# -*- coding: utf-8 -*-

import os
from PIL import Image
import os.path
import time
import torch
import torchvision.datasets as dset
import torchvision.transforms as trn
import torch.utils.data as data
import numpy as np

from PIL import Image

import skimage as sk
from skimage.filters import gaussian
from io import BytesIO
from wand.image import Image as WandImage
from wand.api import library as wandlibrary
import wand.color as WandColor
import ctypes
from PIL import Image as PILImage
import cv2
from scipy.ndimage import zoom as scizoom
from scipy.ndimage.interpolation import map_coordinates
import warnings

warnings.simplefilter("ignore", UserWarning)


def disk(radius, alias_blur=0.1, dtype=np.float32):
    if radius <= 8:
        L = np.arange(-8, 8 + 1)
        ksize = (3, 3)
    else:
        L = np.arange(-radius, radius + 1)
        ksize = (5, 5)
    X, Y = np.meshgrid(L, L)
    aliased_disk = np.array((X ** 2 + Y ** 2) <= radius ** 2, dtype=dtype)
    aliased_disk /= np.sum(aliased_disk)

    # supersample disk to antialias
    return cv2.GaussianBlur(aliased_disk, ksize=ksize, sigmaX=alias_blur)


# Tell Python about the C method
wandlibrary.MagickMotionBlurImage.argtypes = (ctypes.c_void_p,  # wand
                                              ctypes.c_double,  # radius
                                              ctypes.c_double,  # sigma
                                              ctypes.c_double)  # angle


class MotionImage(WandImage):
    def motion_blur(self, radius=0.0, sigma=0.0, angle=0.0):
        wandlibrary.MagickMotionBlurImage(self.wand, radius, sigma, angle)


def plasma_fractal(mapsize=32, wibbledecay=3):
    """
    Generate a heightmap using diamond-square algorithm.
    Return square 2d array, side length 'mapsize', of floats in range 0-255.
    'mapsize' must be a power of two.
    """
    assert (mapsize & (mapsize - 1) == 0)
    maparray = np.empty((mapsize, mapsize), dtype=np.float_)
    maparray[0, 0] = 0
    stepsize = mapsize
    wibble = 100

    def wibbledmean(array):
        return array / 4 + wibble * np.random.uniform(-wibble, wibble, array.shape)

    def fillsquares():
        """For each square of points stepsize apart,
           calculate middle value as mean of points + wibble"""
        cornerref = maparray[0:mapsize:stepsize, 0:mapsize:stepsize]
        squareaccum = cornerref + np.roll(cornerref, shift=-1, axis=0)
        squareaccum += np.roll(squareaccum, shift=-1, axis=1)
        maparray[stepsize // 2:mapsize:stepsize,
        stepsize // 2:mapsize:stepsize] = wibbledmean(squareaccum)

    def filldiamonds():
        """For each diamond of points stepsize apart,
           calculate middle value as mean of points + wibble"""
        mapsize = maparray.shape[0]
        drgrid = maparray[stepsize // 2:mapsize:stepsize, stepsize // 2:mapsize:stepsize]
        ulgrid = maparray[0:mapsize:stepsize, 0:mapsize:stepsize]
        ldrsum = drgrid + np.roll(drgrid, 1, axis=0)
        lulsum = ulgrid + np.roll(ulgrid, -1, axis=1)
        ltsum = ldrsum + lulsum
        maparray[0:mapsize:stepsize, stepsize // 2:mapsize:stepsize] = wibbledmean(ltsum)
        tdrsum = drgrid + np.roll(drgrid, 1, axis=1)
        tulsum = ulgrid + np.roll(ulgrid, -1, axis=0)
        ttsum = tdrsum + tulsum
        maparray[stepsize // 2:mapsize:stepsize, 0:mapsize:stepsize] = wibbledmean(ttsum)

    while stepsize >= 2:
        fillsquares()
        filldiamonds()
        stepsize //= 2
        wibble /= wibbledecay

    maparray -= maparray.min()
    return maparray / maparray.max()


def clipped_zoom(img, zoom_factor):
    h = img.shape[0]
    # ceil crop height(= crop width)
    ch = int(np.ceil(h / zoom_factor))

