import os
import pathlib
from typing import overload
import datasets
import json

from datasets.info import DatasetInfo

_DESCRIPTION = """\
CtkFactsNLI is a NLI version of the Czech CTKFacts dataset
"""

_CITATION = """\
todo
"""


class CtkfactsNli(datasets.GeneratorBasedBuilder):
    def _info(self):
        return datasets.DatasetInfo(
            description=_DESCRIPTION,
            features=datasets.Features(
                {
                    "id": datasets.Value("int32"),
                    "label": datasets.ClassLabel(names=["SUPPORTS", "REFUTES", "NOT ENOUGH INFO"]),
                    # datasets.features.Sequence({"text": datasets.Value("string"),"answer_start": datasets.Value("int32"),})
                    "evidence": datasets.Value("string"),
                    "claim": datasets.Value("string"),
                }
            ),
            # No default supervised_keys (as we have to pass both question
            # and context as input).
            supervised_keys=None,
            homepage="https://fcheck.fel.cvut.cz/dataset/",
            citation=_CITATION,
        )

    def _split_generators(self, dl_managers):
        dir = pathlib.Path(__file__).parent.resolve()
        return [
            datasets.SplitGenerator(datasets.Split.TRAIN, {
                "filepath": os.path.join(dir, "data", "train.jsonl")
            }),
            datasets.SplitGenerator(datasets.Split.VALIDATION, {
                "filepath": os.path.join(dir, "data", "validation.jsonl")
            }),
            datasets.SplitGenerator(datasets.Split.TEST, {
                "filepath": os.path.join(dir, "data", "test.jsonl")
            }),
        ]

    def _generate_examples(self, filepath):
        """This function returns the examples in the raw (text) form."""
        key = 0
        with open(filepath, encoding="utf-8") as f:
            for line in f:
                datapoint = json.loads(line)
                yield key, {
                    "id": datapoint["id"],
                    "evidence": " ".join(datapoint["evidence"]),
                    "claim": datapoint["claim"],
                    "label": datapoint["label"]
                }
                key += 1