#!/usr/bin/perl -w

use strict;
use POSIX qw( :sys_wait_h );
use Sys::SigAction qw( set_sig_handler );
use Date::Parse;
use Date::Format;
use FS::Daemon ':all'; #daemonize1 drop_root daemonize2 myexit logfile sig*
use FS::UID qw( adminsuidsetup forksuidsetup dbh driver_name );
use FS::Record qw( qsearch str2time_sql str2time_sql_closing concat_sql );
use FS::torrus_srvderive;

our $DEBUG = 2;
our $max_kids = 6;
our $search_timeout = 30*60; # 15*60 5*60; #$torrus_srvderive->last_srv_date ? 5*60 : 15*60);
our %kids;

my $user = shift or die &usage;
$FS::Daemon::PID_NEWSTYLE = 1;
daemonize1('torrus-srvderive');

drop_root();

adminsuidsetup($user);

logfile( "%%%FREESIDE_LOG%%%/torrus-srvderive-log.". $FS::UID::datasrc );

daemonize2();

our $conf = new FS::Conf;

die "not running: network_monitoring_system not Torrus_Internal\n"
  unless _shouldrun();

#--

my $str2time = str2time_sql();
my $c = str2time_sql_closing();

my $_date = concat_sql([ 'srvexport.srv_date', "' '", 'srvexport.srv_time' ]);
$_date = "CAST( $_date AS TIMESTAMP )" if driver_name =~ /^Pg/i;
$_date = str2time_sql. $_date.  str2time_sql_closing;

my $other_date = concat_sql([ 'other.srv_date', "' '", 'other.srv_time' ]);
$other_date = "CAST( $other_date AS TIMESTAMP )" if driver_name =~ /^Pg/i;
$other_date = str2time_sql. $other_date.  str2time_sql_closing;

my $in  = concat_sql([ '?', "'_IN'" ]);
my $out = concat_sql([ '?', "'_OUT'" ]);

my $sql = "
  SELECT DISTINCT srv_date, srv_time FROM srvexport
    WHERE NOT EXISTS (
                       SELECT 1 FROM srvexport AS other
                         WHERE other.serviceid IN ( $in, $out )
                           AND srvexport.srv_date = other.srv_date
                           AND ABS( $_date - $other_date ) <= 60
                     )
";

my $orderlimit = "
    ORDER BY srv_date, srv_time
    LIMIT 100
"; #50?

our $kids = 0;

#MAIN: while (1) {
while (1) {

  my $found = 0;

  #SERVICEID: foreach my $torrus_srvderive ( qsearch('torrus_srvderive', {}) ) {
  foreach my $torrus_srvderive ( qsearch('torrus_srvderive', {}) ) {

    &reap_kids;
    if ( $kids >= $max_kids ) {
      sleep 5;
      myexit() if sigterm() || sigint();
      redo;
    }

    defined( my $pid = fork ) or do {
      #warn "WARNING: can't fork: $!\n";
      #next; #don't increment the kid counter
      die "can't fork: $!\n";
    };

    if ( $pid ) {
      $kids++;
      $kids{$pid} = 1;
    } else { #kid time

      #get new db handle
      $FS::UID::dbh->{InactiveDestroy} = 1;

      forksuidsetup($user);

      my $serviceid = $torrus_srvderive->serviceid;

      my @serviceids = $torrus_srvderive->component_serviceids;
      exit unless @serviceids; #don't try to search for empty virtual ports

      #nonlocking select statements; rows in this table never change
      if ( driver_name eq 'mysql' ) {
        dbh->do('SET SESSION TRANSACTION ISOLATION LEVEL READ UNCOMMITTED');
        dbh->commit or die dbh->errstr;
      }

      my @in = ();
      for my $dir ('_IN', '_OUT') {
        push @in, map dbh->quote("$_$dir"), @serviceids;
      }
      my $in = join(',', @in);

      if ( ! $torrus_srvderive->last_srv_date ) {
        warn "finding initial last_srv_date for $serviceid\n" if $DEBUG;
        my $dsql = "SELECT srv_date FROM srvexport WHERE serviceid IN ($in)
                    ORDER BY srv_date LIMIT 1";
        my $dsth = dbh->prepare($dsql) or die $DBI::errstr;
        $dsth->execute or die $dsth->errstr;
        my $date = $dsth->fetchrow_arrayref->[0];
        if ( $date ) {
          warn "found initial last_srv_date of $date; updating $serviceid\n"
            if $DEBUG;
          $torrus_srvderive->last_srv_date($date);
          my $error = $torrus_srvderive->replace;
          die $error if $error;
        } else {
          warn "no initial last_srv_date for $serviceid; skipping\n" if $DEBUG;
          exit;
        }
      }

      my $ssql = "
        $sql AND EXISTS (
                         SELECT 1 FROM srvexport AS other
                           WHERE other.serviceid IN ($in)
                             AND srvexport.srv_date = other.srv_date
                             AND ABS( $_date - $other_date ) <= 60
                       )
      ";

