"""Utility module for face detection."""

import cv2
import numpy as np
from typing import List, Tuple
from PIL import Image


def detect_faces(image: Image.Image) -> List[Tuple[int, int, int, int]]:
    """
    Detect faces in an image.
    
    Args:
        image: PIL Image
        
    Returns:
        List of face bounding boxes (x, y, w, h)
    """
    # Convert PIL to OpenCV format
    img_array = np.array(image)
    gray = cv2.cvtColor(img_array, cv2.COLOR_RGB2GRAY)
    
    # Load Haar Cascade
    face_cascade = cv2.CascadeClassifier(
        cv2.data.haarcascades + 'haarcascade_frontalface_default.xml'
    )
    
    # Detect faces
    faces = face_cascade.detectMultiScale(
        gray,
        scaleFactor=1.1,
        minNeighbors=5,
        minSize=(30, 30)
    )
    
    return faces.tolist() if len(faces) > 0 else []