/**
 * CSGuestbook.java
 * Pete Willemsen
 * CoolServlets.com
 * February 3, 2000
 * Version 1.01
 *
 * Any errors or feature requests can be reported on CoolServlets.com.
 * We hope you enjoy this program!
 *
 *    Copyright (C) 1999  Pete Willemsen
 *
 *    This program is free software; you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation; either version 2 of the License, or
 *    (at your option) any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

import javax.servlet.*;
import javax.servlet.ServletRequest;
import javax.servlet.http.*;

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

import com.coolservlets.guestbook.*;
import com.coolservlets.util.*;

/**
 * The main Java servlet for the CSGuestbook system.
 *
 * Three modes of operation: DISPLAY_MODE, RECORD_MODE, ADMIN_MODE
 * 
 * "mode" - determines mode of operation
 *          VALUES: "display", "record", "admin" (default="display")
 *
 * MODE 1 PARAMETERS - DISPLAY_MODE - mode="display" || mode=null
 *
 * "key" - specifies the name of the guestbook to use
 *         VALUES: a string representing name of guestbook (default="default")
 *
 * "html" - determines whether guestbook should return full HTML, or
 *          just guestbook entries (I envision use of the SERVLET tag
 *          in the * latter case)
 *          VALUES: "on", "off" (default="on")
 * 
 * "sty" - specifies the style type for printing of guestbook entries
 *         VALUES: "s1", "s2", "s3", "s4", "s5" (default="s1")
 *
 * "fltr" - specifies whether to filter words in the comment section;
 *          currently uses built-in list of words
 *          VALUES: "on", "off" (default="off")
 *
 * "fltrlist" - specifies a comma-delimited list of strings to use as 
 *              the filter in the comment section.  This option is 
 *              only effective when fltr="on".  The comma-delimited list
 *              of words overrides the built-in list of words.  The 
 *              filter currently only works well with words, so things
 *              like "filter this" won't work well as a filter, but 
 *              unique separate words like "shit" will work.  Future 
 *              versions will be more robust about filtering.
 *              VALUES: comma-delimited list of strings to filter
 *
 * "cnt" - number of entries to return (returns most recent entries)
 *         VALUES: any positive number (default=all)
 *
 * "title" - specifies the title to be used on the guestbook page
 * "fontFace" - sets the style of the font face for the document
 *              VALUES: any font face (default=normal)
 * "fontSize" - sets the style for the font size for the document
 *              VALUES: any font size (default=normal)
 * "background" - uses the file given as parameter for a background
 *                image.  VALUES: an image file (default=none)
 * "bgcolor" - specifies the background color for the guestbook page.
 *             VALUES: any browser specified color (default=normal)
 * "text" - specifies the color for normal text
 *          VALUES: any browser defined color (default="#000000")
 * "link" - specifies the color for links
 *          VALUES: any browser defined color (default="#0000ff")
 * "vlink" - specifies the color for visited links
 *           VALUES: any browser defined color (default="#800080")
 * "alink" - specifies the color for active links
 *           VALUES: any browser defined color (default="#ff0000")
 *
 * MODE 2 PARAMETERS - RECORD_MODE - mode="record"
 *
 * "key" - specifies the name of the guestbook to use
 * "name" - form input parameter that holds their name
 * "email" - form input parameter that holds their email address
 * "url" - form input parameter that holds their url
 * "city" - form input parameter that holds their city
 * "state" - form input parameter that holds their state
 * "country" - form input parameter that holds their country
 * "comment" - form input parameter (textarea) that holds their comment
 *
 * "response" - specifies a thank you response used when an entry has
 *              been added to the database.
 * "linkBack" - Specifies the link to use as a return link.
 *              VALUES: any URL such as "http://www.cnn.com" (default=none)
 * "textBack" - The text that is associated with the linkBack parameter.
 *              VALUES: a string (default="Go Back")
 *
 * "title" - specifies the title to be used on the guestbook page
 * "fontFace" - sets the style of the font face for the document
 *              VALUES: any font face (default=normal)
 * "fontSize" - sets the style for the font size for the document
 *              VALUES: any font size (default=normal)
 * "background" - uses the file given as parameter for a background
 *                image.  VALUES: an image file (default=none)
 * "bgcolor" - specifies the background color for the guestbook page.
 *             VALUES: any browser specified color (default=normal)
 * "text" - specifies the color for normal text
 *          VALUES: any browser defined color (default="#000000")
 * "link" - specifies the color for links
 *          VALUES: any browser defined color (default="#0000ff")
 * "vlink" - specifies the color for visited links
 *           VALUES: any browser defined color (default="#800080")
 * "alink" - specifies the color for active links
 *           VALUES: any browser defined color (default="#ff0000")
 *
 *
 * MODE 3 PARAMETERS - ADMIN_MODE - mode="admin" - NOT IMPLEMENTED
 * 
 * */
public class CSGuestbook extends HttpServlet implements MaintainedServlet {

