import os
import pyarrow.parquet as pq
import datasets
import pandas as pd
import numpy as np
import io

class WyvernEOConfig(datasets.BuilderConfig):
    def __init__(self, **kwargs):
        super().__init__(**kwargs)

class WyvernEO(datasets.GeneratorBasedBuilder):
    BUILDER_CONFIGS = [
        WyvernEOConfig(name="default", version=datasets.Version("1.0.0"), description="Wyvern EO imagery with masks")
    ]

    DEFAULT_CONFIG_NAME = "default"

    def _info(self):
        return datasets.DatasetInfo(
            description="Wyvern dataset at 2400m tiles with imagery and quality masks.",
            features=datasets.Features({
                "tile_id": datasets.Value("string"),
                "scene_id": datasets.Value("string"),
                "start_datetime": datasets.Value("timestamp[us]"),
                "end_datetime": datasets.Value("timestamp[us]"),
                "image": datasets.Value("binary"),
                "data_mask": datasets.Value("binary"),
                "pixel_quality_mask": datasets.Value("binary"),
                "shape": [datasets.Value("int32")],
            }),
            supervised_keys=None,
        )

    def _split_generators(self, dl_manager):
        # Define relative path inside the repo
        parquet_dir = "datasets_EO/Wyvern/grid_2400m"
        return [
            datasets.SplitGenerator(
                name=datasets.Split.TRAIN,
                gen_kwargs={"folder_path": parquet_dir},
            )
        ]

    def _generate_examples(self, folder_path):
        idx = 0
        for fname in sorted(os.listdir(folder_path)):
            if fname.endswith(".parquet"):
                fpath = os.path.join(folder_path, fname)
                table = pq.read_table(fpath)
                df = table.to_pandas()
                for _, row in df.iterrows():
                    yield idx, {
                        "tile_id": row["tile_id"],
                        "scene_id": row["scene_id"],
                        "start_datetime": row["start_datetime"],
                        "end_datetime": row["end_datetime"],
                        "image": row["image"],
                        "data_mask": row["data_mask"],
                        "pixel_quality_mask": row["pixel_quality_mask"],
                        "shape": row["shape"],
                    }
                    idx += 1