#!/usr/bin/env bash
#
# Use rofi/zenity to change system runstate thanks to systemd.
#
# Note: this currently relies on associative array support in the shell.
#
# Inspired from i3pystatus wiki:
# https://github.com/enkore/i3pystatus/wiki/Shutdown-Menu
#
# Copyright 2015 Benjamin Chrétien <chretien at lirmm dot fr>
#
# 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 3 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, see <http://www.gnu.org/licenses/>.

#######################################################################
#                            BEGIN CONFIG                             #
#######################################################################

# Use a custom lock script
#LOCKSCRIPT="i3lock-extra -m pixelize"

# Colors: FG (foreground), BG (background), HL (highlighted)
FG_COLOR="${FG_COLOR:-#bbbbbb}"
BG_COLOR="${BG_COLOR:-#111111}"
HLFG_COLOR="${HLFG_COLOR:-#111111}"
HLBG_COLOR="${HLBG_COLOR:-#bbbbbb}"
BORDER_COLOR="${BORDER_COLOR:-#222222}"

# Options not related to colors
ROFI_TEXT="${ROFI_TEXT:-Menu:}"
ROFI_OPTIONS=(${ROFI_OPTIONS:--width 11 -location 3 -hide-scrollbar -bw 2})

# Zenity options
ZENITY_TITLE="${ZENITY_TITLE:-Menu}"
ZENITY_TEXT="${ZENITY_TEXT:-Action:}"
ZENITY_OPTIONS=(${ZENITY_OPTIONS:---column= --hide-header})

#######################################################################
#                             END CONFIG                              #
#######################################################################

# Whether to ask for user's confirmation
enable_confirmation=${ENABLE_CONFIRMATIONS:-false}

# Preferred launcher if both are available
preferred_launcher="${LAUNCHER:-rofi}"

usage="$(basename "$0") [-h] [-c] [-p name] -- display a menu for shutdown, reboot, lock etc.

where:
    -h  show this help text
    -c  ask for user confirmation
    -p  preferred launcher (rofi or zenity)

This script depends on:
  - systemd,
  - i3,
  - rofi or zenity."

# Check whether the user-defined launcher is valid
launcher_list=(rofi zenity)
function check_launcher() {
  if [[ ! "${launcher_list[@]}" =~ (^|[[:space:]])"$1"($|[[:space:]]) ]]; then
    echo "Supported launchers: ${launcher_list[*]}"
    exit 1
  else
    # Get array with unique elements and preferred launcher first
    # Note: uniq expects a sorted list, so we cannot use it
    i=1
    launcher_list=($(for l in "$1" "${launcher_list[@]}"; do printf "%i %s\n" "$i" "$l"; let i+=1; done \
      | sort -uk2 | sort -nk1 | cut -d' ' -f2- | tr '\n' ' '))
  fi
}

# Parse CLI arguments
while getopts "hcp:" option; do
  case "${option}" in
    h) echo "${usage}"
       exit 0
       ;;
    c) enable_confirmation=true
       ;;
    p) preferred_launcher="${OPTARG}"
       check_launcher "${preferred_launcher}"
       ;;
    *) exit 1
       ;;
  esac
done
check_launcher "${preferred_launcher}"

# Check whether a command exists
function command_exists() {
  command -v "$1" &> /dev/null 2>&1
}

# systemctl required
if ! command_exists systemctl ; then
  exit 1
fi

# menu defined as an associative array
typeset -A menu

# Menu with keys/commands
menu=(
  [Shutdown]="systemctl poweroff"
  [Reboot]="systemctl reboot"
  [Hibernate]="systemctl hibernate"
  [Suspend]="systemctl suspend"
  [Halt]="systemctl halt"
  [Lock]="${LOCKSCRIPT:-i3lock --color=${BG_COLOR#"#"}}"
  [Logout]="i3-msg exit"
  [Cancel]=""
)
menu_nrows=${#menu[@]}

# Menu entries that may trigger a confirmation message
menu_confirm="Shutdown Reboot Hibernate Suspend Halt Logout"

launcher_exe=""
launcher_options=""
rofi_colors=""

function prepare_launcher() {
  if [[ "$1" == "rofi" ]]; then
    rofi_colors=(-bc "${BORDER_COLOR}" -bg "${BG_COLOR}" -fg "${FG_COLOR}" \
        -hlfg "${HLFG_COLOR}" -hlbg "${HLBG_COLOR}")
    launcher_exe="rofi"
    launcher_options=(-dmenu -i -lines "${menu_nrows}" -p "${ROFI_TEXT}" \
        "${rofi_colors}" "${ROFI_OPTIONS[@]}")
  elif [[ "$1" == "zenity" ]]; then
    launcher_exe="zenity"
    launcher_options=(--list --title="${ZENITY_TITLE}" --text="${ZENITY_TEXT}" \
        "${ZENITY_OPTIONS[@]}")
  fi
}

for l in "${launcher_list[@]}"; do
  if command_exists "${l}" ; then
    prepare_launcher "${l}"
    break
  fi
done

# No launcher available
if [[ -z "${launcher_exe}" ]]; then
  exit 1
fi

launcher=(${launcher_exe} "${launcher_options[@]}")
selection="$(printf '%s\n' "${!menu[@]}" | sort | "${launcher[@]}")"

function ask_confirmation() {
  if [ "${launcher_exe}" == "rofi" ]; then
    confirmed=$(echo -e "Yes\nNo" | rofi -dmenu -i -lines 2 -p "${selection}?" \
      "${rofi_colors}" "${ROFI_OPTIONS[@]}")
    [ "${confirmed}" == "Yes" ] && confirmed=0
  elif [ "${launcher_exe}" == "zenity" ]; then
    zenity --question --text "Are you sure you want to ${selection,,}?"
    confirmed=$?
  fi

  if [ "${confirmed}" == 0 ]; then
    i3-msg -q "exec ${menu[${selection}]}"
  fi
}

if [[ $? -eq 0 && ! -z ${selection} ]]; then
  if [[ "${enable_confirmation}" = true && \
        ${menu_confirm} =~ (^|[[:space:]])"${selection}"($|[[:space:]]) ]]; then
    ask_confirmation
  else
    i3-msg -q "exec ${menu[${selection}]}"
  fi
fi