  /** ****************************************
    * Initialize global variables
    */
  public void init(ServletConfig config) throws ServletException {
    super.init(config);
	
    // Read the guestbook database from file.
    database = readDatabaseFile();
	
    //Startup a maintenance thread that will write the guestbook database
    //to file every 10 minutes.
    maintenance = new ServletMaintenance(this, 10, ServletMaintenance.MINUTES);
  }

    /**
     * Process HTTP requests.
     */
    public void service(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException
    {
      
      response.setContentType("text/html");
      
      // --------------------------------------------------------
      // acquire basic options used in all modes
      // --------------------------------------------------------
      thankyou_response   = request.getParameter( "response" );
      if (thankyou_response == null)
	  thankyou_response = "Thanks for signing our guestbook!";
      title      = request.getParameter( "title" );
      if (title == null || title.length() == 0)
	  title = "CSGuestbook";
      fontFace   = request.getParameter( "fontFace" );
      fontSize   = request.getParameter( "fontSize" );
      linkBack   = request.getParameter( "linkBack" );
      textBack   = request.getParameter( "textBack" );
      background = request.getParameter( "background" );
      bgcolor    = request.getParameter( "bgcolor" );
      text       = request.getParameter( "text" );
      link       = request.getParameter( "link" );
      vlink      = request.getParameter( "vlink" );
      alink      = request.getParameter( "alink" );

      // --------------------------------------------------------
      // Check mode type first: DISPLAY, RECORD, ADMIN
      // --------------------------------------------------------
      String mode = request.getParameter("mode");
      if (mode != null) {
	if (mode.equals( "record" )) {
	  
	  // enter RECORD_MODE and process request
	  enterRecordMode( request, response );
	  
	}
	// else if (mode.equals( "admin" )) {
	// do admin duties - not yet completed and will be release
	// in next version
	// }
	else {
	  // assume DISPLAY_MODE if no "known" mode is specified
	  enterDisplayMode( request, response );
	}
      } 
      else {
	// assume DISPLAY_MODE if no mode is specified
	enterDisplayMode( request, response );
      }

  }


  /** ****************************************
    *
    */
  public void doMaintenance() {
    writeDatabaseFile();
  }


  /** ****************************************
    * Called as the servlet is being destroyed. It saves the counter
    * database and stops the maintenance thread.
    */
  public void destroy() {
    writeDatabaseFile();
    maintenance.shutDown();
  } 


  /** ****************************************
    * Get Servlet information
    */
  public String getServletInfo() {
    return "CSGuestbook v1.0 - CoolServlets.com";
  }


  /** ****************************************
    *
    */
    private void printGuestbookHeader( PrintWriter out ) {

          out.println( "<html>" );
          // use buffers for a little more string efficiency
          StringBuffer body = new StringBuffer();
	  body.append( "<body " );
	  if (background != null)
	      body.append( "background=\""+background+"\" " );
	  if ((bgcolor != null) && !(bgcolor.equals("")))
	      body.append( "bgcolor=\""+bgcolor+"\" " );
	  if (text != null)
	      body.append( "text=\""+text+"\" " );
	  if (link != null)
	      body.append( "link=\""+link+"\" " );
	  if (vlink != null)
	      body.append( "vlink=\""+vlink+"\" " );
	  if (alink != null)
	      body.append( "alink=\""+alink+"\"" );
	  body.append(">");
          out.println( body.toString() );

	  if (fontFace!=null || fontSize!=null) {
	      out.println( "<font" );
	      if (fontFace != null)
		  out.println("face=\"" + fontFace + "\"");
	      if (fontSize != null)
		  out.println("size=" + fontSize + ">" );
	  }
	
