# coding=utf-8
# Copyright 2020 The HuggingFace Datasets Authors and the current dataset script contributor.
#
# 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.
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"""The Yelp Review Full dataset for text classification."""

from __future__ import absolute_import, division, print_function

import csv
import os

import datasets


_CITATION = """\
@inproceedings{zhang2015character,
  title={Character-level convolutional networks for text classification},
  author={Zhang, Xiang and Zhao, Junbo and LeCun, Yann},
  booktitle={Advances in neural information processing systems},
  pages={649--657},
  year={2015}
}
"""

_DESCRIPTION = """\
The Yelp reviews dataset consists of reviews from Yelp. It is extracted from the Yelp Dataset Challenge 2015 data.
The Yelp reviews full star dataset is constructed by Xiang Zhang (xiang.zhang@nyu.edu) from the above dataset.
It is first used as a text classification benchmark in the following paper: Xiang Zhang, Junbo Zhao, Yann LeCun.
Character-level Convolutional Networks for Text Classification. Advances in Neural Information Processing Systems 28 (NIPS 2015).
"""

_HOMEPAGE = "https://www.yelp.com/dataset"

_LICENSE = "https://s3-media3.fl.yelpcdn.com/assets/srv0/engineering_pages/bea5c1e92bf3/assets/vendor/yelp-dataset-agreement.pdf"

_URLs = {
    "yelp_review_full": "https://drive.google.com/uc?export=download&id=0Bz8a_Dbh9QhbZlU4dXhHTFhZQU0",
}


class YelpReviewFullConfig(datasets.BuilderConfig):
    """BuilderConfig for YelpReviewFull."""

    def __init__(self, **kwargs):
        """BuilderConfig for YelpReviewFull.

        Args:
          **kwargs: keyword arguments forwarded to super.
        """
        super(YelpReviewFullConfig, self).__init__(**kwargs)


class YelpReviewFull(datasets.GeneratorBasedBuilder):
    """Yelp Review Full Star Dataset 2015."""

    VERSION = datasets.Version("1.0.0")

    BUILDER_CONFIGS = [
        YelpReviewFullConfig(
            name="yelp_review_full", version=VERSION, description="Yelp Review Full Star Dataset 2015"
        ),
    ]

    def _info(self):
        features = datasets.Features(
            {
                "label": datasets.features.ClassLabel(
                    names=[
                        "1 star",
                        "2 star",
                        "3 stars",
                        "4 stars",
                        "5 stars",
                    ]
                ),
                "text": datasets.Value("string"),
            }
        )
        return datasets.DatasetInfo(
            description=_DESCRIPTION,
            features=features,
            supervised_keys=None,
            homepage=_HOMEPAGE,
            license=_LICENSE,
            citation=_CITATION,
        )

    def _split_generators(self, dl_manager):
        """Returns SplitGenerators."""
        my_urls = _URLs[self.config.name]
        data_dir = dl_manager.download_and_extract(my_urls)
        return [
            datasets.SplitGenerator(
                name=datasets.Split.TRAIN,
                gen_kwargs={
                    "filepath": os.path.join(data_dir, "yelp_review_full_csv", "train.csv"),
                    "split": "train",
                },
            ),
            datasets.SplitGenerator(
                name=datasets.Split.TEST,
                gen_kwargs={"filepath": os.path.join(data_dir, "yelp_review_full_csv", "test.csv"), "split": "test"},
            ),
        ]

    def _generate_examples(self, filepath, split):
        """ Yields examples. """

        with open(filepath, encoding="utf-8") as f:
            data = csv.reader(f, delimiter=",", quoting=csv.QUOTE_NONNUMERIC)
            for id_, row in enumerate(data):
                yield id_, {
                    "text": row[1],
                    "label": int(row[0]) - 1,
                }