/*

 * 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: SymbolTable.java,v 1.5 2005/09/28 13:48:16 pvedula Exp $

 */

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

import java.util.Hashtable;

import java.util.Stack;

import java.util.StringTokenizer;

import java.util.Vector;

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

/**

 * @author Jacek Ambroziak

 * @author Santiago Pericas-Geertsen

 * @author Morten Jorgensen

 */

final class SymbolTable {

    // These hashtables are used for all stylesheets

    private final Hashtable _stylesheets = new Hashtable();

    private final Hashtable _primops     = new Hashtable();

    // These hashtables are used for some stylesheets

    private Hashtable _variables = null;

    private Hashtable _templates = null;

    private Hashtable _attributeSets = null;

    private Hashtable _aliases = null;

    private Hashtable _excludedURI = null;

    private Stack     _excludedURIStack = null;

    private Hashtable _decimalFormats = null;

    private Hashtable _keys = null;

    public DecimalFormatting getDecimalFormatting(QName name) {

        if (_decimalFormats == null) return null;

        return((DecimalFormatting)_decimalFormats.get(name));

    }

    public void addDecimalFormatting(QName name, DecimalFormatting symbols) {

        if (_decimalFormats == null) _decimalFormats = new Hashtable();

        _decimalFormats.put(name, symbols);

    }

    public Key getKey(QName name) {

        if (_keys == null) return null;

        return (Key) _keys.get(name);

    }

    public void addKey(QName name, Key key) {

        if (_keys == null) _keys = new Hashtable();

        _keys.put(name, key);

    }

    public Stylesheet addStylesheet(QName name, Stylesheet node) {

        return (Stylesheet)_stylesheets.put(name, node);

    }

    public Stylesheet lookupStylesheet(QName name) {

        return (Stylesheet)_stylesheets.get(name);

    }

    public Template addTemplate(Template template) {

        final QName name = template.getName();

        if (_templates == null) _templates = new Hashtable();

        return (Template)_templates.put(name, template);

    }

    public Template lookupTemplate(QName name) {

        if (_templates == null) return null;

        return (Template)_templates.get(name);

    }

    public Variable addVariable(Variable variable) {

        if (_variables == null) _variables = new Hashtable();

        final String name = variable.getName().getStringRep();

        return (Variable)_variables.put(name, variable);

    }

    public Param addParam(Param parameter) {

        if (_variables == null) _variables = new Hashtable();

        final String name = parameter.getName().getStringRep();

        return (Param)_variables.put(name, parameter);

    }

    public Variable lookupVariable(QName qname) {

        if (_variables == null) return null;

        final String name = qname.getStringRep();

        final Object obj = _variables.get(name);

        return obj instanceof Variable ? (Variable)obj : null;

    }

    public Param lookupParam(QName qname) {

        if (_variables == null) return null;

        final String name = qname.getStringRep();

        final Object obj = _variables.get(name);

        return obj instanceof Param ? (Param)obj : null;

    }

    public SyntaxTreeNode lookupName(QName qname) {

        if (_variables == null) return null;

        final String name = qname.getStringRep();

        return (SyntaxTreeNode)_variables.get(name);

    }

    public AttributeSet addAttributeSet(AttributeSet atts) {

        if (_attributeSets == null) _attributeSets = new Hashtable();

        return (AttributeSet)_attributeSets.put(atts.getName(), atts);

    }

    public AttributeSet lookupAttributeSet(QName name) {

        if (_attributeSets == null) return null;

        return (AttributeSet)_attributeSets.get(name);

    }

    /**

     * Add a primitive operator or function to the symbol table. To avoid

     * name clashes with user-defined names, the prefix <tt>PrimopPrefix</tt>

     * is prepended.

     */

    public void addPrimop(String name, MethodType mtype) {

        Vector methods = (Vector)_primops.get(name);

        if (methods == null) {

            _primops.put(name, methods = new Vector());

        }

        methods.addElement(mtype);

    }

    /**

     * Lookup a primitive operator or function in the symbol table by

     * prepending the prefix <tt>PrimopPrefix</tt>.

