/*
 * ====================================================================
 * 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 ch.boye.httpclientandroidlib.client.protocol;

import java.io.IOException;

import ch.boye.httpclientandroidlib.HttpException;
import ch.boye.httpclientandroidlib.HttpRequest;
import ch.boye.httpclientandroidlib.annotation.Immutable;
import ch.boye.httpclientandroidlib.auth.AUTH;
import ch.boye.httpclientandroidlib.auth.AuthState;
import ch.boye.httpclientandroidlib.conn.HttpRoutedConnection;
import ch.boye.httpclientandroidlib.conn.routing.HttpRoute;
import ch.boye.httpclientandroidlib.protocol.ExecutionContext;
import ch.boye.httpclientandroidlib.protocol.HttpContext;

/**
 * Generates authentication header for the proxy host, if required,
 * based on the actual state of the HTTP authentication context.
 *
 * @since 4.0
 */
@Immutable
public class RequestProxyAuthentication extends RequestAuthenticationBase {

    public RequestProxyAuthentication() {
        super();
    }

    public void process(final HttpRequest request, final HttpContext context)
            throws HttpException, IOException {
        if (request == null) {
            throw new IllegalArgumentException("HTTP request may not be null");
        }
        if (context == null) {
            throw new IllegalArgumentException("HTTP context may not be null");
        }

        if (request.containsHeader(AUTH.PROXY_AUTH_RESP)) {
            return;
        }

        HttpRoutedConnection conn = (HttpRoutedConnection) context.getAttribute(
                ExecutionContext.HTTP_CONNECTION);
        if (conn == null) {
            this.log.debug("HTTP connection not set in the context");
            return;
        }
        HttpRoute route = conn.getRoute();
        if (route.isTunnelled()) {
            return;
        }

        // Obtain authentication state
        AuthState authState = (AuthState) context.getAttribute(
                ClientContext.PROXY_AUTH_STATE);
        if (authState == null) {
            this.log.debug("Proxy auth state not set in the context");
            return;
        }
        if (this.log.isDebugEnabled()) {
            this.log.debug("Proxy auth state: " + authState.getState());
        }
        process(authState, request, context);
    }

}
