"""Restore Aether SQLite db from HF Dataset.

Downloads `latest-backup.tar.gz` from the configured Dataset repo,
unpacks it into AETHER_BACKUP_DIR, and prints a status line.
Quietly succeeds if the backup file does not exist yet (first launch).
"""
import os
import sys
import tarfile
from pathlib import Path

from huggingface_hub import HfApi, hf_hub_download
from huggingface_hub.utils import EntryNotFoundError, RepositoryNotFoundError

token = os.environ["HF_TOKEN"]
repo_id = os.environ["AETHER_BACKUP_REPO"]
dest_dir = Path(os.environ.get("AETHER_BACKUP_DIR", "/opt/aether/data"))
filename = os.environ.get("AETHER_BACKUP_LATEST_NAME", "latest-backup.tar.gz")

dest_dir.mkdir(parents=True, exist_ok=True)
api = HfApi(token=token)

try:
    local_tar = hf_hub_download(
        repo_id=repo_id,
        filename=filename,
        repo_type="dataset",
        token=token,
        force_download=True,
    )
except EntryNotFoundError:
    print("aether-restore: no backup yet, fresh start", file=sys.stderr)
    sys.exit(0)
except RepositoryNotFoundError:
    print(
        f"aether-restore: backup repo {repo_id} not found, skip",
        file=sys.stderr,
    )
    sys.exit(0)
except Exception as exc:
    print(f"aether-restore: download error: {exc}", file=sys.stderr)
    sys.exit(1)

print(f"aether-restore: downloaded {local_tar}", file=sys.stderr)
with tarfile.open(local_tar, "r:gz") as tar:
    tar.extractall(path=dest_dir)
print(f"aether-restore: restored into {dest_dir}", file=sys.stderr)