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#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
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#
#     http://www.apache.org/licenses/LICENSE-2.0
#
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# distributed under the License is distributed on an "AS IS" BASIS,
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"""RVL-CDIP-N_mp (Ryerson Vision Lab Complex Document Information Processing) -New -Multipage dataset"""


import os
import datasets
from pathlib import Path
from tqdm import tqdm
import pdf2image

datasets.logging.set_verbosity_info()
logger = datasets.logging.get_logger(__name__)

_MODE = "binary"

_CITATION = """\
@inproceedings{larson2022evaluating,
	title={Evaluating Out-of-Distribution Performance on Document Image Classifiers},
	author={Larson, Stefan and Lim, Gordon and Ai, Yutong and Kuang, David and Leach, Kevin},
	booktitle={Thirty-sixth Conference on Neural Information Processing Systems Datasets and Benchmarks Track},
	year={2022}
}
    
@inproceedings{bdpc,
    title = {Beyond Document Page Classification},
    author = {Anonymous},
    booktitle = {Under Review},
    year = {2023}
}
"""

_DESCRIPTION = """\
The RVL-CDIP-N (Ryerson Vision Lab Complex Document Information Processing) dataset consists of newly gathered documents in 16 classes 
There are 991 documents for testing purposes. There were 10 documents from the original dataset that could not be retrieved based on the metadata or were out-of-scope (language). 
"""


_HOMEPAGE = "https://www.cs.cmu.edu/~aharley/rvl-cdip/"
_LICENSE = "https://www.industrydocuments.ucsf.edu/help/copyright/"


SOURCE = "bdpc/rvl_cdip_n_mp"
_URL = f"https://huggingface.co/datasets/{SOURCE}/resolve/main/data.tar.gz"
_BACKOFF_folder = "/mnt/lerna/data/RVL-CDIP-NO/RVL-CDIP-N_pdf/data"

_CLASSES = [
    "letter",
    "form",
    "email",
    "handwritten",
    "advertisement",
    "scientific report",
    "scientific publication",
    "specification",
    "file folder",
    "news article",
    "budget",
    "invoice",
    "presentation",
    "questionnaire",
    "resume",
    "memo",
]


def batched_conversion(pdf_file):
    info = pdf2image.pdfinfo_from_path(pdf_file, userpw=None, poppler_path=None)
    maxPages = info["Pages"]

    logger.info(f"{pdf_file} has {str(maxPages)} pages")

    images = []

    for page in range(1, maxPages + 1, 10):
        images.extend(
            pdf2image.convert_from_path(pdf_file, dpi=200, first_page=page, last_page=min(page + 10 - 1, maxPages))
        )
    return images


def open_pdf_binary(pdf_file):
    with open(pdf_file, "rb") as f:
        return f.read()


class RvlCdipNMp(datasets.GeneratorBasedBuilder):
    VERSION = datasets.Version("1.0.0")
    DEFAULT_CONFIG_NAME = "default"

    def _info(self):
        if isinstance(self.config.data_dir, str):
            folder = self.config.data_dir  # contains the folder structure at someone local disk
        else:
            folder = _URL if not os.path.exists(_BACKOFF_folder) else _BACKOFF_folder
        self.config.data_dir = folder

        return datasets.DatasetInfo(
            description=_DESCRIPTION,
            features=datasets.Features(
                {
                    "id": datasets.Value("string"),
                    "file": datasets.Value("binary"),
                    "labels": datasets.features.ClassLabel(names=_CLASSES),
                }
            ),
            homepage=_HOMEPAGE,
            citation=_CITATION,
            license=_LICENSE,
            task_templates=None,
        )

    def _split_generators(self, dl_manager):
        if self.config.data_dir.endswith(".tar.gz"):
            archive_path = dl_manager.download(self.config.data_dir)
            data_files = dl_manager.iter_archive(archive_path)
        else:
            data_files = self.config.data_dir

        return [datasets.SplitGenerator(name="test", gen_kwargs={"archive_path": data_files})]

    def generate_example(self, path, file=None):
        labels = self.info.features["labels"]
        extensions = {".pdf", ".PDF"}

        path = Path(path)  # ensure path is a pathlib object
        if path.suffix in extensions:
            if file is None:
                if _MODE == "binary":
                    file = open_pdf_binary(path)
                    # batched_conversion(path)
                else:
                    file = path
            else:
                file = file.read()

            a = dict(
                id=path.name,
                file=file,
                labels=labels.encode_example(path.parent.name.lower()),
            )

        return path.name, a

    def _generate_examples(self, archive_path):
        if self.config.data_dir.endswith(".tar.gz"):
            iterator = archive_path
        else:
            iterator = Path(archive_path).glob("**/*")

        for i, path in tqdm(enumerate(iterator), desc=f"{archive_path}"):
            file = None
            if isinstance(path, tuple):
                file = path[1]
                path = path[0]
            try:
                yield self.generate_example(path, file=file)
            except Exception as e:
                logger.warning(f"{e} failed to parse {path}")