    top = (h - ch) // 2
    img = scizoom(img[top:top + ch, top:top + ch], (zoom_factor, zoom_factor, 1), order=1)
    # trim off any extra pixels
    trim_top = (img.shape[0] - h) // 2

    return img[trim_top:trim_top + h, trim_top:trim_top + h]


def gaussian_noise(x, severity=1):
    c = [0.04, 0.06, .08, .09, .10][severity - 1]

    x = np.array(x) / 255.
    return np.clip(x + np.random.normal(size=x.shape, scale=c), 0, 1) * 255


def shot_noise(x, severity=1):
    c = [500, 250, 100, 75, 50][severity - 1]

    x = np.array(x) / 255.
    return np.clip(np.random.poisson(x * c) / c, 0, 1) * 255


def impulse_noise(x, severity=1):
    c = [.01, .02, .03, .05, .07][severity - 1]

    x = sk.util.random_noise(np.array(x) / 255., mode='s&p', amount=c)
    return np.clip(x, 0, 1) * 255


def speckle_noise(x, severity=1):
    c = [.06, .1, .12, .16, .2][severity - 1]

    x = np.array(x) / 255.
    return np.clip(x + x * np.random.normal(size=x.shape, scale=c), 0, 1) * 255


def gaussian_blur(x, severity=1):
    c = [.4, .6, 0.7, .8, 1][severity - 1]

    x = gaussian(np.array(x) / 255., sigma=c, multichannel=True)
    return np.clip(x, 0, 1) * 255


def glass_blur(x, severity=1):
    # sigma, max_delta, iterations
    c = [(0.05,1,1), (0.25,1,1), (0.4,1,1), (0.25,1,2), (0.4,1,2)][severity - 1]

    x = np.uint8(gaussian(np.array(x) / 255., sigma=c[0], multichannel=True) * 255)

    # locally shuffle pixels
    for i in range(c[2]):
        for h in range(32 - c[1], c[1], -1):
            for w in range(32 - c[1], c[1], -1):
                dx, dy = np.random.randint(-c[1], c[1], size=(2,))
                h_prime, w_prime = h + dy, w + dx
                # swap
                x[h, w], x[h_prime, w_prime] = x[h_prime, w_prime], x[h, w]

    return np.clip(gaussian(x / 255., sigma=c[0], multichannel=True), 0, 1) * 255


def defocus_blur(x, severity=1):
    c = [(0.3, 0.4), (0.4, 0.5), (0.5, 0.6), (1, 0.2), (1.5, 0.1)][severity - 1]

    x = np.array(x) / 255.
    kernel = disk(radius=c[0], alias_blur=c[1])

    channels = []
    for d in range(3):
        channels.append(cv2.filter2D(x[:, :, d], -1, kernel))
    channels = np.array(channels).transpose((1, 2, 0))  # 3x32x32 -> 32x32x3

    return np.clip(channels, 0, 1) * 255


def motion_blur(x, severity=1):
    c = [(6,1), (6,1.5), (6,2), (8,2), (9,2.5)][severity - 1]

    output = BytesIO()
    x.save(output, format='PNG')
    x = MotionImage(blob=output.getvalue())

    x.motion_blur(radius=c[0], sigma=c[1], angle=np.random.uniform(-45, 45))

    x = cv2.imdecode(np.fromstring(x.make_blob(), np.uint8),
                     cv2.IMREAD_UNCHANGED)

    if x.shape != (32, 32):
        return np.clip(x[..., [2, 1, 0]], 0, 255)  # BGR to RGB
    else:  # greyscale to RGB
        return np.clip(np.array([x, x, x]).transpose((1, 2, 0)), 0, 255)


def zoom_blur(x, severity=1):
    c = [np.arange(1, 1.06, 0.01), np.arange(1, 1.11, 0.01), np.arange(1, 1.16, 0.01),
         np.arange(1, 1.21, 0.01), np.arange(1, 1.26, 0.01)][severity - 1]

    x = (np.array(x) / 255.).astype(np.float32)
    out = np.zeros_like(x)
    for zoom_factor in c:
        out += clipped_zoom(x, zoom_factor)

