/*
 * 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.jackrabbit.oak.jcr.namespace;

import java.util.Locale;

import javax.jcr.NamespaceException;
import javax.jcr.NamespaceRegistry;
import javax.jcr.RepositoryException;

import org.apache.jackrabbit.oak.api.CommitFailedException;
import org.apache.jackrabbit.oak.api.ContentSession;
import org.apache.jackrabbit.oak.plugins.name.NamespaceMappings;

/**
 * Implementation of {@link NamespaceRegistry} based on {@link NamespaceMappings}.
 */
public class NamespaceRegistryImpl implements NamespaceRegistry {

    private final NamespaceMappings nsMappings;

    public NamespaceRegistryImpl(ContentSession session) {
        this.nsMappings = new NamespaceMappings(session);
    }

    //--------------------------------------------------< NamespaceRegistry >---
    @Override
    public void registerNamespace(String prefix, String uri)
            throws RepositoryException {
        checkMutablePrefix(prefix);
        checkMutableURI(uri);
        try {
            nsMappings.registerNamespace(prefix, uri);
        } catch (CommitFailedException e) {
            throw new RepositoryException(
                    "Failed to register namespace mapping from "
                    + prefix + " to " + uri, e);
        }
    }

    @Override
    public void unregisterNamespace(String prefix) throws RepositoryException {
        checkMutablePrefix(prefix);
        try {
            if (nsMappings.getURI(prefix) == null) {
                throw new NamespaceException("prefix '" + prefix + "' is unused");
            }
            nsMappings.unregisterNamespace(prefix);
        } catch (CommitFailedException e) {
            throw new RepositoryException(
                    "Failed to unregister a namespace mapping with prefix "
                    + prefix, e);
        }
    }

    @Override
    public String[] getPrefixes() throws RepositoryException {
        try {
            return nsMappings.getPrefixes();
        } catch (RuntimeException e) {
            throw new RepositoryException(
                    "Failed to retrieve registered namespace prefixes", e);
        }
    }

    @Override
    public String[] getURIs() throws RepositoryException {
        try {
            return nsMappings.getURIs();
        } catch (RuntimeException e) {
            throw new RepositoryException(
                    "Failed to retrieve registered namespace URIs", e);
        }
    }

    @Override
    public String getURI(String prefix) throws RepositoryException {
        try {
            String uri = nsMappings.getURI(prefix);
            if (uri == null) {
                throw new NamespaceException(
                        "No namespace registered for prefix " + prefix);
            }
            return uri;
        } catch (RuntimeException e) {
            throw new RepositoryException(
                    "Failed to retrieve the namespace URI for prefix "
                    + prefix, e);
        }
    }

    @Override
    public String getPrefix(String uri) throws RepositoryException {
        try {
            String prefix = nsMappings.getPrefix(uri);
            if (prefix == null) {
                throw new NamespaceException(
                        "No namespace registered for prefix " + prefix);
            }
            return prefix;
        } catch (RuntimeException e) {
            throw new RepositoryException(
                    "Failed to retrieve the namespace prefix for URI "
                    + uri, e);
        }
    }

    private void checkMutablePrefix(String prefix) throws NamespaceException {
        if ("jcr".equals(prefix) || "nt".equals(prefix) || "mix".equals(prefix) || "sv".equals(prefix)
                || prefix.toLowerCase(Locale.ENGLISH).startsWith("xml")) {
            throw new NamespaceException("Can not map or remap prefix '" + prefix + "'");
        }
    }

    private void checkMutableURI(String uri) throws NamespaceException {
        if ("http://www.jcp.org/jcr/1.0".equals(uri) || "http://www.jcp.org/jcr/nt/1.0".equals(uri)
                || "http://www.jcp.org/jcr/mix/1.0".equals(uri) || "http://www.jcp.org/jcr/sv/1.0".equals(uri)) {
            throw new NamespaceException("Can not map or remap uri '" + uri + "'");
        }
    }
}

@@ -868,24 +868,57 @@
 il.Locale;%0A%0A
+import javax.annotation.Nonnull;%0A
 import javax
@@ -2643,32 +2643,45 @@
 %0A%0A    @Override%0A
+    @Nonnull%0A
     public Strin
@@ -2719,32 +2719,32 @@
 toryException %7B%0A
-
         try %7B%0A  
@@ -2967,32 +2967,45 @@
 %0A%0A    @Override%0A
+    @Nonnull%0A
     public Strin
@@ -3279,32 +3279,45 @@
 %0A%0A    @Override%0A
+    @Nonnull%0A
     public Strin
@@ -3833,32 +3833,45 @@
 %0A%0A    @Override%0A
+    @Nonnull%0A
     public Strin
@@ -4125,33 +4125,28 @@
 red for 
-prefix %22 + prefix
+uri: %22 + uri
 );%0A     

Use nullability annotation to enforce/document API contract (WIP), also fix exception message