#!/usr/bin/perl -w

=head1 NAME

freeside-selfservice-server

=cut

use strict;
use vars qw( $FREESIDE_LOG $FREESIDE_LOCK );
use vars qw( $Debug %kids $kids $max_kids $ssh_pid %old_ssh_pid $keepalives );
use subs qw( lock_write unlock_write myshutdown usage );
use Fcntl qw(:flock);
use POSIX qw(:sys_wait_h);
use IO::Handle;
use IO::Select;
use IO::File;
use Storable 2.09 qw(nstore_fd fd_retrieve);
use Net::SSH qw(sshopen2);
use FS::Daemon qw(daemonize1 drop_root logfile daemonize2 sigint sigterm);
use FS::UID qw(adminsuidsetup forksuidsetup);
use FS::ClientAPI qw( load_clientapi_modules );
use FS::ClientAPI_SessionCache;
use FS::Record qw( qsearch qsearchs );
use FS::TicketSystem;

use FS::Conf;
use FS::cust_svc;
use FS::agent;

$FREESIDE_LOG = "%%%FREESIDE_LOG%%%";
$FREESIDE_LOCK = "%%%FREESIDE_LOCK%%%";

$Debug = 1; # 2 will turn on more logging
            # 3 will log packet contents, including passwords

$max_kids = '10'; #?
$keepalives = 0; #let clientd turn it on, so we don't barf on old ones
$kids = 0;

my $user = shift or die &usage;
my $machine = shift or die &usage;
my $tag = scalar(@ARGV) ? shift : '';

my $lock_file = "$FREESIDE_LOCK/selfservice.$machine.writelock";

# to keep pid files unique w/multi machines (and installs!)
# $FS::UID::datasrc not posible
daemonize1("freeside-selfservice-server","$user.$machine");

#false laziness w/Daemon::drop_root
my $freeside_gid = scalar(getgrnam('freeside'))
  or die "can't find freeside group\n";

open(LOCKFILE,">$lock_file") or die "can't open $lock_file: $!";
chown $FS::UID::freeside_uid, $freeside_gid, $lock_file;

drop_root();

$ENV{HOME} = (getpwuid($>))[7]; #for ssh

load_clientapi_modules;

adminsuidsetup $user;

#logfile("/usr/local/etc/freeside/selfservice.". $FS::UID::datasrc); #MACHINE
logfile("$FREESIDE_LOG/selfservice.$machine.log");

daemonize2();

my $conf = new FS::Conf;
my $ticket_system = $conf->config('ticket_system');
if ( $conf->exists('selfservice-ignore_quantity') ) {
  $FS::cust_svc::ignore_quantity = 1;
  $FS::cust_svc::ignore_quantity = 1; #now it is used twice.
}
if ( $conf->exists('selfservice-db_profile') ) {
  eval "use DBIx::Profile";
  warn $@ if $@;
}

#clear the signup info cache so an "/etc/init.d/freeside restart" will pick
#up new info... (better as a callback in Signup.pm?)
my $cache = new FS::ClientAPI_SessionCache( {
  'namespace' => 'FS::ClientAPI::Signup',
} );
$cache->remove('signup_info_cache');

#and also clear the selfservice skin info cache, for the same reason
my $ss_cache = new FS::ClientAPI_SessionCache( {
  'namespace' => 'FS::ClientAPI::MyAccount',
} );
$ss_cache->remove($_)
  foreach grep /^skin_info_cache_agent/, $ss_cache->get_keys();

my $clientd = "/usr/local/sbin/freeside-selfservice-clientd"; #better name?

my $warnkids=0;
while (1) {
  my($writer,$reader,$error) = (new IO::Handle, new IO::Handle, new IO::Handle);
  warn "connecting to $machine\n" if $Debug;

  $ssh_pid = sshopen2($machine,$reader,$writer,$clientd,$tag);

#  nstore_fd(\*writer, {'hi'=>'there'});

  warn "entering main loop\n" if $Debug;
  my $undisp = 0;
  my $keepalive_count = 0;
  my $s = IO::Select->new( $reader );
  while (1) {

