require('dotenv').config();
const express = require('express');
const http = require('http');
const cors = require('cors');
const bodyParser = require('body-parser');
const { google } = require('googleapis');
const fs = require('fs');
const path = require('path');
const { Server } = require("socket.io");
const nodemailer = require('nodemailer');

const app = express();
const server = http.createServer(app);
const io = new Server(server, {
  cors: {
    origin: "*", // allow all domains to connect for real-time updates (you can restrict this later)
    methods: ["GET", "POST"]
  }
});

const port = process.env.PORT || 3000;

// Middleware
app.use(cors());
app.use(bodyParser.json({ limit: '10mb' }));
app.use(bodyParser.urlencoded({ extended: true, limit: '10mb' }));

// Basic Auth for UI Protection
app.use((req, res, next) => {
  // Always permit the API and integration scripts
  if (req.path.startsWith('/api/') || req.path === '/embed.js' || req.path === '/live-site-integration.js') {
    return next();
  }

  // For HTML pages and other assets, require a password
  const b64auth = (req.headers.authorization || '').split(' ')[1] || '';
  const [login, password] = Buffer.from(b64auth, 'base64').toString().split(':');

  // Let them use 'admin' as the username, and the SMTP password (or fallback to 'admin' if not deployed yet)
  const expectedPassword = process.env.UI_PASSWORD || process.env.SMTP_PASS || 'admin';

  // We allow 'admin' user or ANY user as long as the password matches. Browsers usually prompt for both.
  if (password === expectedPassword) {
    return next();
  }

  res.set('WWW-Authenticate', 'Basic realm="Restricted WallAPI Space"');
  res.status(401).send('Authentication required. Username: admin. Password matches your SMTP_PASS Secret (or "admin" if not set).');
});

app.use(express.static('public')); // Serve the frontend assets

// Google Sheets Setup
const SCOPES = ['https://www.googleapis.com/auth/spreadsheets'];

async function getAuth() {
  if (process.env.GOOGLE_CREDENTIALS) {
    // Hosted on Hugging Face: we read the JSON string directly from the secret
    try {
      const credentials = JSON.parse(process.env.GOOGLE_CREDENTIALS);
      const auth = new google.auth.GoogleAuth({
        credentials,
        scopes: SCOPES,
      });
      return auth;
    } catch (e) {
      console.error("Failed to parse GOOGLE_CREDENTIALS secret. Is it valid JSON?", e);
      throw new Error("Invalid Google Credentials Secret");
    }
  } else if (fs.existsSync(process.env.GOOGLE_CREDENTIALS_PATH)) {
    // Local fallback: read from the file
    const auth = new google.auth.GoogleAuth({
      keyFile: process.env.GOOGLE_CREDENTIALS_PATH,
      scopes: SCOPES,
    });
    return auth;
  } else {
    throw new Error('Google Credentials not found. Please set GOOGLE_CREDENTIALS secret or provide a local credentials.json.');
  }
}

// Ensure the Google Sheet ID is configured
const spreadsheetId = process.env.GOOGLE_SHEET_ID;

// API Endpoint to receive form submissions
app.post('/api/submit', async (req, res) => {
  try {
    const { name, email, message, phone, subject, origin } = req.body;

    const hasIdentifier = name || email || phone ||
      req.body.submitterEmail || req.body.submitterName || req.body.submitterPhone ||
      req.body.vetFirstName || req.body.contactName || req.body.groupName;
    if (!hasIdentifier) {
      return res.status(400).json({ error: 'Please provide at least a name, email, or phone number.' });
    }

    if (!spreadsheetId || spreadsheetId === 'your_google_sheet_id_here') {
      console.error('SERVER SETUP ERROR: GOOGLE_SHEET_ID is not properly configured in .env');
      return res.status(500).json({ error: 'Server configuration error.' });
    }

    const auth = await getAuth();
    const sheets = google.sheets({ version: 'v4', auth });

