#!/usr/bin/perl
require 5.006;

BEGIN {
   use File::Basename;
   my $binDir  = dirname($0);
   unshift(@INC, "$binDir" );
}


use setup;

setup::setupEnv();

while (@ARGV) {
  $arg = shift @ARGV;
  if ( $arg =~ /^-verbose\z/ ) {
    $VERBOSE = 1;
  } elsif ( $arg =~ /-v/ ) {
    $GET_VERSION = 1;
    $WDOG = undef;
    last;
  } elsif ( $arg =~ /-email/ ) {
    $EMAIL = shift @ARGV;
  } elsif ( $arg =~ /-pause/ ) {
    $PAUSE = shift @ARGV;
  } elsif ( $arg =~ /-wdog/ ) {
    $WDOG = 1;
  } else {
    usage();
  }
}


if ($WDOG) {
  defined(my $dpid = fork) or die "**F: Failed to fork - $!";
  if ($dpid) {
    #print "Detach terminal\n";
    exit 0;  # detach the terminal, child continues below
  } else {
    setpgrp (0,0) if ($setup::sysname != /^win/i );
  }
}

$BUILD_ROOTDIR = $setup::BUILD_ROOTDIR;
$JAVA_BIN = $setup::JAVA_BIN;

use reputils;

reputils::checkJava($JAVA_BIN);


$PREFS_ROOT = $setup::PREFS_ROOT;
$LOG_DIR = $setup::LOG_DIR;
mkdir($LOG_DIR) if !-e $LOG_DIR;
$DB_DIR = "$BUILD_ROOTDIR/systemdb";
if (!-e $DB_DIR) {
  $created = mkdir($DB_DIR);
  if (!$created) {
    die "Failed to mkdir $DB_DIR\n";
  }
}

$CORRUPTED_FLAG = "$DB_DIR/corrupted";
if (-e $CORRUPTED_FLAG) {
  my $MSG =<<  "EOM";
FATAL ERROR: The recovery logs are corrupted.

\tReport the problem with a talkback tarball to <support\@wandisco.com>.
\tThen, follow the CLEAN RESTART procedure described in the Admin Guide.

EOM

  die "$MSG";
}

$CP = $setup::CP;

$PERL_PATH = reputils::path2perl();

$SYS_PROPS = "$setup::EGD -Dlog.dir=$BUILD_ROOTDIR -Dprefs.root=$PREFS_ROOT -Derr.catalog.dir=$BUILD_ROOTDIR/config -Djava.io.tmpdir=$DB_DIR -Duse.soap=off -Dperl.path=$PERL_PATH";

# Ony version check needs ?
version() if ($GET_VERSION); # will exit

# Check  another process running
#$JPDA = $ENV{JPDA};
$CHECK = "org.nirala.admin.DConeUpChecker";
$checkCmd = "$JAVA_BIN/java  $reputils::CLIENT_JVM_ARGS  $JPDA -cp \"$CP\" $SYS_PROPS $CHECK";
system($checkCmd);
if ($? != 0) {
  exit(-1);
}

# Execute Main Program
$MAIN = "org.nirala.communication.transport.cvsproxy.ProxyServer";

$SYS_PROPS .= " -Demail=$EMAIL" if $EMAIL;
$READONLY_SYS_PROPS = "$SYS_PROPS -Dproxy.mode=readonly";
$JVMARGS = "$reputils::SERVER_JVM_ARGS";
$runCmd = "$JAVA_BIN/java $JVMARGS  $JPDA -cp \"$CP\" $SYS_PROPS $MAIN";
$runReadOnlyCmd = "$JAVA_BIN/java $JVMARGS  $JPDA -cp \"$CP\" $READONLY_SYS_PROPS $MAIN";

#=== Run Main Now ====

mainrun();

#=== END ============

#---- SUBS -------------
sub mainrun {
  $PGID = $$;
  if ($WDOG) {
    $MAX_DEATHS = 10;
    $MAX_RW = $MAX_DEATHS - 1;
    watchdog();
  } else {
    executeMain();
  }
}

sub watchdog {
  my $done = 0;
  my $ndeaths = 0;
  $readonly = 0;
  my $MIN_UPTIME = 30; # 30s

  while($ndeaths < $MAX_DEATHS) { # If 10 successive deaths every 30s bail out
    if ($ndeaths == ($MAX_RW - 1)) {
      $readonly = 1;
    }
    defined(my $pid = fork) or die "**F: Failed to fork - $!";
    if ($pid) {
      ## parent:
      if ($ndeaths == 0) {
        emailRestart($EMAIL) if $EMAIL;
      }
      if ($readonly == 1) {
        emailReadonly($EMAIL) if $EMAIL;
      }
      my $start  = time;
      waitpid $pid, 0; # block
      my $end = time;
      my $rc = $? >> 8;
      if ($rc == 19) {
        emailNormalShutdown($EMAIL) if $EMAIL; ;
        exit($rc);   # Normal shutdown
      }
      if ($rc == 37) {  # corrupted recovery log
        emailCorrupt($EMAIL) if $EMAIL;
        system("touch $CORRUPTED_FLAG");
        exit($rc);
      }
      my $life = $end - $start;
      if ($life < $MIN_UPTIME) {
        $ndeaths++;
      } else {
        $ndeaths = 0; # reset count
        $readonly = 0;
      }
      sleep $PAUSE; # before restarting service
    } else {
      ## child:
      executeMain();
    }
  }
  # exceeded the death rate
  my $minUptimeSec = int($MIN_UPTIME/1000);
  emailShutdown($EMAIL) if $EMAIL;
  die "**F: Watchdog is terminating....$MAX_DEATHS process exits occured within ${minUptimeSec}s of each other\n";
}

