plagiarism.py

import time
from nltk.tokenize import sent_tokenize
from googleapiclient.discovery import build
from collections import Counter
import re, math
from sentence_transformers import SentenceTransformer, util
import asyncio
import httpx
from bs4 import BeautifulSoup
import numpy as np
import concurrent
from multiprocessing import Pool


WORD = re.compile(r"\w+")
model = SentenceTransformer("sentence-transformers/all-MiniLM-L6-v2")


months = {
    "January": "01",
    "February": "02",
    "March": "03",
    "April": "04",
    "May": "05",
    "June": "06",
    "July": "07",
    "August": "08",
    "September": "09",
    "October": "10",
    "November": "11",
    "December": "12",
}

color_map = [
    "#cf2323",
    "#eb9d59",
    "#c2ad36",
    "#e1ed72",
    "#c2db76",
    "#a2db76",
]


def text_to_vector(text):
    words = WORD.findall(text)
    return Counter(words)


def cosineSim(text1, text2):
    vector1 = text_to_vector(text1)
    vector2 = text_to_vector(text2)
    # print vector1,vector2
    cosine = get_cosine(vector1, vector2)
    return cosine


def get_cosine(vec1, vec2):
    intersection = set(vec1.keys()) & set(vec2.keys())
    numerator = sum([vec1[x] * vec2[x] for x in intersection])
    sum1 = sum([vec1[x] ** 2 for x in vec1.keys()])
    sum2 = sum([vec2[x] ** 2 for x in vec2.keys()])
    denominator = math.sqrt(sum1) * math.sqrt(sum2)
    if denominator == 0:
        return 0.0
    else:
        return float(numerator) / denominator


def split_sentence_blocks(text, size):
    if size == "Paragraph":
        blocks = text.split("\n")
        return blocks
    else:
        blocks = []
        size = int(size)
        for para in text.split("\n\n"):
            sents = sent_tokenize(para)
            for i in range(len(sents)):
                if (i % size) == 0:
                    blocks.append(sents[i])
                else:
                    blocks[int(i / size)] += " " + sents[i]
        return blocks


def build_date(year=2024, month="March", day=1):
    return f"{year}{months[month]}{day}"


def split_ngrams(text, n):
    words = text.split()
    return [words[i : i + n] for i in range(len(words) - n + 1)]


def sentence_similarity(text1, text2):
    embedding_1 = model.encode(text1, convert_to_tensor=True)
    embedding_2 = model.encode(text2, convert_to_tensor=True)
    o = util.pytorch_cos_sim(embedding_1, embedding_2)
    return o.item()


async def get_url_data(url, client):
    try:
        r = await client.get(url)
        if r.status_code == 200:
            soup = BeautifulSoup(r.content, "html.parser")
            return soup
    except Exception:
        return None


async def parallel_scrap(urls):
    async with httpx.AsyncClient(timeout=30) as client:
        tasks = []
        for url in urls:
            tasks.append(get_url_data(url=url, client=client))
        results = await asyncio.gather(*tasks, return_exceptions=True)
    return results


def matching_score(sentence_content_tuple):
    sentence, content = sentence_content_tuple
    if sentence in content:
        return 1
    else:
        n = 5
        ngrams = split_ngrams(sentence, n)
        if len(ngrams) == 0:
            return 0
        matched = [x for x in ngrams if " ".join(x) in content]
        return len(matched) / len(ngrams)


def process_with_multiprocessing(input_data):
    with Pool(processes=4) as pool:
        scores = pool.map(matching_score, input_data)
    return scores


def map_sentence_url(sentences, score_array):
    sentenceToMaxURL = [-1] * len(sentences)
    for j in range(len(sentences)):
        if j > 0:
            maxScore = score_array[sentenceToMaxURL[j - 1]][j]
            sentenceToMaxURL[j] = sentenceToMaxURL[j - 1]
        else:
            maxScore = -1
        for i in range(len(score_array)):
            margin = (
                0.05
                if (j > 0 and sentenceToMaxURL[j] == sentenceToMaxURL[j - 1])
                else 0
            )
            if score_array[i][j] - maxScore > margin:
                maxScore = score_array[i][j]
                sentenceToMaxURL[j] = i
    return sentenceToMaxURL


def google_search(
    plag_option,
    sentences,
    url_count,
    score_array,
    url_list,
    sorted_date,
    domains_to_skip,
    api_key,
    cse_id,
    **kwargs,
):
    service = build("customsearch", "v1", developerKey=api_key)
    for i, sentence in enumerate(sentences):
        results = (
            service.cse()
            .list(q=sentence, cx=cse_id, sort=sorted_date, **kwargs)
            .execute()
        )
        if "items" in results and len(results["items"]) > 0:
            for count, link in enumerate(results["items"]):
                # stop after 3 pages
                if count >= 3:
                    break
                # skip user selected domains
                if (domains_to_skip is not None) and any(
                    ("." + domain) in link["link"] for domain in domains_to_skip
                ):
                    continue
                # clean up snippet of '...'
                snippet = link["snippet"]
                ind = snippet.find("...")
                if ind < 20 and ind > 9:
                    snippet = snippet[ind + len("... ") :]
                ind = snippet.find("...")
                if ind > len(snippet) - 5:
                    snippet = snippet[:ind]

