const express = require('express');
const cors = require('cors');
const path = require('path');
const db = require('./db');
require('dotenv').config();

const app = express();
const PORT = process.env.PORT || 3000;

app.use(cors());
app.use(express.json());
app.use(express.static(path.join(__dirname, 'public')));

// Store active Server-Sent Events (SSE) clients
let sseClients = [];

// SSE Registration Endpoint
app.get('/api/sse', (req, res) => {
  res.setHeader('Content-Type', 'text/event-stream');
  res.setHeader('Cache-Control', 'no-cache');
  res.setHeader('Connection', 'keep-alive');
  res.flushHeaders();

  sseClients.push(res);
  console.log(`🔌 Client connected to SSE stream. Total clients: ${sseClients.length}`);

  req.on('close', () => {
    sseClients = sseClients.filter(client => client !== res);
    console.log(`🔌 Client disconnected. Total clients: ${sseClients.length}`);
  });
});

// Function to broadcast new request details to all connected SSE clients
function broadcastNewRequest(request) {
  const data = JSON.stringify(request);
  sseClients.forEach(client => {
    client.write(`data: ${data}\n\n`);
  });
}

// API: Get all requests (ordered by newest first)
app.get('/api/requests', async (req, res) => {
  try {
    const rows = await db.query('SELECT * FROM requests ORDER BY created_at DESC');
    res.json(rows);
  } catch (error) {
    console.error('Error fetching requests:', error);
    res.status(500).json({ error: 'Database query failed' });
  }
});

// API: Post new request (receives external data)
app.post('/api/requests', async (req, res) => {
  const { title, description, external_id, status, payload, cedula } = req.body;
  const tipo_solicitud = req.body.tipo_solicitud || req.body['Tipo de solicitud'] || req.body.tipo_de_solicitud || null;

  if (!title) {
    return res.status(400).json({ error: 'Title is required' });
  }

  try {
    const queryText = `
      INSERT INTO requests (title, description, external_id, status, cedula, tipo_solicitud, payload)
      VALUES (?, ?, ?, ?, ?, ?, ?)
    `;
    
    const parsedPayload = payload ? (typeof payload === 'object' ? payload : { raw: payload }) : {};
    
    const values = [
      title,
      description || '',
      external_id || null,
      status || 'Pending',
      cedula || null,
      tipo_solicitud,
      JSON.stringify(parsedPayload)
    ];

    const result = await db.query(queryText, values);
    const insertId = result.insertId;

    // Fetch the newly inserted record to broadcast
    const rows = await db.query('SELECT * FROM requests WHERE id = ?', [insertId]);
    const newRequest = rows[0];

    // Broadcast the new request to UI clients in real time
    broadcastNewRequest(newRequest);

    res.status(201).json(newRequest);
  } catch (error) {
    console.error('Error saving new request:', error);
    res.status(500).json({ error: 'Database insertion failed' });
  }
});

// API: Update request (save status, handling time, and optionally payload)
app.put('/api/requests/:id', async (req, res) => {
  const { id } = req.params;
  const { status, handling_time, payload } = req.body;

  try {
    if (payload !== undefined) {
      const parsedPayload = typeof payload === 'object' ? payload : { raw: payload };
      await db.query(
        'UPDATE requests SET status = ?, handling_time = ?, payload = ? WHERE id = ?',
        [status || 'Pending', handling_time || 0, JSON.stringify(parsedPayload), id]
      );
    } else {
      await db.query(
        'UPDATE requests SET status = ?, handling_time = ? WHERE id = ?',
        [status || 'Pending', handling_time || 0, id]
      );
    }

    const rows = await db.query('SELECT * FROM requests WHERE id = ?', [id]);
    if (rows.length === 0) {
      return res.status(404).json({ error: 'Request not found' });
    }

    res.json(rows[0]);
  } catch (error) {
    console.error('Error updating request:', error);
    res.status(500).json({ error: 'Database update failed' });
  }
});

// API: Delete request
app.delete('/api/requests/:id', async (req, res) => {
  const { id } = req.params;

  try {
    await db.query('DELETE FROM requests WHERE id = ?', [id]);
    res.json({ success: true, message: 'Request deleted successfully' });
  } catch (error) {
    console.error('Error deleting request:', error);
    res.status(500).json({ error: 'Database deletion failed' });
  }
});

// Start server after ensuring DB connection and schema setup
async function startServer() {
  await db.initializeSchema();

  app.listen(PORT, () => {
    console.log(`🚀 Claro Cases server running at http://localhost:${PORT}`);
  });
}

startServer().catch(err => {
  console.error('💥 Server startup failed:', err);
});