/*
 * ====================================================================
 * 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.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 */
package org.apache.http.auth;

import java.util.ArrayList;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

import org.apache.http.HttpRequest;
import org.apache.http.annotation.Contract;
import org.apache.http.annotation.ThreadingBehavior;
import org.apache.http.config.Lookup;
import org.apache.http.params.HttpParams;
import org.apache.http.protocol.ExecutionContext;
import org.apache.http.protocol.HttpContext;
import org.apache.http.util.Args;

Authentication scheme registry that can be used to obtain the corresponding
authentication scheme implementation for a given type of authorization challenge.
Since:
4.0
Deprecated:
(4.3) use Registry/**
 * Authentication scheme registry that can be used to obtain the corresponding
 * authentication scheme implementation for a given type of authorization challenge.
 *
 * @since 4.0
 *
 * @deprecated (4.3) use {@link org.apache.http.config.Registry}
 */
@Contract(threading = ThreadingBehavior.SAFE)
@Deprecated
public final class AuthSchemeRegistry implements Lookup<AuthSchemeProvider> {

    private final ConcurrentHashMap<String,AuthSchemeFactory> registeredSchemes;

    public AuthSchemeRegistry() {
        super();
        this.registeredSchemes = new ConcurrentHashMap<String,AuthSchemeFactory>();
    }

    
Registers a AuthSchemeFactory with the given identifier. If a factory with the given name already exists it will be overridden. This name is the same one used to retrieve the authentication scheme from getAuthScheme. 
 Please note that custom authentication preferences, if used, need to be updated accordingly for the new authentication scheme to take effect. 
Params:
name – the identifier for this scheme
factory – the AuthSchemeFactory class to register
See Also:
getAuthScheme/**
     * Registers a {@link AuthSchemeFactory} with  the given identifier. If a factory with the
     * given name already exists it will be overridden. This name is the same one used to
     * retrieve the {@link AuthScheme authentication scheme} from {@link #getAuthScheme}.
     *
     * <p>
     * Please note that custom authentication preferences, if used, need to be updated accordingly
     * for the new {@link AuthScheme authentication scheme} to take effect.
     * </p>
     *
     * @param name the identifier for this scheme
     * @param factory the {@link AuthSchemeFactory} class to register
     *
     * @see #getAuthScheme
     */
    public void register(
            final String name,
            final AuthSchemeFactory factory) {
         Args.notNull(name, "Name");
        Args.notNull(factory, "Authentication scheme factory");
        registeredSchemes.put(name.toLowerCase(Locale.ENGLISH), factory);
    }

    
Unregisters the class implementing an authentication scheme with the given name. 
Params:
name – the identifier of the class to unregister/**
     * Unregisters the class implementing an {@link AuthScheme authentication scheme} with
     * the given name.
     *
     * @param name the identifier of the class to unregister
     */
    public void unregister(final String name) {
         Args.notNull(name, "Name");
        registeredSchemes.remove(name.toLowerCase(Locale.ENGLISH));
    }

    
Gets the authentication scheme with the given name. 
Params:
name – the authentication scheme identifier
params – the HTTP parameters for the authentication scheme.
Throws:
IllegalStateException – if a scheme with the given name cannot be found
Returns:
authentication scheme/**
     * Gets the {@link AuthScheme authentication scheme} with the given name.
     *
     * @param name the {@link AuthScheme authentication scheme} identifier
     * @param params the {@link HttpParams HTTP parameters} for the authentication
     *  scheme.
     *
     * @return {@link AuthScheme authentication scheme}
     *
     * @throws IllegalStateException if a scheme with the given name cannot be found
     */
    public AuthScheme getAuthScheme(final String name, final HttpParams params)
        throws IllegalStateException {

        Args.notNull(name, "Name");
        final AuthSchemeFactory factory = registeredSchemes.get(name.toLowerCase(Locale.ENGLISH));
        if (factory != null) {
            return factory.newInstance(params);
        }
        throw new IllegalStateException("Unsupported authentication scheme: " + name);
    }

    
Obtains a list containing the names of all registered authentication
schemes 
Returns:
list of registered scheme names/**
     * Obtains a list containing the names of all registered {@link AuthScheme authentication
     * schemes}
     *
     * @return list of registered scheme names
     */
    public List<String> getSchemeNames() {
        return new ArrayList<String>(registeredSchemes.keySet());
    }

    
Populates the internal collection of registered authentication schemes with the content of the map passed as a parameter. 
Params:
map – authentication schemes/**
     * Populates the internal collection of registered {@link AuthScheme authentication schemes}
     * with the content of the map passed as a parameter.
     *
     * @param map authentication schemes
     */
    public void setItems(final Map<String, AuthSchemeFactory> map) {
        if (map == null) {
            return;
        }
        registeredSchemes.clear();
        registeredSchemes.putAll(map);
    }

    @Override
    public AuthSchemeProvider lookup(final String name) {
        return new AuthSchemeProvider() {

            @Override
            public AuthScheme create(final HttpContext context) {
                final HttpRequest request = (HttpRequest) context.getAttribute(
                        ExecutionContext.HTTP_REQUEST);
                return getAuthScheme(name, request.getParams());
            }

        };
    }

}