#!/bin/bash
#

# Copyright (C) 2011 Google Inc.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
# 02110-1301, USA.

SSH_USER='root'
SSH_FLAGS='-q -oStrictHostKeyChecking=no'

EXIT_SUCCESS=0
EXIT_FAILURE=1
EXIT_UNKNOWN=2

_run_ssh() {
  local host="$1"
  local command="$2"

  ssh $SSH_FLAGS "$SSH_USER@$host" "$command" 1>&2
  return $?
}

_power_on() {
  echo 'power-on not supported in this script' >&2
  exit $EXIT_FAILURE
}

_power_off() {
  local host="$1"

  if ! _run_ssh "$host" 'shutdown -h now'; then
    echo "Failure during ssh to $host" >&2
    exit $EXIT_FAILURE
  fi
}

_power_cycle() {
  local host="$1"

  if ! _run_ssh "$host" 'shutdown -r now'; then
    echo "Failure during ssh to $host" >&2
    exit $EXIT_FAILURE
  fi
}

_power_status() {
  local host="$1"

  if fping -q "$host" > /dev/null 2>&1; then
    echo '{ "powered": true }'
  else
    echo '{ "powered": false }'
  fi
}

_health() {
  echo 'health not supported in this script' >&2
  exit $EXIT_FAILURE
}

_action() {
  local command="$1"
  local host="$2"

  case "$command" in
    power-on)
      _power_on "$host"
      ;;
    power-off)
      _power_off "$host"
      ;;
    power-cycle)
      _power_cycle "$host"
      ;;
    power-status)
      _power_status "$host"
      ;;
    health)
      _health "$host"
      ;;
    *)
      echo "Unsupported command '$command'" >&2
      exit $EXIT_FAILURE
      ;;
  esac
}

main() {
  if [[ $# != 2 ]]; then
    echo "Wrong argument count, got $#, expected 2" >&2
    exit $EXIT_FAILURE
  fi

  _action "$@"

  exit $EXIT_SUCCESS
}

main "$@"