#!/bin/bash
# scripts/backup.sh — Back up the ShortLink PostgreSQL database.
# Run from the sk1 directory: ./scripts/backup.sh
# Optionally set BACKUP_DIR in .env to change the backup location.

set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
cd "${SCRIPT_DIR}/.."

# Load env
set -a
# shellcheck disable=SC1091
source .env
set +a

BACKUP_DIR="${BACKUP_DIR:-./backups}"
TIMESTAMP="$(date +"%Y%m%d_%H%M%S")"
BACKUP_FILE="${BACKUP_DIR}/shortlink_${TIMESTAMP}.sql.gz"

mkdir -p "${BACKUP_DIR}"

echo "Creating database backup..."
docker exec shortlink_db pg_dump \
  -U "${DB_USER}" \
  -d "${DB_NAME}" \
  --no-owner \
  --clean \
  | gzip > "${BACKUP_FILE}"

SIZE="$(du -sh "${BACKUP_FILE}" | cut -f1)"
echo "✓ Backup saved: ${BACKUP_FILE} (${SIZE})"

# Keep only the 7 most recent backups
KEPT=7
OLDER=$(ls -t "${BACKUP_DIR}"/shortlink_*.sql.gz 2>/dev/null | tail -n +"$((KEPT + 1))")
if [ -n "$OLDER" ]; then
  echo "$OLDER" | xargs rm -f
  echo "  Old backups removed (keeping last ${KEPT})."
fi

# ── To restore a backup ───────────────────────────────────────────────────────
# gunzip -c backups/shortlink_<timestamp>.sql.gz \
#   | docker exec -i shortlink_db psql -U "$DB_USER" -d "$DB_NAME"