#!/usr/bin/perl

use CGI qw(:standard);
use CGI::Carp qw(fatalsToBrowser warningsToBrowser);
use DBI;
use strict;


my $cgi = new CGI;
my $fname;
my $lname;
my $email;
my $userid;
my $register;
my @error;

$register = $cgi->param('login');

if ($register) {
if ($cgi->param('fname') && $cgi->param('lname') && $cgi->param('email')) {
  #Copy user input into variables in the program
  $fname = $cgi->param('fname');
  $lname = $cgi->param('lname');
  $email = $cgi->param('email');

  # Validate user input
  my $ok_data;
  $ok_data = &validate_data;

  #If data is good, generate a userid
  if ($ok_data == 1) {
    $userid = &create_id;
    #connect to the database;
    my $dbh = DBI->connect("DBI:mysql:host=db-mysql;database=int322_101b06;port=zenit.senecac.on.ca:20684", "", "") or die("Can't connect to database.");
    #Get the table "users"
    #Select all data and try to match lname||userid. If lname||userid does not
    #  exist, then lname||userid can be stored.
    my $sth = $dbh->prepare("SELECT * FROM users");
    $sth->execute;
    my $username_taken = 0;
    my @result;
    while (($username_taken == 0) && (@result = $sth->fetchrow_array())) {
      if (($lname == $result[2]) && ($userid == $result[0])) {
        $username_taken = 1;
      }
    }
    $dbh->disconnect();
    #If lname||userid already, exists, ask user for a new set of info
    if ($username_taken == 1) {
      push(@error, "Username already exists. Please register a different name.");
      &show_form(\@error);
    }
    else { #if lname and userid combo is unique, add to the database
      # Display user info back to the user
      &add_to_database;
      &repeat_info;
    }
  } #if ok_data != 1
  else {
    #Then @error would be filled. Pass this on to the form.
    &show_form(\@error);
  }
}
else {
  &show_form;
}
}

sub add_to_database {
  my $dbh = DBI->connect("DBI:mysql:host=db-mysql;database=int322_101b06;port=zenit.senecac.on.ca:20684", "", "") or die("Can't connect to database.");
  my $sth = $dbh->prepare("INSERT INTO users VALUES(?,?,?,?)");
  $sth->execute($userid, $fname, $lname, $email);
  $sth->finish;
  $dbh->disconnect();
  my $userfile = $lname . $userid . '.' . 'acct';
  open FILE, ">accounts/$userfile";
  my $string = $userid . ',' . $fname . ',' . $lname . ',' . $email;
  print FILE $string;
  close(FILE);
}

sub repeat_info {
  print $cgi->header(),
        $cgi->start_html('Your account information'),
        $cgi->h3('Account information'),
        $cgi->p('You need your last name and userid to sign in next time'),
        $cgi->p('Userid: ', $userid);
  print $cgi->table({-border=>'0', -cellspacing=>'3', -cellpadding=>'3'},
               Tr(
                [
                td(['First Name: ', $fname]),
                td(['Last Name: ', $lname]),
                td(['Email: ', $email])
                ]
               )
               );
  print $cgi->a({-href=>"start.cgi"}, "Go here to start");
  print $cgi->end_html;
}

sub validate_data {
  #Validate first name
  if ($fname =~ /^[A-Za-z\ ]+$/) {
    push(@error, "ok-fname");
  }
  else {
    push(@error, "First name can only have letters<br/>");
  }
  #Validate last name
  if ($lname =~ /^[A-Za-z\ ]+$/) {
    push(@error, "ok-lname");
  }
  else {
    push(@error, "Last name can only have letters<br/>");
  }
  #Validate email
  if ($email =~ /^[A-Za-z:\/.~\?=\+&@]+$/){
    push(@error, "ok-email");
  }
  else  {
    push(@error, "Email field has invalid characters<br/>");
  }
  #Count the number of errors in the register page
  my $i; #counter for the elements in the @error array
  my $numErrors = 3;
  for ($i = 0; $i < 3; $i++) {
    if ($error[$i] =~ /^ok/) {
      delete $error[$i];
      $numErrors -= 1;
    }
  }
  #If there are errors, display form with user input and msg where errors are
  if ($numErrors > 0) {
    return 0; #Return false, data is not good
  }
  else {
    return 1; #Return true, data is good
  }
}

sub show_form {
  print  $cgi->header(),
         $cgi->start_html("Register - Soccer Pool"),
         $cgi->h3('Register to join the soccer pool');
  if (@error) {
    print join("", @error);
  }
  print  $cgi->startform();
  print  $cgi->table({-border=>'0', -cellspacing=>'3'},
                Tr(
                [
                 td(['First Name', $cgi->textfield(-name=>'fname', -maxlength=>'25', -value=>"$fname")]),
                 td(['Last Name', $cgi->textfield(-name=>'lname', -maxlength=>'25', -value=>"$lname")]),
                 td(['Email', $cgi->textfield(-name=>'email', -maxlength=>'60', -value=>"$email")])
                ]
                )
               );
  print $cgi->submit(-value=>'Submit'), $cgi->reset();
  print $cgi->endform;
  print $cgi->end_html;
}

sub create_id {
  my $number = int(rand(9999999999));
  while (length($number) < 10) {
    $number = '0' . $number;
  }
  return $number;
}