"""Repo-relative path resolution. No absolute user paths in committed code."""

from __future__ import annotations

import os
from functools import lru_cache
from pathlib import Path

import yaml


@lru_cache(maxsize=1)
def repo_root() -> Path:
    """Walk up from this file until a directory containing pyproject.toml."""
    p = Path(__file__).resolve()
    for parent in p.parents:
        if (parent / "pyproject.toml").exists():
            return parent
    raise RuntimeError("repo root not found (no pyproject.toml above package)")


@lru_cache(maxsize=1)
def path_config() -> dict:
    with open(repo_root() / "config" / "paths.yaml") as f:
        return yaml.safe_load(f)


def get(key: str) -> Path:
    """Resolve a named path from config/paths.yaml, honoring IFRAG_DATA_ROOT."""
    rel = path_config()[key]
    override = os.environ.get("IFRAG_DATA_ROOT")
    if override and (rel == "data" or rel.startswith("data/")):
        return Path(override) / rel[len("data"):].lstrip("/")
    return repo_root() / rel


def base_config() -> dict:
    with open(repo_root() / "config" / "base.yaml") as f:
        return yaml.safe_load(f)