import csv
import os
from datasets import Dataset, DatasetDict

class VulnAIDataset:
    def __init__(self, data_dir):
        self.data_dir = data_dir
    def load(self):
        splits = {}
        for split in ["train", "validation", "test"]:
            path = os.path.join(self.data_dir, "data", f"{split}.csv")
            if os.path.exists(path):
                with open(path, "r", encoding="utf-8") as f:
                    reader = csv.DictReader(f)
                    rows = list(reader)
                splits[split] = Dataset.from_list(rows)
        return DatasetDict(splits)

def load_dataset(data_dir):
    return VulnAIDataset(data_dir).load()