"""
Storage backend factory for DocuVault.

Mirrors backend/ai/__init__.py — exposes a get_storage_backend() factory
that returns the configured StorageBackend implementation.

Phase 1 always returns MinIOBackend. Phase 5 will extend this factory to
support OneDrive, Google Drive, Nextcloud, and WebDAV backends.
"""
from storage.base import StorageBackend
from storage.minio_backend import MinIOBackend
from config import settings


def get_storage_backend() -> StorageBackend:
    """Return a MinIOBackend instance configured from config.settings.

    secure=False is correct for Docker internal HTTP traffic between containers
    (RESEARCH.md Pattern 3).

    public_endpoint is the browser-resolvable hostname for presigned PUT URLs.
    RESEARCH.md Finding 3 — dual-client pattern: internal endpoint for all
    server-side operations; public endpoint for generate_presigned_put_url only.
    """
    public_ep = settings.minio_public_endpoint or None
    return MinIOBackend(
        endpoint=settings.minio_endpoint,
        access_key=settings.minio_access_key,
        secret_key=settings.minio_secret_key,
        bucket=settings.minio_bucket,
        secure=False,
        public_endpoint=public_ep,
    )