttext = new CharArrayWriter();
        // Output the first character
        int ch = reader.nextChar();
        if (ch == '\\') {
            reader.pushChar();
        } else {
            ttext.write(ch);
        }

        while (reader.hasMoreInput()) {
            ch = reader.nextChar();
            if (ch == '<') {
                reader.pushChar();
                break;
            }
            else if( ch == '$' ) {
                if (!reader.hasMoreInput()) {
                    ttext.write('$');
                    break;
                }
                ch = reader.nextChar();
                if (ch == '{') {
                    reader.pushChar();
                    reader.pushChar();
                    break;
                }
                ttext.write('$');
                reader.pushChar();
                continue;
            }
            else if (ch == '\\') {
                if (!reader.hasMoreInput()) {
                    ttext.write('\\');
                    break;
                }
                // Look for \% or \$
                // Only recognize \$ if isELIgnored is false, but since it can
                // be set in a page directive, it cannot be determined yet.
                char next = (char)reader.peekChar();
                if (next == '%') {
                    ch = reader.nextChar();
                } else if(next == '$') {
                    // Skip the $ and use a hack to flag this sequence
                    reader.nextChar();
                    ch = Constants.HACK_CHAR;
                }
            }
            ttext.write(ch);
        }
        new Node.TemplateText(ttext.toString(), start, parent);
    }
    
    /*
     * XMLTemplateText ::=   ( S? '/>' )
     *                     | ( S? '>'
     *                         ( ( Char* - ( Char* ( '<' | '${' ) ) )
     *                           ( '${' ELExpressionBody )?
     *                           CDSect?
     *                         )* ETag
     *                       )
     *                     | <TRANSLATION_ERROR>
     */
    private void parseXMLTemplateText(Node parent) throws JasperException {
        reader.skipSpaces();
        if( !reader.matches( "/>" ) ) {
            if( !reader.matches( ">" ) ) {
                err.jspError(start, "jsp.error.unterminated",
                    "&lt;jsp:text&gt;" );
            }
            CharArrayWriter ttext = new CharArrayWriter();
            while (reader.hasMoreInput()) {
                int ch = reader.nextChar();
                if( ch == '<' ) {
                    // Check for <![CDATA[
                    if (!reader.matches("![CDATA[")) {
                        break;
                    }
                    start = reader.mark();
                    Mark stop = reader.skipUntil("]]>");
                    if (stop == null) {
                        err.jspError(start, "jsp.error.unterminated", "CDATA");
                    }
                    String text = reader.getText(start, stop);
                    ttext.write(text, 0, text.length());
                }
                else if( ch == '\\') {
                    if (!reader.hasMoreInput()) {
                        ttext.write('\\');
                        break;
                    }
                    ch = reader.nextChar();
                    if (ch != '$' ) {
                        ttext.write('\\');
                    }
                    ttext.write(ch);
                }
                else if( ch == '$' ) {
                    if (!reader.hasMoreInput()) {
                        ttext.write('$');
                        break;
                    }
                    ch = reader.nextChar();
                    if (ch != '{') {
                        ttext.write('$');
                        reader.pushChar();
                        continue;
                    }
                    // Create a template text node
                    new Node.TemplateText( ttext.toString(), start, parent);

                    // Mark and parse the EL expression and create its node:
                    start = reader.mark();
                    parseELExpression(parent);

                    start = reader.mark();
                    ttext = new CharArrayWriter();
                }
                else {
                    ttext.write( ch );
                }
            }

            new Node.TemplateText( ttext.toString(), start, parent );

            if (! reader.hasMoreInput()) {
                err.jspError( start, "jsp.error.unterminated",
                    "&lt;jsp:text&gt;" );
            } else if( !reader.matchesETagWithoutLessThan( "jsp:text" ) ) {
                err.jspError( start, "jsp.error.jsptext.badcontent");
            }
        }
    }

