# Copyright 2021 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,
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"""Utility functions for dataloader."""

import tensorflow as tf

from official.vision.detection.utils import input_utils


def process_source_id(source_id):
  """Processes source_id to the right format."""
  if source_id.dtype == tf.string:
    source_id = tf.cast(tf.strings.to_number(source_id), tf.int64)
  with tf.control_dependencies([source_id]):
    source_id = tf.cond(
        pred=tf.equal(tf.size(input=source_id), 0),
        true_fn=lambda: tf.cast(tf.constant(-1), tf.int64),
        false_fn=lambda: tf.identity(source_id))
  return source_id


def pad_groundtruths_to_fixed_size(gt, n):
  """Pads the first dimension of groundtruths labels to the fixed size."""
  gt['boxes'] = input_utils.pad_to_fixed_size(gt['boxes'], n, -1)
  gt['is_crowds'] = input_utils.pad_to_fixed_size(gt['is_crowds'], n, 0)
  gt['areas'] = input_utils.pad_to_fixed_size(gt['areas'], n, -1)
  gt['classes'] = input_utils.pad_to_fixed_size(gt['classes'], n, -1)
  return gt
