/**
 * ForumServer.java  1.1  5.1.97 Michael Shoffner
 *
 * Copyright (c) 1997 Michael Shoffner. All Rights Reserved.
 *
 * Permission to use, copy, modify, and distribute this software
 * for non-commercial purposes and without fee is hereby granted
 * provided that this copyright notice appears in all copies.
 *
 * http://prominence.com/                  shoffner@prominence.com
 */                   

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

public class ForumServer extends Thread {

  static final String DEFAULT_FORUM_CONFIGFILE = "forum.cfg";
  static final String CONFIGFILE_THREADS = "basicThreads";

  // port for server to listen for Forum clients
  static final int FORUM_PORT = 5000;

  String databaseName;
  long connections = 0;
  Vector threads, acl;
  ThreadGroup handlers;
  ServerSocket listener;
  String argv[];

  public ForumServer (String argv[]) {
    handlers = new ThreadGroup ("Forum Connection Handlers");
    this.argv = argv;
    threads = new Vector ();
  }

  public void run() {
    try {
      setup (argv);
      listener = new ServerSocket (FORUM_PORT);
      while (true) {
	Socket c = listener.accept();
	if (aclCheck (c)) {
	  ForumConnectionHandler h = new ForumConnectionHandler (++ connections, c, handlers, threads);
	  h.start();
	}
	else {
	  // could send client a "denied" message here
	  InetAddress denied = c.getInetAddress();
	  System.out.println ("Denied connection from: " + denied + ".\n");
	  try {
	    c.close();
	  } catch (IOException ex) {
	    System.out.println ("Denied close failed: " + ex + ".\n");
	  }
	}
      } 
    } catch (IOException ex) {
      // this is to ignore bug when closing down ServerSocket
      if (!(ex instanceof SocketException))
	ex.printStackTrace();
    }
    finally {
      try {
	if (listener != null)
	  listener.close();
      } catch (IOException ex) {
	System.out.println ("ServerSocket close failed.\n");
      }
      handlers.stop();
      System.out.println ("The server has shut down.");
    }
  }
  
  void setup (String argv[]) throws IOException {
    // read from config file
    String configFileName = DEFAULT_FORUM_CONFIGFILE;
    if (argv.length > 0)
      configFileName = argv[0];    
    File configFile = new File (configFileName);
    if (! configFile.exists()) {
      throw new IOException ("Config file " + configFileName + " not found.\nSpecify a an alternate config file or provide a file named " + DEFAULT_FORUM_CONFIGFILE + ".\n");
    }
    Properties config = getConfig (configFile);

    // load database name and driver name could go here
    
    // load threads from config file
    String t = config.getProperty (CONFIGFILE_THREADS);
    StringTokenizer strtok = new StringTokenizer (t, ",");
    while (strtok.hasMoreElements ())
      threads.addElement (strtok.nextElement ());
    
    // load in memoryLimit, 
    // load in inbound connection ACL here
    
    // print config to console
    System.out.println ("FORUM SERVER CONFIGURATION\n");
    System.out.println ("Discussion threads:\n");
    Enumeration en = threads.elements ();
    while (en.hasMoreElements())
      System.out.println (en.nextElement());
    System.out.println ("");
    // System.out.println ("IP restrictions: ");
    System.out.println ("Client connection listing:\n");
  }

  Properties getConfig (File configFile) throws IOException {
    Properties props = new Properties();
    FileInputStream f = new FileInputStream (configFile);
    DataInputStream dIn = null;
    try {
      dIn = new DataInputStream (f);
      String line;
      int lineNo = 0;
      // readLine () is deprecated
      while ((line = dIn.readLine()) != null) {
        ++ lineNo;
        line = line.trim();
        if ((line.length() > 0) && (!line.startsWith ("#"))) {
          int idx = line.indexOf ("=");
          if (idx >= 0)
            props.put (line.substring (0, idx).trim(), line.substring (idx + 1).trim());
          else
            throw new IOException ("line " + lineNo + " not understood: " + line + "\n");
        }
      }
    } catch (IOException ex) {
      throw new IOException ("Error reading " + configFile + ": " + ex.getMessage());
   
    } finally {
      if (dIn != null)
	dIn.close();
    }
    return props;
  }
  
  
  boolean aclCheck (Socket c) {
    // unimplemented
    return true;
  }

  public static void main (String argv[]) throws IOException {
    ForumServer accept = new ForumServer (argv);
    accept.start();
  }
}