#!/usr/bin/env bash
#
# check_mail_usage.sh
#
# Checks Maildir usage by executing du inside the Docker-Mailserver container.
#
# Usage:
#   ./check_mail_usage.sh
#

CONTAINER="mailserver"
MAILDIR="/var/mail"

echo "Scanning Maildir sizes inside container '$CONTAINER' ..."
echo

TMPFILE=$(mktemp)

# List <domain>/<user> directories inside container
docker exec "$CONTAINER" bash -c "
    find $MAILDIR -mindepth 2 -maxdepth 2 -type d
" | while read -r DIR; do
    SIZE_MB=$(docker exec "$CONTAINER" bash -c "du -sm \"$DIR\" | awk '{print \$1}'")
    USER=$(basename "$DIR")
    DOMAIN=$(basename "$(dirname "$DIR")")
    echo \"$SIZE_MB MB  $USER@$DOMAIN\" >> "$TMPFILE"
done

echo "======================"
echo "   MAILDIR USAGE"
echo "======================"
echo

sort -nr "$TMPFILE" | head -n 10

echo
echo "----------------------"
TOTAL=$(docker exec "$CONTAINER" bash -c "du -sm $MAILDIR | awk '{print \$1}'")
echo "Total mail storage used: $TOTAL MB"
echo "----------------------"

rm "$TMPFILE"