"""
ByteAstra backend — application settings.
All values are loaded from environment variables (or .env file via python-dotenv).
"""
from pydantic_settings import BaseSettings, SettingsConfigDict
from functools import lru_cache


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

    # --- Application ---
    app_env: str = "development"
    app_host: str = "0.0.0.0"
    app_port: int = 8000
    app_secret_key: str = "change-me"

    # --- Database ---
    database_url: str = "sqlite:///./byteastra.db"
    mongo_url: str = "mongodb://localhost:27017"

    # --- ChromaDB ---
    chroma_persist_path: str = "./chroma_store"

    # --- Local LLM ---
    # llm_base_url reads LLM_BASE_URL or OPENAI_BASE_URL (set by start.sh)
    llm_base_url: str = "http://127.0.0.1:8001/v1"
    openai_base_url: str | None = None  # alias set by start.sh
    llm_api_key: str = "not-needed"
    # llm_model_name reads LLM_MODEL_NAME or MODEL_NAME (set by start.sh)
    llm_model_name: str = "qwen2.5-3b-instruct.Q4_K_M.gguf"
    model_name: str | None = None  # alias set by start.sh
    llm_max_tokens: int = 400   # CPU model — 400 is enough for a complete answer
    llm_temperature: float = 0.2

    @property
    def resolved_llm_base_url(self) -> str:
        """Returns OPENAI_BASE_URL if set by start.sh, else llm_base_url."""
        return self.openai_base_url or self.llm_base_url

    @property
    def resolved_model_name(self) -> str:
        """Returns MODEL_NAME if set by start.sh, else llm_model_name."""
        return self.model_name or self.llm_model_name

    # --- Embedding ---
    embedding_model: str = "all-MiniLM-L6-v2"

    # --- CORS ---
    cors_origins: str = "http://localhost:3000,http://127.0.0.1:3000,http://localhost:7860,http://127.0.0.1:7860,https://byteastra-psi.vercel.app,https://byteastra.vercel.app"

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


@lru_cache
def get_settings() -> Settings:
    return Settings()