from flask import Flask, request, render_template, jsonify
from nltk.tokenize import word_tokenize, sent_tokenize
from urllib.request import urlopen
from bs4 import BeautifulSoup
import nltk
import socket
from difflib import SequenceMatcher
from sklearn.feature_extraction.text import TfidfVectorizer
from sklearn.cluster import KMeans

nltk.download('punkt')

app = Flask(__name__)

def simple_summary(text, max_sentences=3):
    sents = sent_tokenize(text)
    return " ".join(sents[:max_sentences]) if sents else text[:200] + "..."

@app.route("/")
def home():
    return render_template("index.html")

@app.route("/process_urls", methods=["POST"])
def process_urls():
    data = request.form
    selected_sites = request.form.getlist("sites")
    mode = data.get("mode", "tokenize")

    articles = {}
    for url in selected_sites:
        try:
            page = urlopen(url)
            soup = BeautifulSoup(page, "html.parser")
            text = soup.get_text(separator=" ")
            articles[url] = text
        except Exception as e:
            articles[url] = f"Error fetching: {str(e)}"

    # -----------------------------
    # Compare articles side-by-side
    # -----------------------------
    comparison_results = []
    urls = list(articles.keys())
    for i in range(len(urls)):
        for j in range(i+1, len(urls)):
            a, b = articles[urls[i]], articles[urls[j]]
            sents_a, sents_b = sent_tokenize(a), sent_tokenize(b)
            diff_a = []
            for sent in sents_a:
                if any(SequenceMatcher(None, sent, s).ratio() < 0.8 for s in sents_b):
                    diff_a.append(sent)
            comparison_results.append({
                "site1": urls[i],
                "site2": urls[j],
                "diff_sentences_site1": diff_a
            })

    # -----------------------------
    # Cluster articles by topic
    # -----------------------------
    clusters = {}
    if len(articles) > 0:
        vectorizer = TfidfVectorizer(stop_words='english')
        X = vectorizer.fit_transform(list(articles.values()))
        n_clusters = min(3, len(articles))
        kmeans = KMeans(n_clusters=n_clusters, random_state=42).fit(X)
        for idx, label in enumerate(kmeans.labels_):
            clusters.setdefault(int(label), []).append(urls[idx])


    # -----------------------------
    # Summarize each article using NLTK simple summary
    # -----------------------------
    summaries = {}
    for url, text in articles.items():
        summaries[url] = simple_summary(text, max_sentences=3)

    return jsonify({
        "articles": articles,
        "comparisons": comparison_results,
        "clusters": clusters,
        "summaries": summaries
    })

if __name__ == "__main__":
    socket.setdefaulttimeout(20)
    app.run(host="0.0.0.0", port=7860, debug=False)