/*

 */

/*

 * 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 com.sun.org.apache.xerces.internal.util;

import java.util.Enumeration;

import java.util.Iterator;

import java.util.NoSuchElementException;

/**

 * Namespace support for XML document handlers. This class doesn't

 * perform any error checking and assumes that all strings passed

 * as arguments to methods are unique symbols. The SymbolTable class

 * can be used for this purpose.

 *

 * @author Andy Clark, IBM

 *

 */

public class NamespaceSupport implements NamespaceContext {

    //

    // Data

    //

    /**

     * Namespace binding information. This array is composed of a

     * series of tuples containing the namespace binding information:

     * <prefix, uri>. The default size can be set to anything

     * as long as it is a power of 2 greater than 1.

     *

     * @see #fNamespaceSize

     * @see #fContext

     */

    protected String[] fNamespace = new String[16 * 2];

    /** The top of the namespace information array. */

    protected int fNamespaceSize;

    // NOTE: The constructor depends on the initial context size

    //       being at least 1. -Ac

    /**

     * Context indexes. This array contains indexes into the namespace

     * information array. The index at the current context is the start

     * index of declared namespace bindings and runs to the size of the

     * namespace information array.

     *

     * @see #fNamespaceSize

     */

    protected int[] fContext = new int[8];

    /** The current context. */

    protected int fCurrentContext;

    protected String[] fPrefixes = new String[16];

    //

    // Constructors

    //

    /** Default constructor. */

    public NamespaceSupport() {

    } // <init>()

    /**

     * Constructs a namespace context object and initializes it with

     * the prefixes declared in the specified context.

     */

    public NamespaceSupport(NamespaceContext context) {

        pushContext();

        // copy declaration in the context

        while (prefixes.hasMoreElements()){

            String uri = context.getURI(prefix);

            declarePrefix(prefix, uri);

        }

    } // <init>(NamespaceContext)

    //

    // Public methods

    //

    /**

     * @see com.sun.org.apache.xerces.internal.xni.NamespaceContext#reset()

     */

    public void reset() {

        // reset namespace and context info

        fNamespaceSize = 0;

        fCurrentContext = 0;

        // bind "xml" prefix to the XML uri

        fNamespace[fNamespaceSize++] = XMLSymbols.PREFIX_XML;

        fNamespace[fNamespaceSize++] = NamespaceContext.XML_URI;

        // bind "xmlns" prefix to the XMLNS uri

        fNamespace[fNamespaceSize++] = XMLSymbols.PREFIX_XMLNS;

        fNamespace[fNamespaceSize++] = NamespaceContext.XMLNS_URI;

        fContext[fCurrentContext] = fNamespaceSize;

        //++fCurrentContext;

    } // reset(SymbolTable)

    /**

     * @see com.sun.org.apache.xerces.internal.xni.NamespaceContext#pushContext()

     */

    public void pushContext() {

        // extend the array, if necessary

        if (fCurrentContext + 1 == fContext.length) {

            int[] contextarray = new int[fContext.length * 2];

            System.arraycopy(fContext, 0, contextarray, 0, fContext.length);

            fContext = contextarray;

        }

        // push context

        fContext[++fCurrentContext] = fNamespaceSize;

        //System.out.println("calling push context, current context = " + fCurrentContext);

    } // pushContext()

    /**

     * @see com.sun.org.apache.xerces.internal.xni.NamespaceContext#popContext()

     */

    public void popContext() {

        fNamespaceSize = fContext[fCurrentContext--];

        //System.out.println("Calling popContext, fCurrentContext = " + fCurrentContext);

    } // popContext()

    /**

     * @see com.sun.org.apache.xerces.internal.xni.NamespaceContext#declarePrefix(String, String)

     */

    public boolean declarePrefix(String prefix, String uri) {

        // ignore "xml" and "xmlns" prefixes

        if (prefix == XMLSymbols.PREFIX_XML || prefix == XMLSymbols.PREFIX_XMLNS) {

            return false;

        }

        // see if prefix already exists in current context

        for (int i = fNamespaceSize; i > fContext[fCurrentContext]; i -= 2) {

            if (fNamespace[i - 2] == prefix) {

                // REVISIT: [Q] Should the new binding override the

                //          previously declared binding or should it

                //          it be ignored? -Ac

                // NOTE:    The SAX2 "NamespaceSupport" helper allows

                //          re-bindings with the new binding overwriting

                //          the previous binding. -Ac

                fNamespace[i - 1] = uri;

                return true;

            }

        }

        // resize array, if needed

        if (fNamespaceSize == fNamespace.length) {

            String[] namespacearray = new String[fNamespaceSize * 2];

            System.arraycopy(fNamespace, 0, namespacearray, 0, fNamespaceSize);

            fNamespace = namespacearray;

        }

        // bind prefix to uri in current context

        fNamespace[fNamespaceSize++] = prefix;

        fNamespace[fNamespaceSize++] = uri;

        return true;

    } // declarePrefix(String,String):boolean

    /**

     * @see com.sun.org.apache.xerces.internal.xni.NamespaceContext#getURI(String)

     */

    public String getURI(String prefix) {

        // find prefix in current context

        for (int i = fNamespaceSize; i > 0; i -= 2) {

            if (fNamespace[i - 2] == prefix) {

                return fNamespace[i - 1];

            }

        }

        // prefix not found

        return null;