     */

    public Vector lookupPrimop(String name) {

        return (Vector)_primops.get(name);

    }

    /**

     * This is used for xsl:attribute elements that have a "namespace"

     * attribute that is currently not defined using xmlns:

     */

    private int _nsCounter = 0;

    public String generateNamespacePrefix() {

        return("ns"+(_nsCounter++));

    }

    /**

     * Use a namespace prefix to lookup a namespace URI

     */

    private SyntaxTreeNode _current = null;

    public void setCurrentNode(SyntaxTreeNode node) {

        _current = node;

    }

    public String lookupNamespace(String prefix) {

        if (_current == null) return(Constants.EMPTYSTRING);

        return(_current.lookupNamespace(prefix));

    }

    /**

     * Adds an alias for a namespace prefix

     */

    public void addPrefixAlias(String prefix, String alias) {

        if (_aliases == null) _aliases = new Hashtable();

        _aliases.put(prefix,alias);

    }

    /**

     * Retrieves any alias for a given namespace prefix

     */

    public String lookupPrefixAlias(String prefix) {

        if (_aliases == null) return null;

        return (String)_aliases.get(prefix);

    }

    /**

     * Register a namespace URI so that it will not be declared in the output

     * unless it is actually referenced in the output.

     */

    public void excludeURI(String uri) {

        // The null-namespace cannot be excluded

        if (uri == null) return;

        // Create new hashtable of exlcuded URIs if none exists

        if (_excludedURI == null) _excludedURI = new Hashtable();

        // Register the namespace URI

        Integer refcnt = (Integer)_excludedURI.get(uri);

        if (refcnt == null)

            refcnt = new Integer(1);

        else

            refcnt = new Integer(refcnt.intValue() + 1);

        _excludedURI.put(uri,refcnt);

    }

    /**

     * Exclude a series of namespaces given by a list of whitespace

     * separated namespace prefixes.

     */

    public void excludeNamespaces(String prefixes) {

        if (prefixes != null) {

            StringTokenizer tokens = new StringTokenizer(prefixes);

            while (tokens.hasMoreTokens()) {

                final String prefix = tokens.nextToken();

                final String uri;

                if (prefix.equals("#default"))

                    uri = lookupNamespace(Constants.EMPTYSTRING);

                else

                    uri = lookupNamespace(prefix);

                if (uri != null) excludeURI(uri);

            }

        }

    }

    /**

     * Check if a namespace should not be declared in the output (unless used)

     */

    public boolean isExcludedNamespace(String uri) {

        if (uri != null && _excludedURI != null) {

            final Integer refcnt = (Integer)_excludedURI.get(uri);

            return (refcnt != null && refcnt.intValue() > 0);

        }

        return false;

    }

    /**

     * Turn of namespace declaration exclusion

     */

    public void unExcludeNamespaces(String prefixes) {

        if (_excludedURI == null) return;

        if (prefixes != null) {

            StringTokenizer tokens = new StringTokenizer(prefixes);

            while (tokens.hasMoreTokens()) {

                final String prefix = tokens.nextToken();

                final String uri;

                if (prefix.equals("#default"))

                    uri = lookupNamespace(Constants.EMPTYSTRING);

                else

                    uri = lookupNamespace(prefix);

                Integer refcnt = (Integer)_excludedURI.get(uri);

                if (refcnt != null)

                    _excludedURI.put(uri, new Integer(refcnt.intValue() - 1));

            }

        }

    }

    /**

     * Exclusion of namespaces by a stylesheet does not extend to any stylesheet

     * imported or included by the stylesheet.  Upon entering the context of a

     * new stylesheet, a call to this method is needed to clear the current set

     * of excluded namespaces temporarily.  Every call to this method requires

     * a corresponding call to {@link #popExcludedNamespacesContext()}.

     */

    public void pushExcludedNamespacesContext() {

        if (_excludedURIStack == null) {

            _excludedURIStack = new Stack();

        }

        _excludedURIStack.push(_excludedURI);

        _excludedURI = null;

    }

    /**

     * Exclusion of namespaces by a stylesheet does not extend to any stylesheet

     * imported or included by the stylesheet.  Upon exiting the context of a

     * stylesheet, a call to this method is needed to restore the set of

     * excluded namespaces that was in effect prior to entering the context of

     * the current stylesheet.

     */

    public void popExcludedNamespacesContext() {

        _excludedURI = (Hashtable) _excludedURIStack.pop();

        if (_excludedURIStack.isEmpty()) {

            _excludedURIStack = null;

        }

    }

}