    /*
     * AllBody ::=       ( '<%--'              JSPCommentBody     )
     *                 | ( '<%@'               DirectiveBody      )
     *                 | ( '<jsp:directive.'   XMLDirectiveBody   )
     *                 | ( '<%!'               DeclarationBody    )
     *                 | ( '<jsp:declaration'  XMLDeclarationBody )
     *                 | ( '<%='               ExpressionBody     )
     *                 | ( '<jsp:expression'   XMLExpressionBody  )
     *                 | ( '${'                ELExpressionBody   )
     *                 | ( '<%'                ScriptletBody      )
     *                 | ( '<jsp:scriptlet'    XMLScriptletBody   )
     *                 | ( '<jsp:text'         XMLTemplateText    )
     *                 | ( '<jsp:'             StandardAction     )
     *                 | ( '<'                 CustomAction
     *                                         CustomActionBody   )
     *                       | TemplateText
     */
    private void parseElements(Node parent) 
        throws JasperException 
    {
        if( scriptlessCount > 0 ) {
            // vc: ScriptlessBody
            // We must follow the ScriptlessBody production if one of
            // our parents is ScriptlessBody.
            parseElementsScriptless( parent );
            return;
        }
        
        start = reader.mark();
        if (reader.matches("<%--")) {
            parseComment(parent);
        } else if (reader.matches("<%@")) {
            parseDirective(parent);
        } else if (reader.matches("<jsp:directive.")) {
            parseXMLDirective(parent);
        } else if (reader.matches("<%!")) {
            parseDeclaration(parent);
        } else if (reader.matches("<jsp:declaration")) {
            parseXMLDeclaration(parent);
        } else if (reader.matches("<%=")) {
            parseExpression(parent);
        } else if (reader.matches("<jsp:expression")) {
            parseXMLExpression(parent);
        } else if (reader.matches("<%")) {
            parseScriptlet(parent);
        } else if (reader.matches("<jsp:scriptlet")) {
            parseXMLScriptlet(parent);
        } else if (reader.matches("<jsp:text")) {
            parseXMLTemplateText(parent);
        } else if (reader.matches("${")) {
            parseELExpression(parent);
        } else if (reader.matches("<jsp:")) {
            parseStandardAction(parent);
        } else if (!parseCustomTag(parent)) {
            checkUnbalancedEndTag();
            parseTemplateText(parent);
        }
    }

    /*
     * ScriptlessBody ::=  ( '<%--'              JSPCommentBody      )
     *                   | ( '<%@'               DirectiveBody       )
     *                   | ( '<jsp:directive.'   XMLDirectiveBody    )
     *                   | ( '<%!'               <TRANSLATION_ERROR> )
     *                   | ( '<jsp:declaration'  <TRANSLATION_ERROR> )
     *                   | ( '<%='               <TRANSLATION_ERROR> )
     *                   | ( '<jsp:expression'   <TRANSLATION_ERROR> )
     *                   | ( '<%'                <TRANSLATION_ERROR> )
     *                   | ( '<jsp:scriptlet'    <TRANSLATION_ERROR> )
     *                   | ( '<jsp:text'         XMLTemplateText     )
     *                   | ( '${'                ELExpressionBody    )
     *                   | ( '<jsp:'             StandardAction      )
     *                   | ( '<'                 CustomAction
     *                                           CustomActionBody    )
     *                   | TemplateText
     */
    private void parseElementsScriptless(Node parent) 
        throws JasperException 
    {
        // Keep track of how many scriptless nodes we've encountered
        // so we know whether our child nodes are forced scriptless
        scriptlessCount++;
        
