# Copyright 2017 The TensorFlow 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.
# ==============================================================================

r"""Convert the Oxford pet dataset to TFRecord for object_detection.

See: O. M. Parkhi, A. Vedaldi, A. Zisserman, C. V. Jawahar
     Cats and Dogs
     IEEE Conference on Computer Vision and Pattern Recognition, 2012
     http://www.robots.ox.ac.uk/~vgg/data/pets/

Example usage:
    python object_detection/dataset_tools/create_pet_tf_record.py \
        --data_dir=/home/user/pet \
        --output_dir=/home/user/pet/output
"""

import hashlib
import io
import logging
import os
import random
import re

from lxml import etree
import numpy as np
import PIL.Image
import tensorflow as tf

from object_detection.utils import dataset_util
from object_detection.utils import label_map_util

flags = tf.app.flags
flags.DEFINE_string('data_dir', '', 'Root directory to raw pet dataset.')
flags.DEFINE_string('output_dir', '', 'Path to directory to output TFRecords.')
flags.DEFINE_string('label_map_path', 'data/pet_label_map.pbtxt',
                    'Path to label map proto')
FLAGS = flags.FLAGS




def dict_to_tf_example(data,
                       label_map_dict,
                       image_subdirectory,
                       ignore_difficult_instances=False):
  """Convert XML derived dict to tf.Example proto.

  Notice that this function normalizes the bounding box coordinates provided
  by the raw data.

  Args:
    data: dict holding PASCAL XML fields for a single image (obtained by
      running dataset_util.recursive_parse_xml_to_dict)
    mask_path: String path to PNG encoded mask.
    label_map_dict: A map from string label names to integers ids.
    image_subdirectory: String specifying subdirectory within the
      Pascal dataset directory holding the actual image data.
    ignore_difficult_instances: Whether to skip difficult instances in the
      dataset  (default: False).
    faces_only: If True, generates bounding boxes for pet faces.  Otherwise
      generates bounding boxes (as well as segmentations for full pet bodies).
    mask_type: 'numerical' or 'png'. 'png' is recommended because it leads to
      smaller file sizes.

  Returns:
    example: The converted tf.Example.

  Raises:
    ValueError: if the image pointed to by data['filename'] is not a valid JPEG
  """
  img_path = os.path.join(image_subdirectory, data['filename'].split('.')[0]+'.jpg')
  with tf.gfile.GFile(img_path, 'rb') as fid:
    encoded_jpg = fid.read()
  encoded_jpg_io = io.BytesIO(encoded_jpg)
  image = PIL.Image.open(encoded_jpg_io)
  if image.format != 'JPEG':
    raise ValueError('Image format not JPEG')
  key = hashlib.sha256(encoded_jpg).hexdigest() 


  width = int(data['size']['width'])
  height = int(data['size']['height'])

  xmins = []
  ymins = []
  xmaxs = []
  ymaxs = []
  classes = []
  classes_text = []
  truncated = []
  poses = []
  difficult_obj = []
  
  if 'object' in data:
    for obj in data['object']:
      difficult = bool(int(obj['difficult']))
      if ignore_difficult_instances and difficult:
        continue
      difficult_obj.append(int(difficult))


      xmin = float(obj['bndbox']['xmin'])
      xmax = float(obj['bndbox']['xmax'])
      ymin = float(obj['bndbox']['ymin'])
      ymax = float(obj['bndbox']['ymax'])


      xmins.append(xmin / width)
      ymins.append(ymin / height)
      xmaxs.append(xmax / width)
      ymaxs.append(ymax / height)

      classes_text.append(obj['name'].encode('utf8'))
      classes.append(label_map_dict[obj['name']])
      truncated.append(int(obj['truncated']))
      poses.append(obj['pose'].encode('utf8'))
  

