# coding=utf-8

import json
import os

import datasets
from datasets.download.download_manager import DownloadManager
from datasets.tasks import TextClassification

logger = datasets.logging.get_logger(__name__)

_DESCRIPTION = "`azaheadhealth`"

_VARIANTS = {
    "micro": {
        "version": "1.0.0",
        "splits": {
            "train": "data/micro_train.json",
            "test": "data/micro_test.json"
        }
    },
    "small": {
        "version": "1.0.0",
        "splits": {
            "train": "data/small_train.json",
            "test": "data/small_test.json"
        }
    },
}

class AZAheadHealthConfig(datasets.BuilderConfig):
    """BuildConfig for AZAheadHealth"""

    def __init__(self, **kwargs):
        super(AZAheadHealthConfig, self).__init__(**kwargs)

class AZAheadHealth(datasets.GeneratorBasedBuilder):
    """AZAheadHealth: A custom dataset in the health domain for the AZAhead project."""

    use_auth_token = True

    BUILDER_CONFIGS = [
        AZAheadHealthConfig(name=name, version=config["version"])
        for name, config in _VARIANTS.items()
    ]
    
    DEFAULT_CONFIG_NAME = "small"

    def _info(self):
        return datasets.DatasetInfo(
            description=_DESCRIPTION,
            features=datasets.Features(
                {
                    "text": datasets.Value("string"),
                    "label": datasets.ClassLabel(num_classes=2, names=["NEGATIVE", "POSITIVE"]),
                }
            ),
            supervised_keys=None,
            task_templates=[
                TextClassification(
                    text_column="text", label_column="label"
                )
            ]
        )
    
    def _split_generators(self, dl_manager: DownloadManager):

        downloaded_files = dl_manager.download(_VARIANTS[self.config.name]["splits"])

        return [
            datasets.SplitGenerator(name=datasets.Split.TRAIN, gen_kwargs={"filepath": downloaded_files["train"]}),
            datasets.SplitGenerator(name=datasets.Split.TEST, gen_kwargs={"filepath": downloaded_files["test"]})
        ]
    
    def _generate_examples(self, filepath):
        logger.info("generating examples from = %s", filepath)
        
        with open(filepath) as fin:
            content = json.load(fin)

        key = 0
        for sample in content:
            yield key, {
                "text": sample["text"],
                "label": sample["label"]
            }
            key+=1