import streamlit as st
import pdfplumber
import requests
from bs4 import BeautifulSoup
from transformers import AutoTokenizer, AutoModel
import torch

# Load model and tokenizer
tokenizer = AutoTokenizer.from_pretrained('sentence-transformers/all-MiniLM-L6-v2')
model = AutoModel.from_pretrained('sentence-transformers/all-MiniLM-L6-v2')

def extract_text_from_pdf(pdf_file):
    text = ''
    with pdfplumber.open(pdf_file) as pdf:
        for page in pdf.pages:
            text += page.extract_text()
    return text

def fetch_job_description(url):
    response = requests.get(url)
    soup = BeautifulSoup(response.content, 'html.parser')
    return ' '.join(p.text for p in soup.find_all('p'))

def encode(text):
    encoded_input = tokenizer(text, return_tensors='pt', padding=True, truncation=True, max_length=128)
    with torch.no_grad():
        model_output = model(**encoded_input)
    return model_output.pooler_output[0]

def cosine_similarity(a, b):
    return (a @ b) / (a.norm() * b.norm())

def calculate_score(resume_text, job_desc_text):
    resume_emb = encode(resume_text)
    job_desc_emb = encode(job_desc_text)
    return cosine_similarity(resume_emb, job_desc_emb).item()

st.title('ATS Resume Scorer')

with st.sidebar:
    num_resumes = st.slider("Select number of resumes", 1, 5, 1)

uploaded_files = st.file_uploader("Upload resumes", type=['pdf'], accept_multiple_files=True, key="resumes")

job_description_input = st.text_area("Paste job description here", height=150)
job_url = st.text_input("Or enter job posting URL")

if st.button('Score Resumes'):
    if job_url:
        job_description = fetch_job_description(job_url)
    else:
        job_description = job_description_input

    if uploaded_files and job_description:
        scores = []
        for uploaded_file in uploaded_files:
            resume_text = extract_text_from_pdf(uploaded_file)
            score = calculate_score(resume_text, job_description)
            scores.append((uploaded_file.name, score))

        for name, score in scores:
            st.write(f"Resume: {name} - Score: {score:.2f}")
    else:
        st.error("Please upload at least one resume and provide a job description.")