#!/bin/bash

trap 'echo "$0:$LINENO:error: \"$BASH_COMMAND\" returned $?" >&2' ERR
set -eE -o pipefail

# verbose command
v() {
  printf "$0 running: %s\n" "$*"
  "$@"
}


usage() {
  cat <<EOF
Basic Usage: libremanage poweroff|poweron|reboot HOSTNAME

Available HOSTNAMEs defined in /etc/libremanage.conf on this machine:

EOF

  if [[ -e /etc/libremanage.conf ]]; then
    sed -r '/\s*#/d;/^\s*$/d;s/_.*//' /etc/libremanage.conf
  else
    echo "/etc/libremanage.conf does not exist."
  fi

  cat <<EOF

Thats all you need to know unless you are defining configuration or
setting up a new device.





Advanced Usage: libremanage [--switch] poweroff|poweron|reboot HOSTNAME|CHANNEL [BOARD_ID]

Note, the relay's channels default state when plugged in are off.

Example /etc/libremanage.conf:

# This config is sourced from bash, so make sure its valid bash.
cephserver3_channel=1
cephserver3_board_id=HURTM
cephserver2_channel=2
cephserver2_board_id=HURTM

librecmc1_type=switch
cephserver2_type=button # default

# end of config


Example use:

$ libremanage reboot cephserver3

--switch means means that the relay controls on an on/off switch (with
default on), instead of a pc power button, which is the default. This
corresponds to the config option HOST_type=switch.

BOARD_ID is not needed if only 1 relay device is connected, or if it is
defined in the config. To understand CHANNEL and BOARD_ID, run
hidusb-relay-cmd and hidusb-relay-cmd state.


WARNING: Avoid ever manually running "hidusb-relay-cmd on" in
production, because if you lose connectivity and can't turn it off, its
like the server's power button is stuck being pushed in and it won't
turn on in that state. You will need to physically replug usb power to
the relay so the channel goes back to its default off state. If this
script somehow dies after turning a relay on, running it again will turn
it off. That is why this script runs locally and ignores signals when
its running. If you run this script over ssh and lose connection as this
script is running, it will continue to run and complete.

EOF
  if [[ -e /etc/libremanage.conf ]]; then
    echo "Current /etc/libremanage.conf:"
    cat /etc/libremanage.conf
  else
    echo "Note: /etc/libremanage.conf does not exist on the current machine"
  fi
  exit 0
}



switch=false
if [[ $1 == --switch ]]; then
  switch=true
  shift
fi

if (( $# < 2 )); then
  usage
fi

read action hostchan board_id  <<<"$@"

if [[ -e /etc/libremanage.conf ]]; then
  source /etc/libremanage.conf
fi

# Use config vars when appropriate. We know the arg is a HOSTNAME if it
# doesn't start with a number.
case $hostchan in
  [0-9]*)
    chan=$hostchan
    ;;
  *)

    # allow board_id to be empty if its unset
    if [[ ! $board_id ]]; then
      board_id_var=${hostchan}_board_id
      board_id=${!board_id_var}
    fi

    chan_var=${hostchan}_channel
    chan=${!chan_var}
    if [[ ! $chan ]]; then
      echo "error: channel not set on cli and not found in /etc/libremanage.conf" >&2
      exit 1
    fi

    type_var=${hostchan}_type
    type=${!type_var}
    if [[ $type == switch ]]; then
      switch=true
    fi
    ;;
esac


if ! $switch && hidusb-relay-cmd state | grep -F R$CHAN=ON; then
  cat >&2 <<EOF
$0: ERROR: Output from hidusb-relay-cmd state shows an ON relay, as if
the power button is stuck in the pressed state. This could mean another
command instance is running, or it got stuck on due to an uncompleted
run. Exiting now so you can investigate. To manually switch it back to
OFF, run the following command, or unplug the relay from usb power.

hidusb-relay-cmd $board_id_arg off $chan

EOF
  exit 1
fi


case $(hidusb-relay-cmd state|wc -l) in
  0)
    echo "error: got 0 lines from running hidusb-relay-cmd state" >&2
    exit 1
    ;;
  1) : ;;
  *)
    if [[ ! $board_id ]]; then
      echo "error: more than 1 relay device, so passing its id is required" >&2
      exit 1
    fi
    ;;
esac


if [[ $board_id ]]; then
  # leave this as an empty var if its not passed
  board_id_arg="id=$board_id"
fi

# ignore errors and continue on if a command fails from here
set +eE +o pipefail
# ignore hup so we complete even if there is a connection problem, and
# force anyone to kill -9 so we might complete in more cases, for
# example if a reboot is happening
trap '' HUP INT QUIT TERM
echo "$0: doing $action. shell commands will be printed to the terminal."
case $action in
  poweroff)
    if $switch; then
      v hidusb-relay-cmd $board_id_arg on $chan
    else
      v hidusb-relay-cmd $board_id_arg on $chan
      v sleep 6
      v hidusb-relay-cmd $board_id_arg off $chan
    fi
    ;;
  poweron)
    if $switch; then
      v hidusb-relay-cmd $board_id_arg off $chan
    else
      v hidusb-relay-cmd $board_id_arg on $chan
      v sleep 1
      v hidusb-relay-cmd $board_id_arg off $chan
    fi
    ;;
  reboot)
    if $switch; then
      v hidusb-relay-cmd $board_id_arg on $chan
      v sleep 4
      v hidusb-relay-cmd $board_id_arg off $chan
    else
      v hidusb-relay-cmd $board_id_arg on $chan
      v sleep 6
      v hidusb-relay-cmd $board_id_arg off $chan
      v sleep 1
      v hidusb-relay-cmd $board_id_arg on $chan
      v sleep 1
      v hidusb-relay-cmd $board_id_arg off $chan
    fi
    ;;
  *)
    echo "error: action arg not supported" >&2
    exit 1
esac
echo "$0: script ended. exiting"