import json
import datasets
from datasets.tasks import QuestionAnsweringExtractive


logger = datasets.logging.get_logger(__name__)
_VERSION = "1.0.0"
_NAME = "test"
_DESCRIPTION = """QA pairs generated in https://aclanthology.org/P18-1177/"""
_CITATION = ""
_BASE_URL = "https://huggingface.co/datasets/DrakuTheDragon/Test/resolve/main/"
_URLS = {
    str("0_train"): f'{_BASE_URL}/0_wiki_train.json',
    str("1_train"): f'{_BASE_URL}/1_wiki_train.json',
    str("2_train"): f'{_BASE_URL}/2_wiki_train.json',
    str("3_train"): f'{_BASE_URL}/3_wiki_train.json',
    str("4_train"): f'{_BASE_URL}/4_wiki_train.json',
    str("5_train"): f'{_BASE_URL}/5_wiki_train.json',
    str("6_train"): f'{_BASE_URL}/6_wiki_train.json',
    str("7_train"): f'{_BASE_URL}/7_wiki_train.json',
    str("8_train"): f'{_BASE_URL}/8_wiki_train.json',
    str("9_train"): f'{_BASE_URL}/9_wiki_train.json',
    
}


class QAHarvestingFromWikipediaConfig(datasets.BuilderConfig):
    """BuilderConfig"""

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


class QAHarvestingFromWikipedia(datasets.GeneratorBasedBuilder):

    BUILDER_CONFIGS = [
        QAHarvestingFromWikipediaConfig(name=_NAME, version=datasets.Version(_VERSION), description=_DESCRIPTION),
    ]
    
    def _info(self):
        return datasets.DatasetInfo(
            description=_DESCRIPTION,
            features=datasets.Features(
                {
                    "id": datasets.Value("string"),
                    "title": datasets.Value("string"),
                    "context": datasets.Value("string"),
                    "question": datasets.Value("string"),
                    "answers": datasets.features.Sequence(
                        {
                            "text": datasets.Value("string"),
                            "answer_start": datasets.Value("int32"),
                        }
                    ),
                }
            ),
            supervised_keys=None,
            homepage="https://github.com/asahi417/lm-question-generation",
            task_templates=[
                QuestionAnsweringExtractive(
                    question_column="question", context_column="context", answers_column="answers"
                )
            ],
        )

    def _split_generators(self, dl_manager):
        downloaded_file = dl_manager.download_and_extract(_URLS)
        return [datasets.SplitGenerator(name=i, gen_kwargs={"filepath": downloaded_file[str(i)]})
                for i in ["0_train","1_train","2_train","3_train","4_train","5_train","6_train","7_train","8_train","9_train"]]

    def _generate_examples(self, filepath):
        """This function returns the examples in the raw (text) form."""
        logger.info("generating examples from = %s", filepath)
        key = 0
        with open(filepath, encoding="utf-8") as f:
            squad = json.load(f)
            for article in squad["data"]:
                title = article.get("title", "")
                for paragraph in article["paragraphs"]:
                    context = paragraph["context"]  # do not strip leading blank spaces GH-2585
                    for qa in paragraph["qas"]:
                        answer_starts = [answer["answer_start"] for answer in qa["answers"]]
                        answers = [answer["text"] for answer in qa["answers"]]
                        # Features currently used are "context", "question", and "answers".
                        # Others are extracted here for the ease of future expansions.
                        yield key, {
                            "title": title,
                            "context": context,
                            "question": qa["question"],
                            "id": qa["id"],
                            "answers": {
                                "answer_start": answer_starts,
                                "text": answers,
                            },
                        }
                        key += 1