# coding=utf-8
# Copyright 2020 The HuggingFace Datasets Authors and Antoine SIMOULIN.
#
# 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.
"""Wikitext-fr language modeling dataset consists of over 70 million tokens 
extracted from the set of french Wikipedia articles that are classified as 
"quality articles" or "good articles.". The aim is to replicate the English 
benchmark."""


import csv
import json
import os

import datasets


# TODO: Add BibTeX citation
# Find for instance the citation on arxiv or on the dataset repo/website
_CITATION = """\
@inproceedings{simoulin:hal-03265900,
  TITLE = {{Un mod{\`e}le Transformer G{\'e}n{\'e}ratif Pr{\'e}-entrain{\'e} pour le \_\_\_\_\_\_ fran{\c c}ais}},
  AUTHOR = {Simoulin, Antoine and Crabb{\'e}, Benoit},
  URL = {https://hal.archives-ouvertes.fr/hal-03265900},
  BOOKTITLE = {{Traitement Automatique des Langues Naturelles}},
  ADDRESS = {Lille, France},
  EDITOR = {Denis, Pascal and Grabar, Natalia and Fraisse, Amel and Cardon, R{\'e}mi and Jacquemin, Bernard and Kergosien, Eric and Balvet, Antonio},
  PUBLISHER = {{ATALA}},
  PAGES = {246-255},
  YEAR = {2021},
  KEYWORDS = {fran{\c c}ais. ; GPT ; G{\'e}n{\'e}ratif ; Transformer ; Pr{\'e}-entra{\^i}n{\'e}},
  PDF = {https://hal.archives-ouvertes.fr/hal-03265900/file/7.pdf},
  HAL_ID = {hal-03265900},
  HAL_VERSION = {v1},
}
"""

# TODO: Add description of the dataset here
# You can copy an official description
_DESCRIPTION = """\
Wikitext-fr language modeling dataset consists of over 70 million tokens 
extracted from the set of french Wikipedia articles that are classified as 
"quality articles" or "good articles.". The aim is to replicate the English 
benchmark."""

# TODO: Add a link to an official homepage for the dataset here
_HOMEPAGE = "https://github.com/AntoineSimoulin/gpt-fr"

# TODO: Add the licence for the dataset here if you can find it
_LICENSE = "Creative Commons Attribution-ShareAlike License."

# TODO: Add link to the official dataset URLs here
# The HuggingFace dataset library don't host the datasets but only point to the original files
# This can be an arbitrary nested dict/list of URLs (see below in `_split_generators` method)
# _URLs = {
#     'wikitext-35': "./wikitext_35/",
#     'wikitext-72': "./wikitext_72/",
# }
_URLs = {
    'wikitext-35': "wikitext_35/wiki.zip",
    'wikitext-72': "wikitext_72/wiki.zip",
}


# TODO: Name of the dataset usually match the script name with CamelCase instead of snake_case
class NewDataset(datasets.GeneratorBasedBuilder):
    """Wikitext-fr language modeling dataset consists of over 70 million tokens 
    extracted from the set of french Wikipedia articles that are classified as 
    "quality articles" or "good articles.". The aim is to replicate the English benchmark.
    """

    VERSION = datasets.Version("1.1.0")

    # This is an example of a dataset with multiple configurations.
    # If you don't want/need to define several sub-sets in your dataset,
    # just remove the BUILDER_CONFIG_CLASS and the BUILDER_CONFIGS attributes.

    # If you need to make complex sub-parts in the datasets with configurable options
    # You can create your own builder configuration class to store attribute, inheriting from datasets.BuilderConfig
    # BUILDER_CONFIG_CLASS = MyBuilderConfig

    # You will be able to load one or the other configurations in the following list with
    # data = datasets.load_dataset('my_dataset', 'first_domain')
    # data = datasets.load_dataset('my_dataset', 'second_domain')
    BUILDER_CONFIGS = [
        datasets.BuilderConfig(name="wikitext-35", version=VERSION, description="This part covers quality articles only"),
        datasets.BuilderConfig(name="wikitext-72", version=VERSION, description="This part covers quality articles and good articles"),
    ]

    DEFAULT_CONFIG_NAME = "wikitext-35"  # It's not mandatory to have a default configuration. Just use one if it make sense.

    def _info(self):
        features = datasets.Features({"paragraph": datasets.Value("string")})
        return datasets.DatasetInfo(
            # This is the description that will appear on the datasets page.
            description=_DESCRIPTION,
            # This defines the different columns of the dataset and their types
            features=features,  # Here we define them above because they are different between the two configurations
            # If there's a common (input, target) tuple from the features,
            # specify them here. They'll be used if as_supervised=True in
            # builder.as_dataset.
            supervised_keys=None,
            # Homepage of the dataset for documentation
            homepage=_HOMEPAGE,
            # License for the dataset if available
            license=_LICENSE,
            # Citation for the dataset
            citation=_CITATION,
        )

    def _split_generators(self, dl_manager):
        """Returns SplitGenerators."""
        # TODO: This method is tasked with downloading/extracting the data and defining the splits depending on the configuration
        # If several configurations are possible (listed in BUILDER_CONFIGS), the configuration selected by the user is in self.config.name

        # dl_manager is a datasets.download.DownloadManager that can be used to download and extract URLs
        # It can accept any type or nested list/dict and will give back the same structure with the url replaced with path to local files.
        # By default the archives will be extracted and a path to a cached folder where they are extracted is returned instead of the archive
        my_urls = _URLs[self.config.name]
        data_dir = dl_manager.download_and_extract(my_urls)
        return [
            datasets.SplitGenerator(
                name=datasets.Split.TRAIN,
                # These kwargs will be passed to _generate_examples
                gen_kwargs={
                    "filepath": os.path.join(data_dir, "wiki.train.tokens"),
                    "split": "train",
                },
            ),
            datasets.SplitGenerator(
                name=datasets.Split.TEST,
                # These kwargs will be passed to _generate_examples
                gen_kwargs={
                    "filepath": os.path.join(data_dir, "wiki.test.tokens"),
                    "split": "test"
                },
            ),
            datasets.SplitGenerator(
                name=datasets.Split.VALIDATION,
                # These kwargs will be passed to _generate_examples
                gen_kwargs={
                    "filepath": os.path.join(data_dir, "wiki.valid.tokens"),
                    "split": "dev",
                },
            ),
        ]

    def _generate_examples(
        self, filepath, split  # method parameters are unpacked from `gen_kwargs` as given in `_split_generators`
    ):
        """ Yields examples as (key, example) tuples. """
        # This method handles input defined in _split_generators to yield (key, example) tuples from the dataset.
        # The `key` is here for legacy reason (tfds) and is not important in itself.
        
        with open(filepath, 'r') as f:
          data = f.readlines()
          for id_, paragraph in enumerate(data):
            yield id_, {"paragraph": paragraph, }