"""MinIO client — S3-compatible object storage for invoice / proforma attachments.

The `minio` SDK is synchronous; every call is wrapped with
``asyncio.to_thread`` so the event loop is never blocked.
"""
import asyncio
import io
import logging
from functools import lru_cache

from minio import Minio

from app.config import settings

logger = logging.getLogger(__name__)


@lru_cache(maxsize=1)
def get_client() -> Minio:
    """Lazily built Minio client from the PROCUREMENT_MINIO_* settings."""
    return Minio(
        settings.MINIO_ENDPOINT,
        access_key=settings.MINIO_ACCESS_KEY,
        secret_key=settings.MINIO_SECRET_KEY,
        secure=settings.MINIO_SECURE,
    )


async def ensure_bucket() -> None:
    """Create the attachments bucket if it does not exist (idempotent)."""
    client = get_client()
    try:
        exists = await asyncio.to_thread(client.bucket_exists, settings.MINIO_BUCKET)
        if not exists:
            await asyncio.to_thread(client.make_bucket, settings.MINIO_BUCKET)
            logger.info("Created MinIO bucket %r", settings.MINIO_BUCKET)
    except Exception:
        logger.exception("MinIO bucket check failed — is the minio service reachable?")


async def put_object(key: str, content: bytes, mime_type: str) -> None:
    """Upload a byte payload to the bucket (overwrites any existing object)."""
    await asyncio.to_thread(
        get_client().put_object,
        settings.MINIO_BUCKET,
        key,
        io.BytesIO(content),
        length=len(content),
        content_type=mime_type,
    )


async def get_object_bytes(key: str) -> bytes:
    """Download an object's bytes from the bucket."""
    response = await asyncio.to_thread(get_client().get_object, settings.MINIO_BUCKET, key)
    try:
        return response.read()
    finally:
        response.close()
        response.release_conn()


async def remove_object(key: str) -> None:
    """Delete an object; missing objects are ignored (best-effort)."""
    try:
        await asyncio.to_thread(get_client().remove_object, settings.MINIO_BUCKET, key)
    except Exception:
        logger.warning("Could not remove MinIO object %r — ignoring", key)