                # update cosine similarity between snippet and given text
                url = link["link"]
                if url not in url_list:
                    url_list.append(url)
                    score_array.append([0] * len(sentences))
                url_count[url] = url_count[url] + 1 if url in url_count else 1
                if plag_option == "Standard":
                    score_array[url_list.index(url)][i] = cosineSim(
                        sentence, snippet
                    )
                else:
                    score_array[url_list.index(url)][i] = sentence_similarity(
                        sentence, snippet
                    )
    return url_count, score_array


def plagiarism_check(
    plag_option,
    input,
    year_from,
    month_from,
    day_from,
    year_to,
    month_to,
    day_to,
    domains_to_skip,
    source_block_size,
):
    # api_key = "AIzaSyCLyCCpOPLZWuptuPAPSg8cUIZhdEMVf6g"
    # api_key = "AIzaSyCS1WQDMl1IMjaXtwSd_2rA195-Yc4psQE"
    # api_key = "AIzaSyCB61O70B8AC3l5Kk3KMoLb6DN37B7nqIk"
    # api_key = "AIzaSyCg1IbevcTAXAPYeYreps6wYWDbU0Kz8tg"
    api_key = "AIzaSyA5VVwY1eEoIoflejObrxFDI0DJvtbmgW8"
    cse_id = "851813e81162b4ed4"

    url_scores = []
    sentence_scores = []
    sentences = split_sentence_blocks(input, source_block_size)
    url_count = {}
    score_array = []
    url_list = []
    date_from = build_date(year_from, month_from, day_from)
    date_to = build_date(year_to, month_to, day_to)
    sort_date = f"date:r:{date_from}:{date_to}"
    # get list of URLS to check
    url_count, score_array = google_search(
        plag_option,
        sentences,
        url_count,
        score_array,
        url_list,
        sort_date,
        domains_to_skip,
        api_key,
        cse_id,
    )
    # Scrape URLs in list
    soups = asyncio.run(parallel_scrap(url_list))
    input_data = []
    for i, soup in enumerate(soups):
        if soup:
            page_content = soup.text
            for j, sent in enumerate(sentences):
                input_data.append((sent, page_content))
    scores = process_with_multiprocessing(input_data)

    k = 0
    # Update score array for each (soup, sentence)
    for i, soup in enumerate(soups):
        if soup:
            for j, _ in enumerate(sentences):
                score_array[i][j] = scores[k]
                k += 1

    sentenceToMaxURL = map_sentence_url(sentences, score_array)
    index = np.unique(sentenceToMaxURL)

    url_source = {}
    for url in index:
        s = [
            score_array[url][sen]
            for sen in range(len(sentences))
            if sentenceToMaxURL[sen] == url
        ]
        url_source[url] = sum(s) / len(s)
    index_descending = sorted(url_source, key=url_source.get, reverse=True)
    urlMap = {}
    for count, i in enumerate(index_descending):
        urlMap[i] = count + 1

    # build results
    for i, sent in enumerate(sentences):
        ind = sentenceToMaxURL[i]
        if url_source[ind] > 0.1:
            sentence_scores.append(
                [sent, url_source[ind], url_list[ind], urlMap[ind]]
            )
        else:
            sentence_scores.append([sent, None, url_list[ind], -1])
    for ind in index_descending:
        if url_source[ind] > 0.1:
            url_scores.append(
                [url_list[ind], round(url_source[ind] * 100, 2), urlMap[ind]]
            )

    return sentence_scores, url_scores


def html_highlight(
    plag_option,
    input,
    year_from,
    month_from,
    day_from,
    year_to,
    month_to,
    day_to,
    domains_to_skip,
    source_block_size,
):
    sentence_scores, url_scores = plagiarism_check(
        plag_option,
        input,
        year_from,
        month_from,
        day_from,
        year_to,
        month_to,
        day_to,
        domains_to_skip,
        source_block_size,
    )

    html_content = "<link href='https://fonts.googleapis.com/css?family=Roboto' rel='stylesheet'>\n<div style='font-family: {font}; border: 2px solid black; background-color: #333333; padding: 10px; color: #FFFFFF;'>"
    prev_idx = None
    combined_sentence = ""
    for sentence, _, _, idx in sentence_scores:
        if idx != prev_idx and prev_idx is not None:
            color = color_map[prev_idx - 1]
            index_part = f'<span style="background-color: {color}; padding: 2px;">[{prev_idx}]</span>'
            formatted_sentence = f"<p>{combined_sentence} {index_part}</p>"
            html_content += formatted_sentence
            combined_sentence = ""
        combined_sentence += " " + sentence
        prev_idx = idx

    if combined_sentence:
        color = color_map[prev_idx - 1]
        index_part = f'<span style="background-color: {color}; padding: 2px;">[{prev_idx}]</span>'
        formatted_sentence = f"<p>{combined_sentence} {index_part}</p>"
        html_content += formatted_sentence

    html_content += "<hr>"
    for url, score, idx in url_scores:
        color = color_map[idx - 1]
        formatted_url = f'<p style="background-color: {color}; padding: 5px;">({idx}) <b>{url}</b></p><p> --- Matching Score: {score}%</p>'
        html_content += formatted_url

    html_content += "</div>"

    return html_content