from __future__ import annotations

import os
from dataclasses import dataclass

from ingestion.common.env import require_env
from ingestion.common.load_config import LoadConfigBase, TableTargets, load_config_file

# Re-exported so existing importers (and tests) keep ``from ...config import TableTargets``.
__all__ = ["LoadConfig", "TableTargets", "load_load_config"]


@dataclass(frozen=True)
class LoadConfig(LoadConfigBase):
    """S3 bulk-load source: the storage-agnostic base plus S3 read credentials.

    The base supplies the Cloud Lake DSN, target databases, setup files, and source-
    contract resolution; this subclass adds only how to read the S3 bulk extract. The
    physical column schema for COPY comes from the run manifest, not from here.
    """

    @property
    def aws_region(self) -> str | None:
        return self.data.get("s3", {}).get("region") or os.environ.get("AWS_REGION")

    @property
    def aws_profile(self) -> str | None:
        return self.data.get("aws", {}).get("profile") or os.environ.get("AWS_PROFILE")

    @property
    def s3_credentials_env(self) -> dict[str, str]:
        return self.data.get("s3", {}).get("credentials", {})

    @property
    def s3_access_key_id_env(self) -> str:
        return self.s3_credentials_env.get("access_key_id_env", "S3_ACCESS_KEY_ID")

    @property
    def s3_secret_access_key_env(self) -> str:
        return self.s3_credentials_env.get("secret_access_key_env", "S3_SECRET_ACCESS_KEY")

    @property
    def s3_access_key_id(self) -> str:
        return require_env(self.s3_access_key_id_env)

    @property
    def s3_secret_access_key(self) -> str:
        return require_env(self.s3_secret_access_key_env)

    @property
    def s3_session_token_env(self) -> str | None:
        """Optional: an env var holding a session token, for temporary/STS/SSO credentials."""
        return self.s3_credentials_env.get("session_token_env")

    @property
    def s3_session_token(self) -> str | None:
        name = self.s3_session_token_env
        return os.environ.get(name) if name else None

    @property
    def s3_credential_env_names(self) -> list[str]:
        names = [self.s3_access_key_id_env, self.s3_secret_access_key_env]
        if self.s3_session_token_env:
            names.append(self.s3_session_token_env)
        return names


def load_load_config(path) -> LoadConfig:
    return load_config_file(path, LoadConfig)