#!/usr/bin/env python3
# Simple script to convert StackExchange XML to Open Assistant format
# Original code by https://github.com/b-mc2

from bs4 import BeautifulSoup as bs
import pandas as pd
import os
import glob
import sys
import re
from html2text import html2text
from datasets import load_dataset

CACHE_DIR = "xml/"
SOURCE = "stackexchange-{0}"
MAX_ANSWERS = 10
QUESTION_SCORE_TRESHOLD = 0
ANSWER_SCORE_TRESHOLD = 0
HF_DATASET = "donfu/oa-stackexchange"

xml_format_map = {
    "Id": int,
    "PostTypeId": int,
    "CreationDate": str,
    "Score": int,
    "ViewCount": int,
    "Body": str,
    "AnswerCount": int,
    "CommentCount": int,
    "ContentLicense": str,
    "AcceptedAnswerId": int,
    "ParentId": int,
}


def main():
    datasets = sys.argv[1:] if len(sys.argv) > 1 else list_cached_datasets()
    for dataset in datasets:
        process_dataset(dataset)


def list_cached_datasets():
    xml_files = glob.glob(f"{CACHE_DIR}/*.xml")
    datasets = [os.path.splitext(os.path.basename(file))[0] for file in xml_files]
    datasets.sort()
    return datasets


def process_dataset(dataset):
    xml_file = f"{CACHE_DIR}/{dataset}.xml"
    source = SOURCE.format(dataset)
    if os.path.exists(xml_file):
        df = xml_to_df(xml_file, source)
        # df = filter_only_questions_with_accepted_answers(df)
        # df = filter_scores_above(df, QUESTION_SCORE_TRESHOLD, ANSWER_SCORE_TRESHOLD)
        # df = clean_tags(df)
        # df = convert_html_to_markdown(df)
        # df = group_qa(df)
        oa = convert_to_oa(df)
        save_parquet(oa, dataset)
        # upload_hf(dataset)
    else:
        print(f"XML file {xml_file} not found, please download first. Skipping...")


def convert_to_oa(all):
    """
    Convert dataframe to Open Assistant format with INSTRUCTION, RESPONSE, SOURCE, METADATA columns

    Only include questions with an AcceptedAnswerId
    """
    create_metadata = lambda row: {
        "tags": row["Tags_q"]
        .replace("-", " ")
        .replace("><", ", ")
        .replace("<", "")
        .replace(">", "")
        if isinstance(row["Tags_q"], str)
        else "",
        "score": row["Score_q"],
        "views": row["ViewCount_q"],
    }
    questions = all[all["AcceptedAnswerId"] != 0]
    merged = pd.merge(
        questions,
        all,
        how="left",
        left_on="AcceptedAnswerId",
        right_on="Id",
        suffixes=("_q", "_a"),
    )
    merged["INSTRUCTION"] = (
        merged["Title_q"] + "\n" + merged["Body_q"].apply(to_markdown)
    )
    merged["RESPONSE"] = merged["Body_a"].apply(to_markdown)
    merged["SOURCE"] = merged["DataSource_q"]
    merged["METADATA"] = merged.apply(create_metadata, axis=1)

    return merged[["INSTRUCTION", "RESPONSE", "SOURCE", "METADATA"]]


def save_parquet(df, dataset):
    """
    Save Dataframe to Parquet. See here for specs:
    https://projects.laion.ai/Open-Assistant/docs/data/datasets#creating-a-dataset-on-hugging-face
    """
    parquet_file = f"{dataset}.parquet"
    df.to_parquet(parquet_file, row_group_size=100, engine="pyarrow", index=False)
    print("Converted data into parquet format: " + parquet_file)


def upload_hf(dataset):
    """
    Upload to Hugging Face
    """
    parquet_file = f"{dataset}.parquet"
    dataset = load_dataset("parquet", data_files=parquet_file, name=dataset)
    dataset.push_to_hub(HF_DATASET, max_shard_size="500MB")
    print("Uploaded to Hugging Face: " + HF_DATASET)


def xml_to_df(path: str, source: str):
    """
    Collect and Manually import XML into Dataframe

    pd.read_xml() errors when XML trees are too large, this is just a hack to
    download a XML file and parse into a Dataframe. **Not Tested on huge XML files**

    Parameters:
    response (Requests.Response): Requests response object with the XML data

    Returns:
    df (DataFrame): A Dataframe from the XML file
    """
    with open(path, "rb") as f:
        soup = bs(f, "xml")
        posts = soup.find_all("row")

        all_posts = [post.attrs for post in posts]

        df = pd.DataFrame(all_posts)
        df.AnswerCount.fillna(0, inplace=True)
        df.ViewCount.fillna(0, inplace=True)
        df.AcceptedAnswerId.fillna(0, inplace=True)
        df.ParentId.fillna(0, inplace=True)
        df["DataSource"] = source
        df = df.astype(xml_format_map)
        return df


def filter_only_questions_with_accepted_answers(df):
    """
    Filter only to Questions with Accepted Answers

    Filter dataframe by questions that have accepted answers, should also include
    all rows of answers for those questions, even if not accepted.

