"""Storage backends and factory for notebook snapshots."""

from pathlib import Path

from .base import StorageAdapter, validate_key
from .local import LocalFileStorage
from .s3 import S3ConnectionError, S3Storage


def create_storage(
    storage_type: str,
    root_dir: str | Path,
    **kwargs,
) -> StorageAdapter:
    """Create a storage adapter from a configuration string.

    Parameters
    ----------
    storage_type: str
        One of ``"local"`` or ``"s3"`` (covers AWS S3, MinIO, and any
        S3-API-compatible service via the ``endpoint`` parameter).
    root_dir: str | Path
        Root directory used by local storage. For S3 this is ignored.
    **kwargs
        Extra arguments forwarded to the backend constructor. For S3,
        expected keys include ``endpoint``, ``access_key``, ``secret_key``,
        ``bucket``, ``secure``, and ``prefix``. For local, ``local_root`` may
        override the default ``root_dir / ".notebook_versions"`` path.

    Returns
    -------
    StorageAdapter
        Configured storage adapter instance.

    Raises
    ------
    ValueError
        If ``storage_type`` is unknown.
    S3ConnectionError
        If ``storage_type="s3"`` and the endpoint is unreachable or
        credentials are missing/invalid.
    """
    storage_type = storage_type.lower()
    if storage_type == "local":
        local_root = kwargs.get("local_root")
        if local_root:
            return LocalFileStorage(local_root)
        return LocalFileStorage(Path(root_dir) / ".notebook_versions")
    if storage_type == "s3":
        return S3Storage(
            endpoint=kwargs["endpoint"],
            access_key=kwargs["access_key"],
            secret_key=kwargs["secret_key"],
            bucket=kwargs.get("bucket", "notebook-snapshot"),
            secure=kwargs.get("secure", False),
            prefix=kwargs.get("prefix", ""),
        )
    raise ValueError(f"Unknown storage type: {storage_type!r}")


__all__ = [
    "create_storage",
    "LocalFileStorage",
    "S3ConnectionError",
    "S3Storage",
    "StorageAdapter",
    "validate_key",
]