#!/bin/ksh
#DEBUG=false
DEBUG=:
if [ $# != 1 ]; then
cat <<EOF
usage: $0 enable|disable
EOF
  exit 1
fi

fstrftime_l() {
  stat -f '%Sm' -t '%Y%m%d%H%M%S' "$1"
}

$DEBUG && PREFIX=. || PREFIX=
facility="$(basename "$0" -logging.sh)"
asl_facility_log=$PREFIX/etc/asl/org.sample."${facility}"-log
syslogd_plist=$PREFIX/System/Library/LaunchDaemons/com.apple.syslogd.plist
if $DEBUG; then
  mkdir -p "$(dirname "$asl_facility_log")"
  mkdir -p "$(dirname "$syslogd_plist")"
fi

value_Sockets_NetworkListener='
<dict>
  <key>SockServiceName</key>
  <string>syslog</string>
  <key>SockType</key>
  <string>dgram</string>
</dict>
'

check_Sockets_NetworkListener_in_syslogd_plist() {
  plutil -extract Sockets.NetworkListener xml1 -o - "$syslogd_plist" > /dev/null
  rv=$? 
  return $rv
}
insert_Sockets_NetworkListener_in_syslogd_plist() {
  plutil -insert Sockets.NetworkListener -xml "$value_Sockets_NetworkListener" "$syslogd_plist"
  rv=$?
  #! $DEBUG || plutil -convert xml1 -o - "$syslogd_plist"
  diff -u <(plutil -convert xml1 -o - "$syslogd_plist_bak") <(plutil -convert xml1 -o - "$syslogd_plist")
  return $rv
}
remove_Sockets_NetworkListener_in_syslogd_plist() {
  plutil -remove Sockets.NetworkListener "$syslogd_plist"
  rv=$?
  #! $DEBUG || plutil -convert xml1 -o - "$syslogd_plist"
  diff -u <(plutil -convert xml1 -o - "$syslogd_plist_bak") <(plutil -convert xml1 -o - "$syslogd_plist")
  return $rv
}
write_etc_asl_org_sample_asl_facility_log() {
  cat <<EOF | dd of="$asl_facility_log" 2> /dev/null
? [= Facility ${facility}] [<= Level info] file /var/log/${facility}-log
EOF
  return $?  
}
successfully_finished() {
  ! $DEBUG || echo 'sudo killall -HUP syslogd' 1>&2
}
modified=false

if [ "$1" == enable ]; then
  if $DEBUG && [ ! -f "$syslogd_plist" ]; then
    cp -p /System/Library/LaunchDaemons/com.apple.syslogd.plist "$syslogd_plist"
  fi
  [ ! -f "$syslogd_plist" ] || syslogd_plist_bak="${syslogd_plist}-$(fstrftime_l "$syslogd_plist")"
  if [ ! -f "$asl_facility_log" ]; then
    echo "write $asl_facility_log"
    write_etc_asl_org_sample_asl_facility_log && modified=:
  else
    echo "$asl_facility_log already exists" 1>&2
  fi
  if ! check_Sockets_NetworkListener_in_syslogd_plist; then
    if [ "$syslogd_plist_bak" != "" ]; then
      mv "$syslogd_plist" "$syslogd_plist_bak"
      cp -p "$syslogd_plist_bak" "$syslogd_plist"
    fi
    insert_Sockets_NetworkListener_in_syslogd_plist && modified=:
  else
    echo "$syslogd_plist already has Sockets.NetworkListener key" 1>&2
  fi
else
  [ ! -f "$syslogd_plist" ] || syslogd_plist_bak="${syslogd_plist}-$(fstrftime_l "$syslogd_plist")"
  if [ -f "$asl_facility_log" ]; then
    echo "remove $asl_facility_log"
    rm "$asl_facility_log" && modified=:
  else
    echo "$asl_facility_log does not exist" 1>&2
  fi
  if check_Sockets_NetworkListener_in_syslogd_plist; then
    if [ "$syslogd_plist_bak" != "" ]; then
      mv "$syslogd_plist" "$syslogd_plist_bak"
      cp -p "$syslogd_plist_bak" "$syslogd_plist"
    fi
    remove_Sockets_NetworkListener_in_syslogd_plist && modified=:
  else
    echo "$syslogd_plist does not have Sockets.NetworkListener key" 1>&2
  fi
fi
$modified && successfully_finished