//  RemoveHTMLComments.java  (c) Kari Laitinen

//  http://www.naturalprogramming.com

//  2014-05-22  File created.
//  2014-05-22  Last modification.


/*

The 'better' regex in the following page did not work:

http://stackoverflow.com/questions/1657066/java-regular-expression-finding-comments-in-code


http://stackoverflow.com/questions/9205988/writing-a-java-program-to-remove-the-comments-in-same-java-program


http://ostermiller.org/findcomment.html
*/

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


import java.util.regex.Matcher;
import java.util.regex.Pattern;

class RemoveHTMLComments
{
   public static void main( String[] not_in_use )
   {
      Scanner keyboard = new Scanner( System.in ) ;

      System.out.print( "\n This program removes comments from a file."
                     +  "\n Give a file name: " ) ;

      String  file_name_from_user  = "TestFile.html" ; // keyboard.nextLine() ;


      StringBuilder file_as_stringbuilder = new StringBuilder() ;

      try
      {
         BufferedReader file_to_print =
             new BufferedReader( new FileReader( file_name_from_user ) ) ;

         int line_counter  =  0 ;
         boolean  end_of_file_encountered  =  false ;

         while ( end_of_file_encountered  ==  false )
         {
            String text_line_from_file  =  file_to_print.readLine() ;

            if ( text_line_from_file  ==  null )
            {
               end_of_file_encountered  =  true ;
            }
            else
            {
               line_counter ++ ;

               file_as_stringbuilder.append( text_line_from_file + "\n" ) ; 

            }
         }

         file_to_print.close() ;
         System.out.print( "\n  " + line_counter + " lines processed.\n" ) ;


         // we'll remove the <!-- and --> in a very crude way

         int index_of_comment_start = file_as_stringbuilder.indexOf( "<!--" ) ;
         int index_of_comment_end   = file_as_stringbuilder.indexOf( "-->" ) ;

         while( index_of_comment_start != -1 &&
                index_of_comment_end   != -1 )

         {
            file_as_stringbuilder.replace( index_of_comment_start,
                                           index_of_comment_end + 3,
                                           " " ) ;

            index_of_comment_start = file_as_stringbuilder.indexOf( "<!--" ) ;
            index_of_comment_end   = file_as_stringbuilder.indexOf( "-->" ) ;
         }


         String file_as_string = file_as_stringbuilder.toString() ;


         System.out.print( "" + file_as_string ) ;
      }
      catch ( FileNotFoundException  caught_file_not_found_exception )
      {
         System.out.print( "\n \"" + file_name_from_user + "\" not found.\n" ) ;
      }
      catch ( IOException  caught_io_exception )
      {
         System.out.print( "\n\n  File reading error.  \n" ) ;
      }
   }
}