"""Feature 자동 탐색 + 등록.

features/ 하위 디렉토리를 스캔하여 FEATURE_CONFIG가 있는 모듈을 수집하고 order로 정렬.
"""

import importlib
from pathlib import Path

_REQUIRED_CONFIG_FIELDS = {"name", "icon", "order"}


def discover_features() -> list[dict]:
    """features/ 하위 디렉토리를 스캔, FEATURE_CONFIG 있는 모듈 수집, order 정렬.

    Returns:
        List of dicts with 'config' and 'module' keys, sorted by order.
    """
    features_dir = Path(__file__).parent / "features"
    if not features_dir.exists():
        return []

    results = []
    for child in sorted(features_dir.iterdir()):
        if not child.is_dir() or child.name.startswith("_"):
            continue

        init_file = child / "__init__.py"
        if not init_file.exists():
            continue

        try:
            module = importlib.import_module(f"features.{child.name}")
            config = getattr(module, "FEATURE_CONFIG", None)
            if not config or not isinstance(config, dict):
                continue

            missing = _REQUIRED_CONFIG_FIELDS - set(config.keys())
            if missing:
                import streamlit as st
                st.warning(f"Feature '{child.name}': 필수 필드 누락 {missing}")
                continue

            if not hasattr(module, "render") or not callable(module.render):
                import streamlit as st
                st.warning(f"Feature '{child.name}': render() 함수 없음")
                continue

            results.append({
                "config": config,
                "module": module,
            })
        except Exception as e:
            import streamlit as st
            st.warning(
                f"Feature '{child.name}' 로드 실패: "
                f"{type(e).__name__}: {e}"
            )

    results.sort(key=lambda x: x["config"].get("order", 99))
    return results