import numpy as np
from PIL import Image
import torch
import cv2

def numpy2tensor(image: Image.Image):
    return torch.from_numpy(image).unsqueeze(0)

class LightColorCulling:
    @classmethod
    def INPUT_TYPES(self):
        return {
            "required": {
                "image": ("IMAGE",),
                "white_threshold": ("FLOAT", {"default": 0.7, "min": 0.0, "max": 0.9, "step": 0.01}),
                "transition_range": ("FLOAT", {"default": 0.2, "min": 0.0, "max": 1.0, "step": 0.01}),
            },
        }
    RETURN_TYPES = ("IMAGE", )
    RETURN_NAMES = ("image", )
    FUNCTION = 'Preprocessing'
    CATEGORY = 'StickerEdit/LightColorCulling'

    def Preprocessing(self, image, white_threshold=0.7, transition_range=0.2):
        image_np = (image.cpu().numpy().squeeze()*255).astype(np.uint8)
        # 检查图像是否有透明通道
        has_alpha = image_np.shape[2] == 4

        # 转换为灰度图
        gray = cv2.cvtColor(image_np, cv2.COLOR_BGR2GRAY)

        # 归一化灰度图像到0-1范围
        normalized_gray = gray / 255.0

        # 创建结果图像
        result_image = image_np.copy()

            # 创建透明度通道
        if has_alpha:
            b_channel, g_channel, r_channel, alpha_channel = cv2.split(result_image)
        else:
            alpha_channel = np.ones_like(gray, dtype=float) * 255
            b_channel, g_channel, r_channel = cv2.split(result_image)
        
        # 计算渐变透明度
        mask = normalized_gray >= white_threshold
        transition_mask = (normalized_gray >= (white_threshold - transition_range)) & (normalized_gray < white_threshold)
        alpha_channel[mask] = 0
        alpha_channel[transition_mask] = (1 - (normalized_gray[transition_mask] - (white_threshold - transition_range)) / transition_range) * 255

        # 更新结果图像的alpha通道
        # import pdb;pdb.set_trace()
        result_image = cv2.merge((b_channel, g_channel, r_channel, alpha_channel.astype(np.uint8)))

        res_tensor = numpy2tensor(result_image/255.0)
        return (res_tensor,)


NODE_CLASS_MAPPINGS = {
    "LightColorCulling": LightColorCulling,
}

NODE_DISPLAY_NAME_MAPPINGS = {
    "LightColorCulling": "LightColorCulling",
}