app/config.py

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")

    # Vertex AI (primary)
    gcp_project: str = ""
    gcp_location: str = "us-central1"
    vertex_model: str = "gemini-2.0-flash-001"
    google_application_credentials: str = ""

    # Fallback: Groq (kept for local dev without gcloud)
    groq_api_key: str = ""
    groq_model: str = "llama-3.3-70b-versatile"

    cors_origins: str = "http://localhost:3000"
    log_level: str = "INFO"

    max_clauses_per_doc: int = 80
    devil_advocate_min_severity: str = "medium"
    rag_top_k: int = 2
    llm_concurrency: int = 2

    @property
    def use_vertex(self) -> bool:
        return bool(self.gcp_project)

    @property
    def active_model(self) -> str:
        return self.vertex_model if self.use_vertex else self.groq_model

    @property
    def cors_origin_list(self) -> list[str]:
        return [origin.strip() for origin in self.cors_origins.split(",") if origin.strip()]


@lru_cache(maxsize=1)
def get_settings() -> Settings:
    return Settings()