"""
Most codes from https://github.com/carpedm20/DCGAN-tensorflow
"""
from __future__ import division
import math
import random
import pprint
import scipy.misc
import numpy as np
from time import gmtime, strftime
from six.moves import xrange
import os, gzip

import tensorflow as tf
import tensorflow.contrib.slim as slim

def load_mnist(dataset_name):
    data_dir = os.path.join("./data", dataset_name)

    def extract_data(filename, num_data, head_size, data_size):
        with gzip.open(filename) as bytestream:
            bytestream.read(head_size)
            buf = bytestream.read(data_size * num_data)
            data = np.frombuffer(buf, dtype=np.uint8).astype(np.float)
        return data

    data = extract_data(data_dir + '/train-images-idx3-ubyte.gz', 60000, 16, 28 * 28)
    trX = data.reshape((60000, 28, 28, 1))

    data = extract_data(data_dir + '/train-labels-idx1-ubyte.gz', 60000, 8, 1)
    trY = data.reshape((60000))

    data = extract_data(data_dir + '/t10k-images-idx3-ubyte.gz', 10000, 16, 28 * 28)
    teX = data.reshape((10000, 28, 28, 1))

    data = extract_data(data_dir + '/t10k-labels-idx1-ubyte.gz', 10000, 8, 1)
    teY = data.reshape((10000))

    trY = np.asarray(trY)
    teY = np.asarray(teY)

    X = np.concatenate((trX, teX), axis=0)
    y = np.concatenate((trY, teY), axis=0).astype(np.int)

    seed = 547
    np.random.seed(seed)
    np.random.shuffle(X)
    np.random.seed(seed)
    np.random.shuffle(y)

    y_vec = np.zeros((len(y), 10), dtype=np.float)
    for i, label in enumerate(y):
        y_vec[i, y[i]] = 1.0

    return X / 255., y_vec

def check_folder(log_dir):
    if not os.path.exists(log_dir):
        os.makedirs(log_dir)
    return log_dir

def show_all_variables():
    model_vars = tf.trainable_variables()
    slim.model_analyzer.analyze_vars(model_vars, print_info=True)

def get_image(image_path, input_height, input_width, resize_height=64, resize_width=64, crop=True, grayscale=False):
    image = imread(image_path, grayscale)
    return transform(image, input_height, input_width, resize_height, resize_width, crop)

def save_images(images, size, image_path):
    return imsave(inverse_transform(images), size, image_path)

def imread(path, grayscale = False):
    if (grayscale):
        return scipy.misc.imread(path, flatten = True).astype(np.float)
    else:
        return scipy.misc.imread(path).astype(np.float)

def merge_images(images, size):
    return inverse_transform(images)

def merge(images, size):
    h, w = images.shape[1], images.shape[2]
    if (images.shape[3] in (3,4)):
        c = images.shape[3]
        img = np.zeros((h * size[0], w * size[1], c))
        for idx, image in enumerate(images):
            i = idx % size[1]
            j = idx // size[1]
            img[j * h:j * h + h, i * w:i * w + w, :] = image
        return img
    elif images.shape[3]==1:
        img = np.zeros((h * size[0], w * size[1]))
        for idx, image in enumerate(images):
            i = idx % size[1]
            j = idx // size[1]
            img[j * h:j * h + h, i * w:i * w + w] = image[:,:,0]
        return img
    else:
        raise ValueError('in merge(images,size) images parameter ''must have dimensions: HxW or HxWx3 or HxWx4')

def imsave(images, size, path):
    image = np.squeeze(merge(images, size))
    return scipy.misc.imsave(path, image)

def center_crop(x, crop_h, crop_w, resize_h=64, resize_w=64):
    if crop_w is None:
        crop_w = crop_h
    h, w = x.shape[:2]
    j = int(round((h - crop_h)/2.))
    i = int(round((w - crop_w)/2.))
    return scipy.misc.imresize(x[j:j+crop_h, i:i+crop_w], [resize_h, resize_w])

def transform(image, input_height, input_width, resize_height=64, resize_width=64, crop=True):
    if crop:
        cropped_image = center_crop(image, input_height, input_width, resize_height, resize_width)
    else:
        cropped_image = scipy.misc.imresize(image, [resize_height, resize_width])
    return np.array(cropped_image)/127.5 - 1.

def inverse_transform(images):
    return (images+1.)/2.

