#!/usr/bin/env bash

## CHECK DEPS

if ! type readlink >/dev/null 2>&1; then
  printf "readlink command not found.\n"
  exit 1
fi

## UTIL FUNCTIONS

reverse_array () {
  unset _b
  for a in $@; do
    [ -n "$_b" ] && _b="$a $_b" || _b="$a"
  done
  echo $_b
}

## FIND INIT

INIT="$(basename $(readlink $(type init)))"
if `type s6-rc >/dev/null 2>&1`; then
  S6=y
else
  unset S6
fi

case "$INIT" in
  "openrc-init") OPENRC=y ; unset DINIT RUNIT SYSTEMD ;;
  "runit-init")  RUNIT=y ; unset DINIT OPENRC SYSTEMD ;;
  "systemd") SYSTEMD=y ; unset DINIT OPENRC RUNIT ;;
  "*") print "Unknown init!\n"
esac

## CHECK INIT HELPER

if [ -n "$RUNIT" ]; then
  if `type rsm >/dev/null 2>&1`; then
    RSM=y
  else
    unset RSM
  fi
fi

## CHECK PRIVS

if [ "$(whoami)" != "root" ]; then
  ROOTCMD="sudo"
fi

## SERVICE FUNCTIONS

start_service () {
  if [ -n "$S6" ]; then
    $ROOTCMD s6-rc -u change $1
  fi
  if [ -n "$OPENRC" ]; then
    $ROOTCMD rc-service $1 start
  elif [ -n "$RUNIT" ]; then
    if [ -n "$RSM" ]; then
      $ROOTCMD rsm start $1
    else
      $ROOTCMD sv start $1
    fi
  elif [ -n "$SYSTEMD" ]; then
    $ROOTCMD systemctl start $1
  fi
}

stop_service () {
  if [ -n "$S6" ]; then
    $ROOTCMD s6-rc -d change $1
  fi
  if [ -n "$OPENRC" ]; then
    $ROOTCMD rc-service $1 stop
  elif [ -n "$RUNIT" ]; then
    if [ -n "$RSM" ]; then
      $ROOTCMD rsm stop $1
    else
      $ROOTCMD sv stop $1
    fi
  elif [ -n "$SYSTEMD" ]; then
    $ROOTCMD systemctl stop $1
  fi
}

enable_service () {
  if [ -n "$S6" ]; then
    $ROOTCMD s6-service add default $1
  fi
  if [ -n "$OPENRC" ]; then
    $ROOTCMD rc-update add $1 default
  elif [ -n "$RUNIT" ]; then
    if [ -n "$RSM" ]; then
      $ROOTCMD rsm enable $1
    else
      print "enabling runit services manually not presently supported; use rsm\n"
    fi
  elif [ -n "$SYSTEMD" ]; then
    $ROOTCMD systemctl enable $1
  fi
}

disable_service () {
  if [ -n "$S6" ]; then
    $ROOTCMD s6-service delete default $1
  fi
  if [ -n "$OPENRC" ]; then
    $ROOTCMD rc-update del $1 default
  elif [ -n "$RUNIT" ]; then
    if [ -n "$RSM" ]; then
      $ROOTCMD rsm disable $1
    else
      print "disabling runit services manually not presently supported; use rsm\n"
    fi
  elif [ -n "$SYSTEMD" ]; then
    $ROOTCMD systemctl disable $1
  fi
}

status_service () {
  if [ -n "$S6" ]; then
    $ROOTCMD s6-rc -a list
  fi
  if [ -n "$OPENRC" ]; then
    $ROOTCMD rc-service status
  elif [ -n "$RUNIT" ]; then
    if [ -n "$RSM" ]; then
      $ROOTCMD rsm status
    else
      print "getting status of runit services manually not presently supported; use rsm\n"
    fi
  elif [ -n "$SYSTEMD" ]; then
    $ROOTCMD systemctl status
  fi
}

## MAIN LOOP

case "$1" in
  "start")
    for i in "${@:2}"; do
      printf "start $i\n"
      start_service $i
    done
    ;;
  "stop")
    for i in "${@:2}"; do
      printf "stop $i\n"
      stop_service $i
    done
    ;;
  "enable")
    for i in "${@:2}"; do
      printf "enable $i\n"
      enable_service $i
    done
    ;;
  "disable")
    for i in "${@:2}"; do
      printf "disable $i\n"
      disable_service $i
    done
    ;;
  "restart")
    for i in `reverse_array ${@:2}`; do
      printf "stop $i\n"
      stop_service $i
    done
    for i in ${@:2}; do
      printf "start $i\n"
      start_service $i
    done
    ;;
  "status")
    status_service
esac