import os
import argparse
from pydantic_settings import BaseSettings, PydanticBaseSettingsSource, YamlConfigSettingsSource


def _parse_args() -> argparse.Namespace:
    parser = argparse.ArgumentParser()
    parser.add_argument(
        "--transport",
        choices=["stdio", "sse"],
        default="stdio",
    )
    parser.add_argument("--host", default="0.0.0.0")
    parser.add_argument("--port", type=int, default=8080)
    parser.add_argument(
        "--config",
        default=os.environ.get("CONFIG_FILE", "config.yaml"),
    )
    return parser.parse_args()


_args = _parse_args()

class Settings(BaseSettings):
    """Server configuration populated from env vars and a YAML config file."""

    model_config = {"env_file": ".env", "yaml_file": _args.config}

    project_id: str
    location: str
    bucket: str
    index_name: str
    deployed_index_id: str
    endpoint_name: str
    endpoint_domain: str
    embedding_model: str = "gemini-embedding-001"
    search_limit: int = 10

    @classmethod
    def settings_customise_sources(
        cls,
        settings_cls: type[BaseSettings],
        init_settings: PydanticBaseSettingsSource,
        env_settings: PydanticBaseSettingsSource,
        dotenv_settings: PydanticBaseSettingsSource,
        file_secret_settings: PydanticBaseSettingsSource,
    ) -> tuple[PydanticBaseSettingsSource, ...]:
        return (
            init_settings,
            env_settings,
            dotenv_settings,
            YamlConfigSettingsSource(settings_cls),
            file_secret_settings,
        )