import os
import requests
import pdfplumber
import numpy as np
from flask import Flask, render_template, request, redirect, url_for, flash
from werkzeug.utils import secure_filename
from sentence_transformers import SentenceTransformer, util
import nltk
from nltk.stem import WordNetLemmatizer, PorterStemmer
from nltk.tokenize import word_tokenize
from nltk.corpus import stopwords

nltk.download("punkt")
nltk.download("wordnet")
nltk.download("stopwords")

lemmatizer = WordNetLemmatizer()
stemmer = PorterStemmer()
stop_words = set(stopwords.words("english"))

app = Flask(__name__)
app.config["UPLOAD_FOLDER"] = "uploads"
os.makedirs(app.config["UPLOAD_FOLDER"], exist_ok=True)

model = SentenceTransformer("allenai/scibert_scivocab_uncased")

def extract_pdf_text(pdf_path):
    text = ""
    try:
        with pdfplumber.open(pdf_path) as pdf:
            for page in pdf.pages:
                text += page.extract_text() or " "
    except Exception as e:
        print(f"Errore estrazione testo: {e}")
    return text.lower().strip()

def preprocess_text(text):
    text = text.lower()
    words = word_tokenize(text)
    words = [stemmer.stem(lemmatizer.lemmatize(w)) for w in words if w.isalnum() and w not in stop_words]
    return " ".join(words)

def calculate_token_overlap(text1, text2):
    tokens1 = set(text1.split())
    tokens2 = set(text2.split())
    overlap = len(tokens1 & tokens2)
    return round((overlap / max(len(tokens1), 1)) * 100, 2)

def calculate_oui(similarity, token_overlap, alpha=0.7, beta=0.3):
    oui = alpha * (1 - similarity / 100) + beta * (1 - token_overlap / 100)
    return round(max(0, min(oui * 100, 100)), 2)

def validate_document(pdf_path, comparison_sources, method="local", titles=None):
    pdf_text = extract_pdf_text(pdf_path)
    results = []
    for i, doc in enumerate(comparison_sources):
        doc_text = extract_pdf_text(doc) if method == "local" else doc
        similarity = util.pytorch_cos_sim(
            model.encode(pdf_text, convert_to_tensor=True),
            model.encode(doc_text, convert_to_tensor=True)
        ).item() * 100
        token_overlap = calculate_token_overlap(pdf_text, doc_text)
        oui = calculate_oui(similarity, token_overlap)
        title = titles[i] if titles and i < len(titles) else os.path.basename(doc) if method == "local" else "Unknown Title"
        results.append({"title": title, "similarity": round(similarity, 2), "token_overlap": round(token_overlap, 2), "oui": round(oui, 2)})
    return results

def fetch_pubmed_details(article_id):
    base_url = "https://eutils.ncbi.nlm.nih.gov/entrez/eutils/efetch.fcgi"
    params = {"db": "pubmed", "id": article_id, "retmode": "xml"}
    try:
        response = requests.get(base_url, params=params)
        response.raise_for_status()
        import xml.etree.ElementTree as ET
        root = ET.fromstring(response.text)
        title = root.find(".//ArticleTitle").text if root.find(".//ArticleTitle") is not None else "No Title"
        abstract = root.find(".//AbstractText").text if root.find(".//AbstractText") is not None else "No Abstract"
        keywords = root.findall(".//Keyword")
        keyword_text = " ".join([kw.text for kw in keywords if kw.text]) if keywords else "No Keywords"
        print(f"\n🔍 ARTICOLO RECUPERATO\n📖 Titolo: {title}\n📝 Abstract: {abstract[:500]}...\n🔑 Keywords: {keyword_text}\n")
        return title, f"{abstract} {keyword_text}"
    except requests.exceptions.RequestException as e:
        print(f"Errore recupero abstract: {e}")
        return "No Title", "No Abstract"

def fetch_pubmed(query, year_start, year_end, max_results=10):
    base_url = "https://eutils.ncbi.nlm.nih.gov/entrez/eutils/esearch.fcgi"
    params = {"db": "pubmed", "term": f"{query} AND ({year_start}[PDAT] : {year_end}[PDAT])", "retmax": max_results, "retmode": "json"}
    try:
        response = requests.get(base_url, params=params)
        response.raise_for_status()
        return response.json().get("esearchresult", {}).get("idlist", [])
    except requests.exceptions.RequestException as e:
        print(f"Errore recupero articoli PubMed: {e}")
        
        return []

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

@app.route("/validate", methods=["POST"])
def validate():
    pdf_file = request.files.get("pdf_file")
    analysis_type = request.form.get("analysis_type")
    local_dir = request.form.get("local_directory", "").strip()
    query = request.form.get("query", "").strip()
    if not pdf_file:
        flash("Carica un file PDF valido.", "error")
        return redirect(url_for("index"))
    filename = secure_filename(pdf_file.filename)
    pdf_path = os.path.join(app.config["UPLOAD_FOLDER"], filename)
    pdf_file.save(pdf_path)
    results = []
    if analysis_type == "local":
        if not os.path.isdir(local_dir):
            flash("Seleziona una directory valida.", "error")
            return redirect(url_for("index"))
        comparison_files = [os.path.join(local_dir, f) for f in os.listdir(local_dir) if f.endswith(".pdf")]
        if not comparison_files:
            flash("La directory non contiene PDF.", "error")
            return redirect(url_for("index"))
        results = validate_document(pdf_path, comparison_files, method="local")
    elif analysis_type == "pubmed":
        year_start = request.form.get("year_start", "2000")
        year_end = request.form.get("year_end", "2025")
        num_articles = int(request.form.get("num_articles", "10"))
        pubmed_ids = fetch_pubmed(query, year_start, year_end, num_articles)
        pubmed_results = [fetch_pubmed_details(article_id) for article_id in pubmed_ids]
        results = validate_document(pdf_path, [result[1] for result in pubmed_results], method="pubmed", titles=[result[0] for result in pubmed_results])
    return render_template("NORUS.html", results=results)

if __name__ == "__main__":
    app.run(debug=True, port=7860)