    }


  /** ****************************************
    *
    */
    private void printGuestbookFooter( PrintWriter out ) {
	out.println( "</body>" );
	out.println( "</html>" );
    }


  /** ****************************************
    *
    */
  private void printGuestbookEntry(PrintWriter out, GuestbookEntry entry) {
    entry.print( out, _style, _filter );
  }


  /** ****************************************
    *
    */
  private synchronized void writeDatabaseFile() {
    try {
      ObjectOutputStream out = new ObjectOutputStream(new FileOutputStream( "coolservlets/data/GuestbookDatabase" ));
      out.writeObject(database);
      out.close();
    }
    catch (Exception e) { 
      System.out.println("ERROR writing database file");	
    }
  }


  /** ****************************************
    *
    */
  private synchronized GuestbookDatabase readDatabaseFile() {
    GuestbookDatabase tempdatabase = new GuestbookDatabase();
    try {
      ObjectInputStream in = new ObjectInputStream(new FileInputStream( "coolservlets/data/GuestbookDatabase" ));
      tempdatabase = (GuestbookDatabase)in.readObject();
      in.close();
    }
    catch (Exception e) { }
    
    return tempdatabase;
  }


  /** ****************************************
    * EnterDisplayMode
    */
  private void enterDisplayMode( HttpServletRequest request, HttpServletResponse response ) 
    throws IOException {
      
      PrintWriter out = response.getWriter();

      // --------------------------------------------------------
      // determine which guestbook to use - if no "key" PARAM is
      // specified, use the "DEFAULT" specified guestbook
      // --------------------------------------------------------
      String gbkey = request.getParameter("key");
      if (gbkey == null) {
	  gbkey = DEFAULT_DATABASE_KEY;
      }

      // --------------------------------------------------------
      // if number of entries to output is specified, record that here
      // --------------------------------------------------------
      String count = request.getParameter( "cnt" );
      if (count != null) {
	  try {
	      _entry_output_count = Integer.parseInt( count );
	      if (_entry_output_count < 0 || _entry_output_count > database.size( gbkey )) {
		  _entry_output_count = database.size( gbkey );  // default is to display all
	      }
	      else {
		  // use the default number of entries to print
		  _entry_output_count = database.size( gbkey );
	      }
	  }
	  catch (NumberFormatException nfe) {
	      // use the default number of entries to print
	      _entry_output_count = database.size( gbkey );	      
	  }
      }

      // --------------------------------------------------------
      // check for output format style and record
      // --------------------------------------------------------
      String style = request.getParameter( "sty" );    
      if (style != null) {
	if (style.equals( "s1" )) 
	  _style = new GuestbookStyle( GuestbookStyle.STYLE_1 );
	else if (style.equals( "s2" ))
	  _style = new GuestbookStyle( GuestbookStyle.STYLE_2 );
	else if (style.equals( "s3" )) 
	  _style = new GuestbookStyle( GuestbookStyle.STYLE_3 );
	else if (style.equals( "s4" )) 
	  _style = new GuestbookStyle( GuestbookStyle.STYLE_4 );
	else if (style.equals( "s5" )) 
	  _style = new GuestbookStyle( GuestbookStyle.STYLE_5 );
	else 
	  _style = new GuestbookStyle( GuestbookStyle.STYLE_1 );
      }
      else {
	// use the default style
	_style = new GuestbookStyle( GuestbookStyle.STYLE_1 );
      }

      // --------------------------------------------------------
      // check for whether filter is on or not
      // --------------------------------------------------------
      String filter = request.getParameter( "fltr" );
      String filter_list = request.getParameter( "fltrlist" );
      if ( filter != null ) {
	if (filter.equals( "on" )) {
	    _filter = new GuestbookFilter( true, filter_list );
	}
	else 
	    _filter = new GuestbookFilter( false );
      }
      else 
	  _filter = new GuestbookFilter( false );

      // --------------------------------------------------------
      // check for whether to output full html or not - by default,
      // full html will be printed - default parameter value is "on"
      // --------------------------------------------------------
      String html_param = request.getParameter( "html" );
      if ( html_param != null ) {
	if (html_param.equals( "off" )) {
           _full_html = false;
	}
      }

