/*
 * [EchoServer.java]
 *
 * Summary: a mindlessly simple HTTP server.
 *
 * Copyright: (c) 2004-2017 Roedy Green, Canadian Mind Products, http://mindprod.com
 *
 * Licence: This software may be copied and used freely for any purpose but military.
 *          http://mindprod.com/contact/nonmil.html
 *
 * Requires: JDK 1.8+
 *
 * Created with: JetBrains IntelliJ IDEA IDE http://www.jetbrains.com/idea/
 *
 * Version History:
 *  1.0 2004-04-03 initial version
 *  1.1 2005-01-01 copyright update
 *  1.2 2006-01-01 copyright update
 *  1.3 2006-03-06 improve docs.
 */
package com.mindprod.echoserver;

import java.io.IOException;
import java.io.InputStream;
import java.net.ServerSocket;
import java.net.Socket;

import static java.lang.System.*;

/**
 * a mindlessly simple HTTP server.
 * <p/>
 * It just dumps what it receives on the server console. It does not
 * even echo back to the sender in an HTML sandwich. Send things to it with http://localhost:808/xxxx May be use freely
 *
 * @author Roedy Green, Canadian Mind Products
 * @version 1.3 2006-03-06 improve docs.
 * @since 2004-04-03
 */
public final class EchoServer
    {
    /**
     * How to display Cr control characters. Set to 15 to dislay as Crs. 3=heart in IBMOEM font.
     */
    private static final char SHOW_CR_AS = 3;

    private static final int FIRST_COPYRIGHT_YEAR = 2004;

    /**
     * Port the server expects data on.
     */
    private static final int PORT = 8081;

    /**
     * undisplayed copyright notice
     */
    private static final String EMBEDDED_COPYRIGHT =
            "Copyright: (c) 2004-2017 Roedy Green, Canadian Mind Products, http://mindprod.com";

    private static final String RELEASE_DATE = "2006-03-06";

    /**
     * embedded version string.
     */
    private static final String VERSION_STRING = "1.3";

    /**
     * main runs until you Ctrl-C kill it echoing messages that it receives on the port.
     *
     * @param args not used.
     */
    public static void main( String[] args )
        {
        int streamCount = 0;
        try
            {
            out.println( "EchoServer waiting on port " + PORT + " ..." );
            ServerSocket echo = new ServerSocket( PORT );
            while ( true )
                {
                Socket socket = echo.accept();
                ( new EchoClientThread( ++streamCount, socket ) ).start();
                }
            }
        catch ( IOException e )
            {
            err.println( e );
            System.exit( 1 );
            }
        }

    /**
     * Inner class, one per stream.
     * <p/>
     * created with Intellij Idea
     *
     * @author Roedy Green, Canadian Mind Products
     */
    static final class EchoClientThread extends Thread
        {
        private final Socket socket;

        private final int id;

        /**
         * Contructor
         *
         * @param id     Unique number to identify this thread.
         * @param socket opened Socket no receive on.
         */
        public EchoClientThread( int id, Socket socket )
            {
            this.id = id;
            this.socket = socket;
            }

        /**
         * Thread that reads the stream and closes the socket for one message.
         */
        public void run()
            {
            out.println( ">>starting socket " + id );
            try
                {
                InputStream in = socket.getInputStream();
                int c;
                while ( ( c = in.read() ) >= 0 )
                    {
                    if ( c == '\r' )
                        {
                        c = SHOW_CR_AS/* show Cr as heart in IBMOEM font */;
                        }
                    // echo to console
                    out.print( ( char ) c );
                    }
                out.println( ">>closing socket " + id );
                in.close();
                socket.close();
                }
            catch ( IOException e )
                {
                err.println( e.getMessage() );
                }
            }
        }
    }