import csv
import json
import os

import datasets
from PIL import Image
import tarfile
from io import BytesIO

import logging
import datasets
from datasets.utils.logging import get_logger, tqdm

logger = get_logger(__name__)          # <- same pattern used in HF scripts


_DESCRIPTION = "WikiChurches is a dataset for architectural style classification"
_HOMEPAGE = "https://huggingface.co/datasets/LZSI-2/WikiChurches"
_LICENSE = "cc-by-nc-4.0"
_CITATION = """@article{barz2021wikichurches,
    title={WikiChurches: A Fine-Grained Dataset of Architectural Styles with Real-World Challenges},
    author={Barz, Björn and Denzler, Joachim},
    journal={arXiv preprint arXiv:2108.06959},
    year={2021}
}"""

TAR_PARTS = 40

_TAR_URLS =[f"https://huggingface.co/datasets/LZSI-2/WikiChurches/resolve/main/images/images_part{part_id}.tar" for part_id in range(1, TAR_PARTS + 1)]

_URLS = {
    "churches_json": "https://huggingface.co/datasets/LZSI-2/WikiChurches/resolve/main/churches.json",
    "style_levels": "https://huggingface.co/datasets/LZSI-2/WikiChurches/resolve/main/style_levels.json",
    "style_names": "https://huggingface.co/datasets/LZSI-2/WikiChurches/resolve/main/style_names.txt",
}

class SacredBuildingsDataset(datasets.GeneratorBasedBuilder):
    """Sacred Buildings Dataset with support for different hierarchy levels."""

    VERSION = datasets.Version("0.0.1")

    BUILDER_CONFIGS = [
        datasets.BuilderConfig(
            name="wc4", 
            version=VERSION, 
            description="Wiki Churches 4 main classes"
        ),
        datasets.BuilderConfig(
            name="wc6", 
            version=VERSION, 
            description="Wiki Churches 6 largest classes"
        ),
        datasets.BuilderConfig(
            name="wc14", 
            version=VERSION, 
            description="Wiki Churches 14 first-level classes"
        ),
    ]

    DEFAULT_CONFIG_NAME = "wc4"

    def _info(self):
        features = datasets.Features({
            "image": datasets.Image(),
            "style": datasets.Value("string"),
            "church_id": datasets.Value("string"),

        })

        return datasets.DatasetInfo(
            description=_DESCRIPTION,
            features=features,
            homepage=_HOMEPAGE,
            license=_LICENSE,
            citation=_CITATION,
        )


    def _get_style_names(self, style_levels):
        return style_levels.get(self.config.name, {})

    def _split_generators(self, dl_manager):
        """Returns SplitGenerators."""

        downloaded_files = dl_manager.download(_TAR_URLS)
        data_dir = dl_manager.download_and_extract(_URLS)


        return [
            datasets.SplitGenerator(
                name=datasets.Split.TRAIN,
                gen_kwargs={
                    "file_paths": downloaded_files,
                    "data_dir": data_dir,
                },
            ),
        ]


    def _trace_to_top_parent(self, style_id, hierarchy):
        while style_id in hierarchy and hierarchy[style_id]["parent"]:
            style_id = hierarchy[style_id]["parent"]
        return style_id

    def _generate_examples(self, file_paths, data_dir):
        with open(data_dir["churches_json"], "r") as f:
            churches_data = json.load(f)

        with open(data_dir["style_levels"], "r") as f:
            style_levels = json.load(f)

        
        style_levels = json.load(open(data_dir["style_levels"], "r"))
        if self.config.name == "wc4":
            domain_styles = list(style_levels["statistics"]["styles_by_size"].keys())[:5]
        elif self.config.name == "wc6":
            domain_styles = list(style_levels["statistics"]["styles_by_size"].keys())[:7]
        elif self.config.name == "wc14":
            domain_styles = list(style_levels["statistics"]["styles_by_size"].keys())[:15]

  

        """Yields examples."""
        # Load churches data
        for filepath in file_paths:
            logger.info(f"Processing {filepath.split('/')[-1]}")
            with tarfile.open(filepath, "r") as tar:
                for member in tqdm(tar.getmembers(),
                                desc=f"{os.path.basename(filepath)}"):
                    if member.isfile():
                        logger.debug(f"Processing {member.name}")

                        image_file = tar.extractfile(member)


                        church_id = member.name.split("_")[0]
                        image_name = member.name
                        if church_id not in churches_data:
                            continue

                        church_styles = churches_data[church_id]["styles"]

                        top_level_set = set()
                        for s_id in church_styles:
                            top_parent = self._trace_to_top_parent(s_id, style_levels["hierarchy"])
                            if top_parent in domain_styles:
                                top_level_set.add(top_parent)

                        if len(top_level_set) == 1:
                            label_name = top_level_set.pop()

                            with Image.open(image_file) as image:
                                image = image.convert("RGB")
                                yield image_name, {
                                    "image": image,
                                    "style": label_name,
                                    "church_id": church_id,
                                }
                        else:
                            continue