from functools import lru_cache

from pydantic_settings import BaseSettings, SettingsConfigDict


class Settings(BaseSettings):
    model_config = SettingsConfigDict(
        env_file=".env",
        env_file_encoding="utf-8",
        extra="ignore",
    )

    # --- App ---
    env: str = "development"
    log_level: str = "info"
    port: int = 8002

    # --- LLM ---
    groq_api_key: str
    nvidia_api_key: str = ""
    
    # --- Internal service auth (shared secret with Django) ---
    chat_service_internal_token: str = ""

    # --- Postgres (read-only role) ---
    postgres_readonly_url: str = ""

    # --- Neo4j (Aura Free — no RBAC, enforcement is app-level only) ---
    neo4j_uri: str = ""
    neo4j_user: str = ""
    neo4j_password: str = ""

    # --- Redis ---
    redis_url: str = ""

    # --- Chat session behavior ---
    chat_session_ttl_seconds: int = 86400
    chat_history_max_turns: int = 10

    # --- NLP EMBED ---
    nlp_service_url: str = ""
    nlp_service_token: str = ""


@lru_cache
def get_settings() -> Settings:
    """Cached settings instance — reads .env once per process."""
    return Settings()