#borrow some code from https://github.com/xuebinqin/U-2-Net

import torch
from torchvision import transforms
from skimage import transform, color
import numpy as np

class RescaleT(object):
	def __init__(self,output_size):
		assert isinstance(output_size,(int,tuple))
		self.output_size = output_size

	def __call__(self,sample):
		imidx, image, label = sample['imidx'], sample['image'],sample['label']

		h, w = image.shape[:2]

		if isinstance(self.output_size,int):
			if h > w:
				new_h, new_w = self.output_size*h/w,self.output_size
			else:
				new_h, new_w = self.output_size,self.output_size*w/h
		else:
			new_h, new_w = self.output_size

		new_h, new_w = int(new_h), int(new_w)

		# #resize the image to new_h x new_w and convert image from range [0,255] to [0,1]
		# img = transform.resize(image,(new_h,new_w),mode='constant')
		# lbl = transform.resize(label,(new_h,new_w),mode='constant', order=0, preserve_range=True)

		img = transform.resize(image,(self.output_size,self.output_size),mode='constant')
		lbl = transform.resize(label,(self.output_size,self.output_size),mode='constant', order=0, preserve_range=True)

		return {'imidx':imidx, 'image':img,'label':lbl}


class ToTensorLab(object):
	"""Convert ndarrays in sample to Tensors."""
	def __init__(self,flag=0):
		self.flag = flag

	def __call__(self, sample):

		imidx, image, label =sample['imidx'], sample['image'], sample['label']

		tmpLbl = np.zeros(label.shape)

		if(np.max(label)<1e-6):
			label = label
		else:
			label = label/np.max(label)

		# change the color space
		if self.flag == 2: # with rgb and Lab colors
			tmpImg = np.zeros((image.shape[0],image.shape[1],6))
			tmpImgt = np.zeros((image.shape[0],image.shape[1],3))
			if image.shape[2]==1:
				tmpImgt[:,:,0] = image[:,:,0]
				tmpImgt[:,:,1] = image[:,:,0]
				tmpImgt[:,:,2] = image[:,:,0]
			else:
				tmpImgt = image
			tmpImgtl = color.rgb2lab(tmpImgt)

			# nomalize image to range [0,1]
			tmpImg[:,:,0] = (tmpImgt[:,:,0]-np.min(tmpImgt[:,:,0]))/(np.max(tmpImgt[:,:,0])-np.min(tmpImgt[:,:,0]))
			tmpImg[:,:,1] = (tmpImgt[:,:,1]-np.min(tmpImgt[:,:,1]))/(np.max(tmpImgt[:,:,1])-np.min(tmpImgt[:,:,1]))
			tmpImg[:,:,2] = (tmpImgt[:,:,2]-np.min(tmpImgt[:,:,2]))/(np.max(tmpImgt[:,:,2])-np.min(tmpImgt[:,:,2]))
			tmpImg[:,:,3] = (tmpImgtl[:,:,0]-np.min(tmpImgtl[:,:,0]))/(np.max(tmpImgtl[:,:,0])-np.min(tmpImgtl[:,:,0]))
			tmpImg[:,:,4] = (tmpImgtl[:,:,1]-np.min(tmpImgtl[:,:,1]))/(np.max(tmpImgtl[:,:,1])-np.min(tmpImgtl[:,:,1]))
			tmpImg[:,:,5] = (tmpImgtl[:,:,2]-np.min(tmpImgtl[:,:,2]))/(np.max(tmpImgtl[:,:,2])-np.min(tmpImgtl[:,:,2]))

			# tmpImg = tmpImg/(np.max(tmpImg)-np.min(tmpImg))

			tmpImg[:,:,0] = (tmpImg[:,:,0]-np.mean(tmpImg[:,:,0]))/np.std(tmpImg[:,:,0])
			tmpImg[:,:,1] = (tmpImg[:,:,1]-np.mean(tmpImg[:,:,1]))/np.std(tmpImg[:,:,1])
			tmpImg[:,:,2] = (tmpImg[:,:,2]-np.mean(tmpImg[:,:,2]))/np.std(tmpImg[:,:,2])
			tmpImg[:,:,3] = (tmpImg[:,:,3]-np.mean(tmpImg[:,:,3]))/np.std(tmpImg[:,:,3])
			tmpImg[:,:,4] = (tmpImg[:,:,4]-np.mean(tmpImg[:,:,4]))/np.std(tmpImg[:,:,4])
			tmpImg[:,:,5] = (tmpImg[:,:,5]-np.mean(tmpImg[:,:,5]))/np.std(tmpImg[:,:,5])

		elif self.flag == 1: #with Lab color
			tmpImg = np.zeros((image.shape[0],image.shape[1],3))

			if image.shape[2]==1:
				tmpImg[:,:,0] = image[:,:,0]
				tmpImg[:,:,1] = image[:,:,0]
				tmpImg[:,:,2] = image[:,:,0]
			else:
				tmpImg = image

			tmpImg = color.rgb2lab(tmpImg)

			# tmpImg = tmpImg/(np.max(tmpImg)-np.min(tmpImg))

			tmpImg[:,:,0] = (tmpImg[:,:,0]-np.min(tmpImg[:,:,0]))/(np.max(tmpImg[:,:,0])-np.min(tmpImg[:,:,0]))
			tmpImg[:,:,1] = (tmpImg[:,:,1]-np.min(tmpImg[:,:,1]))/(np.max(tmpImg[:,:,1])-np.min(tmpImg[:,:,1]))
			tmpImg[:,:,2] = (tmpImg[:,:,2]-np.min(tmpImg[:,:,2]))/(np.max(tmpImg[:,:,2])-np.min(tmpImg[:,:,2]))

			tmpImg[:,:,0] = (tmpImg[:,:,0]-np.mean(tmpImg[:,:,0]))/np.std(tmpImg[:,:,0])
			tmpImg[:,:,1] = (tmpImg[:,:,1]-np.mean(tmpImg[:,:,1]))/np.std(tmpImg[:,:,1])
			tmpImg[:,:,2] = (tmpImg[:,:,2]-np.mean(tmpImg[:,:,2]))/np.std(tmpImg[:,:,2])

		else: # with rgb color
			tmpImg = np.zeros((image.shape[0],image.shape[1],3))
			image = image/np.max(image)
			if image.shape[2]==1:
				tmpImg[:,:,0] = (image[:,:,0]-0.485)/0.229
				tmpImg[:,:,1] = (image[:,:,0]-0.485)/0.229
				tmpImg[:,:,2] = (image[:,:,0]-0.485)/0.229
			else:
				tmpImg[:,:,0] = (image[:,:,0]-0.485)/0.229
				tmpImg[:,:,1] = (image[:,:,1]-0.456)/0.224
				tmpImg[:,:,2] = (image[:,:,2]-0.406)/0.225

		tmpLbl[:,:,0] = label[:,:,0]

		# change the r,g,b to b,r,g from [0,255] to [0,1]
		#transforms.Normalize(mean = (0.485, 0.456, 0.406), std = (0.229, 0.224, 0.225))
		tmpImg = tmpImg.transpose((2, 0, 1))
		tmpLbl = label.transpose((2, 0, 1))

		return {'imidx':torch.from_numpy(imidx), 'image': torch.from_numpy(tmpImg), 'label': torch.from_numpy(tmpLbl)}