#!/usr/bin/env bash

DIR=$(dirname $PWD)

current_day=$(date +"%e")
current_month=$(date +"%m")
current_year=$(date +"%Y")

month=$(date +"%-m")
year=$(date +"%Y")
previous_month="◀"
next_month="▶"
last_selected_option=""

format_calendar () {
  echo "$1" \
  | sed -E 's/([[:alpha:]])__/\1\n/g' \
  | sed -E 's/___([[:digit:]])/.\n\1/g' \
  | sed -e 's/___/\n./g' \
  | sed -e 's/__/\n/g' \
  | sed -e 's/_/\n/g'
}

print_month() {
  calendar="$(cal --monday -v -- $1 $2 | tail -n +2 | sed -e 's/ /_/g')"
  echo "$(format_calendar "$calendar")"
}

find_day_index() {
  index=0
  while IFS=' ' read -ra arr; do
    for i in "${arr[@]}"; do
      if [[ "$i" == "$2" ]]; then
        echo "$index"
        break
      fi
      ((index++))
    done
  done <<< "$1"
}

calendar_menu() {
  calendar_header=$(cal -v -- $month $year | head -n 1)

  month_page="$(print_month $month $year)"
  calendar_body="\n\n\n$previous_month\n\n\n\n$month_page\n\n\n\n$next_month\n\n\n"

  previous_month_index="3"
  next_month_index="59"
  calendar_body_column="7"
  urgent="-u $previous_month_index,$next_month_index"
  active=""
  selected_row=""

  if [[ "$(echo $current_month | bc) $current_year" == "$(echo $month | bc) $year" ]]; then
    current_day_index=$(($(find_day_index "$month_page" $current_day) + $calendar_body_column))
    active="-a $current_day_index"
    selected_row="-selected-row $current_day_index"
  fi

  if [[ $last_selected_option == $previous_month ]]; then
    selected_row="-selected-row $previous_month_index"
  fi

  if [[ $last_selected_option == $next_month ]]; then
    selected_row="-selected-row $next_month_index"
  fi

  echo -e "$calendar_body" | rofi -dmenu \
  -theme /home/chatlanin/.config/bspwm/rofi/themes/calendar.rasi\
  -p "$calendar_header" $urgent $active $selected_row
}

while [[ true ]]; do
  selected=$(calendar_menu)
  last_selected_option="$selected"
  case $selected in
    $previous_month)
      ((month--))
      if [[ $month -lt 1 ]]; then
        month=12
        ((year--))
      fi
      ;;
    $next_month)
      ((month++))
      if [[ $month -gt 12 ]]; then
        month=1
        ((year++))
      fi
      ;;
    *)
    break
      ;;
  esac
done