#! /bin/bash
### BEGIN INIT INFO
# Provides: kiwix-plug
# Required-Start: $all
# Required-Stop: $all
# Default-Start: 2 3 4 5
# Default-Stop: 0 1 6
# Short-Description: Start kiwix-plug at the boot time
# Description: Make everything necessary to have a kiwix-plug running
### END INIT INFO

INOTIFY_FIFO=/var/run/kiwix-inotify
PLUG_LOCK=/var/lock/kiwix-plug

start_inotify() {
  if [ ! -e $INOTIFY_FIFO ] ; then
    mkfifo $INOTIFY_FIFO
  else
    return
  fi
  inotifywait -m -e create /media > "$INOTIFY_FIFO" &
  INOTIFY_PID=$!
  trap "exit_inotify" 2 3 15
  
  while read file ; do
    MOUNT=$(check_mounts)
    if [ -n "$MOUNT" ] ; then
      execute_kiwixplug $MOUNT
    fi
  done < "$INOTIFY_FIFO"
}

exit_inotify() {
  echo "Killing following inotify PID $INOTIFY_PID..."
  kill -9 $INOTIFY_PID
  echo "Removinf following inotify FIF $INOTIFY_PID..."
  rm -f $INOTIFY_FIFO
  exit 0
}

check_mounts() {
  IFS=$'\n'
  sync
  for MOUNT in `df | sed "s/^ *//;s/ *$//;s/ \{1,\}/ /g" | cut --delimiter=" " -f6- | grep "/media/"`
  do
    if [ -f "$MOUNT/system/kiwix-plug" ]
    then
      break
    fi
    MOUNT=
  done
  unset IFS
  echo $MOUNT
}

execute_kiwixplug() {
  echo "Found kiwix-plug USB key at $1"
  cp "$1/system/kiwix-plug" /tmp/
  chmod +x /tmp/kiwix-plug
  /tmp/kiwix-plug "$1" > /tmp/kiwix-plug.log 2>/dev/null &
  touch $PLUG_LOCK
  exit_inotify
}

# Carry out specific functions when asked to by the system
case "$1" in
  start)
    echo "Starting script kiwix-plug"
    MOUNT=$(check_mounts)

    if [ "$MOUNT" = "" ]
    then
      echo "Unable to find a kiwix-plug USB key plugged :("
      start_inotify
    else
      execute_kiwixplug $MOUNT
    fi
    ;;
  stop)
    echo "Stopping script kiwix-plug"
    rm $PLUG_LOCK
    ;;
  *)
    echo "Usage: /etc/init.d/kiwix-plug {start|stop}"
    exit 1
    ;;
esac

exit 0