"""
Script used to process UIT-ViQuAD 2.0.
Source: https://github.com/tuanbc88/ai_question_answering/tree/master/machine_reading_comprehension/02_datasets
"""
import os
import json
import pandas as pd
from itertools import groupby
from datasets import Dataset, DatasetDict

def deduplicate_answers(answers):
    answers_sorted = sorted(answers, key=lambda x: (x['text'], x['answer_start']))
    unique_answers = [next(group) for _, group in groupby(answers_sorted, key=lambda x: (x['text'], x['answer_start']))]
    return unique_answers

data_dir = "UIT-ViQuAD 2.0"
dataset_dict = {}

for split in ["train", "dev", "test"]:
    fname = os.path.join(data_dir, f"{split}.json")
    data = json.load(open(fname))
    rows = []
    title_i = 0

    for title_data in data["data"]:
        title = title_data["title"]
        ctx_i = 0
        title_i += 1

        for ctx_and_qs in title_data["paragraphs"]:
            questions = ctx_and_qs["qas"]
            context = ctx_and_qs["context"]
            q_i = 0
            ctx_i += 1
            question_set = set()
            # define default wherever answer is empty
            answer_default: list = [{'answer_start': -1, 'text': ''}]
            for q in questions:
                question = q["question"]
                answers = q["answers"] if "answers" in q else answer_default
                plausible_answers = q["plausible_answers"] if "plausible_answers" in q else answer_default
                # Dedup answers
                answers = deduplicate_answers(answers)
                plausible_answers = deduplicate_answers(plausible_answers)
                uit_id = q["id"]
                is_impossible = q["is_impossible"] if "is_impossible" in q else False

                # Check duplicate questions
                if question in question_set:
                    print("---Found duplicate question: ", question, "---")
                    print("Answer: ", answers)
                    print("Answer plaus: ", plausible_answers)
                    print("Impossible: ", is_impossible)
                    continue

                q_i += 1
                overall_id = f"{title_i:04d}-{ctx_i:04d}-{q_i:04d}"
                rows.append({
                    "id": overall_id,
                    "uit_id": uit_id,
                    "title": title,
                    "context": context,
                    "question": question,
                    "answers": answers,
                    "is_impossible": is_impossible,
                    "plausible_answers": plausible_answers
                })
                question_set.add(question)
    # Convert to Dataset
    df = pd.DataFrame(rows)
    dataset_dict[split if split!="dev" else "validation"] = Dataset.from_pandas(df)

print(dataset_dict)
hf_dataset = DatasetDict(dataset_dict)
hf_name = "UIT-ViQuAD2.0"
hf_dataset.push_to_hub(f"taidng/{hf_name}")
print("Dataset uploaded successfully!")