program convcase;

uses crt,dos;

const
   TYPE1 = true;
   {true changes to lowercase and false changes to uppercase}


function file_exists(filename : string) : boolean;

var
   tmpfile : text;

begin
   file_exists := false;

   assign(tmpfile,filename);
   {$I-} reset(tmpfile); {$I+}

   if IOResult = 0 then
   begin
      file_exists := true;
      close(tmpfile);
   end;
end;


procedure type_filename(var textfile : text;
                            var path : string);

var
   filename : string;
   ch : char;
   ok : boolean;
   rnd : integer;

begin
   textcolor(black);
   clrscr;
   repeat
      ok := false;

      gotoxy(30,9);
      textcolor(5);
      write('Convert case program');
      gotoxy(24,10);
      textcolor(1);
      write('Type end and press Return to exit');

      textcolor(6);
      gotoxy(1,13);
      write('Please type filename and path : ');
      textcolor(4);
      readln(path);

{      if filename = '' then
      begin
         rnd := random(3);
         case rnd of
            0 : filename := 'fm2000\fm2000.pas';
            1 : filename := 'batty\batty.pas';
         end;
      end;}

      if path = 'end' then
      begin
         textcolor(lightgray);
         clrscr;
         halt;
      end;

      if file_exists(path) then
      begin
         assign(textfile,path);
         reset(textfile);
         ok := true;
      end else
      begin
         textcolor(7);
         gotoxy(33,16);
         write('There''s no file');
         textcolor(black);
         ch := readkey;
         gotoxy(33,13);
         clreol;
         gotoxy(33,16);
         clreol;
      end;
   until ok;
   textcolor(black);
   clrscr;
end;


procedure convert_case1(var textfile,results : text);

var
   line     : string;
   i        : integer;
   tmpchar  : char;

begin
   while not eof(textfile) do
   begin
      readln(textfile,line);
      for i := 1 to 256 do
      begin
         tmpchar := line[i];
         if TYPE1 then
         begin
            if tmpchar in ['A'..'Z'] then {change to lowercase}
               inc(tmpchar,32);
         end
         else
         begin
            if tmpchar in ['a'..'z'] then {change to uppercase}
               dec(tmpchar,32);
         end;
         line[i] := tmpchar;
      end;
      writeln(results,line);
   end;
end;

var
   textfile : text;
   results  : text;
   path     : string;

   P : PathStr;
   D : DirStr;
   N : NameStr;
   E : ExtStr;

begin
   textmode(80);

   type_filename(textfile,path);

   {this is used to save the file in the save folder as the source file}
   P := path;
   Fsplit(P,D,N,E);

   E := '.txt'; {saves file with .txt extension}
   P := D+N+E;

   textcolor(black);
   clrscr;
   textcolor(5);

   assign(results,P);
   {$I-} rewrite(results); {$I+}

   if IOResult <> 0 then
   begin
      writeln('Error saving file');
      readln;
      textcolor(lightgray);
      clrscr;
      halt;
   end else
   begin
      writeln('File saved at '+P);
      readln;
   end;

   convert_case1(textfile,results);

   close(results);
   close(textfile);
end.