import os
import csv
from datasets import Dataset, DatasetInfo, Features, Value, Sequence, GeneratorBasedBuilder, DownloadManager, Split

class FreshWikiDataset(GeneratorBasedBuilder):
    def _info(self):
        return DatasetInfo(
            description="The FreshWiki Dataset is a collection of high-quality Wikipedia articles focusing on the most-edited pages from February 2022 to September 2023.",
            features=Features({
                "json_file": Value("string"),
                "txt_file": Value("string"),
                "topic": Value("string"),
            }),
        )

    def _split_generators(self, dl_manager: DownloadManager):
        data_dir = dl_manager.download_and_extract("https://huggingface.co/datasets/EchoShao8899/FreshWiki")
        return [
            Split(
                name=Split.TRAIN,
                gen_kwargs={
                    "json_files": os.path.join(data_dir, "json"),
                    "txt_files": os.path.join(data_dir, "txt"),
                    "topic_list_csv": os.path.join(data_dir, "topic_list.csv"),
                },
            ),
        ]

    def _generate_examples(self, json_files, txt_files, topic_list_csv):
        with open(topic_list_csv, "r", encoding="utf-8") as csv_file:
            reader = csv.DictReader(csv_file)
            for idx, row in enumerate(reader):
                topic_name = row['topic'].replace(' ', '_').replace('/', '_')
                json_path = os.path.join(json_files, f'{topic_name}.json')
                txt_path = os.path.join(txt_files, f'{topic_name}.txt')
                
                if os.path.exists(json_path) and os.path.exists(txt_path):
                    with open(json_path, "r", encoding="utf-8") as json_file, \
                         open(txt_path, "r", encoding="utf-8") as txt_file:
                        yield idx, {
                            "json_file": json_file.read(),
                            "txt_file": txt_file.read(),
                            "topic": row['topic'],
                        }
                else:
                    print(f"Warning: Files for topic '{row['topic']}' not found. Skipping.")