from __future__ import annotations

import os
from dataclasses import dataclass
from pathlib import Path


@dataclass(frozen=True)
class Settings:
    data_dir: Path
    database_path: Path
    hf_cache_dir: Path
    admin_api_token: str
    frontend_dist_dir: Path
    host: str
    port: int

    @classmethod
    def from_env(cls) -> "Settings":
        root_dir = Path(__file__).resolve().parents[1]
        data_dir = Path(os.getenv("TOPOBENCH_DATA_DIR", "/data")).resolve()
        frontend_dist_dir = Path(
            os.getenv("TOPOBENCH_FRONTEND_DIST", root_dir / "frontend" / "dist")
        ).resolve()
        database_path = Path(
            os.getenv("TOPOBENCH_DATABASE_PATH", data_dir / "topobench.sqlite")
        ).resolve()
        hf_cache_dir = Path(
            os.getenv("HF_HOME", data_dir / "hf-cache")
        ).resolve()
        return cls(
            data_dir=data_dir,
            database_path=database_path,
            hf_cache_dir=hf_cache_dir,
            admin_api_token=os.getenv("ADMIN_API_TOKEN", "dev-admin-token"),
            frontend_dist_dir=frontend_dist_dir,
            host=os.getenv("TOPOBENCH_HOST", "0.0.0.0"),
            port=int(os.getenv("PORT", os.getenv("TOPOBENCH_PORT", "7860"))),
        )

    def prepare(self) -> None:
        self.data_dir.mkdir(parents=True, exist_ok=True)
        self.hf_cache_dir.mkdir(parents=True, exist_ok=True)
        os.environ.setdefault("HF_HOME", str(self.hf_cache_dir))