from __future__ import annotations

from ingestion.common.gcp import list_objects as _gcs_list
from ingestion.common.sql import sql_string

from .config import LoadConfig


class GcsStorage:
    """StorageAdapter for the shared external loader: lists GCS objects and builds the
    Databend gcs:// external stage. Databend addresses GCS with the ``gcs://`` scheme (not
    Google's ``gs://``) and authenticates with a base64 service-account key."""

    def __init__(self, config: LoadConfig) -> None:
        self._config = config

    def list_objects(self, uri: str) -> list[dict]:
        return _gcs_list(uri)

    def create_stage_sql(self, stage_name: str, uri: str) -> str:
        databend_uri = "gcs://" + uri.removeprefix("gs://")
        return (
            f"CREATE OR REPLACE STAGE {stage_name} "
            f"URL = {sql_string(databend_uri)} "
            f"CONNECTION = (CREDENTIAL = {sql_string(self._config.gcs_credential)})"
        )

    def credential_env_names(self) -> list[str]:
        return self._config.gcs_credential_env_names