    &reap_kids;

    warn "waiting for packet from client\n" if $Debug && !$undisp;
    $undisp = 1;
    my @handles = $s->can_read(5);
    unless ( @handles ) {
      myshutdown() if sigint() || sigterm();
      if ( $keepalives && $keepalive_count++ > 10 ) {
        $keepalive_count = 0;
        lock_write;
        nstore_fd( { _token => '_keepalive' }, $writer );
        unlock_write;
      }
      next;
    }

    $undisp = 0;

    warn "receiving packet from client\n" if $Debug;

    my $packet = eval { fd_retrieve($reader); };
    if ( $@ ) {
      warn "Storable error receiving packet from client".
           " (assuming lost connection): $@\n"
        if $Debug;
      if ( $ssh_pid ) {
        warn "sending TERM signal to ssh process $ssh_pid\n" if $Debug;
        kill 'TERM', $ssh_pid;
        $old_ssh_pid{$ssh_pid} = 1;
        $ssh_pid = 0;
      }
      last;
    }
    warn "packet received\n".
         join('', map { " $_=>$packet->{$_}\n" } keys %$packet )
      if $Debug > 2;

    if ( $packet->{_packet} eq '_enable_keepalive' ) {
      warn "enabling keep alives\n" if $Debug;
      $keepalives=1;
      next;
    }

    #prevent runaway forking
    my $warnkids = 0;
    while ( $kids >= $max_kids ) {
      warn "WARNING: maximum $kids children reached\n" unless $warnkids++;
      &reap_kids;
      sleep 1;
    }

    warn "forking child\n" if $Debug;
    defined( my $pid = fork ) or die "can't fork: $!";
    if ( $pid ) {
      $kids++;
      $kids{$pid} = 1;
      warn "child $pid spawned\n" if $Debug;
    } else { #kid time

      $FS::UID::dbh->{InactiveDestroy} = 1;
      forksuidsetup($user);

      FS::TicketSystem->init() if $ticket_system;

      my $type = $packet->{_packet};
      warn "calling $type handler\n" if $Debug; 
      my $rv = eval { FS::ClientAPI->dispatch($type, $packet); };
      if ( $@ ) {
        warn my $error = "WARNING: error dispatching $type: $@";
        $rv = { _error => $error };
      }
      $rv->{_token} = $packet->{_token}; #identifier

      open(LOCKFILE,">$lock_file") or die "can't open $lock_file: $!";
      lock_write;
      warn "sending response\n" if $Debug;
      nstore_fd($rv, $writer) or die "FATAL: can't send response: $!";
      $writer->flush or die "FATAL: can't flush: $!";
      unlock_write;

      warn "child exiting\n" if $Debug;
      exit; #end-of-kid
    }

  }

  myshutdown if sigint() || sigterm();
  warn "connection lost, reconnecting\n" if $Debug;
  sleep 3;

}

###
# utility subroutines
###

sub reap_kids {
  #warn "reaping kids\n";
  foreach my $pid ( keys %kids ) {
    my $kid = waitpid($pid, WNOHANG);
    if ( $kid > 0 ) {
      $kids--;
      delete $kids{$kid};
    }
  }

  foreach my $pid ( keys %old_ssh_pid ) {
    waitpid($pid, WNOHANG) and delete $old_ssh_pid{$pid};
  }
  #warn "done reaping\n";
}

sub myshutdown {
  &reap_kids;
  my $wait = 12; #wait up to 1 minute
  while ( $kids > 0 && $wait-- ) {
    warn "waiting for $kids children to terminate";
    sleep 5;
    &reap_kids;
  }
  warn "abandoning $kids children" if $kids;
  kill 'TERM', $ssh_pid if $ssh_pid;
  die "exiting";
}

sub lock_write {
  warn "locking $lock_file mutex for write to write stream\n" if $Debug > 1;

  #broken on freebsd?
  #flock($writer, LOCK_EX) or die "FATAL: can't lock write stream: $!";

  flock(LOCKFILE, LOCK_EX) or die "FATAL: can't lock $lock_file: $!";

}

sub unlock_write {
  warn "unlocking $lock_file mutex\n" if $Debug > 1;

  #broken on freebsd?
  #flock($writer, LOCK_UN) or die "WARNING: can't release write lock: $!";

  flock(LOCKFILE, LOCK_UN) or die "FATAL: can't unlock $lock_file: $!";

}

sub usage {
  die "Usage:\n\n  freeside-selfservice-server user machine\n";
}