package Qpsmtpd;
use strict;
use vars qw($VERSION $Logger $TraceLevel $Spool_dir $Size_threshold);

use Sys::Hostname;
use Qpsmtpd::Constants;
use Qpsmtpd::Transaction;
use Qpsmtpd::Connection;

$VERSION = "0.40-dev";

sub version { $VERSION };

sub TRACE_LEVEL { $TraceLevel }; # leave for plugin compatibility

sub load_logging {
  # need to do this differently that other plugins so as to 
  # not trigger logging activity
  my $self = shift;
  #warn("load_logging: $self->{hooks}{logging} ", caller(8), "\n");
  return if $self->{hooks}->{"logging"};
  my $configdir = $self->config_dir("logging");
  my $configfile = "$configdir/logging";
  my @loggers = $self->_config_from_file($configfile,'logging');
  my $dir = $self->plugin_dir;

  $self->_load_plugins($dir, @loggers);

  foreach my $logger (@loggers) {
    $self->log(LOGINFO, "Loaded $logger");
  }
  
  return @loggers;
}
  
sub trace_level {
  my $self = shift;
  return $TraceLevel if $TraceLevel;

  my $configdir = $self->config_dir("loglevel");
  my $configfile = "$configdir/loglevel";
  $TraceLevel = $self->_config_from_file($configfile,'loglevel');

  unless (defined($TraceLevel) and $TraceLevel =~ /^\d+$/) {
    $TraceLevel = LOGWARN; # Default if no loglevel file found.
  }

  return $TraceLevel;
}

sub init_logger { # needed for compatibility purposes
  shift->trace_level();
}

sub log {
  my ($self, $trace, @log) = @_;
  $self->varlog($trace,join(" ",@log));
}

sub varlog {
  my ($self, $trace) = (shift,shift);
  my ($hook, $plugin, @log);
  if ( $#_ == 0 ) { # log itself
    (@log) = @_;
  }
  elsif ( $#_ == 1 ) { # plus the hook
    ($hook, @log) = @_;
  }
  else { # called from plugin
    ($hook, $plugin, @log) = @_;
  }

  $self->load_logging; # in case we already don't have this loaded yet

  my ($rc) = $self->run_hooks("logging", $trace, $hook, $plugin, @log);

  unless ( $rc and $rc == DECLINED or $rc == OK ) {
    # no logging plugins registered so fall back to STDERR
    my $fd = $self->fd();
    warn join(" ", $$ .
      (defined $fd ? " fd:$fd" : "") .
      (defined $plugin ? " $plugin plugin:" : 
       defined $hook   ? " running plugin ($hook):"  : ""),
      @log), "\n"
    if $trace <= $self->trace_level();
  }
}

#
# 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, $type) = @_;

  #warn "SELF->config($c) ", ref $self;

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

  my ($rc, @config) = $self->run_hooks("config", $c);
  @config = () unless $rc == OK;

  if (wantarray) {
      @config = $self->get_qmail_config($c, $type) unless @config;
      @config = $defaults{$c} if (!@config and $defaults{$c});
      return @config;
  } 
  else {
      return ($config[0] || $self->get_qmail_config($c, $type) || $defaults{$c});
   }
}

sub config_dir {
  my ($self, $config) = @_;
  my $configdir = ($ENV{QMAIL} || '/var/qmail') . '/control';
  my ($name) = ($0 =~ m!(.*?)/([^/]+)$!);
  $configdir = "$name/config" if (-e "$name/config/$config");
  if (exists $ENV{QPSMTPD_CONFIG}) {
    $ENV{QPSMTPD_CONFIG} =~ /^(.*)$/; # detaint
    $configdir = $1 if -e "$1/$config";
  }
  return $configdir;
}

sub plugin_dir {
    my ($name) = ($0 =~ m!(.*?)/([^/]+)$!);
    my $dir = "$name/plugins";
}

sub get_qmail_config {
  my ($self, $config, $type) = @_;
  $self->log(LOGDEBUG, "trying to get config for $config");
  if ($self->{_config_cache}->{$config}) {
    return wantarray ? @{$self->{_config_cache}->{$config}} : $self->{_config_cache}->{$config}->[0];
  }
  my $configdir = $self->config_dir($config);

