package Qpsmtpd;
use strict;
use Carp;

use Qpsmtpd::Connection;
use Qpsmtpd::Transaction;
use Qpsmtpd::Constants;

use Mail::Address ();
use Sys::Hostname;
use IPC::Open2;
use Data::Dumper;
BEGIN{$^W=0;}
use Net::DNS;
BEGIN{$^W=1;}

$Qpsmtpd::VERSION = "0.10-dev";

# $SIG{ALRM} = sub { respond(421, "Game over pal, game over. You got a timeout; I just can't wait that long..."); exit };


sub new {
  my $proto = shift;
  my $class = ref($proto) || $proto;

  my %args = @_;

  my $self = bless ({ args => \%args }, $class);

  my (@commands) = qw(ehlo helo rset mail rcpt data help vrfy noop quit);
  my (%commands); @commands{@commands} = ('') x @commands;
  # this list of valid commands should probably be a method or a set of methods
  $self->{_commands} = \%commands;

  $self;
}


#
# method to get the configuration.  It just calls get_qmail_config by
# default, but it could be overwritten to look configuration up in a
# database or whatever.
#
sub config {
  my ($self, $c) = @_;

  my %defaults = (
		  me      => hostname,
		  timeout => 1200,
		  );

  return ($self->get_qmail_config($c) || $defaults{$c} || undef);

};

sub log {
  my ($self, $trace, @log) = @_;
  warn join(" ", $$, @log), "\n"
    if $trace <= 10;
}

sub dispatch {
  my $self = shift;
  my ($cmd) = lc shift;

  warn "command: $cmd";

  #$self->respond(553, $state{dnsbl_blocked}), return 1
  #  if $state{dnsbl_blocked} and ($cmd eq "rcpt");

  $self->respond(500, "Unrecognized command"), return 1
    if ($cmd !~ /^(\w{1,12})$/ or !exists $self->{_commands}->{$1});
  $cmd = $1;

  if (1 or $self->{_commands}->{$cmd} and $self->can($cmd)) {
    my ($result) = eval { $self->$cmd(@_) };
    $self->log(0, "XX: $@") if $@;
    return $result if defined $result;
    return $self->fault("command '$cmd' failed unexpectedly");
  }

  return;
}

sub fault {
  my $self = shift;
  my ($msg) = shift || "program fault - command not performed";
  print STDERR "$0[$$]: $msg ($!)\n";
  return $self->respond(451, "Internal error - try again later - " . $msg);
}


sub start_conversation {
    my $self = shift;
    $self->respond(220, $self->config('me') ." qpsmtpd ". $self->version ." Service ready, send me all your stuff!");
}

sub transaction {
  my $self = shift;
  use Data::Dumper;
  #warn Data::Dumper->Dump([\$self], [qw(self)]);
  return $self->{_transaction} || ($self->{_transaction} = Qpsmtpd::Transaction->new());
}

sub connection {
  my $self = shift;
  return $self->{_connection} || ($self->{_connection} = Qpsmtpd::Connection->new());
}


sub helo {
  my ($self, $hello_host, @stuff) = @_;
  my $conn = $self->connection;
  return $self->respond (503, "but you already said HELO ...") if $conn->hello;

  $conn->hello("helo");
  $conn->hello_host($hello_host);
  $self->transaction;
  $self->respond(250, $self->config('me') ." Hi " . $conn->remote_info . " [" . $conn->remote_ip ."]; I am so happy to meet you.");
}

sub ehlo {
  my ($self, $hello_host, @stuff) = @_;
  my $conn = $self->connection;
  return $self->respond (503, "but you already said HELO ...") if $conn->hello;

  $conn->hello("ehlo");
  $conn->hello_host($hello_host);
  $self->transaction;

  $self->respond(250,
		 $self->config("me") . " Hi " . $conn->remote_info . " [" . $conn->remote_ip ."]",
		 "PIPELINING",
		 "8BITMIME",
		 ($self->config('databytes') ? "SIZE ". ($self->config('databytes'))[0] : ()),
		);
}

sub mail {
  my $self = shift;
  return $self->respond(501, "syntax error in parameters") if $_[0] !~ m/^from:/i;
  unless ($self->connection->hello) {
    return $self->respond(503, "please say hello first ...");
  }
  else {
    my $from_parameter = join " ", @_;
    $self->log(2, "full from_parameter: $from_parameter");
    my ($from) = ($from_parameter =~ m/^from:\s*(\S+)/i)[0];
    #warn "$$ from email address : $from\n" if $TRACE;
    if ($from eq "<>" or $from =~ m/\[undefined\]/) {
      $from = Mail::Address->new("<>");
    } 
    else {
      $from = (Mail::Address->parse($from))[0];
    }
    return $self->respond(501, "could not parse your mail from command") unless $from;

