"""South East Asia ID Language mC4 dataset."""
import gzip
import json
import datasets


logger = datasets.logging.get_logger(__name__)

_DESCRIPTION = """South East Asia ID Language mC4 dataset."""
_CITATION = ""  # EMPTY
_HOMEPAGE = ""  # EMPTY

_DATA_URL = "https://huggingface.co/datasets/mohjamwong/pile-id/resolve/main/pile-mc4/{language}/mc4-{language}-{index:05d}-of-{n_shards:05d}.json.gz"

_N_SHARDS_PER_LANGUAGE = {
    "id": 21,
}


class PileConfig(datasets.BuilderConfig):
    """BuilderConfig for Pile mC4 dataset."""

    def __init__(self, language, n_shards, **kwargs):
        """BuilderConfig for Pile mC4.
        Args:
            language (str): Language code for the dataset.
            n_shards (int): Number of shards for this language.
            **kwargs: Keyword arguments forwarded to super.
        """
        super().__init__(**kwargs)
        self.language = language
        self.n_shards = n_shards


class Pile(datasets.GeneratorBasedBuilder):
    """South East Asia mC4 dataset."""

    VERSION = datasets.Version("1.0.0")
    BUILDER_CONFIGS = [
        PileConfig(
            name=lang,
            language=lang,
            n_shards=n_shards,
            description=f"Pile mC4 dataset for {lang} language.",
        )
        for lang, n_shards in _N_SHARDS_PER_LANGUAGE.items()
    ]

    def _info(self):
        return datasets.DatasetInfo(
            description=_DESCRIPTION,
            features=datasets.Features({
                "text": datasets.Value("string"),
            }),
            homepage=_HOMEPAGE,
            citation=_CITATION,
        )

    def _split_generators(self, dl_manager):
        lang = self.config.language
        n_shards = self.config.n_shards

        urls = [
            _DATA_URL.format(
                language=lang,
                index=index,
                n_shards=n_shards,
            )
            for index in range(n_shards)
        ]

        downloaded_files = dl_manager.download(urls)
        return [
            datasets.SplitGenerator(
                name=datasets.Split.TRAIN,
                gen_kwargs={"filepaths": downloaded_files},
            ),
        ]

    def _generate_examples(self, filepaths):
        """Generates examples from JSON lines files."""
        id_ = 0
        for filepath in filepaths:
            logger.info("Processing file: %s", filepath)
            with gzip.open(filepath, "rt", encoding="utf-8") as f:
                for line in f:
                    line = line.strip()
                    if line:
                        example = json.loads(line)
                        yield id_, {
                            "text": example["text"],
                        }
                        id_ += 1