      // print html header if full html is requested
      if (_full_html) {
	  printGuestbookHeader( out );
      }
      
      out.println( "<h1>" + title + "" );
      out.println( "<hr>
" );

      if (_entry_output_count == 0) {
	  out.println( "<p>At the moment, there are no guestbook entries.
" );
      }
      else {
	  // now, print out the specified entries from the specified
	  // guestbook after running the entry info through the filter
	  int idx;
	  for (idx=0; idx<_entry_output_count; idx++) {
	      printGuestbookEntry(out, database.getEntry( gbkey, idx ));
	  }
      }
	  
      // print html footer if full html is requested
      if (_full_html) {
	  printGuestbookFooter( out );
      }

      // close the output stream
      out.close();
  }


  /** ****************************************
    * EnterRecordMode
    */
  private void enterRecordMode( HttpServletRequest request, HttpServletResponse response )
    throws IOException {

      // --------------------------------------------------------
      // determine which guestbook to use - if no "key" PARAM is
      // specified, use the "DEFAULT" specified guestbook
      // --------------------------------------------------------
      String gbkey = request.getParameter("key");
      if (gbkey == null) {
	  gbkey = DEFAULT_DATABASE_KEY;
      }

      // attempt to add entry to specified database
      GuestbookEntry ge = addDatabaseEntry( request, response, gbkey );

      PrintWriter out = response.getWriter();

      printGuestbookHeader( out );

      out.println( "<h1>" + title + "" );
      out.println( "<hr>" );

      out.println( thankyou_response );
      out.println("<p>Here's the information you entered.
");

      GuestbookStyle sty = new GuestbookStyle( GuestbookStyle.FULL );
      GuestbookFilter fltr = new GuestbookFilter( false );
      ge.print( out, sty, fltr );      

      if (linkBack != null) {
	  out.println( "<a href=\""+ linkBack + "\">" );
	  if (textBack != null) 
	      out.println( textBack + "</a>" );
	  else 
	      out.println( "Click Here</a>" );
      }

      out.println("<hr>");

      printGuestbookFooter( out );

      // close the output stream
      out.close();
      
  }


  /** ****************************************
    * 
    */
  private synchronized GuestbookEntry addDatabaseEntry( HttpServletRequest request, HttpServletResponse response, String db ) 
    throws IOException {

      String entry_name = request.getParameter("name");
      if (entry_name == null) entry_name = "";
      String entry_email = request.getParameter("email");
      if (entry_email == null) entry_email = "";
      String entry_url = request.getParameter("url");
      if (urentry_urll == null) entry_url = "";
      String entry_city = request.getParameter("city");
      if (entry_city == null) entry_city = "";
      String entry_state = request.getParameter("state");
      if (entry_state == null) entry_state = "";
      String entry_country = request.getParameter("country");
      if (entry_country == null) entry_country = "";
      String entry_comments = request.getParameter("comment");
      if (entry_comments == null) entry_comments = "";

      // create a guestbook entry and add it to the database

      // Security update -- pass all params through an HTML tag filter before
      // adding them -- added Feb 2000
      GuestbookEntry ge = new GuestbookEntry();
      ge.name = HTMLUtils.escapeHTMLTags(entry_name);
      ge.email = HTMLUtils.escapeHTMLTags(entry_email);
      ge.url = HTMLUtils.escapeHTMLTags(entry_url);
      ge.city = HTMLUtils.escapeHTMLTags(entry_city);
      ge.state = HTMLUtils.escapeHTMLTags(entry_state);
      ge.country = HTMLUtils.escapeHTMLTags(entry_country);
      ge.comments = HTMLUtils.escapeHTMLTags(entry_comments);

      database.addEntry( db, ge );      

      return ge;
  }


  private ServletMaintenance maintenance;
  private GuestbookDatabase database;
  
  private final String VERSION_INFO = "version 1.0";
  private final String DEFAULT_DATABASE_KEY = "default";

  private Date _older_date, _newer_date;
  private int _entry_output_count = -1;
  private boolean _full_html = true;

  private GuestbookStyle _style;
  private GuestbookFilter _filter;

  private String thankyou_response;
  private String title;
  private String fontFace;
  private String fontSize;
  private String linkBack;
  private String textBack;
  private String background;
  private String bgcolor;
  private String text; 
  private String link; 
  private String vlink;
  private String alink;

}