"""Resolve reference algorithm bundle paths and default YAML (read-only; no vendor patches)."""

from __future__ import annotations

import copy
from pathlib import Path
from typing import Any

import yaml

REPO_ROOT = Path(__file__).resolve().parents[2]
DEFAULT_REFERENCE_BUNDLE_RELATIVE = "algorithm_subprocesses/5.15"


def configured_reference_bundle_relative() -> str:
    from app.config import Settings

    raw = (Settings().reference_bundle_relative or "").strip()
    return raw or DEFAULT_REFERENCE_BUNDLE_RELATIVE


def default_reference_bundle_dir() -> Path:
    raw = configured_reference_bundle_relative()
    path = Path(raw).expanduser()
    if path.is_absolute():
        return path.resolve()
    return (REPO_ROOT / path).resolve()


def resolve_reference_bundle_dir(bundle_dir: Path | None = None) -> Path:
    if bundle_dir is None:
        label = configured_reference_bundle_relative()
        root = default_reference_bundle_dir()
    else:
        label = str(bundle_dir)
        root = Path(bundle_dir).expanduser().resolve()
    if not (root / "main.py").is_file():
        raise FileNotFoundError(f"reference bundle main.py not found: {label} -> {root}")
    if not (root / "code" / "repo_root.py").is_file():
        raise FileNotFoundError(f"reference bundle vendor code not found: {label} -> {root / 'code'}")
    return root


def load_reference_default_config(bundle_dir: Path | None = None) -> dict[str, Any]:
    root = resolve_reference_bundle_dir(bundle_dir)
    path = root / "configs" / "default_config.yaml"
    data = yaml.safe_load(path.read_text(encoding="utf-8"))
    if not isinstance(data, dict):
        raise ValueError(f"invalid reference bundle default config: {path}")
    return copy.deepcopy(data)


def resolve_bundle_relative_path(bundle_dir: Path, raw: str) -> Path:
    p = Path((raw or "").strip())
    if not str(p):
        raise ValueError("empty bundle-relative path")
    if p.is_absolute():
        return p.resolve()
    return (bundle_dir / p).resolve()