utils.py

"""
    utils.py - Utility functions for the project.
"""

import re
import subprocess
from collections import defaultdict
from datetime import datetime
from itertools import combinations
from pathlib import Path
from typing import List

import nltk
import torch
from natsort import natsorted
from nltk.corpus import stopwords
from nltk.tokenize import sent_tokenize, word_tokenize
from rapidfuzz import fuzz

import re
from typing import List
from itertools import islice
from collections import defaultdict, deque
from rapidfuzz import fuzz


def validate_pytorch2(torch_version: str = None):
    torch_version = torch.__version__ if torch_version is None else torch_version

    pattern = r"^2\.\d+(\.\d+)*"

    return True if re.match(pattern, torch_version) else False


def get_timestamp() -> str:
    """
    get_timestamp - get a timestamp for the current time
    Returns:
        str, the timestamp
    """
    return datetime.now().strftime("%Y%m%d_%H%M%S")


def truncate_word_count(text, max_words=512):
    """
    truncate_word_count - a helper function for the gradio module
    Parameters
    ----------
    text : str, required, the text to be processed
    max_words : int, optional, the maximum number of words, default=512
    Returns
    -------
    dict, the text and whether it was truncated
    """
    # split on whitespace with regex
    words = re.split(r"\s+", text)
    processed = {}
    if len(words) > max_words:
        processed["was_truncated"] = True
        processed["truncated_text"] = " ".join(words[:max_words])
    else:
        processed["was_truncated"] = False
        processed["truncated_text"] = text
    return processed


def load_examples(src, filetypes=[".txt", ".pdf"]):
    """
    load_examples - a helper function for the gradio module to load examples
    Returns:
        list of str, the examples
    """
    src = Path(src)
    src.mkdir(exist_ok=True)

    pdf_url = (
        "https://www.dropbox.com/s/y92xy7o5qb88yij/all_you_need_is_attention.pdf?dl=1"
    )
    subprocess.run(["wget", pdf_url, "-O", src / "all_you_need_is_attention.pdf"])
    examples = [f for f in src.iterdir() if f.suffix in filetypes]
    examples = natsorted(examples)
    # load the examples into a list
    text_examples = []
    for example in examples:
        with open(example, "r") as f:
            text = f.read()
            text_examples.append([text, "base", 2, 1024, 0.7, 3.5, 3])

    return text_examples


def load_example_filenames(example_path: str or Path):
    """
    load_example_filenames - a helper function for the gradio module to load examples
    Returns:
        dict, the examples (filename:full path)
    """
    example_path = Path(example_path)
    # load the examples into a list
    examples = {f.name: f for f in example_path.glob("*.txt")}
    return examples


def extract_keywords(
    text: str, num_keywords: int = 3, window_size: int = 5
) -> List[str]:
    """
    Extracts keywords from a text using a simplified TextRank algorithm.

    Args:
        text: The text to extract keywords from.
        num_keywords: The number of keywords to extract. Default is 5.
        window_size: The number of words considered for co-occurrence. Default is 5.

    Returns:
        A list of strings, where each string is a keyword extracted from the input text.
    """
    # Define stopwords
    stop_words = set(
        "a about above after again against all am an and any are aren't as at be because been before being below between both but by can't cannot could couldn't did didn't do does doesn't doing don't down during each few for from further had hadn't has hasn't have haven't having he he'd he'll he's her here here's hers herself him himself his how how's i i'd i'll i'm i've if in into is isn't it it's its itself let's me more most mustn't my myself no nor not of off on once only or other ought our ours ourselves out over own same shan't she she'd she'll she's should shouldn't so some such than that that's the their theirs them themselves then there there's these they they'd they'll they're they've this those through to too under until up very was wasn't we we'd we'll we're we've were weren't what what's when when's where where's which while who who's whom why why's with won't would wouldn't you you'd you'll you're you've your yours yourself yourselves".split()
    )

    # Remove stopwords and tokenize the text into words
    words = [
        word
        for word in re.findall(r"\b\w{3,}\b", text.lower())
        if word not in stop_words
    ]

    # Create a graph of word co-occurrences within a moving window of words
    cooccur = defaultdict(lambda: defaultdict(int))
    deque_words = deque(maxlen=window_size)
    for word in words:
        for w1, w2 in combinations(deque_words, 2):
            cooccur[w1][w2] += 1
            cooccur[w2][w1] += 1
        deque_words.append(word)

    # Assign scores to words using a simplified TextRank algorithm
    scores = defaultdict(float)
    for _ in range(10):
        new_scores = defaultdict(float)
        for word, co_words in cooccur.items():
            new_scores[word] = 0.15 + 0.85 * sum(
                cooccur[word][other] / sum(cooccur[other].values()) * scores[other]
                for other in co_words
            )
        scores = new_scores

    # Sort the words by score and return the top num_keywords keywords
    keywords = sorted(scores, key=scores.get, reverse=True)[:num_keywords]

    # Use fuzzy matching to remove similar keywords
    final_keywords = []
    for keyword in keywords:
        if not any(fuzz.ratio(keyword, other) > 70 for other in final_keywords):
            final_keywords.append(keyword)

    return final_keywords


def saves_summary(
    summarize_output, outpath: str or Path = None, add_signature=True, **kwargs
):
    """
    saves_summary - save the summary generated from summarize_via_tokenbatches() to a text file

    summarize_output: output from summarize_via_tokenbatches()
    outpath: path to the output file
    add_signature: whether to add a signature to the output file
    kwargs: additional keyword arguments to include in the output file
    """
    sum_text = [f"\t{s['summary'][0]}\n" for s in summarize_output]
    sum_scores = [f"\n - {round(s['summary_score'],4)}" for s in summarize_output]
    scores_text = "\n".join(sum_scores)
    full_summary = "\n".join(sum_text)

    keywords = "_".join(extract_keywords(full_summary))
    outpath = (
        Path.cwd() / f"document_summary_{get_timestamp()}_{keywords}.txt"
        if outpath is None
        else Path(outpath)
    )

    with open(
        outpath,
        "w",
        encoding="utf-8",
    ) as fo:
        fo.writelines(full_summary)
        fo.write("\n\n")
        if add_signature:
            fo.write("\n\n---\n\n")
            fo.write("Generated with the Document Summarization space :)\n\n")
            fo.write("https://hf.co/spaces/pszemraj/document-summarization\n\n")
    with open(
        outpath,
        "a",
    ) as fo:
        fo.write("\n")
        fo.write(f"## Section Scores:\n\n")
        fo.writelines(scores_text)
        fo.write("\n\n")
        fo.write(f"Date: {get_timestamp()}\n\n")
        if kwargs:
            fo.write("---\n\n")
            fo.write("## Parameters:\n\n")
            for key, value in kwargs.items():
                fo.write(f"{key}: {value}\n")
    return outpath