        start = reader.mark();
        if (reader.matches("<%--")) {
            parseComment(parent);
        } else if (reader.matches("<%@")) {
            parseDirective(parent);
        } else if (reader.matches("<jsp:directive.")) {
            parseXMLDirective(parent);
        } else if (reader.matches("<%!")) {
            err.jspError( reader.mark(), "jsp.error.no.scriptlets" );
        } else if (reader.matches("<jsp:declaration")) {
            err.jspError( reader.mark(), "jsp.error.no.scriptlets" );
        } else if (reader.matches("<%=")) {
            err.jspError( reader.mark(), "jsp.error.no.scriptlets" );
        } else if (reader.matches("<jsp:expression")) {
            err.jspError( reader.mark(), "jsp.error.no.scriptlets" );
        } else if (reader.matches("<%")) {
            err.jspError( reader.mark(), "jsp.error.no.scriptlets" );
        } else if (reader.matches("<jsp:scriptlet")) {
            err.jspError( reader.mark(), "jsp.error.no.scriptlets" );
        } else if (reader.matches("<jsp:text")) {
            parseXMLTemplateText(parent);
        } else if (reader.matches("${")) {
            parseELExpression(parent);
        } else if (reader.matches("<jsp:")) {
            parseStandardAction(parent);
        } else if (!parseCustomTag(parent)) {
            checkUnbalancedEndTag();
            parseTemplateText(parent);
        }
        
        scriptlessCount--;
    }
    
    /*
     * TemplateTextBody ::=   ( '<%--'              JSPCommentBody      )
     *                      | ( '<%@'               DirectiveBody       )
     *                      | ( '<jsp:directive.'   XMLDirectiveBody    )
     *                      | ( '<%!'               <TRANSLATION_ERROR> )
     *                      | ( '<jsp:declaration'  <TRANSLATION_ERROR> )
     *                      | ( '<%='               <TRANSLATION_ERROR> )
     *                      | ( '<jsp:expression'   <TRANSLATION_ERROR> )
     *                      | ( '<%'                <TRANSLATION_ERROR> )
     *                      | ( '<jsp:scriptlet'    <TRANSLATION_ERROR> )
     *                      | ( '<jsp:text'         <TRANSLATION_ERROR> )
     *                      | ( '${'                <TRANSLATION_ERROR> )
     *                      | ( '<jsp:'             <TRANSLATION_ERROR> )
     *                      | TemplateText
     */
    private void parseElementsTemplateText(Node parent)
        throws JasperException
    {
        start = reader.mark();
        if (reader.matches("<%--")) {
            parseComment(parent);
        } else if (reader.matches("<%@")) {
            parseDirective(parent);
        } else if (reader.matches("<jsp:directive.")) {
            parseXMLDirective(parent);
        } else if (reader.matches("<%!")) {
            err.jspError( reader.mark(), "jsp.error.not.in.template",
                "Declarations" );
        } else if (reader.matches("<jsp:declaration")) {
            err.jspError( reader.mark(), "jsp.error.not.in.template",
                "Declarations" );
        } else if (reader.matches("<%=")) {
            err.jspError( reader.mark(), "jsp.error.not.in.template",
                "Expressions" );
        } else if (reader.matches("<jsp:expression")) {
            err.jspError( reader.mark(), "jsp.error.not.in.template",
                "Expressions" );
        } else if (reader.matches("<%")) {
            err.jspError( reader.mark(), "jsp.error.not.in.template",
                "Scriptlets" );
        } else if (reader.matches("<jsp:scriptlet")) {
            err.jspError( reader.mark(), "jsp.error.not.in.template",
                "Scriptlets" );
        } else if (reader.matches("<jsp:text")) {
            err.jspError( reader.mark(), "jsp.error.not.in.template",
                "&lt;jsp:text" );
        } else if (reader.matches("${")) {
            err.jspError( reader.mark(), "jsp.error.not.in.template",
                "Expression language" );
        } else if (reader.matches("<jsp:")) {
            err.jspError( reader.mark(), "jsp.error.not.in.template",
                "Standard actions" );
        } else if (parseCustomTag(parent)) {
            err.jspError( reader.mark(), "jsp.error.not.in.template",
                "Custom actions" );
        } else {
            checkUnbalancedEndTag();
            parseTemplateText(parent);
        }
    }

    /*
     * Flag as error if an unbalanced end tag appears by itself.
     */
    private void checkUnbalancedEndTag() throws JasperException {

        if (!reader.matches("</")) {
            return;
        }

        // Check for unbalanced standard actions
        if (reader.matches("jsp:")) {
            err.jspError(start, "jsp.error.unbalanced.endtag", "jsp:");
        }

