import json
import gzip

import datasets
from datasets import Value, Sequence


logger = datasets.logging.get_logger(__name__)


_DESCRIPTION = """\
V2EX is a dataset curated by https://www.v2ex.com/ open data.
"""

_HOMEPAGE = "https://huggingface.co/datasets/Dialogue-Model-Research-Group/v2ex"

_DATA_URLS = {
    "topic": "v2ex_topic.jsonl.gz",
    "replies": "v2ex_replies.jsonl.gz",
    "conversation": "v2ex_conversation.jsonl.gz",
    "context-response": "v2ex_context_response.jsonl.gz",
}


class V2EXConfig(datasets.BuilderConfig):
    """BuilderConfig for shu."""

    def __init__(self, *args, subsets, **kwargs) -> None:
        """BuilderConfig for shu.
        Args:
            **kwargs: keyword arguments forwarded to super.
        """
        super(V2EXConfig, self).__init__(
            *args,
            name="+".join(subsets),
            **kwargs
        )
        self.subsets = subsets


class V2EX(datasets.GeneratorBasedBuilder):
    """V2EX: Chinese book dataset."""

    VERSION = datasets.Version("0.1.0")

    BUILDER_CONFIG_CLASS = V2EXConfig
    BUILDER_CONFIGS = [V2EXConfig(subsets=[subset]) for subset in _DATA_URLS]
    DEFAULT_CONFIG_NAME = "topic"

    def _info(self):
        if self.config.name == "topic":
            features = datasets.Features({
                "id": Value("int64"),
                "title": Value("string"),
                "content": Value("string"),
                "content_rendered": Value("string"),
                "syntax": Value("int64"),
                "url": Value("string"),
                "replies": Value("int64"),
                "last_reply_by": Value("string"),
                "created": Value("int64"),
                "last_modified": Value("int64"),
                "last_touched": Value("int64"),
                "member": {
                    "id": Value("int64"),
                    "username": Value("string"),
                    "bio": Value("string"),
                    "website": Value("string"),
                    "github": Value("string"),
                    "url": Value("string"),
                    "avatar": Value("string"),
                    "created": Value("int64"),
                },
                "node": {
                    "id": Value("int64"),
                    "url": Value("string"),
                    "name": Value("string"),
                    "title": Value("string"),
                    "header": Value("string"),
                    "footer": Value("string"),
                    "avatar": Value("string"),
                    "topics": Value("int64"),
                    "created": Value("int64"),
                    "last_modified": Value("int64"),
                },
                "supplements": Sequence({
                    "id": Value("int64"),
                    "content": Value("string"),
                    "content_rendered": Value("string"),
                    "syntax": Value("int64"),
                    "created": Value("int64"),
                }),
            })
        elif self.config.name == "replies":
            features = datasets.Features({
                "id": Value(dtype="int64", id=None),
                "content": Value(dtype="string", id=None),
                "content_rendered": Value(dtype="string", id=None),
                "created": Value(dtype="int64", id=None),
                "member": {
                    "id": Value(dtype="int64", id=None),
                    "username": Value(dtype="string", id=None),
                    "bio": Value(dtype="string", id=None),
                    "website": Value(dtype="string", id=None),
                    "github": Value(dtype="string", id=None),
                    "url": Value(dtype="string", id=None),
                    "avatar": Value(dtype="string", id=None),
                    "created": Value(dtype="int64", id=None)
                },
                "topic_id": Value(dtype="int64", id=None),
            })
        elif self.config.name == "conversation":
            features = datasets.Features({
                "conversation": Sequence({
                    "username": Value("string"),
                    "post": Value("string"),
                }),
                "url": Value(dtype="string"),
            })
        elif self.config.name == "context-response":
            features = datasets.Features({
                "context": Value("string"),
                "response": Value("string"),
            })
        else:
            raise NotImplementedError(
                "This dataset is not implemented."
            )

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

    def _split_generators(self, dl_manager):
        data_urls = {subset: _DATA_URLS[subset] for subset in self.config.subsets}
        archive = dl_manager.download(data_urls)

        return [
            datasets.SplitGenerator(
                name=datasets.Split.TRAIN,
                gen_kwargs={
                    "files": {
                        subset: archive[subset] for subset in self.config.subsets
                    },
                },
            ),
        ]

    def _generate_examples(self, files):
        key = 0
        for subset in files:
            filepath = files[subset]
            for line in gzip.open(filepath, "rt", encoding="utf-8"):
                j = json.loads(line)
                yield key, j
                key += 1