/*
 * 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.sling.crankstart.launcher;

import java.io.IOException;

import org.apache.http.HttpException;
import org.apache.http.HttpHost;
import org.apache.http.HttpRequest;
import org.apache.http.HttpRequestInterceptor;
import org.apache.http.auth.AuthScope;
import org.apache.http.auth.AuthState;
import org.apache.http.auth.Credentials;
import org.apache.http.client.CredentialsProvider;
import org.apache.http.client.protocol.ClientContext;
import org.apache.http.impl.auth.BasicScheme;
import org.apache.http.protocol.ExecutionContext;
import org.apache.http.protocol.HttpContext;

/** It's not like httpclient 4.1 makes this simple... */
class PreemptiveAuthInterceptor implements HttpRequestInterceptor {

    public void process(HttpRequest request, HttpContext context) throws HttpException, IOException {

        AuthState authState = (AuthState) context.getAttribute(ClientContext.TARGET_AUTH_STATE);
        CredentialsProvider credsProvider = (CredentialsProvider) context.getAttribute(ClientContext.CREDS_PROVIDER);
        HttpHost targetHost = (HttpHost) context.getAttribute(ExecutionContext.HTTP_TARGET_HOST);

        // If not auth scheme has been initialized yet
        if (authState.getAuthScheme() == null) {
            AuthScope authScope = new AuthScope(targetHost.getHostName(), targetHost.getPort());

            // Obtain credentials matching the target host
            Credentials creds = credsProvider.getCredentials(authScope);

            // If found, generate BasicScheme preemptively
            if (creds != null) {
                authState.setAuthScheme(new BasicScheme());
                authState.setCredentials(creds);
            }
        }
    }
}