    x = (x + out) / (len(c) + 1)
    return np.clip(x, 0, 1) * 255


def fog(x, severity=1):
    c = [(.2,3), (.5,3), (0.75,2.5), (1,2), (1.5,1.75)][severity - 1]

    x = np.array(x) / 255.
    max_val = x.max()
    x += c[0] * plasma_fractal(wibbledecay=c[1])[:32, :32][..., np.newaxis]
    return np.clip(x * max_val / (max_val + c[0]), 0, 1) * 255


def frost(x, severity=1):
    c = [(1, 0.2), (1, 0.3), (0.9, 0.4), (0.85, 0.4), (0.75, 0.45)][severity - 1]
    idx = np.random.randint(5)
    filename = ['./figures/frost1.png', './figures/frost2.png', './figures/frost3.png', './figures/frost4.jpg', './figures/frost5.jpg', './figures/frost6.jpg'][idx]
    frost = cv2.imread(filename)
    frost = cv2.resize(frost, (0, 0), fx=0.2, fy=0.2)
    # randomly crop and convert to rgb
    x_start, y_start = np.random.randint(0, frost.shape[0] - 32), np.random.randint(0, frost.shape[1] - 32)
    frost = frost[x_start:x_start + 32, y_start:y_start + 32][..., [2, 1, 0]]

    return np.clip(c[0] * np.array(x) + c[1] * frost, 0, 255)


def snow(x, severity=1):
    c = [(0.1,0.2,1,0.6,8,3,0.95),
         (0.1,0.2,1,0.5,10,4,0.9),
         (0.15,0.3,1.75,0.55,10,4,0.9),
         (0.25,0.3,2.25,0.6,12,6,0.85),
         (0.3,0.3,1.25,0.65,14,12,0.8)][severity - 1]

    x = np.array(x, dtype=np.float32) / 255.
    snow_layer = np.random.normal(size=x.shape[:2], loc=c[0], scale=c[1])  # [:2] for monochrome

    snow_layer = clipped_zoom(snow_layer[..., np.newaxis], c[2])
    snow_layer[snow_layer < c[3]] = 0

    snow_layer = PILImage.fromarray((np.clip(snow_layer.squeeze(), 0, 1) * 255).astype(np.uint8), mode='L')
    output = BytesIO()
    snow_layer.save(output, format='PNG')
    snow_layer = MotionImage(blob=output.getvalue())

    snow_layer.motion_blur(radius=c[4], sigma=c[5], angle=np.random.uniform(-135, -45))

    snow_layer = cv2.imdecode(np.fromstring(snow_layer.make_blob(), np.uint8),
                              cv2.IMREAD_UNCHANGED) / 255.
    snow_layer = snow_layer[..., np.newaxis]

    x = c[6] * x + (1 - c[6]) * np.maximum(x, cv2.cvtColor(x, cv2.COLOR_RGB2GRAY).reshape(32, 32, 1) * 1.5 + 0.5)
    return np.clip(x + snow_layer + np.rot90(snow_layer, k=2), 0, 1) * 255


def spatter(x, severity=1):
    c = [(0.62,0.1,0.7,0.7,0.5,0),
         (0.65,0.1,0.8,0.7,0.5,0),
         (0.65,0.3,1,0.69,0.5,0),
         (0.65,0.1,0.7,0.69,0.6,1),
         (0.65,0.1,0.5,0.68,0.6,1)][severity - 1]
    x = np.array(x, dtype=np.float32) / 255.

    liquid_layer = np.random.normal(size=x.shape[:2], loc=c[0], scale=c[1])

    liquid_layer = gaussian(liquid_layer, sigma=c[2])
    liquid_layer[liquid_layer < c[3]] = 0
    if c[5] == 0:
        liquid_layer = (liquid_layer * 255).astype(np.uint8)
        dist = 255 - cv2.Canny(liquid_layer, 50, 150)
        dist = cv2.distanceTransform(dist, cv2.DIST_L2, 5)
        _, dist = cv2.threshold(dist, 20, 20, cv2.THRESH_TRUNC)
        dist = cv2.blur(dist, (3, 3)).astype(np.uint8)
        dist = cv2.equalizeHist(dist)

        ker = np.array([[-2, -1, 0], [-1, 1, 1], [0, 1, 2]])
        dist = cv2.filter2D(dist, cv2.CV_8U, ker)
        dist = cv2.blur(dist, (3, 3)).astype(np.float32)

        m = cv2.cvtColor(liquid_layer * dist, cv2.COLOR_GRAY2BGRA)
        m /= np.max(m, axis=(0, 1))
        m *= c[4]

