/*
 * 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.camel.component.http.interceptor;

import java.nio.charset.StandardCharsets;
import java.util.Base64;

import org.apache.hc.core5.http.Header;
import org.apache.hc.core5.http.HttpException;
import org.apache.hc.core5.http.HttpHeaders;
import org.apache.hc.core5.http.HttpRequest;
import org.apache.hc.core5.http.ProtocolException;

public class BasicAuthTokenExtractor {

    public String extract(final HttpRequest request) throws HttpException {
        String auth = null;

        Header h = request.getFirstHeader(HttpHeaders.AUTHORIZATION);
        if (h != null) {
            final String s = h.getValue();
            if (s != null) {
                auth = s.trim();
            }
        }

        if (auth != null) {
            final int i = auth.indexOf(' ');
            if (i == -1) {
                throw new ProtocolException("Invalid Authorization header: " + auth);
            }
            final String authscheme = auth.substring(0, i);
            if (authscheme.equalsIgnoreCase("basic")) {
                final String s = auth.substring(i + 1).trim();
                byte[] credsRaw = s.getBytes(StandardCharsets.US_ASCII);
                Base64.Decoder codec = Base64.getDecoder();
                auth = new String(codec.decode(credsRaw), StandardCharsets.US_ASCII);
            }
        }
        return auth;
    }
}