        // Check for unbalanced custom actions
        String tagName = reader.parseToken(false);
        int i = tagName.indexOf(':');
        if (i == -1 || pageInfo.getURI(tagName.substring(0, i)) == null) {
            reader.reset(start);
            return;
        }

        err.jspError(start, "jsp.error.unbalanced.endtag", tagName);
    }

    /**
     * TagDependentBody := 
     */
    private void parseTagDependentBody(Node parent, String tag)
                throws JasperException{
        Mark bodyStart = reader.mark();
        Mark bodyEnd = reader.skipUntilETag(tag);
        if (bodyEnd == null) {
            err.jspError(start, "jsp.error.unterminated", "&lt;"+tag );
        }
        new Node.TemplateText(reader.getText(bodyStart, bodyEnd), bodyStart,
                              parent);
    }

    /*
     * Parses jsp:body action.
     */
    private void parseJspBody(Node parent, String bodyType) 
        throws JasperException 
    {
        Mark start = reader.mark();
        Node bodyNode = new Node.JspBody(start, parent);

        reader.skipSpaces();
        if (!reader.matches("/>")) {
            if (!reader.matches(">")) {
                err.jspError(start, "jsp.error.unterminated",
                             "&lt;jsp:body");
            }
            parseBody( bodyNode, "jsp:body", bodyType );
        }
    }

    /*
     * Parse the body as JSP content.
     * @param tag The name of the tag whose end tag would terminate the body
     * @param bodyType One of the TagInfo body types
     */
    private void parseBody(Node parent, String tag, String bodyType) 
        throws JasperException 
    {
        if( bodyType.equalsIgnoreCase( TagInfo.BODY_CONTENT_TAG_DEPENDENT ) ) {
            parseTagDependentBody( parent, tag );
        }
        else if( bodyType.equalsIgnoreCase( TagInfo.BODY_CONTENT_EMPTY ) ) {
            if( !reader.matchesETag( tag ) ) {
                err.jspError(start, "jasper.error.emptybodycontent.nonempty",
                             tag);
            }
        }
        else if( bodyType == JAVAX_BODY_CONTENT_PLUGIN ) {
            // (note the == since we won't recognize JAVAX_* 
            // from outside this module).
            parsePluginTags(parent);
            if( !reader.matchesETag( tag ) ) {
                err.jspError( reader.mark(), "jsp.error.unterminated",
                    "&lt;" + tag  );
            }
        }
        else if( bodyType.equalsIgnoreCase( TagInfo.BODY_CONTENT_JSP ) ||
            bodyType.equalsIgnoreCase( TagInfo.BODY_CONTENT_SCRIPTLESS ) ||
            (bodyType == JAVAX_BODY_CONTENT_PARAM) ||
            (bodyType == JAVAX_BODY_CONTENT_TEMPLATE_TEXT) )
        {
            while (reader.hasMoreInput()) {
                if (reader.matchesETag(tag)) {
                    return;
                }
                
                // Check for nested jsp:body or jsp:attribute
                if (tag.equals("jsp:body") || tag.equals("jsp:attribute")) {
                    if (reader.matches("<jsp:attribute")) {
                        err.jspError(reader.mark(), "jsp.error.nested.jspattribute");
                    }
                    else if (reader.matches("<jsp:body")) {
                        err.jspError(reader.mark(), "jsp.error.nested.jspbody");
                    }
                }

                if( bodyType.equalsIgnoreCase( TagInfo.BODY_CONTENT_JSP ) ) {
                    parseElements( parent );
                }
                else if( bodyType.equalsIgnoreCase( 
                    TagInfo.BODY_CONTENT_SCRIPTLESS ) ) 
                {
                    parseElementsScriptless( parent );
                }
                else if( bodyType == JAVAX_BODY_CONTENT_PARAM ) {
                    // (note the == since we won't recognize JAVAX_* 
                    // from outside this module).
                    reader.skipSpaces();
                    parseParam( parent );
                }
                else if (bodyType == JAVAX_BODY_CONTENT_TEMPLATE_TEXT) {
                    parseElementsTemplateText(parent);
                }
            }
            err.jspError(start, "jsp.error.unterminated", "&lt;"+tag );
        }
        else {
            err.jspError(start, "jasper.error.bad.bodycontent.type");
        }
    }

