#!/usr/bin/perl

##### .secret file format #####
#
#  abc,a9993e364706816aba3e25717850c26c9cd0d89d
#  password,5baa61e4c9b93f3f0682250b6cf8331b7ee68fd8
#
#####

## Modules required some functions
use strict;
use warnings;
use Term::ReadKey;
use Digest::SHA1  qw(sha1 sha1_hex sha1_base64);
use Data::Dumper;

my $DEBUG = 1; ## used for debugging with printing output

my $NC = "\e[0;37;40m";
my $GREEN = "\e[0;32;40m";
my $RED = "\e[0;31;40m";
my $AQUA = "\e[0;36;40m";
my $BLUE = "\e[0;34;40m";
my $YELLOW = "\e[1;33;40m";
my $WHITE = "\e[1;37;40m";
my $CLS = "\033[2J"; ## clear the screen
my $HOMECURSER = "\033[0;0H"; ## move the cursor to 0,0
my $fileName = "./.secret"; ## define where the username/password file is located
my @userlist = ();

############## Start of the code ###################

main(); ## this runs the subroutine main which is below

#####
## selecte to login or create new user
sub main
{
   clscr();
   my $done = 0;
   readFile();
   while (!$done)
   {
      print "$YELLOW" . "What would you like to do?:\n\   1) Login\n   2) Create an account\n   0) Quit\n>$NC ";
      my $select = ReadLine 0;
      chomp $select;
      if ($select == 0)
      {
         $done = 1;
      }
      elsif ($select == 1)
      {
         my ($user, $digest) = userPrompt($select);
         login($user, $digest);
      }
      elsif ($select == 2)
      {
         my ($user, $digest) = userPrompt($select);
         my $userNum = userExists($user);
         if ($userNum == -1)
         {
            create($user, $digest);
         }
         else
         {
            print "$YELLOW" . "User alread exists in file.\n\n$NC";
         }
      }
      else {}
   }
   writeFile();
}


#################################
##### COMPLETED SUBROUTINES #####

#####
## check to see if the user exists in the file
sub userExists
{
   my $user = shift;

   my $buffer = @userlist;
   for (my $i = 0; $i < $buffer; $i++)
   {
      if ($user eq $userlist[$i][0])
      {
#         if ($DEBUG == 1)
#         {
#            print "$BLUE" . "sub userExists:$NC User: $user exists.\n";
#         }
         return ($i);
      }
   }
   return (-1);
}

#####
## login with an account
sub login
{
   my $user = $_[0];
   my $digest = $_[1];

   my $userNum = userExists($user);

   if ($userNum == -1)
   {
      print "User does not exist in file.\n";
   }
   else
   {
      if ($digest eq $userlist[$userNum][1])
      {
         print "$YELLOW" . "Login: $GREEN" . "successful!\n$NC";
      }
      else
      {
         print "$YELLOW" . "Login: $RED" . "failed!\n$NC";
      }
   }

#   if ($DEBUG == 1)
#   {
#      print "$BLUE" . "sub login:\n$NC $user : $digest\n";
#      print "$userlist[$userNum][1]\n";
#   }
   print "\n";
}

#####
## create a new account
sub create
{
   my $user = $_[0];
   my $digest = $_[1];

   my $i = @userlist;

   $userlist[$i][0] = $user;
   $userlist[$i][1] = $digest;

#   if ($DEBUG == 1)
#   {
#      print "$BLUE" . "sub create:\n$NC $user : $digest\n";
#      print "\n$BLUE" . "sub create userlist:\n";
#      print Dumper(@userlist);
#      print "$NC\n";
#   }
   print "$GREEN" . "User added$NC\n\n";
}

#####
## read the password file
sub readFile
{
   my @raw_data = (); ## this is an array
   open (USERLIST, $fileName) || die ("File: $fileName could not be read!\n");
   @raw_data=<USERLIST>;
   close (USERLIST);

#   if ($DEBUG == 1)
#   {
#      print "\n$BLUE" . "sub readFile raw_data:\n";
#      print Dumper(@raw_data);
#      print "$NC\n";
#   }

   ## Add something to fliter the raw_data to the array @userlist
   my $i = 0;
   foreach my $user (@raw_data)
   {
      chomp $user; ## remove the newline charater at the end of the string
      ($userlist[$i][0], $userlist[$i][1]) = split(/\,/,$user);
      $i = $i + 1;
   }

#   if ($DEBUG == 1)
#   {
#      print "\n$BLUE" . "sub readFile userlist:\n";
#      print Dumper(@userlist);
#      print "$NC\n";
#   }
}

#####
## write to the password file
sub writeFile
{
#   if ($DEBUG == 1)
#   {
#      print "\n$BLUE" . "sub writeFile userlist:\n";
#      print Dumper(@userlist);
#      print "$NC\n";
#   }

   open (USERLIST, ">$fileName") || die ("File: $fileName could not be opened for wirting!\n");
      my $i = 0;
      foreach (@userlist)
      {
         print USERLIST "$userlist[$i][0]" . "," . "$userlist[$i][1]";
         print USERLIST "\n";
         $i = $i + 1;
      }
   close (USERLIST);
}

#####
## get username and password
sub userPrompt
{
   if ($_[0] == 1)
   {
      print "\n$YELLOW" . "===== Login =====\n$NC";
   }
   else
   {
      print "\n$YELLOW" . "===== New User =====\n$NC";
   }
    my $user = getUserID();
    my $digest = getUserPass();

   print "\n";
   return ($user, $digest);
}

#####
## Prompt for a username
sub getUserID
{
   my $user;
   print "$YELLOW" . "username: $NC";
   $user = ReadLine 0;
   chomp $user;
    return ($user);
}

#####
## Prompt for a password string, do not echo the charaters typed
sub getUserPass
{
   my $pass;
   print "$YELLOW" . "password: $NC";
   ReadMode 'noecho'; # don't echo password
   $pass = ReadLine 0;
   chomp $pass;
   ReadMode 'normal'; # echo back on

   ## generate the hash from the entered password
   my $digest = sha1_hex($pass);

   print "$YELLOW" . "\nSHA-1 of entered password: " . "$BLUE$digest$NC";
    return ($digest);
}

#####
## used to clear the console and reposition the cursor
sub clscr
{
   print "$CLS$HOMECURSER";
}