#!/bin/bash

dir=$(dirname "$(readlink -e "${0}")")
url='https://eckner.net/computer-time-limit.php'

lock_file=~/.computer-time-limit.lock

if [ -d "${dir}"'/.git' ] && [ $# -eq 0 ] && [ "$(stat -c%U "${dir}"'/.git')" = "$(whoami)" ]; then
  timeout 60 git -C "${dir}" fetch --all -p 2>/dev/null
  if [ -z "$(git -C "${dir}" status --porcelain)" ]; then
    git -C "${dir}" pull --ff-only 2>/dev/null
    exec "$0" '-'
  fi
fi

exec 9> "${lock_file}"
if ! flock -n 9; then
  exit
fi

. /etc/computer-time-limit.conf

sende_msg() {
  data="$(uname -n) $1"
  curl \
    -s \
    -X POST \
    --data "msg=${data}" \
    --data "sig=$(
      echo "${data}" \
      | signify -S -s "${key}" -m /dev/stdin -x /dev/stdout \
      | base64 -w0
    )" \
    'https://eckner.net/computer-time-limit.php'
}

wie_lange_noch() {
  if [ ! -f "${key}" ]; then
    noch=0
    ab=$(date +%s)
    return
  fi
  home=$(getent passwd "${user}" | cut -d: -f6)
  if [ -d "${home}" ]; then
    cd "${home}"
    for i in {30..0}; do
      if [ ! -f '.shared_secret' ] \
      || [ ! -f '/usr/src/skripte/ykverify/verify.py' ] \
      || '/usr/src/skripte/ykverify/verify.py'; then
        break
      fi
      if [ "${i}" -eq 0 ]; then
        noch=0
        ab=$(date +%s)
        cd - >/dev/null
        return
      fi
      sleep 1
    done
    cd - >/dev/null
  fi
  erg=$(
    sende_msg start
  )
  if [ -n "${erg}" ] && ! echo "${erg}" | grep -qvx '[0-9]\+'; then
    noch="${erg}"
    ab=$(date +%s)
  else
    noch=$((ab+noch-$(date +%s)))
    ab=$(date +%s)
  fi
}

check_time() {
  if [ "${noch}" -le 0 ]; then
    sende_msg stop >/dev/null
    loginctl terminate-user "${user}"
    (
      sleep 1m
      if is_logged_in "${user}"; then
        poweroff
      fi
    )&
  fi
  if [ "${noch}" -lt 3630 ] && [ "${noch}" -gt 3570 ]; then
    espeak-ng -vde -w /tmp/stunde.wav 'noch eine Stunde'
    xmessage -nearmouse 'Noch 1 Stunde' &
    play /tmp/stunde.wav
    sleep 1m
  fi
  if [ "${noch}" -lt 1830 ] && [ "${noch}" -gt 1770 ]; then
    espeak-ng -vde -w /tmp/halbe_stunde.wav 'noch eine halbe Stunde'
    xmessage -nearmouse 'Noch 1/2 Stunde' &
    play /tmp/halbe_stunde.wav
    sleep 1m
  fi
  if [ "${noch}" -lt 630 ] && [ "${noch}" -gt 570 ]; then
    espeak-ng -vde -w /tmp/zehn.wav 'noch zehn Minuten'
    xmessage -nearmouse 'Noch 10 Minuten' &
    play /tmp/zehn.wav
    sleep 1m
  fi
  if [ "${noch}" -lt 330 ] && [ "${noch}" -gt 270 ]; then
    espeak-ng -vde -w /tmp/fuenf.wav 'noch fünf Minuten'
    xmessage -nearmouse 'Noch 5 Minuten' &
    play /tmp/fuenf.wav
    sleep 1m
  fi
  if [ "${noch}" -lt 90 ] && [ "${noch}" -gt 30 ]; then
    espeak-ng -vde -w /tmp/eins.wav 'noch eine Minute'
    xmessage -nearmouse 'Noch 1 Minute' &
    play /tmp/eins.wav
    sleep 1m
  fi
}

is_logged_in() {
  if users | grep -qwF "${user}"; then
    return 0
  fi
  if loginctl list-users -l | sed -n '2,/^$/p' | awk '{print $2}' | grep -qxF "${user}"; then
    return 0
  fi
  return 1
}

stop_all() {
  for user in "${!keys[@]}"; do
    key="${keys["${user}"]}"
    sende_msg stop >/dev/null
  done
}

trap 'stop_all' EXIT
noch=0
ab=$(date +%s)

while true; do
  for user in "${!keys[@]}"; do
    key="${keys["${user}"]}"
    if is_logged_in; then
      wie_lange_noch
      check_time
    else
      sende_msg stop >/dev/null
    fi
  done
  [ ${noch} -lt 0 ] && noch=0
  sleep $((15 + ((noch + 15) % 30)))
done