# Copyright (c) OpenMMLab. All rights reserved.

import argparse

import os.path as osp

import mmcv

from cityscapesscripts.preparation.json2labelImg import json2labelImg

def convert_json_to_label(json_file):

    label_file = json_file.replace('_polygons.json', '_labelTrainIds.png')

    json2labelImg(json_file, label_file, 'trainIds')

def parse_args():

    parser = argparse.ArgumentParser(

        description='Convert Cityscapes annotations to TrainIds')

    parser.add_argument('cityscapes_path', help='cityscapes data path')

    parser.add_argument('--gt-dir', default='gtFine', type=str)

    parser.add_argument('-o', '--out-dir', help='output path')

    parser.add_argument(

        '--nproc', default=1, type=int, help='number of process')

    args = parser.parse_args()

    return args

def main():

    args = parse_args()

    cityscapes_path = args.cityscapes_path

    out_dir = args.out_dir if args.out_dir else cityscapes_path

    mmcv.mkdir_or_exist(out_dir)

    gt_dir = osp.join(cityscapes_path, args.gt_dir)

    poly_files = []

    for poly in mmcv.scandir(gt_dir, '_polygons.json', recursive=True):

        poly_file = osp.join(gt_dir, poly)

        poly_files.append(poly_file)

    if args.nproc > 1:

        mmcv.track_parallel_progress(convert_json_to_label, poly_files,

                                     args.nproc)

    else:

        mmcv.track_progress(convert_json_to_label, poly_files)

    split_names = ['train', 'val', 'test']

    for split in split_names:

        filenames = []

        for poly in mmcv.scandir(

                osp.join(gt_dir, split), '_polygons.json', recursive=True):

            filenames.append(poly.replace('_gtFine_polygons.json', ''))

        with open(osp.join(out_dir, f'{split}.txt'), 'w') as f:

            f.writelines(f + '\n' for f in filenames)

if __name__ == '__main__':

    main()