#!/usr/bin/perl -w
###############################################
##    Name: QuizTaker                        ##
## Version: 1.08                             ##
##  Author: Thomas Stanley                   ##
###############################################
use strict;
use File::Slurp;
use Text::Wrap;

my $A=0;
my $Choice;

while($A == 0){
  system('clear');
  print"\n";
  print"\t\t     *******************************     \n";
  print"\t\t     ***       QuizTaker.pl      ***     \n";
  print"\t\t     ***       Version 1.08      ***     \n";
  print"\t\t     ***    by Thomas Stanley    ***     \n";
  print"\t\t     *******************************     \n";
  print"\n"x4;

  print"\t\t\t\t1) Take a test\n";
  print"\t\t\t\t2) Exit\n";
  print"\n\n";
  print"\t\t\t\tYour choice: ";
 
  $Choice = <STDIN>;
  chomp($Choice);
  my $B = 0;
 
  while($B == 0){
    if($Choice == 1){
      &Choose();
      $B=1;
    }elsif($Choice == 2){
      print"\n\n\t\t\t\tThanks for playing!\n";
      $A = 1;
    }
    $B = 1;
  }
}
##############################
sub Choose{
  system('clear');
  
  my %File_Lengths=();
  my %NumberOfTests=();
  my $Choice;
  my $MaxQuestions;
  my $Length;
  my $File;
  my $C;
  my $D = 1;
  my $H = 0;
  my $I = 0;

  my $refFile_lengths = GetFileLengths(\%File_Lengths);

  foreach $C(keys %File_Lengths){ 
    $C=~s/\.\w{3}//;
    $NumberOfTests{$D} = $C;
    $D++;
  }
  print"\n";
  foreach $C(keys %NumberOfTests){
    print"\t\t\t$C) $NumberOfTests{$C}\n";     
  }
  
  while($H == 0){
    print"\n\t\t\tEnter the test number: ";
    my $number = <STDIN>;
    chomp $number;
    $Choice = "$NumberOfTests{$number}.psv";

    if(exists $NumberOfTests{$number}){
      while($I == 0){
        print"\n\t\tHow many questions do you wish to answer (Max = $File_Lengths{$Choice}): ";
        my $MaxQuestions = <STDIN>;
        chomp $MaxQuestions;

        if(($MaxQuestions<1)||($MaxQuestions>$File_Lengths{$Choice})){
          print"\n\n\t\tPlease re-enter the number of questions.";
          sleep(2);
	}else{
          $Length = $File_Lengths{$Choice};
          &Randomize($Choice,$Length,$MaxQuestions);
          $I = 1;
        }
      }    
    }else{
      print"\n\t\tPlease choose again!!\n\n";
      sleep(2);
    }
    $H = 1;
  }
  return;
}
##################################
sub GetFileLengths{
  my $File_Lengths = shift;
  my $Directory = "./Questions";
  my $File;
  my @Files = read_dir($Directory);
  my $Check;
  my $path;

  foreach $File(@Files){
    if($File=~/\.psv/){
      $path = $Directory."/".$File;
      $Check = Check($path);
      if($Check<1){}else{
        $$File_Lengths{$File} = $Check;
      }
    }
  }            
  
  my $number = keys %$File_Lengths;

  if($number == 0){
   die"No files available\n";
  }
  return $File_Lengths;
} 
#############################
sub Check{
  my $file=shift;
  my $lines;
  if(-e $file){
   $lines =`wc -l < $file`;
  }else{
    die"Can't find $file!\n";
  }
  return $lines;
}
#############################
sub Randomize{
  my $File = shift;
  my $FileLength = shift;
  my $Max = shift;
  my $Directory = "./Questions";
  my %Randoms = ();
  my %Data=();
  my %TestQuestions=();
  my %TestAnswers=();
  srand();

  my $Path = $Directory."/".$File;
 
  my $ref=Loader(\%Data,$Path);
  
  for(1..$Max){
    my $question_number = int(rand($FileLength)+1);
    redo if exists ($Randoms{$question_number});
    $Randoms{$question_number} = 1;
  }

  my @Randoms = keys %Randoms;
  my $ref2=shuffle(\@Randoms);

  for(my $a=0;$a<$Max;$a++){
    $TestAnswers{$Randoms[$a]} = pop@{$Data{$Randoms[$a]}};
    $TestQuestions{$Randoms[$a]} = $Data{$Randoms[$a]};
  }

  my %QuestionLength = ();
  my $b;

  foreach my $key (keys %TestQuestions){
    $b = @{$TestQuestions{$key}};
    $QuestionLength{$key} = $b;
  }