    /*
     * Parses named attributes.
     */
    private void parseNamedAttributes(Node parent) throws JasperException {
        do {
            Mark start = reader.mark();
            Attributes attrs = parseAttributes();
            Node.NamedAttribute namedAttributeNode =
                new Node.NamedAttribute( attrs, start, parent );

            reader.skipSpaces();
            if (!reader.matches("/>")) {
                if (!reader.matches(">")) {
                    err.jspError(start, "jsp.error.unterminated",
                                 "&lt;jsp:attribute");
                }
                if (namedAttributeNode.isTrim()) {
                    reader.skipSpaces();
                }
                parseBody(namedAttributeNode, "jsp:attribute", 
                          getAttributeBodyType(parent,
                                               attrs.getValue("name")));
                if (namedAttributeNode.isTrim()) {
                    Node.Nodes subElems = namedAttributeNode.getBody();
                    if (subElems != null) {
                        Node lastNode = subElems.getNode(subElems.size() - 1);
                        if (lastNode instanceof Node.TemplateText) {
                            ((Node.TemplateText)lastNode).rtrim();
                        }
                    }
                }
            }
            reader.skipSpaces();
        } while( reader.matches( "<jsp:attribute" ) );
    }

    /**
     * Determine the body type of <jsp:attribute> from the enclosing node
     */
    private String getAttributeBodyType(Node n, String name) {

        if (n instanceof Node.CustomTag) {
            TagInfo tagInfo = ((Node.CustomTag)n).getTagInfo();
            TagAttributeInfo[] tldAttrs = tagInfo.getAttributes();
            for (int i=0; i<tldAttrs.length; i++) {
                if (name.equals(tldAttrs[i].getName())) {
                    if (tldAttrs[i].isFragment()) {
                        return TagInfo.BODY_CONTENT_SCRIPTLESS;
                    }
                    if (tldAttrs[i].canBeRequestTime()) {
                        return TagInfo.BODY_CONTENT_JSP;
                    }
                }
            }
            if (tagInfo.hasDynamicAttributes()) {
                return TagInfo.BODY_CONTENT_JSP;
            }
        } else if (n instanceof Node.IncludeAction) {
            if ("page".equals(name)) {
                return TagInfo.BODY_CONTENT_JSP;
            }
        } else if (n instanceof Node.ForwardAction) {
            if ("page".equals(name)) {
                return TagInfo.BODY_CONTENT_JSP;
            }
        } else if (n instanceof Node.SetProperty) {
            if ("value".equals(name)) {
                return TagInfo.BODY_CONTENT_JSP;
            }
        } else if (n instanceof Node.UseBean) {
            if ("beanName".equals(name)) {
                return TagInfo.BODY_CONTENT_JSP;
            }
        } else if (n instanceof Node.PlugIn) {
            if ("width".equals(name) || "height".equals(name)) {
                return TagInfo.BODY_CONTENT_JSP;
            }
        } else if (n instanceof Node.ParamAction) {
            if ("value".equals(name)) {
                return TagInfo.BODY_CONTENT_JSP;
            }
        } else if (n instanceof Node.JspElement) {
            return TagInfo.BODY_CONTENT_JSP;
        }

        return JAVAX_BODY_CONTENT_TEMPLATE_TEXT;
    }

    private void parseTagFileDirectives(Node parent)
        throws JasperException
    {
        reader.setSingleFile(true);
        reader.skipUntil("<");
        while (reader.hasMoreInput()) {
            start = reader.mark();
            if (reader.matches("%--")) {
                parseComment(parent);
            } else if (reader.matches("%@")) {
                parseDirective(parent);
            } else if (reader.matches("jsp:directive.")) {
                parseXMLDirective(parent);
            }
            reader.skipUntil("<");
        }
    }
}