from typing import Literal

from pydantic_settings import BaseSettings


class Settings(BaseSettings):
    """Application configuration loaded from environment variables."""

    llm_mode: Literal["local", "remote", "openai"] = "local"
    llm_remote_url: str = ""
    llm_remote_token: str = ""

    # OpenAI configuration
    openai_api_key: str = ""
    openai_model: str = "gpt-4o-mini"

    class Config:
        env_file = ".env"
        env_file_encoding = "utf-8"


# Constants
MAX_MESSAGE_LENGTH: int = 10_000

# Global settings instance
settings = Settings()