  my $configfile = "$configdir/$config";

  if ($type and $type eq "map")  {
    return +{} unless -e $configfile . ".cdb";
    eval { require CDB_File };

    if ($@) {
      $self->log(LOGERROR, "No CDB Support! Did NOT read $configfile.cdb, could not load CDB_File module: $@");
      return +{};
    }

    my %h;
    unless (tie(%h, 'CDB_File', "$configfile.cdb")) {
      $self->log(LOGERROR, "tie of $configfile.cdb failed: $!");
      return +{};
    }
    #warn Data::Dumper->Dump([\%h], [qw(h)]);
    # should we cache this?
    return \%h;
  }

  return $self->_config_from_file($configfile, $config);
}

sub _config_from_file {
  my ($self, $configfile, $config, $visited) = @_;
  return unless -e $configfile;

  $visited ||= [];
  push @{$visited}, $configfile;

  open CF, "<$configfile" or warn "$$ could not open configfile $configfile: $!" and return;
  my @config = <CF>;
  chomp @config;
  @config = grep { length($_) and $_ !~ m/^\s*#/ and $_ =~ m/\S/} @config;
  close CF;

  my $pos = 0;
  while ($pos < @config) {
    # recursively pursue an $include reference, if found.  An inclusion which
    # begins with a leading slash is interpreted as a path to a file and will
    # supercede the usual config path resolution.  Otherwise, the normal
    # config_dir() lookup is employed (the location in which the inclusion
    # appeared receives no special precedence; possibly it should, but it'd
    # be complicated beyond justifiability for so simple a config system.
    if ($config[$pos] =~ /^\s*\$include\s+(\S+)\s*$/) {
      my ($includedir, $inclusion) = ('', $1);

      splice @config, $pos, 1; # remove the $include line
      if ($inclusion !~ /^\//) {
        $includedir = $self->config_dir($inclusion);
        $inclusion = "$includedir/$inclusion";
      }

      if (grep($_ eq $inclusion, @{$visited})) {
        $self->log(LOGERROR, "Circular \$include reference in config $config:");
        $self->log(LOGERROR, "From $visited->[0]:");
        $self->log(LOGERROR, "  includes $_")
          for (@{$visited}[1..$#{$visited}], $inclusion);
        return wantarray ? () : undef;
      }
      push @{$visited}, $inclusion;

      for my $inc ($self->expand_inclusion_($inclusion, $configfile)) {
        my @insertion = $self->_config_from_file($inc, $config, $visited);
        splice @config, $pos, 0, @insertion;   # insert the inclusion
        $pos += @insertion;
      }
    } else {
      $pos++;
    }
  }

  $self->{_config_cache}->{$config} = \@config;

  return wantarray ? @config : $config[0];
}

sub expand_inclusion_ {
  my $self = shift;
  my $inclusion = shift;
  my $context = shift;
  my @includes;

  if (-d $inclusion) {
    $self->log(LOGDEBUG, "inclusion of directory $inclusion from $context");

    if (opendir(INCD, $inclusion)) {
      @includes = map { "$inclusion/$_" }
        (grep { -f "$inclusion/$_" and !/^\./ } readdir INCD);
      closedir INCD;
    } else {
      $self->log(LOGERROR, "Couldn't open directory $inclusion,".
                           " referenced from $context ($!)");
    }
  } else {
    $self->log(LOGDEBUG, "inclusion of file $inclusion from $context");
    @includes = ( $inclusion );
  }
  return @includes;
}


sub load_plugins {
  my $self = shift;

#  if ($HOOKS) {
#      return $self->{hooks} = $HOOKS;
#  }

  $self->log(LOGWARN, "Plugins already loaded") if $self->{hooks};
  $self->{hooks} = {};
  
  my @plugins = $self->config('plugins');

  my $dir = $self->plugin_dir;
  $self->log(LOGNOTICE, "loading plugins from $dir");

  @plugins = $self->_load_plugins($dir, @plugins);
  
