# Copyright (c) 2025 Patrick Motsch
# All rights reserved.
"""
Feature discovery utility (Layer L0 - shared).
Dynamically discovers and loads feature main modules from the features directory.
Zero internal dependencies — only os, glob, importlib, logging.
"""

import os
import glob
import importlib
import logging
from typing import Dict, Any

logger = logging.getLogger(__name__)

FEATURES_DIR = os.path.join(
    os.path.dirname(os.path.dirname(os.path.abspath(__file__))), "features"
)

_cachedMainModules = None


def loadFeatureMainModules() -> Dict[str, Any]:
    """
    Dynamically load main modules from all discovered feature containers.
    Results are cached after the first call.
    """
    global _cachedMainModules
    if _cachedMainModules is not None:
        return _cachedMainModules

    mainModules = {}
    pattern = os.path.join(FEATURES_DIR, "*", "main*.py")

    for filepath in glob.glob(pattern):
        filename = os.path.basename(filepath)
        if filename == "__init__.py":
            continue

        featureDir = os.path.basename(os.path.dirname(filepath))
        if featureDir.startswith("_"):
            continue

        if featureDir in mainModules:
            continue

        mainFile = filename[:-3]

        try:
            modulePath = f"modules.features.{featureDir}.{mainFile}"
            module = importlib.import_module(modulePath)
            mainModules[featureDir] = module
            logger.debug(f"Loaded main module: {featureDir}")
        except Exception as e:
            logger.error(f"Failed to load main module from {featureDir}: {e}")

    _cachedMainModules = mainModules
    return mainModules