//  CSharpToJava.java  Copyright (c) 2006 Kari Laitinen

//  http://www.naturalprogramming.com

//  2005-03-02   CSharpToJava.cs file created.
//  2006-02-23   CSharpToJava.java file created.
//  2006-02-23   Last modification.

//  This program helps to convert C# programs to Java 1.5 programs.
//  This is not a fully automatic converter. After a conversion, the
//  conversion result usually needs to be modified by hand.

//  This program is specifically tailored to convert the programs of
//  Kari Laitinen's books.

//  Note that this program is not heavily tested. I used the program
//  CSharpToJava.cs to convert C# programs to Java programs. Then
//  I created this by modifying the CSharpToJava.cs program.
//  According to tests with a few C# files, this program seems to
//  work. DO NOT USE THIS PROGRAM TO CONVERT CSharpToJava.cs TO A
//  JAVA PROGRAM. THE CONVERSION OPERATION DESTROYS ALL THE
//  STRINGS THAT NEED TO BE REPLACED.

//  The best way to execute this program is to run it in a
//  command prompt window where command line parameters can
//  be given. It may be difficult, and even impossible, to
//  supply the command line parameters if this program is 
//  executed with a modern development tool such as JCreator
//  or Eclipse.

import java.util.* ;
import java.io.* ;  // Classes for file handling.

class CSharpToJava
{
   static void
   store_text_lines_to_file( ArrayList<String> given_array_of_text_lines,
                             String            given_file_name )
   {
      try
      {
         PrintWriter output_file  = 
                new PrintWriter( new FileWriter( given_file_name ) ) ;

         for ( int line_index  =  0 ;
                   line_index  <  given_array_of_text_lines.size() ;
                   line_index  ++ )
         {
            output_file.println(
                      given_array_of_text_lines.get( line_index ) ) ;
         }

         output_file.close() ;
      }
      catch ( IOException caught_io_exception )
      {
         System.out.print( "\n\n Cannot write to file \""
                        +  given_file_name  +  "\"\n" ) ;
      }
   }


   static void replace_names_in_file( String  original_file_name )
   {

      ArrayList<String> names_to_replace  =  new  ArrayList<String>() ;
      ArrayList<String> replacement_names  =  new  ArrayList<String>() ;


      names_to_replace.add( "Console.Write" ) ;
      replacement_names.add( "System.out.print" ) ;

      names_to_replace.add( "using System.IO" ) ;
      replacement_names.add( "import java.io.*" ) ;

      names_to_replace.add( "using System" ) ;
      replacement_names.add( "import java.util.*" ) ;

      names_to_replace.add( "static void Main()" ) ;
      replacement_names.add(
                   "public static void main( String[] not_in_use )" ) ;

      names_to_replace.add(
              "static void Main( string[] command_line_parameters )" ) ;
      replacement_names.add(
         "public static void main( String[] command_line_parameters )" ) ;

      names_to_replace.add( "Convert.ToInt32( Console.ReadLine()" ) ;
      replacement_names.add( "keyboard.nextInt(" ) ;

      names_to_replace.add( "Convert.ToDouble( Console.ReadLine()" ) ;
      replacement_names.add( "keyboard.nextDouble(" ) ;

      names_to_replace.add( "Convert.ToChar( Console.ReadLine()" ) ;
      replacement_names.add( "keyboard.nextLine().charAt( 0" ) ;

      names_to_replace.add( "Console.ReadLine()" ) ;
      replacement_names.add( "keyboard.nextLine()" ) ;

      names_to_replace.add( " string " ) ;
      replacement_names.add( " String " ) ;

      names_to_replace.add( " string[" ) ;
      replacement_names.add( " String[" ) ;

      names_to_replace.add( " virtual " ) ;
      replacement_names.add( " " ) ;

      names_to_replace.add( " override " ) ;
      replacement_names.add( " " ) ;

      names_to_replace.add( " bool " ) ;
      replacement_names.add( " boolean " ) ;

      names_to_replace.add( ".cs" ) ;
      replacement_names.add( ".java" ) ;

      names_to_replace.add( "string.Length" ) ;
      replacement_names.add( "string.length()" ) ;

      names_to_replace.add( ".Length" ) ;
      replacement_names.add( ".length" ) ;

      names_to_replace.add( "string[ character_index ]" ) ;
      replacement_names.add( "string.charAt( character_index )" ) ;

      names_to_replace.add( "IndexOf(" ) ;
      replacement_names.add( "indexOf(" ) ;

      names_to_replace.add( "ToUpper(" ) ;
      replacement_names.add( "toUpperCase(" ) ;

