#!/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; 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

if type dinitctl >/dev/null 2>&1; then
  DINIT=y
else
  unset DINIT
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 "$1"
  fi
  if [ -n "$DINIT" ]; then
    $ROOTCMD dinitctl start "$1"
  fi
  if [ -n "$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 "$1"
  fi
  if [ -n "$DINIT" ]; then
    $ROOTCMD dinitctl stop "$1"
  fi
  if [ -n "$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 "$1"
  fi
  if [ -n "$DINIT" ]; then
    $ROOTCMD dinitctl enable "$1"
  fi
  if [ -n "$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 "$1"
  fi
  if [ -n "$DINIT" ]; then
    $ROOTCMD dinitctl disable "$1"
  fi
  if [ -n "$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
    $ROOTCMD s6-rc -a list
  fi
  if [ -n "$DINIT" ]; then
    $ROOTCMD dinitcheck
  fi
  if [ -n "$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 %s\n" "$i"
      start_service "$i"
    done
    ;;
  "stop")
    for i in "${@:2}"; do
      printf "stop %s\n" "$i"
      stop_service "$i"
    done
    ;;
  "enable")
    for i in "${@:2}"; do
      printf "enable %s\n" "$i"
      enable_service "$i"
    done
    ;;
  "disable")
    for i in "${@:2}"; do
      printf "disable %s\n" "$i"
      disable_service "$i"
    done
    ;;
  "restart")
    read -ra services < <(echo "${@:2}")
    read -ra reversed < <(reverse_array "${services[@]}")
    for service in "${reversed[@]}"; do
      printf "stop %s\n" "$service"
      stop_service "$service"
    done
    for service in "${services[@]}"; do
      printf "start %s\n" "$service"
      start_service "$service"
    done
    ;;
  "status")
    status_service
esac