// TcpServer.java SJ
// Alkeellinen palvelin asiakassovellusten testaamiseen
// Kukin uusi yhteys avaa uuden ikkunan jossa palvelimen komentoja voi
// naputella asiakkaalle.
// copy-pastattu omista TCP-esimerkeistä ja Java-tutorialin GUI esimerkeistä

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.net.*;
import java.util.Scanner;
import java.io.*;
import java.lang.Thread;


public class TcpServer {

    ServerSocket ss = null;

    public static void main(String[] args) {

        TcpServer p;

        if (args.length > 0)
            p = new TcpServer(Integer.valueOf(args[0]));
        else
            p = new TcpServer();

        p.waitForConnections();

    } // main()


    // konstruktorit avaavat yhteyden kuuntelulle
    public TcpServer(int portti) {

        try {
            ss = new ServerSocket(portti);
            System.out.println("Kuunnellaan porttia " + portti);
        } catch (Exception e) {
            System.err.println(e);
            ss = null;
        }
    }

    public TcpServer() {
        this(1234);
    }

    public void waitForConnections() {
        try {
            while (true) {

                // odotetaan uutta yhteyttä
                Socket cs = ss.accept();

                // luodaan ja käynnistetää uusi palvelijasäie
                // new TcpServerForClient(cs).start();
                new ConnectionThread(cs).start();
            }
        } catch (Exception e) {
            System.err.println(e);
            ss = null;
        }
    }   // kuuntele()




    private class ConnectionThread extends Thread {
        BufferedReader in = null;
        PrintWriter out = null;
        Socket cs = null;

        boolean stopped = false;

        TcpServerGUI gui = null;

        String title = "Connection";

        public ConnectionThread(Socket s) {
            super();
            cs = s;
            try {
                in = new BufferedReader(new InputStreamReader(cs.getInputStream()));
                out = new PrintWriter(cs.getOutputStream(), true);
            } catch (Exception e) {
                System.err.println(e);
                // TODO exit GUI
                // close socket
            }

            title = "TCPServer " + cs.getInetAddress() + ":" + cs.getPort();

            gui = new TcpServerGUI(this);

        }

        private void createAndShowGUI() {
            //Create and set up the window.
            JFrame frame = new JFrame(title);
            // frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

            //Add contents to the window.
            frame.add(gui);

            frame.addWindowListener(new WindowAdapter() {
                public void windowClosing(WindowEvent winEvent) {
                    closeConnection();
                }
            });



            //Display the window.
            frame.pack();
            frame.setVisible(true);
        }

        public void sendLine(String message) {
            try {
                out.println(message);
            } catch (Exception e) {
                System.err.println(e);
                // TODO exit GUI
                // close socket
            }

        }

        // called when window is closed
        public void closeConnection() {
            stopped = true;
            sendLine("Server Closing");
            try {
                cs.close();
                cs = null;
            } catch (Exception e) {
                System.err.println(e);
                // TODO exit GUI
                // close socket
            }

        }


        public void run() {

            // start GUI
            javax.swing.SwingUtilities.invokeLater(new Runnable() {
                public void run() {
                    createAndShowGUI();
                }
            });


            try {

                while (true) {
                    String rs = in.readLine();
                    if (rs == null) {
                        gui.writeLine("Connection lost");
                        return;
                    }
                    rs = rs.trim();
                    if (rs.isEmpty())
                        continue;

                    gui.writeLine(rs);

                } // while


            } catch (Exception e) {
                if (! stopped) {
                    System.err.println(e);
                    gui.writeLine(e.toString());
                }
            } finally {
                try {
                    cs.close();
                } catch (Exception e2) {};
                cs = null;
                gui.stop();
            }


        } // run()

    } // class ConnectionThread






    // GUI for single user
    // skeleton code copied from Sun Java Tutorial
    private class TcpServerGUI extends JPanel implements ActionListener {


        protected JTextField textField;
        protected JTextArea textArea;
        ConnectionThread thread = null;

        boolean stopped = false;

        String client = "Client>";


        public TcpServerGUI(ConnectionThread conn) {

            // Build GUI
            super(new GridBagLayout());

            textField = new JTextField(50);
            textField.addActionListener(this);

            textArea = new JTextArea(15, 50);
            textArea.setEditable(false);
            JScrollPane scrollPane = new JScrollPane(textArea);

            //Add Components to this panel.
            GridBagConstraints c = new GridBagConstraints();
            c.gridwidth = GridBagConstraints.REMAINDER;

            c.fill = GridBagConstraints.HORIZONTAL;
            add(textField, c);

            c.fill = GridBagConstraints.BOTH;
            c.weightx = 1.0;
            c.weighty = 1.0;
            add(scrollPane, c);

            thread = conn;

        }

        public void stop() {
            final String msg = "STOPPED\n";
            stopped = true;
            SwingUtilities.invokeLater(new Runnable() {
                public void run() {
                    textArea.append(msg);
                }});
        }

        // called from another thread
        public void writeLine(String message) {
            final String msg = message;
            SwingUtilities.invokeLater(new Runnable() {
                public void run() {
                    textArea.append(client + msg + "<\n");
                }});
        }

        public void actionPerformed(ActionEvent evt) {
            if (stopped)
                return;
            String text = textField.getText();
            textArea.append("Server> " + text + "\n");
            textField.selectAll();

            //Make sure the new text is visible, even if there
            //was a selection in the text area.
            textArea.setCaretPosition(textArea.getDocument().getLength());

            thread.sendLine(text);
        }
    }   // class TcpServerGUI



} // class TcpServer