#!/usr/bin/perl
use strict;
use warnings;
use Class::Date qw(:errors date localdate gmdate now -DateParse -EnvC); # Paket: libclass-date-perl
use Text::CSV;
use Data::Dumper;

$Class::Date::DATE_FORMAT="%Y-%m-%d";

my %config = (
        "debug"    => 3, # debug-level 0 or upto 3
        "sendmail" => "/usr/sbin/sendmail -t",
        "from"     => "root", # mail from header-field
        "db_file"  => "./birthdaydb.csv", # database
        "reminder" => 5, # $reminder
        );

$config->{db}=load_db(\%config);

for my $row (@{$config->{db}})
{
  print Dumper($row) if ($config{debug}>0);

  next unless( $row->[0] );

  print "\tdate: $row->[0]\n".
        "\tname: $row->[1]\n".
        "\tmail: $row->[2]\n" if ($config{debug}>1);

  my $date  = Class::Date->new("$row->[0]");
  my $today = Class::Date->new(time);
  my $age   = $today->year - $date->year;

  print "\tToday: $today; Birthday: $date\n" if ($config{debug}>1);

  $today -= [$age,0,-1];
  
  print "\t? Today+1: $today == $date\n" if ($config{debug}>1);
  
  if ( $date->string ne $today->string )
  {
    next if ( $config{reminder} <= 0 );
    $today += [0,0,$config{reminder}-1];
  
    print "\t? Today+$config{reminder}: $today == $date (reminder)\n" if ($config{debug}>1);

    next if ( $date->string ne $today->string );
  }

  print "\tHAPPY ${age}th BIRTHDAY!\n" if ($config{debug}>0);
  $date += [$age,0,0];

  sendmail(\%config, $row->[1], $row->[2], $date, $age);

}

################################################################

sub load_db
{
  my $config=shift;
  my @db;
  my $csv = Text::CSV->new();
  open(my $fh, '<', $config->{db_file}) or die "error open $file ($!)\n";
  while(my $row=$csv->$csv->getline($fh))
  { push(@db,$row); }
  close($fh) or die "error close $file ($!)\n";
  return \@db;
}

sub get_addresses
{
  my $config=shift;
  my $exclude = shift; # exclude birthday child (by name)
  my $s;
  for my $row (@{$config->{db}})
  {
    $s .= $row->[2]."," if (length($row->[2]) && $row->[1] ne $exclude);
  }
  print "\texclude: $exclude\n\t$s\n" if ($config->{debug}>1);
  return $s;
}

sub sendmail
{
  my $config=shift;
  my $user=shift;
  my $reply=shift;
  my $date=shift;
  my $age=shift;

  my $to=get_addresses($config, $user);

  my $mail=<<EOM;
From: $config->{from}
Reply-To: $reply
To: $to
Subject: Der Geburtstag von $user
User-Agent: HAPPY BIRTHDAY!

!!! Test Betrieb der beta-Version vom HAPPY BIRTHDAY! Mailer !!!

Hallo,

diese Mail soll daran erinnern, das $user am $date $age Jahre alt wird.

Mit freundlichen Grüßen
\tIhr HAPPY BIRTHDAY! Team.

PS: Diese E-Mail wurde automatisch verschickt.
.
EOM
  print $mail if ($config->{debug}>2);

#  open(SENDMAIL, "|-", $config->{sendmail}) || die ("$config->{sendmail}: $!\n");
#  print SENDMAIL $mail;
#  close(SENDMAIL);
}