        # water is pale turqouise
        color = np.concatenate((175 / 255. * np.ones_like(m[..., :1]),
                                238 / 255. * np.ones_like(m[..., :1]),
                                238 / 255. * np.ones_like(m[..., :1])), axis=2)

        color = cv2.cvtColor(color, cv2.COLOR_BGR2BGRA)
        x = cv2.cvtColor(x, cv2.COLOR_BGR2BGRA)

        return cv2.cvtColor(np.clip(x + m * color, 0, 1), cv2.COLOR_BGRA2BGR) * 255
    else:
        m = np.where(liquid_layer > c[3], 1, 0)
        m = gaussian(m.astype(np.float32), sigma=c[4])
        m[m < 0.8] = 0

        # mud brown
        color = np.concatenate((63 / 255. * np.ones_like(x[..., :1]),
                                42 / 255. * np.ones_like(x[..., :1]),
                                20 / 255. * np.ones_like(x[..., :1])), axis=2)

        color *= m[..., np.newaxis]
        x *= (1 - m[..., np.newaxis])

        return np.clip(x + color, 0, 1) * 255


def contrast(x, severity=1):
    c = [.75, .5, .4, .3, 0.15][severity - 1]

    x = np.array(x) / 255.
    means = np.mean(x, axis=(0, 1), keepdims=True)
    return np.clip((x - means) * c + means, 0, 1) * 255


def brightness(x, severity=1):
    c = [.05, .1, .15, .2, .3][severity - 1]

    x = np.array(x) / 255.
    x = sk.color.rgb2hsv(x)
    x[:, :, 2] = np.clip(x[:, :, 2] + c, 0, 1)
    x = sk.color.hsv2rgb(x)

    return np.clip(x, 0, 1) * 255


def saturate(x, severity=1):
    c = [(0.3, 0), (0.1, 0), (1.5, 0), (2, 0.1), (2.5, 0.2)][severity - 1]

    x = np.array(x) / 255.
    x = sk.color.rgb2hsv(x)
    x[:, :, 1] = np.clip(x[:, :, 1] * c[0] + c[1], 0, 1)
    x = sk.color.hsv2rgb(x)

    return np.clip(x, 0, 1) * 255


def jpeg_compression(x, severity=1):
    c = [80, 65, 58, 50, 40][severity - 1]

    output = BytesIO()
    x.save(output, 'JPEG', quality=c)
    x = PILImage.open(output)

    return x


def pixelate(x, severity=1):
    c = [0.95, 0.9, 0.85, 0.75, 0.65][severity - 1]

    x = x.resize((int(32 * c), int(32 * c)), PILImage.BOX)
    x = x.resize((32, 32), PILImage.BOX)

    return x


def elastic_transform(image, severity=1):
    IMSIZE = 32
    c = [(IMSIZE*0, IMSIZE*0, IMSIZE*0.08),
         (IMSIZE*0.05, IMSIZE*0.2, IMSIZE*0.07),
         (IMSIZE*0.08, IMSIZE*0.06, IMSIZE*0.06),
         (IMSIZE*0.1, IMSIZE*0.04, IMSIZE*0.05),
         (IMSIZE*0.1, IMSIZE*0.03, IMSIZE*0.03)][severity - 1]

    image = np.array(image, dtype=np.float32) / 255.
    shape = image.shape
    shape_size = shape[:2]