  feature_dict = {
      'image/height': dataset_util.int64_feature(height),
      'image/width': dataset_util.int64_feature(width),
      'image/filename': dataset_util.bytes_feature(
          data['filename'].split('.')[0].encode('utf8')),
      'image/source_id': dataset_util.bytes_feature(
          data['filename'].split('.')[0].encode('utf8')),
      'image/key/sha256': dataset_util.bytes_feature(key.encode('utf8')),
      'image/encoded': dataset_util.bytes_feature(encoded_jpg),
      'image/format': dataset_util.bytes_feature('jpeg'.encode('utf8')),
      'image/object/bbox/xmin': dataset_util.float_list_feature(xmins),
      'image/object/bbox/xmax': dataset_util.float_list_feature(xmaxs),
      'image/object/bbox/ymin': dataset_util.float_list_feature(ymins),
      'image/object/bbox/ymax': dataset_util.float_list_feature(ymaxs),
      'image/object/class/text': dataset_util.bytes_list_feature(classes_text),
      'image/object/class/label': dataset_util.int64_list_feature(classes),
      'image/object/difficult': dataset_util.int64_list_feature(difficult_obj),
      'image/object/truncated': dataset_util.int64_list_feature(truncated),
      'image/object/view': dataset_util.bytes_list_feature(poses),
  }
  

  example = tf.train.Example(features=tf.train.Features(feature=feature_dict))
  return example


def create_tf_record(output_filename,
                     label_map_dict,
                     annotations_dir,
                     image_dir,
                     examples):
  """Creates a TFRecord file from examples.

  Args:
    output_filename: Path to where output file is saved.
    label_map_dict: The label map dictionary.
    annotations_dir: Directory where annotation files are stored.
    image_dir: Directory where image files are stored.
    examples: Examples to parse and save to tf record.
    faces_only: If True, generates bounding boxes for pet faces.  Otherwise
      generates bounding boxes (as well as segmentations for full pet bodies).
    mask_type: 'numerical' or 'png'. 'png' is recommended because it leads to
      smaller file sizes.
  """
  writer = tf.python_io.TFRecordWriter(output_filename)
  for idx, example in enumerate(examples):
    if idx % 100 == 0:
      logging.info('On image %d of %d', idx, len(examples))
    xml_path = os.path.join(annotations_dir, 'xmls', example + '.xml')
    

    if not os.path.exists(xml_path):
      logging.warning('Could not find %s, ignoring example.', xml_path)
      continue
    with tf.gfile.GFile(xml_path, 'r') as fid:
      xml_str = fid.read()
    xml = etree.fromstring(xml_str)
    data = dataset_util.recursive_parse_xml_to_dict(xml)['annotation']

    try:
      tf_example = dict_to_tf_example(
          data,
          label_map_dict,
          image_dir)
      writer.write(tf_example.SerializeToString())
    except ValueError:
      logging.warning('Invalid example: %s, ignoring.', xml_path)

  writer.close()


# TODO(derekjchow): Add test for pet/PASCAL main files.
def main(_):
  data_dir = FLAGS.data_dir
  label_map_dict = label_map_util.get_label_map_dict(FLAGS.label_map_path)

  logging.info('Reading from Pet dataset.')
  image_dir = os.path.join(data_dir, 'images')
  annotations_dir = os.path.join(data_dir, 'annotations')
  examples_path = os.path.join(annotations_dir, 'xmls')
  examples_list=[]
  for root, dirs, files in os.walk(examples_path): 
      for file in files:           
          examples_list.append(file.split('.')[0])



  # Test images are not included in the downloaded data set, so we shall perform
  # our own split.
  random.seed(42)
  random.shuffle(examples_list)
  
 
  num_examples = len(examples_list)
  num_train = int(0.7 * num_examples)
  train_examples = examples_list[:num_train]
  val_examples = examples_list[num_train:]
  logging.info('%d training and %d validation examples.',
               len(train_examples), len(val_examples))

  train_output_path = os.path.join(FLAGS.output_dir, 'pet_train.record')
  val_output_path = os.path.join(FLAGS.output_dir, 'pet_val.record')
  
  create_tf_record(
      train_output_path,
      label_map_dict,
      annotations_dir,
      image_dir,
      train_examples)
  create_tf_record(
      val_output_path,
      label_map_dict,
      annotations_dir,
      image_dir,
      val_examples)


if __name__ == '__main__':
  tf.app.run()