"""
Centralized storage path configuration.

On Hugging Face Spaces (Docker), persistent storage is mounted at /data.
Locally, falls back to ./local_data so the repo stays clean.
"""
import os
from pathlib import Path


def _is_hf_space():
    """Detect if running inside a Hugging Face Space."""
    return os.getenv("SPACE_ID") is not None


def get_storage_root():
    """Return the root directory for all persistent runtime data."""
    if _is_hf_space():
        return Path("/data")
    return Path("./local_data")


def get_pdf_dir():
    """Directory where uploaded PDFs are stored."""
    p = get_storage_root() / "pdfs"
    p.mkdir(parents=True, exist_ok=True)
    return p


def get_chroma_dir():
    """Directory where ChromaDB stores its database."""
    p = get_storage_root() / "chroma"
    p.mkdir(parents=True, exist_ok=True)
    return p


def ensure_dirs():
    """Create all required directories at startup."""
    get_pdf_dir()
    get_chroma_dir()