      names_to_replace.add( "ToCharArray(" ) ;
      replacement_names.add( "toCharArray(" ) ;

      names_to_replace.add( "Close(" ) ;
      replacement_names.add( "close(" ) ;

      names_to_replace.add( "ToLower(" ) ;
      replacement_names.add( "toLowerCase(" ) ;

      names_to_replace.add( "Convert.ToInt32(" ) ;
      replacement_names.add( "Integer.parseInt(" ) ;

      names_to_replace.add( "Equals(" ) ;
      replacement_names.add( "equals(" ) ;

      names_to_replace.add( "Add(" ) ;
      replacement_names.add( "add(" ) ;

      names_to_replace.add( "ToString(" ) ;
      replacement_names.add( "toString(" ) ;

      try
      {
         BufferedReader original_file  =
              new BufferedReader( new FileReader( original_file_name ) ) ;

         ArrayList<String>  original_text_lines  =  new  ArrayList<String>() ;
         ArrayList<String>  modified_text_lines  =  new  ArrayList<String>() ;

         Calendar  current_date  =  new  GregorianCalendar() ;

         //  The following statements add some Kari-Laitinen-style 
         //  comments at the beginning of the modified program file.

         modified_text_lines.add( "" ) ;

         modified_text_lines.add( String.format( 
                     "//  %s  Copyright (c) %d Kari Laitinen",
                     original_file_name,
                     current_date.get( Calendar.YEAR ) ) ) ;

         modified_text_lines.add( "" ) ;

         modified_text_lines.add( "//  http://www.naturalprogramming.com" ) ;

         modified_text_lines.add( "" ) ;

         modified_text_lines.add( 
              String.format( "//  %tF  File created.", current_date ) ) ;

         modified_text_lines.add(
              String.format( "//  %tF  Last modification.", current_date ) ) ;

         boolean opening_brace_of_main_method_found  =  false ;
         boolean start_of_main_method_found  =  false ;

         int  line_counter  =  0 ;
         boolean end_of_file_encountered  =  false ;

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

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

               for ( int name_index  =  0 ;
                         name_index  <  names_to_replace.size() ;
                         name_index  ++ )
               {
                  if ( text_line_from_file.indexOf(
                            names_to_replace.get( name_index  ) )  !=  -1 )
                  {
                     text_line_from_file  =
                          text_line_from_file.replace(
                              names_to_replace.get( name_index ),
                              replacement_names.get( name_index ) ) ;

                     System.out.print( "\n \""
                          +  names_to_replace.get( name_index )
                          +  "\" was replaced with \"" 
                          +  replacement_names.get( name_index )
                          +  "\" on line "  +  line_counter  ) ;

                  }
               }

               //  The following three if constructs are used to find
               //  out when to add the line "Scanner keyboard ... "
               //  to the beginning of the main() method

               if ( opening_brace_of_main_method_found  ==  true )
               {
                  modified_text_lines.add(
                  "      Scanner keyboard = new Scanner( System.in ) ;" ) ;

                  modified_text_lines.add( "" ) ;

                  opening_brace_of_main_method_found  =  false ;
                  start_of_main_method_found  =  false ;
               }

               if ( start_of_main_method_found  ==  true )
               {
                  if ( text_line_from_file.indexOf( "{" ) != -1 )
                  {
                     opening_brace_of_main_method_found  =  true ;
                  }
               }

               if ( text_line_from_file.indexOf( "void main(" ) !=  -1 )
               {
                  start_of_main_method_found  =  true ;
               }

               modified_text_lines.add( text_line_from_file ) ;
            }
         }

         original_file.close() ;

         String  backup_file_name  =  original_file_name  +  ".bak" ;

         store_text_lines_to_file( original_text_lines,
                                   backup_file_name   ) ; 
         store_text_lines_to_file( modified_text_lines,
                                   original_file_name ) ;
      }
      catch ( FileNotFoundException caught_file_not_found_exception )
      {
         System.out.print( "\n Cannot open file " + original_file_name ) ;
      }
      catch ( IOException  caught_io_exception )
      {
         System.out.print( "\n Error in reading " + original_file_name ) ;
      }
   }


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

      String  file_name_given_by_user ;

      if ( command_line_parameters.length  ==  1 )
      {
         file_name_given_by_user  =  command_line_parameters[ 0 ] ;
      }
      else
      {
         System.out.print( "\n This program helps you to convert a C# "
                        +  "\n program to a Java program. Please,"
                        +  "\n type the name of the program file:  " ) ;

         file_name_given_by_user  =  keyboard.nextLine() ;
      }

      replace_names_in_file( file_name_given_by_user ) ;
   }
}