"""Configuration applicative, entierement pilotee par variables d'environnement."""

from __future__ import annotations

from functools import lru_cache

from pydantic import Field
from pydantic_settings import BaseSettings, SettingsConfigDict


class Settings(BaseSettings):
    """Parametres du backend.

    Chaque champ est surchargeable via une variable d'environnement de meme nom
    (insensible a la casse) : APP_NAME, DATABASE_URL, MAX_NODES, ...
    """

    model_config = SettingsConfigDict(env_file=".env", extra="ignore", case_sensitive=False)

    app_name: str = "OpenMind"
    app_port: int = 8080
    app_env: str = "production"

    database_url: str = "sqlite:////app/data/openmind.db"
    static_dir: str = "/app/static"

    max_map_size_mb: float = Field(default=10.0, gt=0)
    max_nodes: int = Field(default=5000, gt=0)
    max_title_length: int = Field(default=200, gt=0)

    # Liste d'origines autorisees, separees par des virgules.
    # Vide = aucune origine externe (l'app est servie par ce meme serveur).
    cors_origins: str = ""

    log_level: str = "INFO"

    @property
    def max_map_size_bytes(self) -> int:
        return int(self.max_map_size_mb * 1024 * 1024)

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

    @property
    def is_debug(self) -> bool:
        return self.app_env.lower() in {"dev", "development", "debug"}


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