# -*- 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

# /////////////// Data Loader ///////////////


IMG_EXTENSIONS = ['.jpg', '.jpeg', '.png', '.ppm', '.bmp', '.pgm']


def is_image_file(filename):
    """Checks if a file is an image.
    Args:
        filename (string): path to a file
    Returns:
        bool: True if the filename ends with a known image extension
    """
    filename_lower = filename.lower()
    return any(filename_lower.endswith(ext) for ext in IMG_EXTENSIONS)


def find_classes(dir):
    classes = [d for d in os.listdir(dir) if os.path.isdir(os.path.join(dir, d))]
    classes.sort()
    class_to_idx = {classes[i]: i for i in range(len(classes))}
    return classes, class_to_idx


def make_dataset(dir, class_to_idx):
    images = []
    dir = os.path.expanduser(dir)
    for target in sorted(os.listdir(dir)):
        d = os.path.join(dir, target)
        if not os.path.isdir(d):
            continue

        for root, _, fnames in sorted(os.walk(d)):
            for fname in sorted(fnames):
                if is_image_file(fname):
                    path = os.path.join(root, fname)
                    item = (path, class_to_idx[target])
                    images.append(item)

    return images


def pil_loader(path):
    # open path as file to avoid ResourceWarning (https://github.com/python-pillow/Pillow/issues/835)
    with open(path, 'rb') as f:
        img = Image.open(f)
        return img.convert('RGB')


def accimage_loader(path):
    import accimage
    try:
        return accimage.Image(path)
    except IOError:
        # Potentially a decoding problem, fall back to PIL.Image
        return pil_loader(path)


def default_loader(path):
    from torchvision import get_image_backend
    if get_image_backend() == 'accimage':
        return accimage_loader(path)
    else:
        return pil_loader(path)


class DistortImageFolder(data.Dataset):
    def __init__(self, root, method, severity, transform=None, target_transform=None,
                 loader=default_loader):
        classes, class_to_idx = find_classes(root)
        imgs = make_dataset(root, class_to_idx)
        if len(imgs) == 0:
            raise (RuntimeError("Found 0 images in subfolders of: " + root + "\n"
                                                                             "Supported image extensions are: " + ",".join(
                IMG_EXTENSIONS)))

        self.root = root
        self.method = method
        self.severity = severity
        self.imgs = imgs
        self.classes = classes
        self.class_to_idx = class_to_idx
        self.idx_to_class = {v: k for k, v in class_to_idx.items()}
        self.transform = transform
        self.target_transform = target_transform
        self.loader = loader

    def __getitem__(self, index):
        path, target = self.imgs[index]
        img = self.loader(path)
        if self.transform is not None:
            img = self.transform(img)
            img = self.method(img, self.severity)
        if self.target_transform is not None:
            target = self.target_transform(target)

        save_path = '/share/data/vision-greg/DistortedImageNet/JPEG/' + self.method.__name__ + \
                    '/' + str(self.severity) + '/' + self.idx_to_class[target]

        if not os.path.exists(save_path):
            os.makedirs(save_path)

        save_path += path[path.rindex('/'):]

        Image.fromarray(np.uint8(img)).save(save_path, quality=85, optimize=True)

        return 0  # we do not care about returning the data

    def __len__(self):
        return len(self.imgs)


# /////////////// Distortion Helpers ///////////////

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 auc(errs):  # area under the alteration error curve
    area = 0
    for i in range(1, len(errs)):
        area += (errs[i] + errs[i - 1]) / 2
    area /= len(errs) - 1
    return area


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


# Extend wand.image.Image class to include method signature
class MotionImage(WandImage):
    def motion_blur(self, radius=0.0, sigma=0.0, angle=0.0):
        wandlibrary.MagickMotionBlurImage(self.wand, radius, sigma, angle)


# modification of https://github.com/FLHerne/mapgen/blob/master/diamondsquare.py
def plasma_fractal(mapsize=256, 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]


# /////////////// End Distortion Helpers ///////////////


# /////////////// Distortions ///////////////

def gaussian_noise(x, severity=1):
    c = [.08, .12, 0.18, 0.26, 0.38][severity - 1]

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

    return Image.fromarray(np.uint8(x))


def shot_noise(x, severity=1):
    c = [60, 25, 12, 5, 3][severity - 1]

