#!/usr/bin/env python3
# -*- coding: utf-8 -*-

import os

import datasets


logger = datasets.logging.get_logger(__name__)


_CITATION = """\
@mastersthesis{naama,
  title={Hebrew Named Entity Recognition},
  author={Ben-Mordecai, Naama},
  advisor={Elhadad, Michael},
  year={2005},
  url="https://www.cs.bgu.ac.il/~elhadad/nlpproj/naama/",
  institution={Department of Computer Science, Ben-Gurion University},
  school={Department of Computer Science, Ben-Gurion University},
},
@misc{bareket2020neural,
      title={Neural Modeling for Named Entities and Morphology (NEMO^2)}, 
      author={Dan Bareket and Reut Tsarfaty},
      year={2020},
      eprint={2007.15620},
      archivePrefix={arXiv},
      primaryClass={cs.CL}
}
"""

_DESCRIPTION = """\
"""

SPLITS = ["split1", "split2", "split3"]

class BMCConfig(datasets.BuilderConfig):
    """BuilderConfig for BMC"""

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


class BMC(datasets.GeneratorBasedBuilder):
    """BMC dataset."""

    BUILDER_CONFIGS = [
        BMCConfig(name=split, version=datasets.Version("1.0.0"), description="BMC dataset")
        for split in SPLITS
    ]

    def _info(self):
        return datasets.DatasetInfo(
            description=_DESCRIPTION,
            features=datasets.Features(
                {
                    "id": datasets.Value("string"),
                    "tokens": datasets.Sequence(datasets.Value("string")),
                    "raw_tags": datasets.Sequence(datasets.Value("string")),
                    "ner_tags": datasets.Sequence(
                        datasets.features.ClassLabel(
                            names=[
                                'B-DATE',
                                'I-DATE',
                                'S-DATE',
                                'E-DATE',
                                'B-LOC',
                                'E-LOC',
                                'S-LOC',
                                'I-LOC',
                                'E-MONEY',
                                'B-MONEY',
                                'S-MONEY',
                                'I-MONEY',
                                'O',
                                'S-ORG',
                                'E-ORG',
                                'I-ORG',
                                'B-ORG',
                                'B-PER',
                                'E-PER',
                                'I-PER',
                                'S-PER',
                                'B-PERCENT',
                                'S-PERCENT',
                                'E-PERCENT',
                                'I-PERCENT',
                                'E-TIME',
                                'I-TIME',
                                'B-TIME',
                                'S-TIME'

                            ]
                        )
                    ),
                }
            ),
            supervised_keys=None,
            homepage="https://www.cs.bgu.ac.il/~elhadad/nlpproj/naama/",
            citation=_CITATION,
        )

    def _split_generators(self, dl_manager):
        """Returns SplitGenerators."""

        folder = f"data/{self.config.name}"
        data_files = {
            "train": dl_manager.download(os.path.join(folder, "bmc_split.train.bmes")),
            "validation": dl_manager.download(os.path.join(folder, "bmc_split.dev.bmes")),
            "test": dl_manager.download(os.path.join(folder, "bmc_split.test.bmes")),
        }
        return [
            datasets.SplitGenerator(name=datasets.Split.TRAIN, gen_kwargs={"filepath": data_files["train"]}),
            datasets.SplitGenerator(name=datasets.Split.VALIDATION, gen_kwargs={"filepath": data_files["validation"]}),
            datasets.SplitGenerator(name=datasets.Split.TEST, gen_kwargs={"filepath": data_files["test"]}),
        ]

    def _generate_examples(self, filepath, sep = " "):
        logger.info("⏳ Generating examples from = %s", filepath)
        with open(filepath, encoding="utf-8") as f:
            guid = 0
            tokens = []
            ner_tags = []
            raw_tags = []
            for line in f:
                if line.startswith("-DOCSTART-") or line == "" or line == "\n":
                    if tokens:
                        yield guid, {
                            "id": str(guid),
                            "tokens": tokens,
                            "raw_tags": raw_tags, 
                            "ner_tags": ner_tags,
                        }
                        guid += 1
                        tokens = []
                        raw_tags = []
                        ner_tags = []
                else:
                    splits = line.split(sep)
                    tokens.append(splits[0])
                    raw_tags.append(splits[1].rstrip())
                    ner_tags.append(splits[1].rstrip())
            # last example
            yield guid, {
                "id": str(guid),
                "tokens": tokens,
                "raw_tags": raw_tags, 
                "ner_tags": ner_tags,
            }