# Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserved.
#
# 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 os
import cv2
import imghdr


def get_image_file_list(img_file):
    imgs_lists = []
    if img_file is None or not os.path.exists(img_file):
        raise ValueError("not found any img file in {}".format(img_file))

    img_end = {'jpg', 'bmp', 'png', 'jpeg', 'rgb', 'tif', 'tiff', 'gif', 'GIF'}
    if os.path.isfile(img_file) and imghdr.what(img_file) in img_end:
        imgs_lists.append(img_file)
    elif os.path.isdir(img_file):
        for single_file in os.listdir(img_file):
            file_path = os.path.join(img_file, single_file)
            if os.path.isfile(file_path) and imghdr.what(file_path) in img_end:
                imgs_lists.append(file_path)
    if len(imgs_lists) == 0:
        raise ValueError("not found any img file in {}".format(img_file))
    return imgs_lists


def check_and_read_gif(img_path):
    if os.path.basename(img_path)[-3:] in ['gif', 'GIF']:
        gif = cv2.VideoCapture(img_path)
        ret, frame = gif.read()
        if not ret:
            print("Cannot read {}. This gif image maybe corrupted.")
            return None, False
        if len(frame.shape) == 2 or frame.shape[-1] == 1:
            frame = cv2.cvtColor(frame, cv2.COLOR_GRAY2RGB)
        imgvalue = frame[:, :, ::-1]
        return imgvalue, True
    return None, False


class ClsPostProcess(object):
    """ Convert between text-label and text-index """

    def __init__(self, label_list, **kwargs):
        super(ClsPostProcess, self).__init__()
        self.label_list = label_list

    def __call__(self, preds, label=None, *args, **kwargs):
        pred_idxs = preds.argmax(axis=1)
        decode_out = [(self.label_list[idx], preds[i, idx])
                      for i, idx in enumerate(pred_idxs)]
        if label is None:
            return decode_out
        label = [(self.label_list[idx], 1.0) for idx in label]
        return decode_out, label