sub executeMain  {

  if ($readonly == 1) {
    $cmd = $runReadOnlyCmd;
  } else {
    $cmd =  "$runCmd";
  }
  if ($VERBOSE) {
    print "Executing ....\n\t$cmd\n";
  } else {
    $log = "$LOG_DIR/console.txt";
    &setup::redirectSTDIO($log);
  }

  # Save PGID for latter shutdown
  $PGID = getpgrp() if ($setup::sysname != /^win/i );
  system("echo $PGID > $LOG_DIR/my.pid");
  system("echo $$ > $LOG_DIR/java.pid");

  # Become the image so that SIGQUIT etc can work on the script itself
  # save output from JVM like thread dump in $LOG_DIR/console.txt file
  exec "$cmd";

}

sub  emailNormalShutdown {
  my $TO = $_[0];
  my $host = (POSIX::uname())[1];
  my $SUBJECT = "[$host:SYSTEM ALERT] WANdisco CVS Replicator Normal Shutdown";
  my $now = `date`;
  my $MSG = "$now\nNormal shutdown was completed\n";
  my $FROM = "wdog\@cvsreplicator.org";

  setup::sendEmail($SUBJECT, $MSG, $TO, $FROM);
}

sub  emailShutdown {
  my $TO = $_[0];
  my $host = (POSIX::uname())[1];
  my $SUBJECT = "[$host:SYSTEM ALERT] WANdisco CVS Replicator Shutdown";
  my $now = `date`;
  my $MSG = "$now\nAfter $MAX_DEATHS attempts, failed to restart service, please look at the ProxyServer*log files";
  my $FROM = "wdog\@cvsreplicator.org";

  setup::sendEmail($SUBJECT, $MSG, $TO, $FROM);
}

sub  emailCorrupt {
  my $TO = $_[0];
  my $host = (POSIX::uname())[1];
  my $SUBJECT = "[$host:SYSTEM ALERT] WANdisco CVS Replicator Shutdown";
  my $now = `date`;
  my $MSG = "$now\nDetected possible corruption of recovery logs. Please look at the ProxyServer*log files";
  my $FROM = "wdog\@cvsreplicator.org";

  setup::sendEmail($SUBJECT, $MSG, $TO, $FROM);
}

sub emailRestart {
  my $TO = $_[0];
  my $host = (POSIX::uname())[1];
  my $SUBJECT = "[$host:SYSTEM ALERT] WANdisco CVS Replicator Restarting";
  my $now = `date`;
  my $MSG = "$now\tThe cvsreplicator watchdog is restarting service";
  my $FROM = "wdog\@cvsreplicator.org";

  setup::sendEmail($SUBJECT, $MSG, $TO, $FROM);
}

sub emailReadonly {
  my $TO = $_[0];
  my $host = (POSIX::uname())[1];
  my $SUBJECT = "[$host:SYSTEM ALERT] WANdisco CVS Replicator Restarting In Readonly Mode";
  my $now = `date`;
  my $MSG = "$now\tThe cvsreplicator watchdog is restarting service in readonly mode";
  my $FROM = "wdog\@cvsreplicator.org";

  setup::sendEmail($SUBJECT, $MSG, $TO, $FROM);
}


sub version {
  $vercheck = "org.nirala.admin.cvsproxy.VersionChecker";
  $checkCmd = "$JAVA_BIN/java  $reputils::CLIENT_JVM_ARGS  $JPDA -cp \"$CP\" $SYS_PROPS $vercheck";
  system($checkCmd);
  if ($? != 0) {
    exit(-1);
  }
  exit(0);
}

sub usage {

  $USG =<<  "EOM";
Usage: cvsreplicator [-v] [-verbose] [ -wdog [-pause time] [-email email-address] ]

\t-v\tPrint the cvsreplicator version

\t-verbose
\t\tVerbose, console messages go to STDOUT/STDERR
\t  \tinstead of logs/console.txt
\t-wdog
\t\tWatchdog mode, cvsreplicator will start a watchdog 
\t     \twhich can automatically restart cvsreplicator process 
\t     \tif it terminates.
\t-pause
\t\tTime in seconds that the watchdog will pause for, before
\t      \trestarting service. Defaults to 0 seconds.
\t-email
\t\tSpecify an email address to send an alert to, whenever the
\t      \tWatchdog restarts/shuts down the cvsreplicator service.
\t      \tFor email alert to work, sendmail or sendmail wrapper must be
\t      \tinstalled in /usr/sbin/sendmail. You may want to test it by
\t      \trunning "sendmail -t" first.

Report any issues to <support\@wandisco.com>.
EOM

  die "$USG";

}