"""Scheduled local backup service. Creates ZIP snapshots of the full Bambuddy data (database + data directories) on a configurable schedule with retention management. """ import asyncio import logging import os from datetime import datetime, timedelta, timezone from pathlib import Path from zoneinfo import ZoneInfo, ZoneInfoNotFoundError from sqlalchemy import select from backend.app.core.config import settings as app_settings from backend.app.core.database import async_session from backend.app.models.settings import Settings logger = logging.getLogger(__name__) def _local_zone() -> ZoneInfo: """Resolve the local timezone for scheduled-backup HH:MM interpretation. Uses the container's ``TZ`` env var (the same value the support package surfaces); falls back to UTC when unset or unrecognised so a missing TZ keeps the legacy behaviour rather than crashing. See #1602 follow-up. """ tz_name = os.environ.get("TZ", "").strip() if not tz_name: return ZoneInfo("UTC") try: return ZoneInfo(tz_name) except ZoneInfoNotFoundError: logger.warning("Unrecognised TZ env value %r, scheduling in UTC", tz_name) return ZoneInfo("UTC") SCHEDULE_INTERVALS = { "hourly": 3600, "daily": 86400, "weekly": 604800, } def _default_backup_dir() -> Path: return app_settings.base_dir / "backups" class LocalBackupService: """Manages scheduled local backup snapshots with retention.""" def __init__(self): self._scheduler_task: asyncio.Task | None = None self._check_interval = 60 self._running: bool = False self._last_backup_at: str | None = None self._last_status: str | None = None self._last_message: str | None = None self._next_run: datetime | None = None async def start_scheduler(self): """Start the background scheduler loop.""" if self._scheduler_task is not None: return logger.info("Starting local backup scheduler") # Seed next_run from settings so the first check has a target await self._seed_next_run() self._scheduler_task = asyncio.create_task(self._scheduler_loop()) def stop_scheduler(self): """Stop the scheduler.""" if self._scheduler_task: self._scheduler_task.cancel() self._scheduler_task = None logger.info("Stopped local backup scheduler") async def _scheduler_loop(self): """Main scheduler loop — checks for due backups every minute.""" while True: try: await asyncio.sleep(self._check_interval) await self._check_scheduled_backup() except asyncio.CancelledError: break except Exception as e: logger.error("Error in local backup scheduler: %s", e) await asyncio.sleep(60) async def _seed_next_run(self): """Load settings and calculate initial next_run.""" try: settings = await self._load_settings() if settings.get("enabled"): self._next_run = self._calculate_next_run( settings.get("schedule", "daily"), settings.get("time", "03:00"), ) except Exception as e: logger.debug("Could not seed local backup next_run: %s", e) async def _load_settings(self) -> dict: """Read local backup settings from the DB.""" async with async_session() as db: keys = [ "local_backup_enabled", "local_backup_schedule", "local_backup_time", "local_backup_retention", "local_backup_path", ] result = await db.execute(select(Settings).where(Settings.key.in_(keys))) rows = {r.key: r.value for r in result.scalars().all()} return { "enabled": rows.get("local_backup_enabled", "false").lower() == "true", "schedule": rows.get("local_backup_schedule", "daily"), "time": rows.get("local_backup_time", "03:00"), "retention": int(rows.get("local_backup_retention", "5")), "path": rows.get("local_backup_path", ""), } async def _check_scheduled_backup(self): """Check if a scheduled backup is due and run it.""" settings = await self._load_settings() if not settings["enabled"]: self._next_run = None return now = datetime.now(timezone.utc) # If no next_run set, schedule one if self._next_run is None: self._next_run = self._calculate_next_run(settings["schedule"], settings["time"]) return if self._next_run <= now: logger.info("Running scheduled local backup") await self.run_backup(settings) self._next_run = self._calculate_next_run(settings["schedule"], settings["time"]) def _calculate_next_run(self, schedule_type: str, time_str: str = "03:00") -> datetime: """Calculate the next scheduled run time. For hourly: next full hour (timezone-agnostic). For daily/weekly: next occurrence of the configured HH:MM, interpreted in the container's local timezone (TZ env var, UTC fallback). Returns a UTC-aware datetime for storage / comparison against ``now``. """ now_utc = datetime.now(timezone.utc) if schedule_type == "hourly": # Next full hour next_run = now_utc.replace(minute=0, second=0, microsecond=0) + timedelta(hours=1) return next_run # Parse HH:MM time try: parts = time_str.strip().split(":") hour = int(parts[0]) minute = int(parts[1]) if len(parts) > 1 else 0 