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

    return Image.fromarray(np.uint8(x))


def impulse_noise(x, severity=1):
    c = [.03, .06, .09, 0.17, 0.27][severity - 1]

    x = sk.util.random_noise(np.array(x) / 255., mode='s&p', amount=c)
    x = np.clip(x, 0, 1) * 255
    return Image.fromarray(np.uint8(x))


def speckle_noise(x, severity=1):
    c = [.15, .2, 0.35, 0.45, 0.6][severity - 1]

    x = np.array(x) / 255.
    x = np.clip(x + x * np.random.normal(size=x.shape, scale=c), 0, 1) * 255
    return Image.fromarray(np.uint8(x))


def fgsm(x, source_net, severity=1):
    c = [8, 16, 32, 64, 128][severity - 1]

    x = V(x, requires_grad=True)
    logits = source_net(x)
    source_net.zero_grad()
    loss = F.cross_entropy(logits, V(logits.data.max(1)[1].squeeze_()), size_average=False)
    loss.backward()

    return standardize(torch.clamp(unstandardize(x.data) + c / 255. * unstandardize(torch.sign(x.grad.data)), 0, 1))


def gaussian_blur(x, severity=1):
    c = [1, 2, 3, 4, 6][severity - 1]

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

    return Image.fromarray(np.uint8(x))


def glass_blur(x, severity=1):
    # sigma, max_delta, iterations
    c = [(0.7, 1, 2), (0.9, 2, 1), (1, 2, 3), (1.1, 3, 2), (1.5, 4, 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(512 - c[1], c[1], -1):
            for w in range(512 - 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]

    x = np.clip(gaussian(x / 255., sigma=c[0], multichannel=True), 0, 1) * 255
    
    return Image.fromarray(np.uint8(x))


def defocus_blur(x, severity=1):
    c = [(3, 0.1), (4, 0.5), (6, 0.5), (8, 0.5), (10, 0.5)][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))  # 3x224x224 -> 224x224x3
    x = np.clip(channels, 0, 1) * 255

    return Image.fromarray(np.uint8(x))


def motion_blur(x, severity=1):
    c = [(10, 3), (15, 5), (15, 8), (15, 12), (20, 15)][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 != (224, 224):
        x = np.clip(x[..., [2, 1, 0]], 0, 255)  # BGR to RGB
        return Image.fromarray(np.uint8(x))
    else:  # greyscale to RGB
        x = np.clip(np.array([x, x, x]).transpose((1, 2, 0)), 0, 255)
        return Image.fromarray(np.uint8(x))


def zoom_blur(x, severity=1):
    c = [np.arange(1, 1.11, 0.01),
         np.arange(1, 1.16, 0.01),
         np.arange(1, 1.21, 0.02),
         np.arange(1, 1.26, 0.02),
         np.arange(1, 1.31, 0.03)][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)
    x = np.clip(x, 0, 1) * 255
    return Image.fromarray(np.uint8(x))


# def barrel(x, severity=1):
#     c = [(0,0.03,0.03), (0.05,0.05,0.05), (0.1,0.1,0.1),
#          (0.2,0.2,0.2), (0.1,0.3,0.6)][severity - 1]
#
#     output = BytesIO()
#     x.save(output, format='PNG')
#
#     x = WandImage(blob=output.getvalue())
#     x.distort('barrel', c)
#
#     x = cv2.imdecode(np.fromstring(x.make_blob(), np.uint8),
#                      cv2.IMREAD_UNCHANGED)
#
#     if x.shape != (224, 224):
#         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 fog(x, severity=1):
    c = [(1.5, 2), (2, 2), (2.5, 1.7), (2.5, 1.5), (3, 1.4)][severity - 1]

    x = np.array(x) / 255.
    max_val = x.max()
    x += c[0] * plasma_fractal(wibbledecay=c[1])[:224, :224][..., np.newaxis]
    x = np.clip(x * max_val / (max_val + c[0]), 0, 1) * 255
    return Image.fromarray(np.uint8(x))


