import json
from collections import defaultdict
from pathlib import Path

from datasets import (
    DatasetInfo,
    DownloadManager,
    Features,
    GeneratorBasedBuilder,
    Image,
    Split,
    SplitGenerator,
    Value,
)

_URLS = [f"data/{i:0>5}.tar" for i in range(2123)]


class Laion2bMultiKoreanSubsetWithImage(GeneratorBasedBuilder):

    VERSION = "0.1.3"

    def _info(self):
        return DatasetInfo(
            description="laion2b_multi_korean_subset data with images",
            features=Features(
                {
                    "image": Image(),
                    "text": Value("string"),
                    "width": Value("int32"),
                    "height": Value("int32"),
                }
            ),
            supervised_keys=None,
            license="cc-by-4.0",
            version=self.VERSION,
        )

    def _split_generators(self, dl_manager: DownloadManager):
        downloaded = dl_manager.download(_URLS)
        return [
            SplitGenerator(
                name=Split.TRAIN,
                gen_kwargs={
                    "archives": [
                        dl_manager.iter_archive(archive) for archive in downloaded
                    ]
                },
            )
        ]

    def _generate_examples(self, archives):
        idx = 0
        temp = defaultdict(dict)

        for archive in archives:
            iter_archive = iter(archive)
            while True:
                # for tarfile.ReadError
                try:
                    path, file = next(iter_archive)
                except Exception:
                    break

                if path.endswith(".txt"):
                    continue

                file_id = Path(path).stem

                if path.endswith(".json"):
                    try:
                        meta = json.loads(file.read())
                    except Exception:
                        continue

                    temp[file_id]["text"] = meta["caption"]
                    temp[file_id]["width"] = meta["width"]
                    temp[file_id]["height"] = meta["height"]

                    if "image" in temp[file_id]:
                        yield idx, temp.pop(file_id)
                        idx += 1

                elif path.endswith(".webp"):
                    try:
                        temp[file_id]["image"] = {"path": path, "bytes": file.read()}
                    except Exception:
                        continue

                    if "text" in temp[file_id]:
                        yield idx, temp.pop(file_id)
                        idx += 1

            temp.clear()