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

use Sys::Hostname;
use Qpsmtpd::Constants;

#use DashProfiler;

$VERSION = "0.92";

my $git;

if (-e ".git") {
    local $ENV{PATH} = "/usr/bin:/usr/local/bin:/opt/local/bin/";
    $git = `git describe`;
    $git && chomp $git;
}

my $hooks = {};
my %defaults = (
                me      => hostname,
                timeout => 1200,
               );
my $_config_cache = {};
my %config_dir_memo;

#DashProfiler->add_profile("qpsmtpd");
#my $SAMPLER = DashProfiler->prepare("qpsmtpd");
my $LOGGING_LOADED = 0;

sub _restart {
    my $self = shift;
    my %args = @_;
    if ($args{restart}) {

        # reset all global vars to defaults
        $self->clear_config_cache;
        $hooks           = {};
        $LOGGING_LOADED  = 0;
        %config_dir_memo = ();
        $TraceLevel      = LOGWARN;
        $Spool_dir       = undef;
        $Size_threshold  = undef;
    }
}

sub DESTROY {

    #warn $_ for DashProfiler->profile_as_text("qpsmtpd");
}

sub version { $VERSION . ($git ? "/$git" : "") }

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

sub hooks { $hooks; }

sub load_logging {

    # need to do this differently than other plugins so as to
    # not trigger logging activity
    return if $LOGGING_LOADED;
    my $self = shift;
    return if $hooks->{"logging"};
    my $configdir  = $self->config_dir("logging");
    my $configfile = "$configdir/logging";
    my @loggers    = $self->_config_from_file($configfile, 'logging');

    $configdir  = $self->config_dir('plugin_dirs');
    $configfile = "$configdir/plugin_dirs";
    my @plugin_dirs = $self->_config_from_file($configfile, 'plugin_dirs');
    unless (@plugin_dirs) {
        my ($name) = ($0 =~ m!(.*?)/([^/]+)$!);
        @plugin_dirs = ("$name/plugins");
    }

    my @loaded;
    for my $logger (@loggers) {
        push @loaded, $self->_load_plugin($logger, @plugin_dirs);
    }

    foreach my $logger (@loaded) {
        $self->log(LOGINFO, "Loaded $logger");
    }

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

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

    $LOGGING_LOADED = 1;

    return @loggers;
}

sub trace_level {
    my $self = shift;
    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 don't have this loaded yet

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

    return if $rc == DECLINED || $rc == OK;    # plugin success
    return if $trace > $TraceLevel;

    # no logging plugins registered, fall back to STDERR
    my $prefix =
        defined $plugin && defined $hook ? " ($hook) $plugin:"
      : defined $plugin ? " $plugin:"
      : defined $hook   ? " ($hook) running plugin:"
      :                   '';

    warn join(' ', $$ . $prefix, @log), "\n";
}

sub clear_config_cache {
    $_config_cache = {};
}

#
# 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) = @_;

    $self->log(LOGDEBUG, "in config($c)");

    # first try the cache
    # XXX - is this always the right thing to do? what if a config hook
    # can return different values on subsequent calls?
    if ($_config_cache->{$c}) {
        $self->log(LOGDEBUG,
                   "config($c) returning (@{$_config_cache->{$c}}) from cache");
        return wantarray ? @{$_config_cache->{$c}} : $_config_cache->{$c}->[0];
    }

    # then run the hooks
    my ($rc, @config) = $self->run_hooks_no_respond("config", $c);
    $self->log(LOGDEBUG, "config($c): hook returned ($rc, @config) ");
    if ($rc == OK) {
        $self->log(LOGDEBUG,
"setting _config_cache for $c to [@config] from hooks and returning it"
        );
        $_config_cache->{$c} = \@config;
        return wantarray ? @{$_config_cache->{$c}} : $_config_cache->{$c}->[0];
    }

    # and then get_qmail_config
    @config = $self->get_qmail_config($c, $type);
    if (@config) {
        $self->log(LOGDEBUG,
"setting _config_cache for $c to [@config] from get_qmail_config and returning it"
        );
        $_config_cache->{$c} = \@config;
        return wantarray ? @{$_config_cache->{$c}} : $_config_cache->{$c}->[0];
    }

    # finally we use the default if there is any:
    if (exists($defaults{$c})) {
        $self->log(LOGDEBUG,
"setting _config_cache for $c to @{[$defaults{$c}]} from defaults and returning it"
        );
        $_config_cache->{$c} = [$defaults{$c}];
        return wantarray ? @{$_config_cache->{$c}} : $_config_cache->{$c}->[0];
    }
    return;
}