  &Tester(\%TestQuestions,\%TestAnswers,\@Randoms,\%QuestionLength,$Max);
  return;
}
######################
sub Loader{
  my $Data=shift;
  my $file=shift;
  my $question_number;
  my $length;
  my $f;
  my @Sorter=();


  open(FH,"$file")||die"Can't open $file: $!\n";

  while(<FH>){
    @Sorter=split /\|/;
    $question_number=shift @Sorter;
    $length=@Sorter;

    for($f=0;$f<$length;$f++){
      $$Data{$question_number}[$f]=$Sorter[$f];
    }
  }

  close FH;
  return $Data;
}
##########################
sub Tester{
  my $Questions=shift;
  my $Answers=shift;
  my $Randoms=shift;
  my $question_length=shift;
  my $Max=shift;
  my $length;
  my $question_number=1;
  my $question_answer="";
  my $answer;
  my $number_correct=0;
  my $key;
  my $g;
  
  system('clear');
  print"\n";

  while($question_number<=$Max){
    $key=shift @$Randoms;
    $length=$$question_length{$key};

    print"Question Number $question_number\n";

    for($g=0;$g<$length;$g++){
      print wrap("","","$$Questions{$key}[$g]\n");
    }
    
    print"\nYour answer: ";
    $answer=<STDIN>;
    chomp $answer;
    $answer=uc $answer;
    $question_answer=$$Answers{$key};
    chomp $question_answer;
    $question_answer = uc $question_answer;

    if($answer eq $question_answer){
      print"That is correct!!\n\n";
      $question_number+=1;
      $number_correct+=1;
    }else{
      print"That is incorrect!\n";
      print"The correct answer is $question_answer.\n\n";
      $question_number+=1;
    }
  }
  &Final_Score($number_correct, $Max);

  return;
}
###########################
sub Final_Score{
  my $Correct=shift;
  my $Max=shift;
  my $Percentage=($Correct/$Max)*100;

  print"You answered $Correct out of $Max correctly.\n";
  printf"For a final score of %.2f%%\n",$Percentage;
  sleep(4);
  return;
}

#
# Fisher-Yates Shuffle
#

sub shuffle {
    my $array = shift;
    my $i;
    for ($i = @$array; --$i; ) {
        my $j = int rand ($i+1);
        next if $i == $j;
        @$array[$i,$j] = @$array[$j,$i];
    }
}
__END__;

=pod

=head1 QuizTaker.pl Version 1.08

This program will allow you to take simple tests,
based upon a file of questions and answers that you
create. A sample file of questions have been included
with this distribution, so you can see how its done.
The values are stored within the file, with the pipe
character "|" as a separator. Please ensure that you
have an extension of .psv on the end of your question/answer
files.

To run this program, type the following at the command prompt in
the directory where you have installed QuizTaker:


		./QuizTaker.pl


This program also requires the File::Slurp module which can be
found on your nearest CPAN mirror.


=head2 Improvements
 
=over 4

=item 1

Now includes this section of POD

=item 2

Now uses the Text::Wrap module found in the core distribution
of Perl, to wrap the lines of long questions

=item 3

Now has a menu based interface, and allows you to choose
which test you would like to take.

=item 4

Cleaned up some syntax within the functions to make them
look better

=item 5

Fixed a bug where if the letter in the answer file
is in lowercase, it would break in the Test subroutine.

=item 6

Implemented the Fisher-Yates shuffling algorithm to provide for
a more random sequence in the array of questions

=back

=head2 To Do List

=over 4

=item 1

Make a graphical user interface using the Tk module

=back

=head2 Questions/Comments

If you have any questions or comments about this program
please email me at Thomas_J_Stanley@msn.com . I am always
striving to make this program better.

=cut