# Copyright 2023 Thinh T. Duong
import os
import datasets
from glob import glob


logger = datasets.logging.get_logger(__name__)


_CITATION = """
"""
_DESCRIPTION = """
"""
_HOMEPAGE = "https://how2sign.github.io/index.html"
_REPO_URL = "https://huggingface.co/datasets/VieSignLang/how2sign-clips/resolve/main"
_URLS = {
    "meta": os.path.join(_REPO_URL, "how2sign_realigned_{split}.csv"),
    "videos": os.path.join(_REPO_URL, "{split}_{subset}/*.zip"),
}


class How2SignConfig(datasets.BuilderConfig):
    """How2Sign configuration."""

    def __init__(self, name, **kwargs):
        """
        Parameters
        ----------
        name : str
            Name of subset.
        kwargs : dict
            Keyword arguments.
        """
        super(How2SignConfig, self).__init__(
            name=name,
            version=datasets.Version("1.0.0"),
            description=_DESCRIPTION,
            **kwargs,
        )


class How2Sign(datasets.GeneratorBasedBuilder):
    """How2Sign dataset."""
    BUILDER_CONFIGS = [
        How2SignConfig(name="raw_videos"),
        How2SignConfig(name="rgb_side_raw_videos"),
        How2SignConfig(name="rgb_front_clips"),
        How2SignConfig(name="rgb_side_clips"),
        How2SignConfig(name="2D_keypoints"),
    ]
    DEFAULT_CONFIG_NAME = "rgb_front_clips"

    def _info(self) -> datasets.DatasetInfo:
        features = datasets.Features({
            "VIDEO_ID": datasets.Value("string"),
            "VIDEO_NAME": datasets.Value("string"),
            "SENTENCE_ID": datasets.Value("string"),
            "SENTENCE_NAME": datasets.Value("string"),
            "START_REALIGNED": datasets.Value("float64"),
            "END_REALIGNED": datasets.Value("float64"),
            "SENTENCE": datasets.Value("string"),
            "VIDEO": datasets.Value("string"),
        })

        return datasets.DatasetInfo(
            description=_DESCRIPTION,
            features=features,
            homepage=_HOMEPAGE,
            citation=_CITATION,
        )

    def _split_generators(
        self, dl_manager: datasets.DownloadManager
    ) -> list[datasets.SplitGenerator]:
        """
        Get splits.

        Parameters
        ----------
        dl_manager : datasets.DownloadManager
            Download manager.

        Returns
        -------
        list[datasets.SplitGenerator]
            Split generators.
        """
        split_dict = {
            "train": datasets.Split.TRAIN,
            "test": datasets.Split.TEST,
            "val": datasets.Split.VALIDATION,
        }

        return [
            datasets.SplitGenerator(
                name=name,
                gen_kwargs={
                    "metadata_path": dl_manager.download(
                        _URLS["meta"].format(split=split)
                    ),
                    "video_dirs": dl_manager.download_and_extract(
                        glob(
                            _URLS["videos"].format(
                                split=split,
                                subset=self.config.name,
                            )
                        )
                    ),
                },
            )
            for split, name in split_dict.items()
        ]

    def _generate_examples(
        self, metadata_path: str,
        video_dirs: list[str],
    ) -> tuple[int, dict]:
        """
        Generate examples.

        Parameters
        ----------
        metadata_path : str
            Path to metadata.
        video_dirs : list[str]
            List of video directories.

        Returns
        -------
        tuple[int, dict]
            Index and sample.
        """
        split = datasets.load_dataset(
            "csv",
            data_files=metadata_path,
            split="train",
            delimiter="\t",
        )
        for i, sample in enumerate(split):
            for video_dir in video_dirs:
                if self.config.name in ["raw_videos", "rgb_side_raw_videos"]:
                    video_path = os.path.join(video_dir, sample["VIDEO_NAME"] + ".mp4")
                else:
                    video_path = os.path.join(video_dir, sample["SENTENCE_NAME"] + ".mp4")

                if os.path.exists(video_path):
                    yield i, {
                        "VIDEO_ID": sample["VIDEO_ID"],
                        "VIDEO_NAME": sample["VIDEO_NAME"],
                        "SENTENCE_ID": sample["SENTENCE_ID"],
                        "SENTENCE_NAME": sample["SENTENCE_NAME"],
                        "START_REALIGNED": sample["START_REALIGNED"],
                        "END_REALIGNED": sample["END_REALIGNED"],
                        "SENTENCE": sample["SENTENCE"],
                        "VIDEO": video_path,
                    }