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

sub plugin_dirs {
    my $self        = shift;
    my @plugin_dirs = $self->config('plugin_dirs');

    unless (@plugin_dirs) {
        my ($path) = ($ENV{PROCESS} ? $ENV{PROCESS} : $0) =~ m!(.*?)/([^/]+)$!;
        @plugin_dirs = ("$path/plugins");
    }
    return @plugin_dirs;
}

sub get_qmail_config {
    my ($self, $config, $type) = @_;
    $self->log(LOGDEBUG, "trying to get config for $config");
    my $configdir = $self->config_dir($config);

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

    # CDB config support really should be moved to a plugin
    if ($type and $type eq "map") {
        unless (-e $configfile . ".cdb") {
            $_config_cache->{$config} ||= [];
            return +{};
        }
        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 +{};
        }

        # We explicitly don't cache cdb entries. The assumption is that
        # the data is in a CDB file in the first place because there's
        # lots of data and the cache hit ratio would be low.
        return \%h;
    }

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

sub _config_from_file {
    my ($self, $configfile, $config, $visited) = @_;
    unless (-e $configfile) {
        $_config_cache->{$config} ||= [];
        return;
    }

    $visited ||= [];
    push @{$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 $_ =~ m/\S/ }
      map { s/^\s+//; s/\s+$//; $_; }    # trim leading/trailing whitespace
      @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++;
        }
    }

    $_config_cache->{$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 !/^\./ } sort 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;

    my @plugins = $self->config('plugins');
    my @loaded;

    if ($hooks->{queue}) {

        #$self->log(LOGWARN, "Plugins already loaded");
        return @plugins;
    }

    for my $plugin_line (@plugins) {
        my $this_plugin = $self->_load_plugin($plugin_line, $self->plugin_dirs);
        push @loaded, $this_plugin if $this_plugin;
    }

    return @loaded;
}

sub _load_plugin {
    my $self = shift;
    my ($plugin_line, @plugin_dirs) = @_;

    # untaint the config data before passing it to plugins
    my ($safe_line) = $plugin_line =~ /^([ -~]+)$/  # all ascii printable
        or die "unsafe characters in config line: $plugin_line\n";
    my ($plugin, @args) = split /\s+/, $safe_line;

    if ($plugin =~ m/::/) {
        return $self->_load_package_plugin($plugin, $safe_line, \@args);
    };

    # regular plugins/$plugin plugin
    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"}) {
        PLUGIN_DIR: for my $dir (@plugin_dirs) {
            if (-e "$dir/$plugin") {
                Qpsmtpd::Plugin->compile($plugin_name, $package,
                                "$dir/$plugin", $self->{_test_mode}, $plugin);
                $self->log(LOGDEBUG, "Loading $safe_line from $dir/$plugin")
                    unless $safe_line =~ /logging/;
                last PLUGIN_DIR;
            }
        }
        die "Plugin $plugin_name not found in our plugin dirs (",
            join(", ", @plugin_dirs), ")"
            unless defined &{"${package}::plugin_name"};
    }

    my $plug = $package->new();
    $plug->_register($self, @args);

    return $plug;
}

sub _load_package_plugin {
    my ($self, $plugin, $plugin_line, $args) = @_;
    # "full" package plugin (My::Plugin)
    my $package = $plugin;
    $package =~ s/[^_a-z0-9:]+//gi;
    my $eval = qq[require $package;\n]
        . qq[sub ${plugin}::plugin_name { '$plugin' }];
    $eval =~ m/(.*)/s;
    $eval = $1;
    eval $eval;
    die "Failed loading $package - eval $@" if $@;
    $self->log(LOGDEBUG, "Loading $package ($plugin_line)")
        unless $plugin_line =~ /logging/;

    my $plug = $package->new();
    $plug->_register($self, @$args);

    return $plug;
};

sub transaction { return {}; }    # base class implements empty transaction

sub run_hooks {
    my ($self, $hook) = (shift, shift);
    if ($hooks->{$hook}) {
        my @r;
        my @local_hooks = @{$hooks->{$hook}};
        $self->{_continuation} = [$hook, [@_], @local_hooks];
        return $self->run_continuation();
    }
    return $self->hook_responder($hook, [0, ''], [@_]);
}

