import os
from glob import glob
from PIL import Image

import datasets

_DESCRIPTION = """\
    Watermark Dataset
"""

_VERSION = datasets.Version("1.0.0")

_REPO = "data"
_URLS = {"train": f"{_REPO}/train.zip", "valid": f"{_REPO}/valid.zip"}

_CATEGORIES = ["watermark"]

class WatermarkPita(datasets.GeneratorBasedBuilder):
    """Watermark Dataset"""

    VERSION = datasets.Version("1.0.0")

    def _info(self):
        return datasets.DatasetInfo(
            features=datasets.Features(
                {
                    "image": datasets.Image(),
                    "objects": datasets.Sequence({
                        "label": datasets.ClassLabel(names=_CATEGORIES),
                        "bbox": datasets.Sequence(datasets.Value("int32"), length=4)
                    }),
                }
            ),

            description=_DESCRIPTION,
        )

    def _split_generators(self, dl_manager):
        data_dir = dl_manager.download_and_extract(_URLS)

        return [
            datasets.SplitGenerator(
                name=datasets.Split.TRAIN,
                gen_kwargs={"split": "train", "data_dir": data_dir["train"]},
            ),
            datasets.SplitGenerator(
                name=datasets.Split.VALIDATION,
                gen_kwargs={"split": "valid", "data_dir": data_dir["valid"]},
            ),
        ]


    def _generate_examples(self, split, data_dir):
        image_dir = os.path.join(data_dir, "images")
        label_dir = os.path.join(data_dir, "labels")

        image_paths = sorted(glob(image_dir + "/*/*.jpg"))
        label_paths = sorted(glob(label_dir + "/*/*.txt"))

        for idx, (image_path, label_path) in enumerate(zip(image_paths, label_paths)):
            im = Image.open(image_path)
            width, height = im.size

            with open(label_path, "r") as f:
                lines = f.readlines()

            objects = []
            for line in lines:
                line = line.strip().split()

                bbox_class = int(line[0])
                bbox_top_left = int(float(line[1]) * width)
                bbox_top_right = int(float(line[2]) * height)
                bbox_bottom_left = int(float(line[3]) * width)
                bbox_bottom_right = int(float(line[4]) * height)


                objects.append({
                    "label": bbox_class,
                    "bbox": [bbox_top_left, bbox_top_right, bbox_bottom_left, bbox_bottom_right]
                })

            yield idx, {"image": image_path, "objects": objects}