      $ssql .= " AND srv_date >= '". $torrus_srvderive->last_srv_date. "' "
        if $torrus_srvderive->last_srv_date;

      $ssql .= $orderlimit;

      warn "searching for times to add $serviceid\n" if $DEBUG;
      warn $ssql if $DEBUG > 2;
      my $sth = dbh->prepare($ssql) or die $DBI::errstr; #better recovery here?

      eval {
        my $h = set_sig_handler( 'ALRM', sub { die "_timeout\n"; } );
        alarm($search_timeout);
        $sth->execute($serviceid, $serviceid) or die $sth->errstr;
        alarm(0);
      };
      alarm(0);
      
      if ( $@ && $@ eq "_timeout\n" ) {
        #warn "search timed out; reconnecting and restarting\n";
        warn "search timed out\n";
        dbh->clone()->do("KILL QUERY ". dbh->{"mysql_thread_id"})
          if driver_name eq 'mysql';
        dbh->rollback; #or die dbh->errstr;
        #adminsuidsetup($user);
        #next SERVICEID; #MAIN;
        exit;
      } elsif ( $@ ) {
        die $@;
      }

      warn "search for $serviceid finished; checking results\n" if $DEBUG;

      my $prev = 0;
      while ( my $row = $sth->fetchrow_arrayref ) {
        last if sigterm() || sigint();

        my( $srv_date, $srv_time ) = @$row;
        my $cur = str2time( "$srv_date $srv_time" );
        next if $cur-$prev <= 60;
        last if time - $cur <= 300;

        warn "no $serviceid for $srv_date $srv_time; adding\n"
          if $DEBUG;
        $found++;

        for my $dir ('_IN', '_OUT') {

          my $sin = join(',', map dbh->quote("$_$dir"), @serviceids);

          my $sum = "
            SELECT COALESCE(SUM(value),0) FROM srvexport AS other
              WHERE other.serviceid IN ($sin)
                AND ABS( $cur - $other_date ) <= 60
          ";

          my $isql = "
            INSERT INTO srvexport ( srv_date, srv_time, serviceid, value, intvl )
              VALUES ( ?, ?, ?, ($sum), ? )
          ";
          my @param = ( time2str('%Y-%m-%d', $cur), #srv_date
                        time2str('%X', $cur),       #srv_time
                        "$serviceid$dir",
                        300, #intvl ... 
                      );
          warn $isql. ' with param '. join(',',@param). "\n"
            if $DEBUG > 2;

          my $isth = dbh->prepare($isql) or die $DBI::errstr; #better recovery?

          #stupid mysql deadlocks all the time on insert, so we need to recover
          unless ( $isth->execute(@param) ) {
            #warn "Error inserting data for $serviceid$dir (restarting): ".
            #     $isth->errstr;
            warn "Error inserting data for $serviceid$dir: ". $isth->errstr;
            dbh->rollback; #or die dbh->errstr;
            #sleep 5;
            #next SERVICEID; #MAIN;
            exit;
          }
                          
        }

        if ( $srv_date ne $torrus_srvderive->last_srv_date ) {
          warn "updating last_srv_date of $serviceid to $srv_date\n" if $DEBUG;
          $torrus_srvderive->last_srv_date($srv_date);
          my $error = $torrus_srvderive->replace;
          die $error if $error;
        }
        dbh->commit or die dbh->errstr;

        $prev = $cur;
      }
      warn "done with $serviceid\n" if $DEBUG;

      exit;
      #end-of-kid
    }

  } #foreach my $torrus_srvderive
  dbh->commit or die dbh->errstr;

  myexit() if sigterm() || sigint();
  warn "restarting main loop\n" if $DEBUG > 1;
  #sleep 60 unless $found;
}

sub _shouldrun {
     $conf->exists('network_monitoring_system')
  && $conf->config('network_monitoring_system') eq 'Torrus_Internal';
}

sub usage { 
  die "Usage:\n\n  freeside-cdrrewrited user\n";
}

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

=head1 NAME

freeside-torrus-srvderive - Freeside's Torrus virtual port daemon.

=head1 SYNOPSIS

  freeside-torrus-srvderive

=head1 DESCRIPTION

Runs continuously, searches for samples in the srvexport table which do not
have an entry for combined virtual ports, and adds them.

=head1 SEE ALSO

=cut

1;