except (ValueError, IndexError): hour, minute = 3, 0 local_tz = _local_zone() now_local = now_utc.astimezone(local_tz) # Next occurrence of HH:MM local time, today or tomorrow. # ``fold=0`` resolves the ambiguous wall-clock window at DST fall-back # to the earlier instance (consistent with cron's behaviour). On the # spring-forward gap the synthesized local time will normalise to the # next valid instant when converted to UTC. next_local = now_local.replace(hour=hour, minute=minute, second=0, microsecond=0, fold=0) if next_local <= now_local: next_local += timedelta(days=1) if schedule_type == "weekly": next_local += timedelta(weeks=1) return next_local.astimezone(timezone.utc) def _resolve_backup_dir(self, path_setting: str) -> Path: """Resolve the backup output directory from settings.""" if path_setting.strip(): return Path(path_setting.strip()) return _default_backup_dir() async def run_backup(self, settings: dict | None = None) -> dict: """Run a backup now. Returns {success, message, filename}.""" if self._running: return {"success": False, "message": "Backup already in progress"} self._running = True try: if settings is None: settings = await self._load_settings() backup_dir = self._resolve_backup_dir(settings["path"]) backup_dir.mkdir(parents=True, exist_ok=True) from backend.app.api.routes.settings import create_backup_zip zip_path, filename = await create_backup_zip(output_path=backup_dir) # Prune old backups retention = max(1, settings["retention"]) self._prune_backups(backup_dir, retention) self._last_backup_at = datetime.now(timezone.utc).isoformat() self._last_status = "success" self._last_message = filename logger.info("Local backup created: %s", zip_path) return {"success": True, "message": "Backup created", "filename": filename} except Exception as e: self._last_backup_at = datetime.now(timezone.utc).isoformat() self._last_status = "failed" self._last_message = str(e) logger.error("Local backup failed: %s", e, exc_info=True) return {"success": False, "message": f"Backup failed: {e}"} finally: self._running = False def _prune_backups(self, backup_dir: Path, retention: int): """Delete oldest backups exceeding the retention count.""" backups = sorted( backup_dir.glob("bambuddy-backup-*.zip"), key=lambda p: p.stat().st_mtime, reverse=True, ) for old_backup in backups[retention:]: try: old_backup.unlink() logger.info("Pruned old backup: %s", old_backup.name) except OSError as e: logger.warning("Could not delete old backup %s: %s", old_backup.name, e) def get_status(self) -> dict: """Return current scheduler status.""" return { "is_running": self._running, "last_backup_at": self._last_backup_at, "last_status": self._last_status, "last_message": self._last_message, "next_run": self._next_run.isoformat() if self._next_run else None, } def resolve_backup_file(self, path_setting: str, filename: str) -> Path | None: """Resolve a backup filename to a full path, with safety checks.""" if "/" in filename or "\\" in filename or ".." in filename: return None if not filename.startswith("bambuddy-backup-") or not filename.endswith(".zip"): return None backup_dir = self._resolve_backup_dir(path_setting) target = ( backup_dir / filename ) # SEC-PATH-OK: filename rejected above on /, \\, .., plus startswith "bambuddy-backup-" + endswith ".zip" gate if not target.exists(): return None return target def list_backups(self, path_setting: str) -> list[dict]: """List backup ZIP files in the backup directory.""" backup_dir = self._resolve_backup_dir(path_setting) if not backup_dir.exists(): return [] backups = [] for f in sorted(backup_dir.glob("bambuddy-backup-*.zip"), key=lambda p: p.stat().st_mtime, reverse=True): stat = f.stat() backups.append( { "filename": f.name, "size": stat.st_size, "created_at": datetime.fromtimestamp(stat.st_mtime, tz=timezone.utc).isoformat(), } ) return backups def delete_backup(self, path_setting: str, filename: str) -> dict: """Delete a specific backup file. Returns {success, message}.""" # Path traversal protection if "/" in filename or "\\" in filename or ".." in filename: return {"success": False, "message": "Invalid filename"} backup_dir = self._resolve_backup_dir(path_setting) target = ( backup_dir / filename ) # SEC-PATH-OK: filename rejected above on /, \\, .., plus startswith "bambuddy-backup-" + endswith ".zip" gate below if not target.exists(): return {"success": False, "message": "Backup not found"} if not target.name.startswith("bambuddy-backup-") or not target.name.endswith(".zip"): return {"success": False, "message": "Invalid backup file"} try: target.unlink() return {"success": True, "message": "Backup deleted"} except OSError as e: return {"success": False, "message": f"Could not delete: {e}"} local_backup_service = LocalBackupService()