#!/bin/sh
# Backup of database, photos and .env into one archive.
#
#   ./scripts/backup.sh [target-dir]        default target: ./backups
#   KEEP=30 ./scripts/backup.sh             keep the newest 30 archives (default 14)
#
# Cron example (daily 03:30):
#   30 3 * * * cd /opt/kochbuch && ./scripts/backup.sh /mnt/nas/kochbuch >> backups/backup.log 2>&1
set -eu
cd "$(dirname "$0")/.."

TARGET=${1:-./backups}
KEEP=${KEEP:-14}
STAMP=$(date +%Y%m%d-%H%M%S)
umask 077
mkdir -p "$TARGET"
WORK=$(mktemp -d)
trap 'rm -rf "$WORK"' EXIT

echo "[$(date)] Sichere Datenbank …"
docker compose exec -T db sh -c 'pg_dump -U "$POSTGRES_USER" -d "$POSTGRES_DB" --format=custom' > "$WORK/db.dump"

echo "[$(date)] Sichere Fotos …"
docker compose exec -T app tar -C /data -czf - media > "$WORK/media.tar.gz"

# .env contains the secrets needed to bring the backup up on a new server.
cp .env "$WORK/env.backup"

ARCHIVE="$TARGET/kochbuch-$STAMP.tar.gz"
tar -C "$WORK" -czf "$ARCHIVE" db.dump media.tar.gz env.backup
echo "[$(date)] Fertig: $ARCHIVE ($(du -h "$ARCHIVE" | cut -f1))"

# Retention: delete everything but the newest $KEEP archives.
ls -1t "$TARGET"/kochbuch-*.tar.gz 2>/dev/null | tail -n +"$((KEEP + 1))" | while read -r old; do
    rm -f -- "$old"
    echo "Altes Backup gelöscht: $old"
done