#!/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"
}

$DEBUG && PREFIX=. || PREFIX=
ssh_plist=$PREFIX/System/Library/LaunchDaemons/ssh.plist
if $DEBUG; then
  mkdir -p "$(dirname "$ssh_plist")"
fi

value_ProgramArguments_orig='
<array>
  <string>/usr/sbin/sshd</string>
  <string>-i</string>
</array>
'
value_ProgramArguments='
<array>
  <string>/usr/sbin/sshd</string>
  <string>-i</string>
  <string>-E</string>
  <string>/var/log/sshd-log</string>
</array>
'

check_ProgramArguments_in_ssh_plist() {
  plutil -extract ProgramArguments xml1 -o - "$ssh_plist" > /dev/null
  rv=$?
  return $rv
}
insert_ProgramArguments_in_ssh_plist() {
  plutil -replace ProgramArguments -xml "$value_ProgramArguments" "$ssh_plist"
  rv=$?
  #! $DEBUG || plutil -convert xml1 -o - "$ssh_plist"
  diff -u <(plutil -convert xml1 -o - "$ssh_plist_bak") <(plutil -convert xml1 -o - "$ssh_plist")
  return $rv
}
remove_ProgramArguments_in_ssh_plist() {
  plutil -replace ProgramArguments -xml "$value_ProgramArguments_orig" "$ssh_plist"
  rv=$?
  #! $DEBUG || plutil -convert xml1 -o - "$ssh_plist"
  diff -u <(plutil -convert xml1 -o - "$ssh_plist_bak") <(plutil -convert xml1 -o - "$ssh_plist")
  return $rv
}
successfully_finished() {
  if ! $DEBUG; then
    echo "sudo launchctl unload $ssh_plist" 1>&2
    echo "sudo launchctl load $ssh_plist" 1>&2
  fi
}
modified=false

if [ "$1" == enable ]; then
  if $DEBUG && [ ! -f "$ssh_plist" ]; then
    cp -p /System/Library/LaunchDaemons/ssh.plist "$ssh_plist"
  fi
  [ ! -f "$ssh_plist" ] || ssh_plist_bak="${ssh_plist}-$(fstrftime_l "$ssh_plist")"
  if check_ProgramArguments_in_ssh_plist; then
    if [ "$ssh_plist_bak" != "" ]; then
      mv "$ssh_plist" "$ssh_plist_bak"
      cp -p "$ssh_plist_bak" "$ssh_plist"
    fi
    insert_ProgramArguments_in_ssh_plist && modified=:
  else
    echo "$ssh_plist does not have ProgramArguments key" 1>&2
  fi
else
  [ ! -f "$ssh_plist" ] || ssh_plist_bak="${ssh_plist}-$(fstrftime_l "$ssh_plist")"
  if check_ProgramArguments_in_ssh_plist; then
    if [ "$ssh_plist_bak" != "" ]; then
      mv "$ssh_plist" "$ssh_plist_bak"
      cp -p "$ssh_plist_bak" "$ssh_plist"
    fi
    remove_ProgramArguments_in_ssh_plist && modified=:
  else
    echo "$ssh_plist does not have ProgramArguments key" 1>&2
  fi
fi
$modified && successfully_finished