# Copyright (c) 2019 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 numpy as np
import logging
logger = logging.getLogger(__name__)

from ppdet.core.workspace import register, serializable
from .dataset import DataSet


@register
@serializable
class WIDERFaceDataSet(DataSet):
    """
    Load WiderFace records with 'anno_path'

    Args:
        dataset_dir (str): root directory for dataset.
        image_dir (str): directory for images.
        anno_path (str): root directory for voc annotation data
        sample_num (int): number of samples to load, -1 means all
        with_background (bool): whether load background as a class.
            if True, total class number will be 2. default True.
    """

    def __init__(self,
                 dataset_dir=None,
                 image_dir=None,
                 anno_path=None,
                 sample_num=-1,
                 with_background=True):
        super(WIDERFaceDataSet, self).__init__(
            image_dir=image_dir,
            anno_path=anno_path,
            sample_num=sample_num,
            dataset_dir=dataset_dir,
            with_background=with_background)
        self.anno_path = anno_path
        self.sample_num = sample_num
        self.with_background = with_background
        self.roidbs = None
        self.cname2cid = None

    def load_roidb_and_cname2cid(self):
        anno_path = os.path.join(self.dataset_dir, self.anno_path)
        image_dir = os.path.join(self.dataset_dir, self.image_dir)

        txt_file = anno_path

        records = []
        ct = 0
        file_lists = _load_file_list(txt_file)
        cname2cid = widerface_label(self.with_background)

        for item in file_lists:
            im_fname = item[0]
            im_id = np.array([ct])
            gt_bbox = np.zeros((len(item) - 2, 4), dtype=np.float32)
            gt_class = np.ones((len(item) - 2, 1), dtype=np.int32)
            for index_box in range(len(item)):
                if index_box >= 2:
                    temp_info_box = item[index_box].split(' ')
                    xmin = float(temp_info_box[0])
                    ymin = float(temp_info_box[1])
                    w = float(temp_info_box[2])
                    h = float(temp_info_box[3])
                    # Filter out wrong labels
                    if w < 0 or h < 0:
                        logger.warn('Illegal box with w: {}, h: {} in '
                                    'img: {}, and it will be ignored'.format(
                                        w, h, im_fname))
                        continue
                    xmin = max(0, xmin)
                    ymin = max(0, ymin)
                    xmax = xmin + w
                    ymax = ymin + h
                    gt_bbox[index_box - 2] = [xmin, ymin, xmax, ymax]

            im_fname = os.path.join(image_dir,
                                    im_fname) if image_dir else im_fname
            widerface_rec = {
                'im_file': im_fname,
                'im_id': im_id,
                'gt_bbox': gt_bbox,
                'gt_class': gt_class,
            }
            # logger.debug
            if len(item) != 0:
                records.append(widerface_rec)

            ct += 1
            if self.sample_num > 0 and ct >= self.sample_num:
                break
        assert len(records) > 0, 'not found any widerface in %s' % (anno_path)
        logger.debug('{} samples in file {}'.format(ct, anno_path))
        self.roidbs, self.cname2cid = records, cname2cid


def _load_file_list(input_txt):
    with open(input_txt, 'r') as f_dir:
        lines_input_txt = f_dir.readlines()

    file_dict = {}
    num_class = 0
    for i in range(len(lines_input_txt)):
        line_txt = lines_input_txt[i].strip('\n\t\r')
        if '.jpg' in line_txt:
            if i != 0:
                num_class += 1
            file_dict[num_class] = []
            file_dict[num_class].append(line_txt)
        if '.jpg' not in line_txt:
            if len(line_txt) > 6:
                split_str = line_txt.split(' ')
                x1_min = float(split_str[0])
                y1_min = float(split_str[1])
                x2_max = float(split_str[2])
                y2_max = float(split_str[3])
                line_txt = str(x1_min) + ' ' + str(y1_min) + ' ' + str(
                    x2_max) + ' ' + str(y2_max)
                file_dict[num_class].append(line_txt)
            else:
                file_dict[num_class].append(line_txt)

    return list(file_dict.values())


def widerface_label(with_background=True):
    labels_map = {'face': 1}
    if not with_background:
        labels_map = {k: v - 1 for k, v in labels_map.items()}
    return labels_map