MAIL_FOLDER=/var/mail

if groups "$USER" | grep -o "sudo" >/dev/null 2>/dev/null; then
   USE_SUPER="sudo"
elif groups "$USER" | grep -o "doas" >/dev/null 2>/dev/null; then
   USE_SUPER="doas"
elif groups "$USER" | grep -o "wheel" >/dev/null 2>/dev/null; then
   USE_SUPER="sudo"
elif groups "$USER" | grep -o "admin" >/dev/null 2>/dev/null; then
   USE_SUPER="sudo"
elif [ "$EUID" -eq 0 ]; then
   USE_SUPER="\$"
else
   USE_SUPER=""
fi

del_mail() {
   if [ ! -f "$MAIL_FOLDER/$1" ]; then
      return
   fi
   if [ $(sudo cat "$MAIL_FOLDER/$1" | wc -l) -eq 0 ]; then
      sudo rm "$MAIL_FOLDER/$1"
      return
   fi

   read -r -p "Would you like to save your mail or delete it [save or delete] : " keep
   if [ "$keep" == "delete" ] || [ "$keep" == "del" ]; then
	echo "Attempting to erase mail for user $1."
	sudo rm "$MAIL_FOLDER/$1"
   fi
}

read_mail() {
   if [ ! -f "$MAIL_FOLDER/$1" ]; then
      return
   fi

   if [ $EUID -ne 0 ] && [ -z "$USE_SUPER" ]; then
      echo "Have your Root user check the mailbox for ${MAIL_FOLDER}/$1 has Mail in it!"
      return
   fi

   echo "Checking if $1 has any mail...."
   if [ $(sudo cat "$MAIL_FOLDER/$1" | wc -l) -eq 0 ]; then
      echo "No new mail"
      sudo rm "$MAIL_FOLDER/$1"
      return
   fi
   echo "$1 HAS Mail!!!"
   if [ -x /usr/bin/mutt ]; then
      if [ "$1" == "root" ]; then
         sudo mutt -f "$MAIL_FOLDER/$1"
      else
         mutt -f "$MAIL_FOLDER/$1"
      fi
   elif [ -x /usr/bin/mail ]; then
      read -r -p "Check mail via [ mail, less, nano, tail, read, or cat ] : " check
      case $check in
          mail) sudo mail -u "$1";;
          less) sudo less "$MAIL_FOLDER/$1";;
          nano) sudo nano "$MAIL_FOLDER/$1";;
          tail) sudo tail -n 50 "$MAIL_FOLDER/$1";;
          *) sudo cat "$MAIL_FOLDER/$1";;
      esac
   else
      read -r -p "Check mail via [ less, nano, tail, read, or cat ] : " check
      case $check in
          less) sudo less "$MAIL_FOLDER/$1";;
          nano) sudo nano "$MAIL_FOLDER/$1";;
          tail) sudo tail -n 50 "$MAIL_FOLDER/$1";;
          *) sudo cat "$MAIL_FOLDER/$1";;
      esac
   fi
   del_mail "$1"
}

# Check for Root Mail Alerts, to keep up to date on Security Issues
read_mail root

if [ "$USER" != "root" ]; then
   read_mail "$USER"
fi