    # random affine
    center_square = np.float32(shape_size) // 2
    square_size = min(shape_size) // 3
    pts1 = np.float32([center_square + square_size,
                       [center_square[0] + square_size, center_square[1] - square_size],
                       center_square - square_size])
    pts2 = pts1 + np.random.uniform(-c[2], c[2], size=pts1.shape).astype(np.float32)
    M = cv2.getAffineTransform(pts1, pts2)
    image = cv2.warpAffine(image, M, shape_size[::-1], borderMode=cv2.BORDER_REFLECT_101)

    dx = (gaussian(np.random.uniform(-1, 1, size=shape[:2]),
                   c[1], mode='reflect', truncate=3) * c[0]).astype(np.float32)
    dy = (gaussian(np.random.uniform(-1, 1, size=shape[:2]),
                   c[1], mode='reflect', truncate=3) * c[0]).astype(np.float32)
    dx, dy = dx[..., np.newaxis], dy[..., np.newaxis]

    x, y, z = np.meshgrid(np.arange(shape[1]), np.arange(shape[0]), np.arange(shape[2]))
    indices = np.reshape(y + dy, (-1, 1)), np.reshape(x + dx, (-1, 1)), np.reshape(z, (-1, 1))
    return np.clip(map_coordinates(image, indices, order=1, mode='reflect').reshape(shape), 0, 1) * 255

import collections

d = collections.OrderedDict()
d['Gaussian Noise'] = gaussian_noise
d['Shot Noise'] = shot_noise
d['Impulse Noise'] = impulse_noise
d['Defocus Blur'] = defocus_blur
d['Glass Blur'] = glass_blur
d['Motion Blur'] = motion_blur
d['Zoom Blur'] = zoom_blur
d['Snow'] = snow
d['Frost'] = frost
d['Fog'] = fog
d['Brightness'] = brightness
d['Contrast'] = contrast
d['Elastic'] = elastic_transform
d['Pixelate'] = pixelate
d['JPEG'] = jpeg_compression

d['Speckle Noise'] = speckle_noise
d['Gaussian Blur'] = gaussian_blur
d['Spatter'] = spatter
d['Saturate'] = saturate

keys = ['Gaussian Noise', 'Shot Noise', 'Impulse Noise', 'Defocus Blur', 'Glass Blur', 'Motion Blur', 'Zoom Blur', 'Snow', 'Frost', 'Fog', 'Brightness', 'Contrast', 'Elastic', 'Pixelate', 'JPEG', 'Speckle Noise', 'Gaussian Blur', 'Spatter', 'Saturate']

import multiprocessing
from joblib import Parallel, delayed

def process_one_img(img, severity_range):
    convert_img = trn.Compose([trn.ToPILImage()])
    transform_img = trn.ToTensor()

    corruption_imgs = []

    for severity in severity_range:
        for method_name in d.keys():
            corruption = lambda clean_img: d[method_name](clean_img, severity)
            corruption_img = np.uint8(corruption(convert_img(img)))
            corruption_imgs.append(transform_img(corruption_img))

    return torch.stack(corruption_imgs, dim=0)

def gen_corruction_image(batch, severity_level = 2):
    batchs = []

    batch = batch.clone()

    severity_range = np.arange(1, severity_level + 1)

    corruption_imgs_list = Parallel(n_jobs=-1)(delayed(process_one_img)(img, severity_range) for img in batch)

    batchs = torch.stack(corruption_imgs_list, dim=0).transpose(0, 1)

    return batchs

def parallel_process_batch(batch, corruption):
    convert_img = trn.Compose([trn.ToPILImage()])
    transform_img = trn.ToTensor()

    imgs = []
    for img in batch:
        corruption_img = np.uint8(corruption(convert_img(img)))
        imgs.append(transform_img(corruption_img))

    return torch.stack(imgs, dim=0)

def gen_random_corruction_image(batch, num_workers=4):
    batch = batch.clone()

    convert_img = trn.Compose([trn.ToPILImage()])
    transform_img = trn.ToTensor()

    random_severity = np.random.randint(2)+1
    random_method_name = keys[np.random.randint(19)]

    corruption = lambda clean_img: d[random_method_name](clean_img, random_severity)

    bs = int(batch.shape[0] / 4)

    imgs_list = Parallel(n_jobs=-1)(delayed(parallel_process_batch)(batch[i*bs:(i+1)*bs], corruption) for i in range(num_workers))

    return torch.cat(imgs_list, dim=0)
