#!/bin/bash

# archypr:summary=Set and show lightweight desktop notification reminders
# archypr:args=<minutes> [message] | show | clear
# archypr:examples=omarchy reminder 5 | omarchy reminder 30 "Check the oven" | omarchy reminder show | omarchy reminder clear

set -euo pipefail

format_remaining() {
  local seconds=$1
  local minutes=$((seconds / 60))
  local remainder=$((seconds % 60))

  if ((minutes > 0 && remainder > 0)); then
    echo "${minutes}m ${remainder}s"
  elif ((minutes > 0)); then
    echo "${minutes}m"
  else
    echo "${remainder}s"
  fi
}

parse_systemd_timespan() {
  local timespan="$1"
  local total=0
  local value unit whole

  while read -r value unit; do
    whole=${value%.*}

    case $unit in
    d) total=$((total + whole * 86400)) ;;
    h) total=$((total + whole * 3600)) ;;
    min) total=$((total + whole * 60)) ;;
    s) total=$((total + whole)) ;;
    ms | us) ;;
    esac
  done < <(grep -oE '[0-9]+([.][0-9]+)?(d|h|min|s|ms|us)' <<<"$timespan" | sed -E 's/^([0-9.]+)([a-z]+)$/\1 \2/')

  echo "$total"
}

show_reminders() {
  local timers timer next next_seconds uptime remaining body=""
  local reminder_dir="${XDG_RUNTIME_DIR:-/tmp}/archypr-eminders"
  local reminder_message=""

  timers=$(systemctl --user list-timers --all --no-legend --no-pager "archypr-reminder-*.timer" 2>/dev/null | awk '{ print $(NF - 1) }')
  uptime=${SECONDS_SINCE_BOOT:-$(awk '{ print int($1) }' /proc/uptime)}

  for timer in $timers; do
    next=$(systemctl --user show -P NextElapseUSecMonotonic "$timer" 2>/dev/null || true)
    [[ -z $next ]] && continue

    next_seconds=$(parse_systemd_timespan "$next")
    ((next_seconds <= uptime)) && continue

    remaining=$((next_seconds - uptime))
    reminder=${timer%.timer}
    reminder=${reminder#archypr-eminder-}
    set_at=${reminder##*-}
    reminder_minutes=${reminder%%m-*}
    reminder_message=""
    [[ -f $reminder_dir/${timer%.timer}.message ]] && reminder_message=$(<"$reminder_dir/${timer%.timer}.message")

    if [[ -n $reminder_message ]]; then
      body+="$reminder_message in $(format_remaining $remaining) ($(date -d "@$((set_at + reminder_minutes * 60))" +%-H:%M))"$'\n'
    else
      body+="${reminder_minutes}-min reminder in $(format_remaining $remaining) ($(date -d "@$((set_at + reminder_minutes * 60))" +%-H:%M))"$'\n'
    fi
  done

  if [[ -z $body ]]; then
    archypr-notification-send "󰔛" "Upcoming reminders" "No outstanding reminders" -u low
  else
    archypr-notification-send "󰔛" "Upcoming reminders" "${body%$'\n'}" -u low
  fi
}

clear_reminders() {
  local units
  local reminder_dir="${XDG_RUNTIME_DIR:-/tmp}/archypr-eminders"

  units=$(systemctl --user list-timers --all --no-legend --no-pager "archypr-reminder-*.timer" 2>/dev/null | awk '{ print $(NF - 1), $NF }')

  if [[ -n $units ]]; then
    xargs -r systemctl --user stop <<<"$units" || true
  fi

  rm -f "$reminder_dir"/archypr-eminder-*.message 2>/dev/null || true
  archypr-notification-send "󰔛" "All reminders have been cleared" -u low
}

case ${1:-} in
show | list)
  show_reminders
  exit 0
  ;;
clear)
  clear_reminders
  exit 0
  ;;
esac

minutes=${1:-}
shift || true
message="$*"
custom_message="$message"

if [[ -z $minutes ]] || [[ ! $minutes =~ ^[0-9]+$ ]] || ((minutes == 0)); then
  echo "Usage: archypr-reminder <minutes> [message]"
  echo "       archypr-reminder show"
  echo "       archypr-reminder clear"
  exit 1
fi

if [[ -z $message ]]; then
  message="Your ${minutes} minutes are up"
fi

set_at=$(date +%s)
remind_at=$(date -d "+${minutes} minutes" +%H:%M)
unit="archypr-reminder-${minutes}m-$set_at"
reminder_dir="${XDG_RUNTIME_DIR:-/tmp}/archypr-eminders"
message_file="$reminder_dir/$unit.message"
confirmation="You'll be reminded at $remind_at"
confirmation_title="Reminder set for ${minutes} minutes"

mkdir -p "$reminder_dir"

if [[ -n $custom_message ]]; then
  printf "%s" "$custom_message" >"$message_file"
  confirmation_title="$custom_message in ${minutes} minutes"
fi

systemd-run --user --quiet --collect --on-active="${minutes}m" --unit="$unit" \
  bash -c 'archypr-otification-send "󰔛" "Reminder" "$1" -u critical; rm -f "$2"' bash "$message" "$message_file"

archypr-otification-send "󰔛" "$confirmation_title" "$confirmation" -u low