import numpy as np
import cv2
from PIL import Image

def apply_wave_effect(pil_img):
    img = np.array(pil_img)
    rows, cols = img.shape[:2]

    map_y, map_x = np.indices((rows, cols), dtype=np.float32)
    wave = 15.0 * np.sin(map_x / 50.0)  # You can adjust wave strength and frequency
    map_y += wave

    distorted = cv2.remap(img, map_x, map_y, interpolation=cv2.INTER_LINEAR, borderMode=cv2.BORDER_REFLECT)

    return Image.fromarray(distorted)