/*
 * 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.commons.net.whois;

import java.io.IOException;
import java.io.InputStream;

import org.apache.commons.net.finger.FingerClient;

/**
 * The WhoisClient class implements the client side of the Internet Whois Protocol defined in RFC 954. To query a host you create a WhoisClient instance,
 * connect to the host, query the host, and finally disconnect from the host. If the whois service you want to query is on a non-standard port, connect to the
 * host at that port. Here's a sample use:
 *
 * <pre>
 * WhoisClient whois;
 *
 * whois = new WhoisClient();
 *
 * try {
 *     whois.connect(WhoisClient.DEFAULT_HOST);
 *     System.out.println(whois.query("foobar"));
 *     whois.disconnect();
 * } catch (IOException e) {
 *     System.err.println("Error I/O exception: " + e.getMessage());
 *     return;
 * }
 * </pre>
 */

public final class WhoisClient extends FingerClient {
    /**
     * The default whois host to query. It is set to whois.internic.net.
     */
    public static final String DEFAULT_HOST = "whois.internic.net";

    /**
     * The default whois port. It is set to 43 according to RFC 954.
     */
    public static final int DEFAULT_PORT = 43;

    /**
     * The default whois constructor. Initializes the default port to <code> DEFAULT_PORT </code>.
     */
    public WhoisClient() {
        setDefaultPort(DEFAULT_PORT);
    }

    /**
     * Queries the connected whois server for information regarding the given handle and returns the InputStream of the network connection. It is up to the
     * programmer to be familiar with the handle syntax of the whois server. You must first connect to a finger server before calling this method, and you
     * should disconnect after finishing reading the stream.
     *
     * @param handle The handle to lookup.
     * @return The InputStream of the network connection of the whois query. Can be read to obtain whois results.
     * @throws IOException If an I/O error occurs during the operation.
     */
    public InputStream getInputStream(final String handle) throws IOException {
        return getInputStream(false, handle);
    }

    /**
     * Queries the connected whois server for information regarding the given handle. It is up to the programmer to be familiar with the handle syntax of the
     * whois server. You must first connect to a whois server before calling this method, and you should disconnect afterward.
     *
     * @param handle The handle to lookup.
     * @return The result of the whois query.
     * @throws IOException If an I/O error occurs during the operation.
     */
    public String query(final String handle) throws IOException {
        return query(false, handle);
    }

}
