"""Configuration from environment variables — no file parsing required for basic use."""

from __future__ import annotations

import os
from pathlib import Path

DATA_DIR = Path(os.environ.get("PAGEPIPER_DATA_DIR", "data"))
DB_PATH = str(DATA_DIR / "pagepiper.db")
VEC_DB_PATH = str(DATA_DIR / "pagepiper_vecs.db")
WATCH_DIR = Path(os.environ.get("PAGEPIPER_WATCH_DIR", "books"))


def get_llm_config() -> dict | None:
    """Build LLMRouter config from env vars. Returns None if PAGEPIPER_OLLAMA_URL is unset."""
    url = os.environ.get("PAGEPIPER_OLLAMA_URL", "").strip()
    if not url:
        return None
    return {
        "fallback_order": ["ollama"],
        "backends": {
            "ollama": {
                "type": "openai_compat",
                "base_url": url.rstrip("/") + "/v1",
                "model": os.environ.get("PAGEPIPER_CHAT_MODEL", "mistral:7b"),
                "embedding_model": os.environ.get(
                    "PAGEPIPER_EMBED_MODEL", "nomic-embed-text"
                ),
                "supports_images": False,
            }
        },
    }