// File: TutorialDescriptionServer.java
//
// Author: Francois Coupleux (coupleux@eleve.emn.fr)
//
// Date: 7-8-1996
//
// Description: Server which sends the description of the tutorial to the applet Visualizer.

import java.net.*;
import java.io.*;
import java.util.*;

// Class TutorialDescriptionServer
// -------------------------------

// This class is the model for the server which will send information
// concerning the tutorial to the applet.

public class TutorialDescriptionServer
{
Vector windowNames , windowTypes , beginningsOfDescriptions;

  // main()
  // ------

  public static void main(String[] args)
  {
    RandomAccessFile descriptionFile;
    Vector windowNames , windowTitles , windowTypes , beginningsOfDescriptions;
    ServerSocket serverSocket;
    Socket clientSocket;
    DataInputStream inputStream;
    PrintStream outputStream;
    String currentLine , keyword , queryKey , sectionDelimiter , windowType;
    StringTokenizer stringTokenizer;
    int i;
    boolean isTitleRequest;

    try
    {
      // Creates the file

      descriptionFile = new RandomAccessFile("tutorialdescription.dat" , "r");

      // Creates the vectors which will be used to look for a specific window

      windowNames = new Vector();
      windowTitles = new Vector();
      windowTypes = new Vector();
      beginningsOfDescriptions = new Vector();

      // Puts elements in the vectors

      while((currentLine = descriptionFile.readLine()) != null)
      {
        stringTokenizer = new StringTokenizer(currentLine , " ");
        keyword = stringTokenizer.nextToken();

        // Locates the beginning of default values section and main menu definition

        if(keyword.equals("DEFAULTVALUES") || keyword.equals("MAINMENU"))
        {
          windowNames.addElement(keyword);
          windowTitles.addElement(keyword);
          windowTypes.addElement(keyword);
          beginningsOfDescriptions.addElement(new Long(descriptionFile.getFilePointer()));
        }

        // If the part read in the file correspond to a menu, a plotting system or a window

        if(keyword.equals("MENU") || keyword.equals("PLOTTINGSYSTEM") || keyword.equals("WINDOW"))
        {
          // Sets the window type and the beginning of the description

          windowTypes.addElement(keyword);
          beginningsOfDescriptions.addElement(new Long(descriptionFile.getFilePointer()));
        }

        // If the keyword NAME is read

        if(keyword.equals("NAME"))
        {
          // Sets the name of the window

          windowNames.addElement(stringTokenizer.nextToken());
        }

        // If the keyword WINDOWTITLE is read

        if(keyword.equals("WINDOWTITLE"))
        {
          // Sets the title of the window

          windowTitles.addElement(currentLine.substring(12));
        }
      }

      // Creates a server socket on the port 8000

      serverSocket = new ServerSocket(8000);

      while(true)
      {
        // Accepts a client

        clientSocket = serverSocket.accept();

        // Opens input and output streams

        inputStream = new DataInputStream(clientSocket.getInputStream());
        outputStream = new PrintStream(clientSocket.getOutputStream());

        while ((queryKey = inputStream.readLine()) == null)
        { ; }

        // By default the request doesn't concern a title

        isTitleRequest = false;

        // If the query key begins with "TITLE"

        if(queryKey.startsWith("TITLE"))
        {
          // Gets the name of the window

          stringTokenizer = new StringTokenizer(queryKey , " ");
          stringTokenizer.nextToken();
          queryKey = stringTokenizer.nextToken();

          // This is a request about a title

          isTitleRequest = true;
        }

        i = 0;

        while(! ((String)windowNames.elementAt(i)).equals(queryKey))
        {
          i++;
        }

        // If the section corresponding to the request is not found

        if(i == windowNames.size())
        {
          outputStream.println("Not Found");
        }

        // If the section is found

        else
        {
          // If the request is about a title

          if(isTitleRequest)
          {
            outputStream.println((String)windowTitles.elementAt(i));
          }

          // If the request is about a window description

          else
          {
            // Places the file pointer at the right position

            descriptionFile.seek(((Long)beginningsOfDescriptions.elementAt(i)).longValue());

            sectionDelimiter = "END" + queryKey;

            // If the request concerns a window

            if(! (queryKey.equals("DEFAULTVALUES") || queryKey.equals("MAINMENU")))
            {
              windowType = (String)windowTypes.elementAt(i);

              sectionDelimiter = "END" + windowType;

              // Sends the type of the window to the applet

              outputStream.println(windowType);
            }

            // Sends description

            while(! (currentLine = descriptionFile.readLine()).equals(sectionDelimiter))
            {
              outputStream.println(currentLine);      
            }
          }
        }

        // Closes streams

        outputStream.close();
        inputStream.close();

        // Closes client socket

        clientSocket.close();
      }
    }

    // If a problem occured

    catch (IOException e)
    {
      System.out.println("Error: Impossible to run the server.");
    }
  }
}