#  $HOOKS = $self->{hooks};
#  
  return @plugins;
}

sub _load_plugins {
  my $self = shift;
  my ($dir, @plugins) = @_;

  my @ret;  
  for my $plugin_line (@plugins) {
    my ($plugin, @args) = split ' ', $plugin_line;
    
    my $plugin_name = $plugin;
    $plugin =~ s/:\d+$//;       # after this point, only used for filename

    # Escape everything into valid perl identifiers
    $plugin_name =~ s/([^A-Za-z0-9_\/])/sprintf("_%2x",unpack("C",$1))/eg;

    # second pass cares for slashes and words starting with a digit
    $plugin_name =~ s{
		      (/+)       # directory
		      (\d?)      # package's first character
		     }[
		       "::" . (length $2 ? sprintf("_%2x",unpack("C",$2)) : "")
		      ]egx;

    my $package = "Qpsmtpd::Plugin::$plugin_name";

    # don't reload plugins if they are already loaded
    unless ( defined &{"${package}::plugin_name"} ) {
      Qpsmtpd::Plugin->compile($plugin_name,
        $package, "$dir/$plugin", $self->{_test_mode});
      $self->log(LOGDEBUG, "Loading $plugin_line") 
        unless $plugin_line =~ /logging/;
    }
    
    my $plug = $package->new();
    push @ret, $plug;
    $plug->_register($self, @args);

  }
  
  return @ret;
}

sub transaction {
  my $self = shift;
  return $self->{_transaction} || $self->reset_transaction();
}

sub reset_transaction {
  my $self = shift;
  $self->run_hooks("reset_transaction") if $self->{_transaction};
  return $self->{_transaction} = Qpsmtpd::Transaction->new();
}


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

sub run_hooks {
  my ($self, $hook) = (shift, shift);
  if ($self->{_continuation} && $hook ne "logging" && $hook ne "config") {
    die "Continuations in progress from previous hook (this is the $hook hook)";
  }
  my $hooks = $self->{hooks};
  if ($hooks->{$hook}) {
    my @r;
    my @local_hooks = @{$hooks->{$hook}};
    while (@local_hooks) {
      my $code = shift @local_hooks;
      @r = $self->run_hook($hook, $code, @_);
      next unless @r;
      if ($r[0] == CONTINUATION) {
        $self->disable_read() if $self->isa('Danga::Client');
        $self->{_continuation} = [$hook, [@_], @local_hooks];
      }
      last unless $r[0] == DECLINED;
    }
    $r[0] = DECLINED if not defined $r[0];
    return @r;
  }
  return (0, '');
}

sub finish_continuation {
  my ($self) = @_;
  die "No continuation in progress" unless $self->{_continuation};
  $self->enable_read() if $self->isa('Danga::Client');
  my $todo = $self->{_continuation};
  $self->{_continuation} = undef;
  my $hook = shift @$todo || die "No hook in the continuation";
  my $args = shift @$todo || die "No hook args in the continuation";
  my @r;
  while (@$todo) {
    my $code = shift @$todo;
    @r = $self->run_hook($hook, $code, @$args);
    if ($r[0] == CONTINUATION) {
      $self->disable_read() if $self->isa('Danga::Client');
      $self->{_continuation} = [$hook, $args, @$todo];
      return @r;
    }
    last unless $r[0] == DECLINED;
  }
  $r[0] = DECLINED if not defined $r[0];
  my $responder = $hook . "_respond";
  if (my $meth = $self->can($responder)) {
    $self->log(LOGNOTICE, "continuation finished on $self\n");
    return $meth->($self, $r[0], $r[1], @$args);
  }
  die "No ${hook}_respond method";
}

sub run_hook {
  my ($self, $hook, $code, @args) = @_;
  my @r;
  if ( $hook eq 'logging' ) { # without calling $self->log()
    eval { (@r) = $code->{code}->($self, $self->{_transaction}, @args); };
    $@ and warn("FATAL LOGGING PLUGIN ERROR: ", $@) and next;
  }
  else {
    $self->varlog(LOGINFO, $hook, $code->{name});
    eval { (@r) = $code->{code}->($self, $self->transaction, @args); };
    $@ and $self->log(LOGCRIT, "FATAL PLUGIN ERROR: ", $@) and return;
  
