#!/usr/bin/perl

use NDBM_File;
use Fcntl ':DEFAULT', ':flock';
use CGI ':standard';
use CGI::Carp 'fatalsToBrowser';

$DIR = $ENV{REMOTE_ADDR} ? '/home/mtrain60/public_html/data' 
                         : '/home/mtrain60/public_html/testdata' ;
chdir $DIR
  or die "Couldn't go to data directory: $!";
$datafile = 'info';
$semaphore = 'info.sem';

my %db;
my @form_fields = qw(first_name last_name phone);
my $page;



if (param('action') eq 'update') {
  my %data = decode_form();
  put_data($data{last_name}, %data);
  my $cookie = cookie(-NAME => last_name, 
                      -VALUE => $data{last_name},
                      -EXPIRES => '+1w',
                     );
  $page = show_form(%data);
} elsif (param('action') eq 'search') {
  my ($who) = param('last_name');
  my %data = get_data($who);
  $page = show_form(%data);
} else {
  if (cookie('last_name')) {
    my %data = get_data(cookie('last_name'));
    $page = show_form(%data);          
  } else {
    $page = show_form();
  }
}

print header(-COOKIE => $cookie), start_html("Form demo");
print $page;
print end_html();


sub get_data {
  my ($key) = @_;
  open S, "< $semaphore" or die "Couldn't open semaphore: $!; aborting";
  flock S, LOCK_SH or die "Couldn't lock: $!; aborting";
  tie %db => NDBM_File, $datafile, O_RDWR, 0666
    or die "Couldn't tie database file $datafile: $!; aborting";
  my @raw_data = split /:::/, $db{$key};
  untie %db;

  my (%data, $field);
  foreach $field (@form_fields) {
    $data{$field} = shift @raw_data;
  }
  close S;
  return %data;
}

sub put_data {
  my ($key, %data) = @_;
  my (@raw_data, $field);

  foreach $field (@form_fields) {
    push @raw_data, $data{$field};
  }

  open S, "> $semaphore" or die "Couldn't open semaphore: $!; aborting";
  flock S, LOCK_EX or die "Couldn't lock: $!; aborting";
  tie %db => NDBM_File, $datafile, O_RDWR|O_CREAT, 0666
    or die "Couldn't tie database file $datafile: $!; aborting";
  $db{$key} = join ':::', @raw_data;
  untie %db;
  close S;
}

sub show_form {
  my %data = @_;
  my $field;
  my $html;

  $html .= join '', h2("Update / Create"), start_form();
  foreach $field (@form_fields) {
    $html .= join '', 
          $field, ": ",
	  textfield(-NAME => $field, -VALUE => $data{$field},
                    -OVERRIDE => 1), 
          br();
  }
  $html .= join '', hidden(-NAME => 'action', -VALUE => 'update', 
                           -OVERRIDE => 1),
                    submit(-VALUE => 'Create / Update');
  $html .= end_form();

  $html .= join '', 
        hr(), start_form(),
        "Name to search for: ",
	  textfield(-NAME => 'last_name'),
          hidden(-NAME => 'action', -VALUE => 'search', 
                           -OVERRIDE => 1),
          br(),
          submit(-VALUE => 'Search'),
          end_form()
       ;

  return $html;
}

sub decode_form {
  my %data ;
  my $field;
  foreach $field (@form_fields) {
    $data{$field} = param($field);
  }
  %data;
}