# coding: utf8
# Copyright (c) 2019 PaddlePaddle Authors. All Rights Reserve.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import glob
import os.path
import argparse
import warnings


def parse_args():
    parser = argparse.ArgumentParser(
        description=
        'A tool for dividing dataset and generating file lists by file directory structure.'
    )
    parser.add_argument('dataset_root', help='dataset root directory', type=str)
    parser.add_argument(
        '--separator',
        dest='separator',
        help='file list separator',
        default=" ",
        type=str)
    parser.add_argument(
        '--folder',
        help='the folder names of images and labels',
        type=str,
        nargs=2,
        default=['images', 'annotations'])
    parser.add_argument(
        '--second_folder',
        help=
        'the second-level folder names of train set, validation set, test set',
        type=str,
        nargs='*',
        default=['train', 'val', 'test'])
    parser.add_argument(
        '--format',
        help='data format of images and labels, default npy, png.',
        type=str,
        nargs=2,
        default=['npy', 'png'])
    parser.add_argument(
        '--label_class',
        help='label class names',
        type=str,
        nargs='*',
        default=['__background__', '__foreground__'])
    parser.add_argument(
        '--postfix',
        help='postfix of images or labels',
        type=str,
        nargs=2,
        default=['', ''])

    return parser.parse_args()


def get_files(image_or_label, dataset_split, args):
    dataset_root = args.dataset_root
    postfix = args.postfix
    format = args.format
    folder = args.folder

    pattern = '*%s.%s' % (postfix[image_or_label], format[image_or_label])

    search_files = os.path.join(dataset_root, folder[image_or_label],
                                dataset_split, pattern)
    search_files2 = os.path.join(dataset_root, folder[image_or_label],
                                 dataset_split, "*", pattern)  # 包含子目录
    search_files3 = os.path.join(dataset_root, folder[image_or_label],
                                 dataset_split, "*", "*", pattern)  # 包含三级目录

    filenames = glob.glob(search_files)
    filenames2 = glob.glob(search_files2)
    filenames3 = glob.glob(search_files3)

    filenames = filenames + filenames2 + filenames3

    return sorted(filenames)


def generate_list(args):
    dataset_root = args.dataset_root
    separator = args.separator

    file_list = os.path.join(dataset_root, 'labels.txt')
    with open(file_list, "w") as f:
        for label_class in args.label_class:
            f.write(label_class + '\n')

    for dataset_split in args.second_folder:
        print("Creating {}.txt...".format(dataset_split))
        image_files = get_files(0, dataset_split, args)
        label_files = get_files(1, dataset_split, args)
        if not image_files:
            img_dir = os.path.join(dataset_root, args.folder[0], dataset_split)
            warnings.warn("No images in {} !!!".format(img_dir))
        num_images = len(image_files)

        if not label_files:
            label_dir = os.path.join(dataset_root, args.folder[1],
                                     dataset_split)
            warnings.warn("No labels in {} !!!".format(label_dir))
        num_label = len(label_files)

        if num_images != num_label and num_label > 0:
            raise Exception(
                "Number of images = {}    number of labels = {} \n"
                "Either number of images is equal to number of labels, "
                "or number of labels is equal to 0.\n"
                "Please check your dataset!".format(num_images, num_label))

        file_list = os.path.join(dataset_root, dataset_split + '.txt')
        with open(file_list, "w") as f:
            for item in range(num_images):
                left = image_files[item].replace(dataset_root, '')
                if left[0] == os.path.sep:
                    left = left.lstrip(os.path.sep)

                try:
                    right = label_files[item].replace(dataset_root, '')
                    if right[0] == os.path.sep:
                        right = right.lstrip(os.path.sep)
                    line = left + separator + right + '\n'
                except:
                    line = left + '\n'

                f.write(line)
                print(line)


if __name__ == '__main__':
    args = parse_args()
    generate_list(args)