#!/usr/bin/env bash
set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
ROOT="$(dirname "$SCRIPT_DIR")"
COMPOSE="$ROOT/compose/docker-compose.yml"
ENV="$ROOT/.env"
BACKUP_DIR="$ROOT/backups"
MAX_BACKUPS=2

# shellcheck source=/dev/null
source "$ENV"

TIMESTAMP=$(date +"%Y%m%d_%H%M%S")
TARGET="$BACKUP_DIR/backup_$TIMESTAMP"
mkdir -p "$TARGET"

echo "[backup] Starte Backup → $TARGET"

# PostgreSQL dump
echo "[backup] Datenbank-Dump..."
docker compose -f "$COMPOSE" exec -T postgres \
  pg_dump -U "$POSTGRES_USER" "$POSTGRES_DB" \
  > "$TARGET/postgres.sql"

# n8n data
echo "[backup] n8n Datendirectory..."
tar -czf "$TARGET/n8n-data.tar.gz" -C "$ROOT/data" n8n

# Compose-Konfiguration
echo "[backup] Compose + .env..."
cp "$COMPOSE" "$TARGET/docker-compose.yml"
cp "$ENV" "$TARGET/.env"

echo "[backup] Backup abgeschlossen: $TARGET"

# Retention: nur die letzten MAX_BACKUPS behalten
EXISTING=$(ls -dt "$BACKUP_DIR"/backup_* 2>/dev/null)
COUNT=$(echo "$EXISTING" | wc -l)
if [ "$COUNT" -gt "$MAX_BACKUPS" ]; then
  TO_DELETE=$(echo "$EXISTING" | tail -n +"$((MAX_BACKUPS + 1))")
  echo "[backup] Lösche alte Backups:"
  echo "$TO_DELETE"
  echo "$TO_DELETE" | xargs rm -rf
fi

echo "[backup] Fertig. Aktuelle Backups:"
ls -lht "$BACKUP_DIR"