import json
from typing import List

import datasets

_VERSION = "1.0.0"

_CITATION = """\
@inproceedings{decao2021autoregressive,
  author    = {Nicola {De Cao} and
               Gautier Izacard and
               Sebastian Riedel and
               Fabio Petroni},
  title     = {Autoregressive Entity Retrieval},
  booktitle = {9th International Conference on Learning Representations, {ICLR} 2021,
               Virtual Event, Austria, May 3-7, 2021},
  publisher = {OpenReview.net},
  year      = {2021},
  url       = {https://openreview.net/forum?id=5k8F6UU39V},
}"""


class EntityDisambiguationConfig(datasets.BuilderConfig):
    """BuilderConfig for EntityDisambiguation."""

    def __init__(self, **kwargs):
        """BuilderConfig for EntityDisambiguation.

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

        self.features = datasets.Features(
            {
                "id": datasets.Value("string"),
                "input": datasets.Value("string"),
                "meta": {
                    "left_context": datasets.Value("string"),
                    "mention": datasets.Value("string"),
                    "right_context": datasets.Value("string"),
                },
                "candidates": datasets.features.Sequence(datasets.Value("string")),
                "answer": datasets.Value("string")
            }
        )


class EntityDisambiguation(datasets.GeneratorBasedBuilder):
    """Entity Disambiguation dataset."""

    VERSION = datasets.Version(_VERSION)

    BUILDER_CONFIGS = [
        EntityDisambiguationConfig(name="ace2004", version=VERSION, description="ACE2004 dataset"),
        EntityDisambiguationConfig(name="aida", version=VERSION, description="AIDA dataset"),
        EntityDisambiguationConfig(name="aquaint", version=VERSION, description="AQUAINT dataset"),
        EntityDisambiguationConfig(name="blink", version=VERSION, description="BLINK dataset"),
        EntityDisambiguationConfig(name="clueweb", version=VERSION, description="CWEB dataset"),
        EntityDisambiguationConfig(name="msnbc", version=VERSION, description="MSNBC dataset"),
        EntityDisambiguationConfig(name="wiki", version=VERSION, description="WIKI dataset"),
    ]

    def _split_generators(self, dl_manager: datasets.DownloadManager) -> List[datasets.SplitGenerator]:
        """Returns SplitGenerators."""

        if self.config.name == "blink":
            available_splits = ["train", "dev"]
        elif self.config.name == "aida":
            available_splits = ["train", "dev", "test"]
        else:
            available_splits = ["test"]

        return [
            datasets.SplitGenerator(
                name=split,
                gen_kwargs={
                    "filepath": dl_manager.download_and_extract(
                        f"http://dl.fbaipublicfiles.com/{'KILT' if self.config.name.lower() == 'blink' else 'GENRE'}"
                        f"/{self.config.name.lower()}-{split}-kilt.jsonl"),
                    "split": split,
                },
            )
            for split in available_splits
        ]

    def _info(self) -> datasets.DatasetInfo:
        return datasets.DatasetInfo(description="Entity Disambiguation dataset", features=self.config.features,
                                    citation=_CITATION)

    def _generate_examples(self, filepath: str, split: str):
        with open(filepath, encoding="utf-8") as f:
            for line in f:
                row = json.loads(line)
                row["answer"] = row["output"][0]["answer"]

                del row["output"]

                yield row["id"], row