"""Restore and upload a compact Home Assistant configuration snapshot."""
from __future__ import annotations
import argparse
import os
import sys
import tarfile
import tempfile
from pathlib import Path

ARCHIVE_NAME = "homeassistant-latest.tar.gz"


def hub_api():
    from huggingface_hub import HfApi
    token = os.environ.get("HF_TOKEN")
    repo_id = os.environ.get("BACKUP_REPO_ID")
    if not token or not repo_id:
        raise RuntimeError("HF_TOKEN and BACKUP_REPO_ID are required for Hub backups")
    api = HfApi(token=token)
    repo_type = os.environ.get("BACKUP_REPO_TYPE", "dataset")
    try:
        api.repo_info(repo_id=repo_id, repo_type=repo_type)
    except Exception:
        api.create_repo(repo_id=repo_id, repo_type=repo_type, private=True, exist_ok=True)
    return api, repo_id, repo_type, token


def archive_config(config: Path, archive: Path) -> None:
    with tarfile.open(archive, "w:gz") as tar:
        for path in config.rglob("*"):
            if not path.is_file() or path.is_symlink(): continue
            relative = path.relative_to(config).as_posix()
            if relative in {"home-assistant_v2.db", "home-assistant.log"}: continue
            if relative.endswith((".db-wal", ".db-shm")): continue
            if relative.startswith((".cloud/", "tts/")): continue
            tar.add(path, arcname=relative, recursive=False)


def backup(config: Path) -> None:
    api, repo_id, repo_type, token = hub_api()
    with tempfile.TemporaryDirectory() as temp_dir:
        archive = Path(temp_dir) / ARCHIVE_NAME
        archive_config(config, archive)
        api.upload_file(path_or_fileobj=str(archive), path_in_repo=ARCHIVE_NAME,
                        repo_id=repo_id, repo_type=repo_type, token=token,
                        commit_message="Update Home Assistant configuration backup")
    print(f"Uploaded {ARCHIVE_NAME} to {repo_type}/{repo_id}", flush=True)


def restore(config: Path) -> None:
    from huggingface_hub.errors import EntryNotFoundError
    try:
        _, repo_id, repo_type, token = hub_api()
        from huggingface_hub import hf_hub_download
        archive = hf_hub_download(repo_id=repo_id, filename=ARCHIVE_NAME,
                                  repo_type=repo_type, token=token, force_download=True)
    except EntryNotFoundError:
        print("No existing Hub snapshot; starting a new configuration.", flush=True)
        return
    except Exception as exc:
        raise RuntimeError("Hub restore failed; refusing to overwrite the remote backup with a fresh configuration.") from exc
    config.mkdir(parents=True, exist_ok=True)
    with tarfile.open(archive, "r:gz") as tar:
        root = config.resolve()
        for member in tar.getmembers():
            target = (config / member.name).resolve()
            if root not in target.parents: raise RuntimeError(f"Unsafe backup path: {member.name}")
        tar.extractall(config, filter="data")
    print(f"Restored {ARCHIVE_NAME} into {config}", flush=True)


def main() -> int:
    parser = argparse.ArgumentParser()
    parser.add_argument("action", choices=("backup", "restore"))
    parser.add_argument("--config", required=True, type=Path)
    args = parser.parse_args()
    if not os.environ.get("HF_TOKEN") or not os.environ.get("BACKUP_REPO_ID"): return 0
    (backup if args.action == "backup" else restore)(args.config)
    return 0


if __name__ == "__main__": raise SystemExit(main())