app.js

const express = require("express");
const fileUpload = require("express-fileupload");
const pdf = require("pdf-parse");
const inquirer = require('inquirer');
const openai = require("openai");
const multer = require('multer');
const upload = multer({ dest: 'uploads/' });

// Set OpenAI API Key
openai.apiKey = "YOUR_API_KEY";

// Initialize app
const app = express();
app.use(fileUpload());

// Set up routing
app.get("/", (req, res) => {
  res.send(`
  <h1>PDF Summary Generator</h1>
  <form action="/upload" method="post" enctype="multipart/form-data">
    <input type="file" name="pdf" accept=".pdf">
    <button type="submit" disabled>Generate Summary</button>
  </form>
  
  <script>
    // Handle file selection
    document.querySelector("input[type=file]").addEventListener("change", (event) => {
      // Enable the submit button if a file is selected
      document.querySelector("button").disabled = !event.target.files.length;
    });
  </script>  
  `);
});

app.post("/upload", upload.single('pdf'), (req, res) => {
    // Read the uploaded PDF file
    pdfExtract.extract(req.file.path, {}, (err, data) => {
      if (err) {
        // Handle error from PDF parsing
        res.send(`
          <h1>Error</h1>
          <p>${err.message}</p>
        `);
        return;
      }
  
      // Convert the extracted text to a string
      const text = data.pages.map(page => page.content).join('\n');
  
      // Use OpenAI's GPT-3 to generate summary
      openai.createCompletion({
        model: "text-davinci-002",
        prompt: text,
        temperature: 0.5,
        max_tokens: text.length,
      })
      .then((response) => {
        // Display summary
        res.send(`
          <h1>PDF Summary</h1>
          <p>${response.data.choices[0].text}</p>
        `);
      })
      .catch((error) => {
        // Handle error from OpenAI API
        res.send(`
          <h1>Error</h1>
          <p>${error.message}</p>
        `);
      });
    });
  });    

// Start server
app.listen(3000, () => {
  console.log("Server listening on port 3000");
});