    Parameters:
    df (DataFrame): containing a "AcceptedAnswerId", "Id", and "ParentId" columns

    Returns:
    df (DataFrame): current dataframe with filtered results
    """
    accepted_ids = df[df["AcceptedAnswerId"] != 0]["Id"].tolist()
    return df[(df["AcceptedAnswerId"] != 0) | (df["ParentId"].isin(accepted_ids))]


def filter_scores_above(
    df, question_score_threshold: int = 20, answer_score_threshold: int = 20
):
    """
    Filter Dataframe by minimum scores

    Filter Question and Answer columns by score thresholds to trim lower scoring results

    Parameters:
    df (DataFrame): containing a "Score" column

    Returns:
    df (DataFrame): current dataframe with filtered results
    """
    return df[
        ((df["Score"] >= question_score_threshold) & (df.PostTypeId == 1))
        | ((df["Score"] >= answer_score_threshold) & (df.PostTypeId == 2))
    ]


remove_markdown_links_pattern = r"\[([^\]]+)\]\(([^\)]+)\)"
remove_remaining_links = r"https?:\/\/[^\s]+"


# Replace HTML content to markdown but remove links
def to_markdown(text):
    text = html2text(text, bodywidth=0).strip()
    text = re.sub(remove_markdown_links_pattern, r"\1", text)
    text = re.sub(remove_remaining_links, "", text)

    if "http" in text:
        raise "Found http in markdown: " + text
    return text


def convert_html_to_markdown(df, column: str = "Body"):
    """
    Convert HTML tags to markdown

    Feeds HTML text body into markdown. Remove final newline from <p> tags

    Parameters:
    df (DataFrame): containing a "Body" column with HTML

    Returns:
    df (DataFrame): current dataframe with parsed column
    """
    df.dropna(subset=[column], inplace=True)
    df[f"{column}Clean"] = df[column].apply(to_markdown)
    return df


def clean_tags(df):
    """
    Convert Tags into Comma separated

    Converts Tag slugs into commas separated tags

    Parameters:
    df (DataFrame): containing a "Tags" column with slugs

    Returns:
    df (DataFrame): current dataframe with parsed column
    """
    df["TagsClean"] = (
        df["Tags"]
        .str.replace("-", " ")
        .str.replace("><", ", ")
        .str.replace("<", "")
        .str.replace(">", "")
    )
    return df


def group_qa(df):
    """
    Group Questions and Answers
    """
    questions = df[df.PostTypeId == 1]
    answers = df[df.PostTypeId == 2]

    df = pd.merge(
        questions,
        answers[
            [
                "Id",
                "CreationDate",
                "Score",
                "ViewCount",
                "CommentCount",
                "ContentLicense",
                "TagsClean",
                "BodyClean",
                "ParentId",
            ]
        ],
        left_on="Id",
        right_on="ParentId",
        suffixes=("_q", "_a"),
        how="left",
    )

    df["AcceptedAnswerFlag"] = df.apply(
        lambda row: row["Id_a"] == row["AcceptedAnswerId"], axis=1
    )

    df = df.rename(
        columns={
            "BodyClean_q": "Question",
            "Score_q": "QuestionScore",
            "TagsClean_q": "QuestionTags",
            "BodyClean_a": "Answer",
            "Score_a": "AnswerScore",
            "ContentLicense_q": "QuestionContentLicense",
            "ContentLicense_a": "AnswerContentLicense",
            "CreationDate_q": "CreationDate",
        }
    )

    df = (
        df.sort_values(
            by=["AcceptedAnswerFlag", "AnswerScore"], ascending=[False, False]
        )
        .groupby("Question")
        .head(MAX_ANSWERS)
        .reset_index(drop=True)
    )
    df = (
        df.groupby(
            [
                "Title",
                "Question",
                "QuestionScore",
                "QuestionTags",
                "QuestionContentLicense",
                "DataSource",
                "CreationDate",
            ]
        )
        .apply(
            lambda x: x[["Answer", "AnswerScore", "AcceptedAnswerFlag"]].to_dict(
                "records"
            )
        )
        .reset_index()
        .rename(columns={0: "Answers"})
    )
    return df


if __name__ == "__main__":
    main()