import os

import datasets


_CITATION = """\
@article{cruz2020investigating,
  title={Investigating the True Performance of Transformers in Low-Resource Languages: A Case Study in Automatic Corpus Creation},
  author={Jan Christian Blaise Cruz and Jose Kristian Resabal and James Lin and Dan John Velasco and Charibeth Cheng},
  journal={arXiv preprint arXiv:2010.11574},
  year={2020}
}
"""

_DESCRIPTION = """\
Large-scale dataset of Filipino news articles. Sourced for the NewsPH-NLI Project (Cruz et al., 2020).
"""
_URL = "https://github.com/jcblaisecruz02/Filipino-Text-Benchmarks"
_LICENSE = "GPL-3.0"
_DATA_URL = "https://s3.us-east-2.amazonaws.com/blaisecruz.com/datasets/newsph"


class NewsphConfig(datasets.BuilderConfig):
    def __init__(self, data_url, **kwargs):
        super(NewsphConfig, self).__init__(
            version=datasets.Version(
                "1.0.0",
            ),
            **kwargs,
        )
        self.data_url = data_url


class Newsph(datasets.GeneratorBasedBuilder):
    VERSION = datasets.Version("1.0.0")
    BUILDER_CONFIGS = [
        NewsphConfig(
            name="newsph",
            data_url=_DATA_URL + "/" + "newsph.zip",
            description=_DESCRIPTION,
        ),
    ]

    BUILDER_CONFIG_CLASS = NewsphConfig

    def _info(self):
        return datasets.DatasetInfo(
            # This is the description that will appear on the datasets page.
            description=_DESCRIPTION,
            features=datasets.Features({"text": datasets.Value("string")}),
            supervised_keys=None,
            # Homepage of the dataset for documentation
            homepage=_URL,
            citation=_CITATION,
            license=_LICENSE,
        )

    def _split_generators(self, dl_manager):
        """Returns SplitGenerators."""
        data_file = dl_manager.download_and_extract(self.config.data_url)
        data_dir = os.path.join(data_file, "newsph")
        return [
            datasets.SplitGenerator(
                name=datasets.Split.TRAIN,
                gen_kwargs={"data_file": os.path.join(data_dir, "train.txt"), "split": "train"},
            ),
        ]

    def _generate_examples(self, data_file, split):
        """Yields examples."""
        with open(data_file, encoding="utf-8") as f:
            for idx, row in enumerate(f):
                if row.strip():
                    yield idx, {"text": row}
                else:
                    yield idx, {"text": ""}