///////////////////////////////////////////////
//                                           //
//  An HTTP 1.1 compliant web server         //
//  (Version 0.5)                            //
//  Copyright 1999-2001 D. Clayton           //
//  You may freely use this code so long as  //
//  this header is not modified.             //
//                                           //
///////////////////////////////////////////////

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

public class WebServer {

  public static int PORT = 8080; // port on which the server runs

  public static void main(String [] args) {
    try {
      ServerSocket s = new ServerSocket(PORT); // create a server socket waiting for client connections
      
      for (;;) { // loop for infinity...
        Socket connection = s.accept(); // a client has opened the connection
        System.out.println("Spawning server thread...");
        new ServerThread( connection ).start(); // start the thread to handle the new connection
	
      } // end server loop
    } catch (Exception e) {
      System.out.println(e); // catch any exceptions
    }
  }
} // end main

class ServerThread extends Thread {

  // these variables configure the default paths for the server

  // mapping from http://www.wherever:8080/ to the filestore representing it
    
  // **** Change this to any path in CS with read access to see better
  // **** demonstrations than the couple of pages I put up. ;)

  public static String WEBDIR = "d:\\nwthack\\";

  // default index page filename
  public static String DEFAULT = "index.html";

  // default "404 File not Found" html page
  public static String FNFPATH = "\\it\\fnf.html";

  // default "403 Forbidden" html page
  public static String FORBPATH = "\\it\\forb.html";

  // the above two files themselves
  private static File fnf404 = new File(FNFPATH);
  private static File forb403 = new File(FORBPATH);

  public ServerThread( Socket c ) {
    connection = c;
  } // end constructor for the thread

  public void run() {
    BufferedReader in;
    BufferedOutputStream out;
    String ver;
    String httpRequestURI;

    try {

      // attach primary (buffered) I/O streams to the socket
      in = new BufferedReader
	(new InputStreamReader(connection.getInputStream()));
      out = new BufferedOutputStream(connection.getOutputStream());

      String input[] = new String[128]; // the input header buffer
      boolean done = false;
      boolean donereading = false; // control variables
      int i = 0;
      String str;

      while (!donereading) { // read the Client's output (request header)
	str = in.readLine();
	if (str == null) {
	  donereading = true;
	  if (i == 0) {
	    done = true;
	  }
	}
	if (!(str.equals(""))) {
	  input[ i++ ] = str;
	} else {
	  donereading = true;
	}
	System.out.println("Input: " + str); // echo to stdout for debugging
      } // end the initial request header read loop

      // now the fun begins... processing the request header and trying to figure out what the client's asking for
      while (!done) { // persistent connection implementation
	
	String httpMethod;

	// get request line and parse
	// split up request line to get method, URI and HTTP version of Client
        StringTokenizer t = new StringTokenizer(input[0], " \n\r");
	try {
          httpMethod = t.nextToken();
          httpRequestURI = t.nextToken();
	  ver = t.nextToken();
        } catch (Exception e) {
	  System.out.println("Malformed URI");
          connection.close(); // this should return a 400er (error)
	  return;
        } // end request line parse

	// process the request. At the moment only the "get" method is supported
	if (httpMethod.equals("GET")) {

	  // create file from URI
	  String path = WEBDIR + httpRequestURI; // construct a full path
	  System.out.println("Request for: " + path);
	  File target = new File(path); // create a new file from the path
	  String MIME = getMIMEtype( target ); // get the MIME type
	  boolean bin = (MIME.equals("text/html") || MIME.equals("text/plain"))
	    ? false : true; // figure out whether file is binary or text from its MIME type

	  // now check whether file is a directory or not
	  if (target.isDirectory()) {
	    if (!path.endsWith("/")) {
	      path = path + "/";
	      httpRequestURI = httpRequestURI + "/";
	    }
	    String defaultPath = path + DEFAULT;
	    File newTarget = new File(defaultPath);
	    if (newTarget.exists()) { // if an index page exists, use that...
	      if (newTarget.canRead()) {
		outputHead(out, 200, newTarget, MIME, httpRequestURI, ver);
		outputBody(out, bin, newTarget, httpRequestURI);
	      } else {
		System.out.println("Forbidden, sending reply");
		outputHead(out, 403, forb403, "text/html", httpRequestURI, ver);
		outputBody(out, false, forb403, httpRequestURI);
	      }
	    } else { // otherwise generate an index page (directory listing)
	      outputHead(out, 200, target, "text/html", httpRequestURI, ver);
	      outputBody(out, false, target, httpRequestURI);
	    }
	  } else {
	    if (target.exists()) {
	      if (target.canRead()) {
		outputHead(out, 200, target, MIME, httpRequestURI, ver);
		outputBody(out, bin, target, httpRequestURI);
	      } else {
		outputHead(out, 403, forb403, "text/html", httpRequestURI, ver);
		outputBody(out, false, forb403, httpRequestURI);
	      }
	    } else {
	      outputHead(out, 404, fnf404, "text/html", httpRequestURI, ver);
	      outputBody(out, false, fnf404, httpRequestURI);
	    }
	  }
	} else if (httpMethod.equals("POST")) {
	  System.out.println("post?");
	  