    // Assuming the first sheet is where data goes.
    // We are going to append to Columns A to G (Timestamp, Name, Email, Message, Phone, Subject, Origin).
    const TIMESTAMP = new Date().toISOString();

    // The range specifies where to append. 
    // Dynamically sort into different tabs based on the origin URL!
    let range = 'Sheet1';
    let rowData = [];

    // Fallbacks if generic integration script used
    const safeName = req.body.name || req.body.Name || req.body._generic_name || '';
    const safePhone = req.body.phone || req.body.Phone || '';
    const safeEmail = req.body.email || req.body.Email || '';
    const safeMessage = req.body.message || req.body.Message || '';

    if (origin) {
      const lowerOrigin = origin.toLowerCase();
      if (lowerOrigin.includes('contact')) {
        range = 'Contact';
        // Match Contact Form: Date, Name, Email, Phone, Subject, Message, Origin
        rowData = [
          TIMESTAMP,
          safeName,
          safeEmail,
          safePhone,
          req.body.subject || '',
          safeMessage,
          origin
        ];
      } else if (lowerOrigin.includes('tours')) {
        range = 'Tours';
        // Map exactly to: Date, Group Name, Tour Type, Contact Name, Contact Title, Email, Phone, Group Size, Date, Time, Special Needs, Additional Info, Origin
        rowData = [
          TIMESTAMP,
          req.body.groupName || '',
          req.body.tourType || '',
          req.body.contactName || '',
          req.body.contactTitle || '',
          req.body.email || '',
          req.body.phone || '',
          req.body.groupSize || '',
          req.body.preferredDate || '',
          req.body.preferredTime || '',
          req.body.specialNeeds || '',
          req.body.additionalInfo || '',
          origin
        ];
      } else if (lowerOrigin.includes('escort')) {
        range = 'Escort';
        // Map exactly to: Date, Name, Email, Phone, Vehicle, Group Affiliation, Origin
        rowData = [
          TIMESTAMP,
          req.body.name || '',
          req.body.email || '',
          req.body.phone || '',
          req.body.vehicle || '',
          req.body.groupAffiliation || '',
          origin
        ];
      } else if (lowerOrigin.includes('honor')) {
        range = 'Honor';

        let vetPhotoUrl = '';
        const photoData = req.body.vetPhoto;
        if (photoData && photoData.startsWith('data:image')) {
          try {
            const matches = photoData.match(/^data:image\/(\w+);base64,(.+)$/s);
            if (matches) {
              const uploadDir = path.join(__dirname, 'public', 'uploads');
              if (!fs.existsSync(uploadDir)) fs.mkdirSync(uploadDir, { recursive: true });
              const fileName = `${Date.now()}.${matches[1]}`;
              fs.writeFileSync(path.join(uploadDir, fileName), Buffer.from(matches[2], 'base64'));
              vetPhotoUrl = `${req.protocol}://${req.get('host')}/uploads/${fileName}`;
            }
          } catch (photoErr) {
            console.error('Failed to save photo:', photoErr);
          }
        }

        rowData = [
          TIMESTAMP,
          req.body.vetFirstName || '',
          req.body.vetMiddleName || '',
          req.body.vetLastName || '',
          req.body.vetRank || '',
          req.body.vetBranch || '',
          req.body.yearsServed || '',
          req.body.conflictEra || '',
          req.body.vetHometown || '',
          req.body.isDeceased || 'No',
          req.body.vetStory || '',
          req.body.specialRecognition || '',
          req.body.submitterName || '',
          req.body.relationship || '',
          req.body.submitterEmail || '',
          req.body.submitterPhone || '',
          req.body.displayPermission ? 'Yes' : 'No',
          origin,
          vetPhotoUrl
        ];
      } else {
        // Fallback catch-all
        rowData = [TIMESTAMP, safeName, safeEmail, safeMessage, safePhone, subject || '', origin];
      }
    } else {
      rowData = [TIMESTAMP, safeName, safeEmail, safeMessage, safePhone, subject || '', origin || 'Unknown'];
    }

    const response = await sheets.spreadsheets.values.append({
      spreadsheetId,
      range,
      valueInputOption: 'USER_ENTERED',
      requestBody: {
        values: [rowData],
      },
    });

    console.log(`Successfully appended row to sheet: ${response.data.updates.updatedRange}`);