    } // getURI(String):String

    /**

     * @see com.sun.org.apache.xerces.internal.xni.NamespaceContext#getPrefix(String)

     */

    public String getPrefix(String uri) {

        // find uri in current context

        for (int i = fNamespaceSize; i > 0; i -= 2) {

            if (fNamespace[i - 1] == uri) {

                if (getURI(fNamespace[i - 2]) == uri)

                    return fNamespace[i - 2];

            }

        }

        // uri not found

        return null;

    } // getPrefix(String):String

    /**

     * @see com.sun.org.apache.xerces.internal.xni.NamespaceContext#getDeclaredPrefixCount()

     */

    public int getDeclaredPrefixCount() {

        return (fNamespaceSize - fContext[fCurrentContext]) / 2;

    } // getDeclaredPrefixCount():int

    /**

     * @see com.sun.org.apache.xerces.internal.xni.NamespaceContext#getDeclaredPrefixAt(int)

     */

    public String getDeclaredPrefixAt(int index) {

        return fNamespace[fContext[fCurrentContext] + index * 2];

    } // getDeclaredPrefixAt(int):String

        int count = 0;

        if (fPrefixes.length < (fNamespace.length/2)) {

            // resize prefix array

            String[] prefixes = new String[fNamespaceSize];

            fPrefixes = prefixes;

        }

        String prefix = null;

        boolean unique = true;

        for (int i = 2; i < (fNamespaceSize-2); i += 2) {

            prefix = fNamespace[i + 2];

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

                if (fPrefixes[k]==prefix){

                    unique = false;

                    break;

                }

            }

            if (unique){

                fPrefixes[count++] = prefix;

            }

            unique = true;

        }

        return new IteratorPrefixes(fPrefixes, count);

    }//getPrefixes

    /**

     * @see com.sun.org.apache.xerces.internal.xni.NamespaceContext#getAllPrefixes()

     */

        int count = 0;

        if (fPrefixes.length < (fNamespace.length/2)) {

            // resize prefix array

            String[] prefixes = new String[fNamespaceSize];

            fPrefixes = prefixes;

        }

        String prefix = null;

        boolean unique = true;

        for (int i = 2; i < (fNamespaceSize-2); i += 2) {

            prefix = fNamespace[i + 2];

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

                if (fPrefixes[k]==prefix){

                    unique = false;

                    break;

                }

            }

            if (unique){

                fPrefixes[count++] = prefix;

            }

            unique = true;

        }

        return new Prefixes(fPrefixes, count);

    }

        int count = 0;

        String prefix = null;

        boolean unique = true;

        for (int i = fNamespaceSize; i >0 ; i -= 2) {

            if(fNamespace[i-1] == uri){

                if(!prefixList.contains(fNamespace[i-2]))

                    prefixList.add(fNamespace[i-2]);

            }

        }

        return prefixList;

    }

    /*

     * non-NamespaceContext methods

     */

    /**

     * Checks whether a binding or unbinding for

     * the given prefix exists in the context.

     *

     * @param prefix The prefix to look up.

     *

     * @return true if the given prefix exists in the context

     */

    public boolean containsPrefix(String prefix) {

        // find prefix in context

        for (int i = fNamespaceSize; i > 0; i -= 2) {

            if (fNamespace[i - 2] == prefix) {

                return true;

            }

        }

        // prefix not found

        return false;

    }

    /**

     * Checks whether a binding or unbinding for

     * the given prefix exists in the current context.

     *

     * @param prefix The prefix to look up.

     *

     * @return true if the given prefix exists in the current context

     */

    public boolean containsPrefixInCurrentContext(String prefix) {

        // find prefix in current context

        for (int i = fContext[fCurrentContext]; i < fNamespaceSize; i += 2) {

            if (fNamespace[i] == prefix) {

                return true;

            }

        }

        // prefix not found

        return false;

    }

        private String[] prefixes;

        private int counter = 0;

        private int size = 0;

        /**

         * Constructor for Prefixes.

         */

        public IteratorPrefixes(String [] prefixes, int size) {

            this.prefixes = prefixes;

            this.size = size;

        }

        /**

         * @see java.util.Enumeration#hasMoreElements()

         */

        public boolean hasNext() {

            return (counter < size);

        }

        /**

         * @see java.util.Enumeration#nextElement()

         */

            if (counter< size){

                return fPrefixes[counter++];

            }

            throw new NoSuchElementException("Illegal access to Namespace prefixes enumeration.");

        }

        public String toString(){

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

                buf.append(prefixes[i]);

                buf.append(" ");

            }

            return buf.toString();

        }

        public void remove(){

            throw new UnsupportedOperationException();

        }

    }

        private String[] prefixes;

        private int counter = 0;

        private int size = 0;

        /**

         * Constructor for Prefixes.

         */

        public Prefixes(String [] prefixes, int size) {

            this.prefixes = prefixes;

            this.size = size;

        }

        /**

         * @see java.util.Enumeration#hasMoreElements()

         */

        public boolean hasMoreElements() {

            return (counter< size);

        }

        /**

         * @see java.util.Enumeration#nextElement()

         */

            if (counter< size){

                return fPrefixes[counter++];

            }

            throw new NoSuchElementException("Illegal access to Namespace prefixes enumeration.");

        }

        public String toString(){

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

                buf.append(prefixes[i]);

                buf.append(" ");

            }

            return buf.toString();

        }

    }

} // class NamespaceSupport