sub run_hooks_no_respond {
    my ($self, $hook) = (shift, shift);
    if ($hooks->{$hook}) {
        my @r;
        for my $code (@{$hooks->{$hook}}) {
            eval { (@r) = $code->{code}->($self, $self->transaction, @_); };
            $@
              and warn("FATAL PLUGIN ERROR [" . $code->{name} . "]: ", $@)
              and next;
            if ($r[0] == YIELD) {
                die "YIELD not valid from $hook hook";
            }
            last unless $r[0] == DECLINED;
        }
        $r[0] = DECLINED if not defined $r[0];
        return @r;
    }
    return (0, '');
}

sub continue_read { }    # subclassed in -async
sub pause_read { die "Continuations only work in qpsmtpd-async" }

sub run_continuation {
    my $self = shift;

    #my $t1 = $SAMPLER->("run_hooks", undef, 1);
    die "No continuation in progress" unless $self->{_continuation};
    $self->continue_read();
    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;

        #my $t2 = $SAMPLER->($hook . "_" . $code->{name}, undef, 1);
        #warn("Got sampler called: ${hook}_$code->{name}\n");
        $self->varlog(LOGDEBUG, $hook, $code->{name});
        my $tran = $self->transaction;
        eval { (@r) = $code->{code}->($self, $tran, @$args); };
        $@
          and
          $self->log(LOGCRIT, "FATAL PLUGIN ERROR [" . $code->{name} . "]: ",
                     $@)
          and next;

        !defined $r[0]
          and $self->log(LOGERROR,
                             "plugin "
                           . $code->{name}
                           . " running the $hook hook returned undef!"
                        )
          and next;

        # note this is wrong as $tran is always true in the
        # current code...
        if ($tran) {
            my $tnotes = $tran->notes($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");
        }

        if ($r[0] == YIELD) {
            $self->pause_read();
            $self->{_continuation} = [$hook, $args, @$todo];
            return @r;
        }
        elsif (   $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 $hook returned "
                         . return_code($r[0])
                         . ", $r[1]"
                      );
            $self->run_hooks_no_respond("deny", $code->{name}, $r[0], $r[1])
              unless ($hook eq "deny");
        }
        else {
            $r[1] = "" if not defined $r[1];
            $self->log(LOGDEBUG,
                           "Plugin "
                         . $code->{name}
                         . ", hook $hook returned "
                         . return_code($r[0])
                         . ", $r[1]"
                      );
            $self->run_hooks_no_respond("ok", $code->{name}, $r[0], $r[1])
              unless ($hook eq "ok");
        }

        last unless $r[0] == DECLINED;
    }
    $r[0] = DECLINED if not defined $r[0];

    # hook_*_parse() may return a CODE ref..
    # ... which breaks when splitting as string:
    @r = map { split /\n/ } @r unless (ref($r[1]) eq "CODE");
    return $self->hook_responder($hook, \@r, $args);
}

sub hook_responder {
    my ($self, $hook, $msg, $args) = @_;

    #my $t1 = $SAMPLER->("hook_responder", undef, 1);
    my $code = shift @$msg;

    my $responder = $hook . '_respond';
    if (my $meth = $self->can($responder)) {
        return $meth->($self, $code, $msg, $args);
    }
    return $code, @$msg;
}

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

    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(LOGDEBUG, "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
        my $Spool_perms = $self->config('spool_perms') || '0700';

        if (!-d $Spool_dir) {    # create it if it doesn't exist
            mkdir($Spool_dir, oct($Spool_perms))
              or die "Could not create spool_dir $Spool_dir: $!";
        }

        # Make sure the spool dir has appropriate rights
        $self->log(LOGWARN,
                   "Permissions on spool_dir $Spool_dir are not $Spool_perms")
          unless ((stat $Spool_dir)[2] & 07777) == oct($Spool_perms);
    }

    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(LOGDEBUG, "size_threshold set to $Size_threshold");
    }
    return $Size_threshold;
}

sub authenticated {
    my $self = shift;
    return (defined $self->{_auth} ? $self->{_auth} : "");
}

sub auth_user {
    my $self = shift;
    return (defined $self->{_auth_user} ? $self->{_auth_user} : "");
}

sub auth_mechanism {
    my $self = shift;
    return (defined $self->{_auth_mechanism} ? $self->{_auth_mechanism} : "");
}

1;

__END__

=head1 NAME

Qpsmtpd - base class for the qpsmtpd mail server

=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 2001-2012 Ask Bjørn Hansen, Develooper LLC.  See the
LICENSE file for more information.

=cut