"""
Runtime AI Config — mutable overrides pour le provider/model actif.

Permet à l'admin de changer le fournisseur/modèle sans redémarrer.
Les overrides sont stockés en mémoire (perdus au redémarrage du backend).
"""
import threading
from typing import Optional


class RuntimeAIConfig:
    """Singleton thread-safe pour les overrides AI runtime."""

    def __init__(self):
        self._lock = threading.Lock()
        self._provider: Optional[str] = None
        self._model: Optional[str] = None

    @property
    def provider(self) -> Optional[str]:
        with self._lock:
            return self._provider

    @property
    def model(self) -> Optional[str]:
        with self._lock:
            return self._model

    @property
    def has_override(self) -> bool:
        with self._lock:
            return self._provider is not None

    def set(self, provider: Optional[str] = None, model: Optional[str] = None) -> None:
        """Définit les overrides. None = utiliser le défaut de settings."""
        with self._lock:
            self._provider = provider
            self._model = model

    def clear(self) -> None:
        """Réinitialise aux valeurs par défaut."""
        with self._lock:
            self._provider = None
            self._model = None

    def to_dict(self) -> dict:
        """Retourne l'état actuel pour les API."""
        from app.config import settings
        with self._lock:
            return {
                "provider": self._provider or settings.AI_PROVIDER,
                "model": self._model or (
                    settings.OPENROUTER_MODEL if (self._provider or settings.AI_PROVIDER) == "openrouter"
                    else settings.GEMINI_MODEL
                ),
                "is_overridden": self._provider is not None,
                "override_provider": self._provider,
                "override_model": self._model,
            }


# Singleton global
runtime_ai_config = RuntimeAIConfig()