import datasets

class ForestSegmentationDataset(datasets.GeneratorBasedBuilder):
    def _info(self):
        return datasets.DatasetInfo(
            features=datasets.Features({
                "sample_id": datasets.Value("string"),
                "image_paths": datasets.Sequence(datasets.Value("string")),  # list of GeoTIFF paths
                "mask": datasets.Value("string"),  # path to mask
                "start_timestamps": datasets.Sequence(datasets.Value("string")),
                "end_timestamps": datasets.Sequence(datasets.Value("string")),
                "sentinel_tile_ids": datasets.Sequence(datasets.Value("string")),
                "bboxes": {
                    "minx": datasets.Sequence(datasets.Value("float32")),
                    "maxx": datasets.Sequence(datasets.Value("float32")),
                    "miny": datasets.Sequence(datasets.Value("float32")),
                    "maxy": datasets.Sequence(datasets.Value("float32")),
                }
            }),
        )

    def _split_generators(self, dl_manager):
        sample_stream = dl_manager.iter_jsonl("index.jsonl")
        return [
            datasets.SplitGenerator(
                name=datasets.Split.TRAIN,
                gen_kwargs={"samples": sample_stream}
            )
        ]

    def _generate_examples(self, samples):
        for sample in samples:
            yield sample["sample_id"], {
                "sample_id": sample["sample_id"],
                "image_paths": sample["image_paths"],
                "mask": sample["mask_path"],
                "start_timestamps": sample["start_timestamps"],
                "end_timestamps": sample["end_timestamps"],
                "sentinel_tile_ids": sample["sentinel_tile_ids"],
                "bboxes": sample["bboxes"],
            }