	}

        // done = true;
	
        if (ver.equals("HTTP/1.0")) {
          done = true;
        } else {
          i = 0;
          while (!donereading) {
            str = in.readLine();
            if (str == null) {
              donereading = true;
              if (i == 0) {
                done = true;
              }
            }
            if (!(str.equals(""))) {
              input[ i++ ] = str;
            } else {
              donereading = true;
            }
            System.out.println("Input: " + str);
          } // end next input read
          
        } // end connection state testing
 
      } // end persistent connection loop

      // Close the connection and terminate this thread

      System.out.println("Connection closed by server");
      connection.close();
    } catch (Exception e) {
      System.out.println(e); // should be to log file
    } // end try block
  } // end run method

  private Socket connection;

  public static synchronized void outputHead( BufferedOutputStream out, int statusCode,
				File content, String MIME, String URI, String ver ) {
    long contentLen = content.length();
    PrintWriter hout = new PrintWriter(out);
    System.out.println("Sending header, mime type " + MIME + ", size "
		       + contentLen );
    hout.println( ver + " " + statusCode + " " + "OK" );
    hout.println("Date: " + getDate());
    System.out.println("Date: " + getDate());
    hout.println("Server: HoshiWebServer 0.2");
    hout.println("Content-base: " + URI);
    hout.println("Content-type: " + MIME);
    hout.println("Content-length: " + contentLen); // unless directory...
    hout.println("Last-modified: Mon, 15 Feb 1999 22:20:00 GMT\n");
    hout.flush();
  } // output header file

  public static synchronized void outputBody( BufferedOutputStream out,
					     boolean bin, File source, String httpRequestURI ) {
    if (source.isDirectory()) {
      // list directory
      System.out.println("Listing directory.");
      PrintWriter dout = new PrintWriter(out);
      String dir[] = new String[128];
      dir = source.list();

      dout.println("<html><head><title>Directory " + httpRequestURI +
		   "</title></head><body bgcolor=\"FFFFFF\"><ul>");
      for (int i = 0; i < dir.length; i++) {
	if (httpRequestURI.equals("/")) {
	  httpRequestURI = "";
	}
	dout.println("<li><a href=\"" + httpRequestURI + "/" + dir[i] + "\">"
		     + dir[i] + "</a>");
      }
      dout.println("</ul></body></html>");      
      dout.flush();
    } else {
      if ( bin ) {
	System.out.println("Sending binary file.");
	BufferedInputStream fin;
	try {
	  fin = new BufferedInputStream
	    (new FileInputStream(source));
	} catch (FileNotFoundException e) {
	  System.out.println("File not found, is someone messing with the filestore?");
	  return; // couldn't send file
	}
	try {
	  System.out.println("Sending binary file.");
	  int b = fin.read();
	  while (b != -1) {
	    out.write(b);
	    b = fin.read();
	  }
	  out.flush();
	  fin.close();
	} catch (IOException e) {
	  System.out.println("IO Exception." + e);
	}
      } else {
	System.out.println("Sending text file.");
	BufferedReader fin;
	try {
	  fin = new BufferedReader
	    (new FileReader(source));
	} catch (FileNotFoundException e) {
	  System.out.println("File not found, is someone messing with the filestore?");
	  return; // couldn't send file
	}
	PrintWriter tout = new PrintWriter(out);
	String str;
	try {
	  str = fin.readLine();
	  while (str != null) {
	    tout.println(str);
	    str = fin.readLine();
	  }
	  fin.close();
	  tout.flush();
	} catch (Exception e) {
	  System.out.println("Exception: " + e);
	}
      }
    }
  }
  
  public static String getMIMEtype( File source ) {
    String fileName = source.getName();
    if (source.isDirectory()) {
      fileName = null;
      return "text/html";
    }
    String fileExt = "???", MIMEtype;

    StringTokenizer s = new StringTokenizer(fileName, ".");
    while (s.hasMoreTokens()) { 
      fileExt = s.nextToken();
    }
    System.out.println("Filename: " + fileName);

    if (fileExt.equals("html")) { 
      MIMEtype = "text/html";
    } else if (fileExt.equals("gif")) {
      MIMEtype = "image/gif";
    } else if (fileExt.equals("jpg")) {
      MIMEtype = "image/jpeg";
    } else if (fileExt.equals("txt")) {
      MIMEtype = "text/plain";
    } else if (fileExt.equals("htm")) {
      MIMEtype = "text/html";
    } else {
      System.out.println("Unknown MIME type: " + fileExt);
      MIMEtype = "application/octet-stream";
    }
    return MIMEtype;
  }

  public static String getDate() {
    Calendar c = new GregorianCalendar();
    int month = c.get(Calendar.MONTH) + 1;
    int h,m,s; String ms,ss;
    if (c.get(Calendar.AM_PM) == 1) {
      h = c.get(Calendar.HOUR) + 12;
      if (h == 24) {
        h = 0;
      }
    } else {
      h = c.get(Calendar.HOUR);
    }
    m = c.get(Calendar.MINUTE);
    s = c.get(Calendar.SECOND);
    if (m < 10) {
      ms = "0" + m;
    } else {
      ms = "" + m;
    }
    if (s < 10) {
      ss = "0" + s;
    } else {
      ss = "" + s;
    }

    return c.get(Calendar.DAY_OF_MONTH)+"/"+month+"/"+c.get(Calendar.YEAR)+
      " "+h+":"+ms+":"+ss;
  }

}