    # this needs to be moved to a plugin --- FIXME
    0 and $from->format ne "<>"
      and $self->config("require_resolvable_fromhost")
      and !check_dns($from->host)
      and return $self->respond(450, $from->host ? "Could not resolve ". $from->host : "FQDN required in the envelope sender");

    $self->log(2, "getting mail from ".$from->format);
    $self->respond(250, $from->format . ", sender OK - I always like getting mail from you!");

    $self->transaction->sender($from);
  }
}

sub rcpt {
  my $self = shift;
  return $self->respond(501, "syntax error in parameters") unless $_[0] =~ m/^to:/i;
  return(503, "Use MAIL before RCPT") unless $self->transaction->sender;

  my $from = $self->transaction->sender;

  # Move to a plugin -- FIXME
  if (0 and $from->format ne "<>" and $self->config('rhsbl_zones')) {
    my %rhsbl_zones = map { (split /\s+/, $_, 2)[0,1] } $self->config('rhsbl_zones');
    my $host = $from->host;
    for my $rhsbl (keys %rhsbl_zones) {
      $self->respond("550", "Mail from $host rejected because it $rhsbl_zones{$rhsbl}"), return 1
	if check_rhsbl($rhsbl, $host);
    }
  }

  my ($rcpt) = ($_[0] =~ m/to:(.*)/i)[0];
  $rcpt = $_[1] unless $rcpt;
  $rcpt = (Mail::Address->parse($rcpt))[0];
  return $self->respond(501, "could not parse recipient") unless $rcpt;
  return $self->respond(550, "will not relay for ". $rcpt->host) unless $self->check_relay($rcpt->host);
  $self->transaction->add_recipient($rcpt);
  $self->respond(250, $rcpt->format . ", recipient OK");
}

 
sub check_relay {
  my $self = shift;
  my $host = lc shift;
  my @rcpt_hosts = $self->config("rcpthosts");
  return 1 if exists $ENV{RELAYCLIENT};
  for my $allowed (@rcpt_hosts) {
    $allowed =~ s/^\s*(\S+)/$1/;
    return 1 if $host eq lc $allowed;
    return 1 if substr($allowed,0,1) eq "." and $host =~ m/\Q$allowed\E$/i;
  }
  return 0;
}

sub get_qmail_config {
  my ($self, $config) = (shift, shift);
  $self->log(5, "trying to get config for $config");
  if ($self->{_config_cache}->{$config}) {
    return wantarray ? @{$self->{_config_cache}->{$config}} : $self->{_config_cache}->{$config}->[0];
  }
  my $configdir = '/var/qmail/control';
  my ($name) = ($0 =~ m!(.*?)/([^/]+)$!);
  $configdir = "$name/config" if (-e "$name/config/$config");
  open CF, "<$configdir/$config" or warn "$$ could not open configfile $config: $!", return;
  my @config = <CF>;
  chomp @config;
  @config = grep { $_ and $_ !~ m/^\s*#/ and $_ =~ m/\S/} @config;
  close CF;
  $self->log(5, "returning get_config for $config ",Data::Dumper->Dump([\@config], [qw(config)]));
  $self->{_config_cache}->{$config} = \@config;
  return wantarray ? @config : $config[0];
}


sub help {
  my $self = shift;
  $self->respond(214, 
	  "This is qpsmtpd " . $self->version,
	  "See http://develooper.com/code/qpsmtpd/",
	  'To report bugs or send comments, mail to <ask@perl.org>.');
}

sub version {
  $Qpsmtpd::VERSION;
}

sub noop {
  my $self = shift;
  warn Data::Dumper->Dump([\$self], [qw(self)]);
  $self->respond(250, "OK");

}

sub vrfy {
  shift->respond(252, "Just try sending a mail and we'll see how it turns out ...");
}

sub rset {
  my $self = shift;
  $self->{_transaction} = undef;
  $self->transaction->start();
  $self->respond(250, "OK");
}

sub quit {
  my $self = shift;
  $self->respond(221, $self->config('me') . " closing connection. Have a wonderful day");
  exit;
}


1;