#!/bin/bash

set -euo pipefail

readonly CONTAINER_NAME="nextcloud-fpm-v1"
readonly OCC_CMD="docker exec --user www-data $CONTAINER_NAME php occ"
readonly THRESHOLD=95
readonly SENDER_EMAIL="knusperkerne@posteo.de"

USERS=$($OCC_CMD user:list | awk '{print $2}' | tr -d :)

for USER in $USERS; do
    EMAIL=$($OCC_CMD user:info "$USER" 2>/dev/null | grep -i "email:" \
            | head -n 1 | sed -E 's/.*email: (.*)/\1/' | tr -d '[:space:]')
    
    # Falls die E-Mail ein "null" String oder leer ist
    if [[ -z "$EMAIL" ]] || [[ "$EMAIL" == "null" ]]; then
        echo "Skipping $USER: No valid email found in occ user:info."
        continue
    fi
    
    if [ -z "$EMAIL" ] || [ "$EMAIL" == "null" ]; then
        echo "Skipping $USER: No valid email found."
        continue
    fi

    QUOTA_RAW=$($OCC_CMD user:setting "$USER" files quota 2>/dev/null) || true

    # Falls Quota auf 'none', leer oder Fehlermeldung
    if [[ -z "$QUOTA_RAW" ]] || [[ "$QUOTA_RAW" == "none" ]] \
        || [[ "$QUOTA_RAW" =~ "not exist" ]]; then
        echo "Skipping $USER: No quota defined (none/default)."
        continue
    fi

    # convert quota into bytes
    CLEAN_VALUE=$(echo "$QUOTA_RAW" | grep -oP '^[0-9]+')
    CLEAN_UNIT=$(echo "$QUOTA_RAW" | 
                 grep -oP '[a-zA-Z]' | head -n 1 | tr '[:lower:]' '[:upper:]')

    if [[ -z "$CLEAN_UNIT" ]]; then
        QUOTA_BYTES=$CLEAN_VALUE
    else
        # numfmt versteht "50G", "2M" etc.
        QUOTA_BYTES=$(numfmt --from=iec "${CLEAN_VALUE}${CLEAN_UNIT}")
    fi

    USED_BYTES=$(docker exec $CONTAINER_NAME \
                 du -sb /var/www/html/data/"$USER"/files 2>/dev/null \
                 | awk '{print $1}')
    
    USED_BYTES=${USED_BYTES:-0}

    if [ "$QUOTA_BYTES" -gt 0 ]; then
        PERCENT=$(( 100 * USED_BYTES / QUOTA_BYTES ))

        if [ "$PERCENT" -ge "$THRESHOLD" ]; then
            echo "WARNUNG: $USER ist bei $PERCENT% ($EMAIL)"

            {
                printf "Hallo %s,\n\n" "$USER"

                printf "Dein Nextcloud-Speicher ist zu %s%% voll.\n\n" \
                    "$PERCENT"

                printf "Belegt: %s von %s.\n\n" \
                    "$(numfmt --to=iec $USED_BYTES)" "$QUOTA_RAW" 

                printf "Bitte lösche nicht mehr benötigte Dateien."
            } \
            | mailx -s "Nextcloud-Speicherwarnung ($PERCENT%)" -r "$SENDER_EMAIL" "$EMAIL"
        else
            echo "Quota usage for $USER is OK"
        fi
    fi
done

echo "Done."