import oss2
from app.config import settings
import logging

logger = logging.getLogger(__name__)


class OSSClient:
    def __init__(self):
        self.auth = oss2.Auth(
            settings.OSS_ACCESS_KEY_ID,
            settings.OSS_ACCESS_KEY_SECRET
        )
        self.bucket = oss2.Bucket(
            self.auth,
            settings.OSS_ENDPOINT,
            settings.OSS_BUCKET_NAME
        )
        self.prefix = settings.OSS_PREFIX.strip("/")
        self.cdn_url = settings.OSS_CDN_URL.rstrip("/")

    def _build_key(self, project_name: str, stage: str, commit_id: str, relative_path: str) -> str:
        """Build OSS object key."""
        return f"{self.prefix}/{project_name}/{stage}/{commit_id}/{relative_path}"

    def get_cdn_url(self, key: str) -> str:
        """Get CDN URL for the object."""
        return f"{self.cdn_url}/{key}"

    def upload(self, key: str, content: bytes) -> bool:
        """Upload content to OSS."""
        try:
            self.bucket.put_object(key, content)
            logger.info(f"Uploaded to OSS: {key}")
            return True
        except Exception as e:
            logger.error(f"Failed to upload to OSS: {e}")
            raise

    def download(self, key: str) -> bytes:
        """Download content from OSS."""
        try:
            result = self.bucket.get_object(key)
            return result.read()
        except oss2.exceptions.NoSuchKey:
            logger.error(f"OSS key not found: {key}")
            return None
        except Exception as e:
            logger.error(f"Failed to download from OSS: {e}")
            raise

    def exists(self, key: str) -> bool:
        """Check if object exists."""
        return self.bucket.object_exists(key)


# Singleton instance
oss_client = OSSClient() if settings.OSS_ACCESS_KEY_ID else None