def frost(x, severity=1):
    c = [(1, 0.4),
         (0.8, 0.6),
         (0.7, 0.7),
         (0.65, 0.7),
         (0.6, 0.75)][severity - 1]
    idx = np.random.randint(5)
    filename = ['./frost1.png', './frost2.png', './frost3.png', './frost4.jpg', './frost5.jpg', './frost6.jpg'][idx]
    frost = cv2.imread(filename)
    # randomly crop and convert to rgb
    x_start, y_start = np.random.randint(0, frost.shape[0] - 224), np.random.randint(0, frost.shape[1] - 224)
    frost = frost[x_start:x_start + 224, y_start:y_start + 224][..., [2, 1, 0]]
    x = np.clip(c[0] * np.array(x) + c[1] * frost, 0, 255)
    return Image.fromarray(np.uint8(x))


def snow(x, severity=1):
    c = [(0.1, 0.3, 3, 0.5, 10, 4, 0.8),
         (0.2, 0.3, 2, 0.5, 12, 4, 0.7),
         (0.55, 0.3, 4, 0.9, 12, 8, 0.7),
         (0.55, 0.3, 4.5, 0.85, 12, 8, 0.65),
         (0.55, 0.3, 2.5, 0.85, 12, 12, 0.55)][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(224, 224, 1) * 1.5 + 0.5)
    x = np.clip(x + snow_layer + np.rot90(snow_layer, k=2), 0, 1) * 255
    return Image.fromarray(np.uint8(x))


def spatter(x, severity=1):
    c = [(0.65, 0.3, 4, 0.69, 0.6, 0),
         (0.65, 0.3, 3, 0.68, 0.6, 0),
         (0.65, 0.3, 2, 0.68, 0.5, 0),
         (0.65, 0.3, 1, 0.65, 1.5, 1),
         (0.67, 0.4, 1, 0.65, 1.5, 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([[-1,-2,-3],[-2,0,0],[-3,0,1]], dtype=np.float32)
        #     ker -= np.mean(ker)
        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
        #         m = np.abs(m) ** (1/c[4])

        # 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])
        x = np.clip(x + color, 0, 1) * 255
        return Image.fromarray(np.uint8(x))


def contrast(x, severity=1):
    c = [0.4, .3, .2, .1, .05][severity - 1]

    x = np.array(x) / 255.
    means = np.mean(x, axis=(0, 1), keepdims=True)
    x = np.clip((x - means) * c + means, 0, 1) * 255
    return Image.fromarray(np.uint8(x))


def brightness(x, severity=1):
    c = [.1, .2, .3, .4, .5][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)
    x = np.clip(x, 0, 1) * 255
    return Image.fromarray(np.uint8(x))


def saturate(x, severity=1):
    c = [(0.3, 0), (0.1, 0), (2, 0), (5, 0.1), (20, 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)
    x = np.clip(x, 0, 1) * 255
    return Image.fromarray(np.uint8(x))


def jpeg_compression(x, severity=1):
    c = [25, 18, 15, 10, 7][severity - 1]

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

    return x


def pixelate(x, severity=1):
    c = [0.6, 0.5, 0.4, 0.3, 0.25][severity - 1]

    x = x.resize((int(256 * c), int(256 * c)), PILImage.BOX)
    x = x.resize((256, 256), PILImage.BOX)

    return Image.fromarray(np.uint8(x))


# mod of https://gist.github.com/erniejunior/601cdf56d2b424757de5
def elastic_transform(image, severity=1):
    c = [(244 * 2, 244 * 0.7, 244 * 0.1),   # 244 should have been 224, but ultimately nothing is incorrect
         (244 * 2, 244 * 0.08, 244 * 0.2),
         (244 * 0.05, 244 * 0.01, 244 * 0.02),
         (244 * 0.07, 244 * 0.01, 244 * 0.02),
         (244 * 0.12, 244 * 0.01, 244 * 0.02)][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


# /////////////// End Distortions ///////////////


# /////////////// Further Setup ///////////////


def save_distorted(method=gaussian_noise):
    for severity in range(1, 6):
        print(method.__name__, severity)
        distorted_dataset = DistortImageFolder(
            root="/share/data/vision-greg/ImageNet/clsloc/images/val",
            method=method, severity=severity,
            transform=trn.Compose([trn.Resize(256), trn.CenterCrop(224)]))
        distorted_dataset_loader = torch.utils.data.DataLoader(
            distorted_dataset, batch_size=100, shuffle=False, num_workers=4)

        for _ in distorted_dataset_loader: continue


# /////////////// End Further Setup ///////////////


# /////////////// Display Results ///////////////
# import collections

# print('\nUsing ImageNet data')

# 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

# for method_name in d.keys():
#     save_distorted(d[method_name])