/*

 */

/*

 * 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.xinclude;

import com.sun.org.apache.xerces.internal.util.NamespaceSupport;

import com.sun.org.apache.xerces.internal.util.XMLSymbols;

import com.sun.org.apache.xerces.internal.xni.NamespaceContext;

/**

 * This implementation of NamespaceContext has the ability to maintain multiple

 * scopes of namespace/prefix bindings.  This is useful in situations when it is

 * not always appropriate for elements to inherit the namespace bindings of their

 * ancestors (such as included elements in XInclude).

 *

 * When searching for a URI to match a prefix, or a prefix to match a URI, it is

 * searched for in the current context, then the ancestors of the current context,

 * up to the beginning of the current scope.  Other scopes are not searched.

 *

 * @author Peter McCracken, IBM

 *

 */

public class MultipleScopeNamespaceSupport extends NamespaceSupport {

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

    protected int fCurrentScope;

    /**

     *

     */

    public MultipleScopeNamespaceSupport() {

        super();

        fCurrentScope = 0;

        fScope[0] = 0;

    }

    /**

     * @param context

     */

    public MultipleScopeNamespaceSupport(NamespaceContext context) {

        super(context);

        fCurrentScope = 0;

        fScope[0] = 0;

    }

    /* (non-Javadoc)

     * @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 = fContext[fScope[fCurrentScope]];

            i <= (fNamespaceSize - 2);

            i += 2) {

            prefix = fNamespace[i];

            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);

    }

    public int getScopeForContext(int context) {

        int scope = fCurrentScope;

        while (context < fScope[scope]) {

            scope--;

        }

        return scope;

    }

    /* (non-Javadoc)

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

     */

    public String getPrefix(String uri) {

        return getPrefix(uri, fNamespaceSize, fContext[fScope[fCurrentScope]]);

    }

    /* (non-Javadoc)

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

     */

    public String getURI(String prefix) {

        return getURI(prefix, fNamespaceSize, fContext[fScope[fCurrentScope]]);

    }

    public String getPrefix(String uri, int context) {

        return getPrefix(uri, fContext[context+1], fContext[fScope[getScopeForContext(context)]]);

    }

    public String getURI(String prefix, int context) {

        return getURI(prefix, fContext[context+1], fContext[fScope[getScopeForContext(context)]]);

    }

    public String getPrefix(String uri, int start, int end) {

        // this saves us from having a copy of each of these in fNamespace for each scope

        if (uri == NamespaceContext.XML_URI) {

            return XMLSymbols.PREFIX_XML;

        }

        if (uri == NamespaceContext.XMLNS_URI) {

            return XMLSymbols.PREFIX_XMLNS;

        }

        // find uri in current context

        for (int i = start; i > end; i -= 2) {

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

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

                    return fNamespace[i - 2];

            }

        }

        // uri not found

        return null;

    }

    public String getURI(String prefix, int start, int end) {

        // this saves us from having a copy of each of these in fNamespace for each scope

        if (prefix == XMLSymbols.PREFIX_XML) {

            return NamespaceContext.XML_URI;

        }

        if (prefix == XMLSymbols.PREFIX_XMLNS) {

            return NamespaceContext.XMLNS_URI;

        }

        // find prefix in current context

        for (int i = start; i > end; i -= 2) {

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

                return fNamespace[i - 1];

            }

        }

        // prefix not found

        return null;

    }

    /**

     * Only resets the current scope -- all namespaces defined in lower scopes

     * remain valid after a call to reset.

     */

    public void reset() {

        fCurrentContext = fScope[fCurrentScope];

        fNamespaceSize = fContext[fCurrentContext];

    }

    /**

     * Begins a new scope.  None of the previous namespace bindings will be used,

     * until the new scope is popped with popScope()

     */

    public void pushScope() {

        if (fCurrentScope + 1 == fScope.length) {

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

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

            fScope = contextarray;

        }

        pushContext();

        fScope[++fCurrentScope] = fCurrentContext;

    }

    /**

     * Pops the current scope.  The namespace bindings from the new current scope

     * are then used for searching for namespaces and prefixes.

     */

    public void popScope() {

        fCurrentContext = fScope[fCurrentScope--];

        popContext();

    }

}