    !defined $r[0]
      and $self->log(LOGERROR, "plugin ".$code->{name}
                     ."running the $hook hook returned undef!")
        and return;
  
    if ($self->transaction) {
      my $tnotes = $self->transaction->notes( $code->{name} );
      $tnotes->{"hook_$hook"}->{'return'} = $r[0]
        if (!defined $tnotes || ref $tnotes eq "HASH");
    } else {
      my $cnotes = $self->connection->notes( $code->{name} );
      $cnotes->{"hook_$hook"}->{'return'} = $r[0]
        if (!defined $cnotes || ref $cnotes eq "HASH");
    }
  
    # should we have a hook for "OK" too?
    if ($r[0] == DENY or $r[0] == DENYSOFT or
        $r[0] == DENY_DISCONNECT or $r[0] == DENYSOFT_DISCONNECT)
    {
      $r[1] = "" if not defined $r[1];
      $self->log(LOGDEBUG, "Plugin $code->{name}, hook $hook returned $r[0], $r[1]");
      $self->run_hooks("deny", $code->{name}, $r[0], $r[1]) unless ($hook eq "deny");
    }
  
  }
  return @r;
}

sub _register_hook {
  my $self = shift;
  my ($hook, $code, $unshift) = @_;

  my $hooks = $self->{hooks};
  if ($unshift) {
    unshift @{$hooks->{$hook}}, $code;
  }
  else {
    push @{$hooks->{$hook}}, $code;
  }
}

sub spool_dir {
  my $self = shift;

  unless ( $Spool_dir ) { # first time through
    $self->log(LOGINFO, "Initializing spool_dir");
    $Spool_dir = $self->config('spool_dir') 
               || Qpsmtpd::Utils::tildeexp('~/tmp/');

    $Spool_dir .= "/" unless ($Spool_dir =~ m!/$!);
  
    $Spool_dir =~ /^(.+)$/ or die "spool_dir not configured properly";
    $Spool_dir = $1; # cleanse the taint

    # Make sure the spool dir has appropriate rights
    if (-e $Spool_dir) {
      my $mode = (stat($Spool_dir))[2];
      $self->log(LOGWARN, 
          "Permissions on spool_dir $Spool_dir are not 0700")
        if $mode & 07077;
    }

    # And finally, create it if it doesn't already exist
    -d $Spool_dir or mkdir($Spool_dir, 0700) 
      or die "Could not create spool_dir $Spool_dir: $!";
  }
    
  return $Spool_dir;
}

# For unique filenames. We write to a local tmp dir so we don't need
# to make them unpredictable.
my $transaction_counter = 0; 

sub temp_file {
  my $self = shift;
  my $filename = $self->spool_dir() 
    . join(":", time, $$, $transaction_counter++);
  return $filename;
} 

sub temp_dir {
  my $self = shift;
  my $mask = shift || 0700;
  my $dirname = $self->temp_file();
  -d $dirname or mkdir($dirname, $mask)
    or die "Could not create temporary directory $dirname: $!";
  return $dirname;
}

sub size_threshold {
  my $self = shift;
  unless ( defined $Size_threshold ) {
    $Size_threshold = $self->config('size_threshold') || 0;
    $self->log(LOGNOTICE, "size_threshold set to $Size_threshold");
  }
  return $Size_threshold;
}

sub auth_user {
  my ($self, $user) = @_;
  $user =~ s/[\r\n].*//s;
  $self->{_auth_user} = $user if $user;    
  return (defined $self->{_auth_user} ? $self->{_auth_user} : "" );
}

sub auth_mechanism {
  my ($self, $mechanism) = @_;
  $mechanism =~ s/[\r\n].*//s;
  $self->{_auth_mechanism} = $mechanism if $mechanism;    
  return (defined $self->{_auth_mechanism} ? $self->{_auth_mechanism} : "" );
}
  
sub fd {
    return shift->{fd};
}

1;

__END__

=head1 NAME

Qpsmtpd

=head1 DESCRIPTION

This is the base class for the qpsmtpd mail server.  See
L<http://smtpd.develooper.com/> and the I<README> file for more information.

=head1 COPYRIGHT

Copyright 2001-2005 Ask Bjoern Hansen, Develooper LLC.  See the
LICENSE file for more information.