    // Broadcast the new submission to all connected clients
    io.emit('new_submission', {
      timestamp: TIMESTAMP,
      name,
      email,
      message,
      phone: phone || '',
      subject: subject || '',
      origin: origin || 'Hugging Face Widget'
    });

    // Send Email Notification if credentials exist
    if (process.env.SMTP_USER && process.env.SMTP_PASS && process.env.NOTIFICATION_EMAIL) {
      try {
        const transporter = nodemailer.createTransport({
          host: process.env.SMTP_HOST || 'smtp.gmail.com',
          port: process.env.SMTP_PORT || 465,
          secure: process.env.SMTP_PORT == 465 || process.env.SMTP_PORT == undefined,
          auth: {
            user: process.env.SMTP_USER,
            pass: process.env.SMTP_PASS
          }
        });

        const mailOptions = {
          from: `"WallAPI Form System" <${process.env.SMTP_USER}>`,
          to: process.env.NOTIFICATION_EMAIL,
          subject: `New Lead: ${name} via ${subject || 'Website'}`,
          html: `
            <h2>New Form Submission</h2>
            <p>You have received a new contact submission.</p>
            <table border="1" cellpadding="8" style="border-collapse: collapse; width: 100%; max-width: 600px;">
              <tr><td width="30%" bgcolor="#f3f4f6"><strong>Name</strong></td><td>${name}</td></tr>
              <tr><td bgcolor="#f3f4f6"><strong>Email</strong></td><td><a href="mailto:${email}">${email}</a></td></tr>
              <tr><td bgcolor="#f3f4f6"><strong>Phone</strong></td><td>${phone || '<i>Not provided</i>'}</td></tr>
              <tr><td bgcolor="#f3f4f6"><strong>Subject</strong></td><td>${subject || '<i>Not provided</i>'}</td></tr>
              <tr><td bgcolor="#f3f4f6"><strong>Origin</strong></td><td>${origin || 'Hugging Face Widget'}</td></tr>
              <tr><td bgcolor="#f3f4f6"><strong>Timestamp</strong></td><td>${TIMESTAMP}</td></tr>
              <tr>
                <td colspan="2" bgcolor="#f3f4f6"><strong>Message</strong></td>
              </tr>
              <tr>
                <td colspan="2" style="white-space: pre-wrap;">${message}</td>
              </tr>
            </table>
          `
        };

        const info = await transporter.sendMail(mailOptions);
        console.log(`Email notification sent: ${info.messageId}`);
      } catch (emailErr) {
        console.error('Failed to send email notification:', emailErr);
        // We do not fail the request if the email fails, since it's already in the Sheet
      }
    }

    return res.status(200).json({ success: true, message: 'Form submitted successfully!' });

  } catch (error) {
    console.error('Error handling form submission:', error);
    if (error.message && (error.message.includes('Credentials file not found') || error.message.includes('Google Credentials not found') || error.message.includes('Invalid Google Credentials'))) {
      return res.status(500).json({ error: 'Server is missing Google Sheets credentials.' });
    }
    return res.status(500).json({ error: 'An error occurred while submitting the form.' });
  }
});

// Socket.IO Connection Handling
io.on('connection', (socket) => {
  console.log('A client connected for real-time updates:', socket.id);

  socket.on('disconnect', () => {
    console.log('Client disconnected:', socket.id);
  });
});

// Start the server (changed from app.listen to server.listen for Socket.IO)
server.listen(port, () => {
  console.log(`Server listening at http://localhost:${port}`);
  console.log(`Test the embeddable form at http://localhost:${port}/index.html`);
});