# coding=utf-8
# Copyright 2019 Google LLC.
#
# 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.

"""Implements the Describable Textures Dataset (DTD) data class."""

from __future__ import absolute_import, division, print_function

import tensorflow_datasets as tfds

from . import base


class DTDData(base.ImageTfdsData):
    """Provides Describable Textures Dataset (DTD) data.

    As of version 1.0.0, the train/val/test splits correspond to those of the
    1st fold of the official cross-validation partition.

    For additional details and usage, see the base class.
    """

    def __init__(self, data_dir=None):

        dataset_builder = tfds.builder("dtd:3.*.*", data_dir=data_dir)
        dataset_builder.download_and_prepare()

        # Defines dataset specific train/val/trainval/test splits.
        tfds_splits = {
            "train": "train",
            "val": "validation",
            "trainval": "train+validation",
            "test": "test",
            "train800": "train[:800]",
            "val200": "validation[:200]",
            "train800val200": "train[:800]+validation[:200]",
        }

        # Creates a dict with example counts for each split.
        train_count = dataset_builder.info.splits["train"].num_examples
        val_count = dataset_builder.info.splits["validation"].num_examples
        test_count = dataset_builder.info.splits["test"].num_examples
        num_samples_splits = {
            "train": train_count,
            "val": val_count,
            "trainval": train_count + val_count,
            "test": test_count,
            "train800": 800,
            "val200": 200,
            "train800val200": 1000,
        }

        super(DTDData, self).__init__(
            dataset_builder=dataset_builder,
            tfds_splits=tfds_splits,
            num_samples_splits=num_samples_splits,
            num_preprocessing_threads=400,
            shuffle_buffer_size=10000,
            # Note: Export only image and label tensors with their original types.
            base_preprocess_fn=base.make_get_tensors_fn(["image", "label"]),
            num_classes=dataset_builder.info.features["label"].num_classes,
        )
