import random

import numpy as np

from PIL import Image

def read_image(path, dtype=np.float32, color=True):

    """

    Read an image from a given path, the image is in (C, H, W) format and the range of its value is between [0, 255]

    :param path: The path of an image file

    :param dtype: data type of an image, default is float32

    :param color: If 'True', the number of channels is three, in this case, RGB

        If 'False', this function returns a gray scale image

    :return:

    """

    f = Image.open(path)

    try:

        if color:

            img = f.convert('RGB')

        else:

            img = f.convert('P')

        img = np.asarray(img, dtype=dtype)

    finally:

        if hasattr(f, 'close'):

            f.close()

    if img.ndim == 2:

        # reshape (H, W) -> (1, H, W)

        return img[np.newaxis]

    else:

        # transpose (H, W, C) -> (C, H, W)

        return img.transpose((2, 0, 1))

def flip_masks(masks, y_flip=False, x_flip=False):

    masks = masks.copy()

    for i in range(masks.shape[0]):

        if y_flip:

            masks[i] = np.flipud(masks[i]).copy()

        if x_flip:

            masks[i] = np.fliplr(masks[i]).copy()

    return masks

def random_flip(img, y_random=False, x_random=False,

                return_param=False, copy=False):

    """

    Randomly flip an image in vertical or horizontal direction.

    :param img (numpy.ndarray): An array that gets flipped.

        This is in CHW format.

    :param y_random (bool): Randomly flip in vertical direction.

    :param x_random (bool): Randomly flip in horizontal direction.

    :param return_param (bool): Returns information of flip.

    :param copy (bool): If False, a view of :obj:`img` will be returned.

    :return (numpy.ndarray or (numpy.ndarray, dict)):

        If :`return_param = False`,

        returns an array :obj:`out_img` that is the result of flipping.

        If :obj:`return_param = True`,

        returns a tuple whose elements are :obj:`out_img, param`.

        :obj:`param` is a dictionary of intermediate parameters whose

        contents are listed below with key, value-type and the description

        of the value.

        * **y_flip** (*bool*): Whether the image was flipped in the\

            vertical direction or not.

        * **x_flip** (*bool*): Whether the image was flipped in the\

            horizontal direction or not.

    """

    y_flip, x_flip = False, False

    if y_random:

        y_flip = random.choice([True, False])

    if x_random:

        x_flip = random.choice([True, False])

    if y_flip:

        img = img[:, ::-1, :]

    if x_flip:

        img = img[:, :, ::-1]

    if copy:

        img = img.copy()

    if return_param:

        return img, {'y_flip': y_flip, 'x_flip': x_flip}

    else:

        return img

if __name__ == '__main__':

    pass