app.py

import streamlit as st
from langchain.chat_models import ChatOpenAI
from langchain.prompts import ChatPromptTemplate
from langchain.schema.runnable import RunnableLambda
from langchain.chains import LLMChain
from langchain.prompts import PromptTemplate
from PyPDF2 import PdfReader
import os

# Streamlit UI setup
st.set_page_config(page_title="AI Job Interview Prep Tool")
st.title("AI-Powered Job Interview Preparation")

# OpenAI API Key input
openai_key = st.text_input("🔐 Enter your OpenAI API Key", type="password")
if not openai_key:
    st.warning("Please enter your OpenAI API Key to continue.")
    st.stop()

os.environ["OPENAI_API_KEY"] = openai_key

# User Inputs
company = st.text_input("Company Name")
profile = st.text_input("Profile Name")
jd = st.text_area("Job Description")
resume_file = st.file_uploader("Upload Resume (Optional)", type=["pdf"])

resume_text = ""
if resume_file is not None:
    pdf_reader = PdfReader(resume_file)
    for page in pdf_reader.pages:
        resume_text += page.extract_text() or ""

# Prompt Template
template = PromptTemplate(
    input_variables=["company", "profile", "jd", "resume"],
    template="""
You are an AI interview coach.
Generate:
- 2 technical rounds with 7-10 questions each
    - Each technical round should have:
        - Conceptual questions
        - 2-3 hands-on tasks (code-oriented)
        - 1 case-study type question
- 1 business + HR round with 7-10 questions

Base the questions on the job description, company, profile and resume.
Company: {company}
Profile: {profile}
Job Description: {jd}
Resume (optional): {resume}

Provide questions clearly labeled under each round.
"""
)

llm = ChatOpenAI(temperature=0.7)
chain = LLMChain(llm=llm, prompt=template)

if st.button("Generate Interview Rounds"):
    with st.spinner("Generating questions..."):
        response = chain.run({
            "company": company,
            "profile": profile,
            "jd": jd,
            "resume": resume_text,
        })
        st.subheader("📋 Interview Questions")
        st.write(response)