from pathlib import Path
from tempfile import NamedTemporaryFile
from pydantic import Field, PrivateAttr
from pydantic_settings import BaseSettings

BASE_PATH = Path(__file__).resolve().parents[4]  # goes up to project root


class GMailSettings(BaseSettings):
    """Settings for Gmail MCP server."""

    creds_json: str = Field(..., env="GMAIL_CREDS_JSON")
    token_json: str = Field(..., env="GMAIL_TOKEN_JSON")
    gmail_mcp_dir: Path = Field(default=BASE_PATH / "src/mcp_servers/gmail-mcp")

    _creds_file: Path | None = PrivateAttr(default=None)
    _token_file: Path | None = PrivateAttr(default=None)

    model_config = {
        "env_file": ".env",
        "env_file_encoding": "utf-8",
    }

    @staticmethod
    def _write_temp(prefix: str, content: str) -> Path:
        with NamedTemporaryFile(delete=False, prefix=f"{prefix}_", suffix=".json") as tmp:
            tmp.write(content.encode("utf-8"))
            return Path(tmp.name)

    def materialize_files(self) -> tuple[Path, Path]:
        """
        Writes the credential and token JSON from env to temp files
        and returns their paths for downstream tooling that expects paths.
        """
        if self._creds_file is None:
            self._creds_file = self._write_temp("gmail_creds", self.creds_json)
        if self._token_file is None:
            self._token_file = self._write_temp("gmail_token", self.token_json)
        return self._creds_file, self._token_file



if __name__ == "__main__":
    settings = GMailSettings()
    creds_path, token_path = settings.materialize_files()
    print(settings)
    print(creds_path)
    print(token_path)