const express = require('express');
const { spawn } = require('child_process');
const cors = require('cors');
const path = require('path');
const fs = require('fs');

const app = express();
const port = 3005;

// Enable CORS for all routes
app.use(cors());

// Serve static files from the 'dist' directory
const staticPath = path.join(__dirname, 'dist');
if (fs.existsSync(staticPath)) {
  app.use(express.static(staticPath));
} else {
  console.warn(`Static path not found: ${staticPath}. The frontend might not be served correctly. Make sure to build the frontend first.`);
}


app.use(express.json({ limit: '50mb' }));

// API endpoint to run the Python script
app.post('/api/run', (req, res) => {
  const { mode, ...payload } = req.body;

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

  // Convert payload to a JSON string and then to a Base64 string to ensure safe command line passing
  const payloadString = JSON.stringify(payload);
  const payloadBase64 = Buffer.from(payloadString).toString('base64');

  const pythonScriptPath = path.join(__dirname, '../gtm_architect_orchestrator.py');
  const pythonProcess = spawn('python3', [
    pythonScriptPath,
    '--mode', mode,
    '--payload_base64', payloadBase64
  ]);

  let stdoutData = '';
  let stderrData = '';

  pythonProcess.stdout.on('data', (data) => {
    stdoutData += data.toString();
  });

  pythonProcess.stderr.on('data', (data) => {
    stderrData += data.toString();
  });

  pythonProcess.on('close', (code) => {
    if (code !== 0) {
      console.error(`Python script exited with code ${code}`);
      console.error('Stderr:', stderrData);
      return res.status(500).json({
        error: 'Python script execution failed.',
        stderr: stderrData,
      });
    }

    try {
      // The Python script is expected to print JSON to stdout
      const result = JSON.parse(stdoutData);
      res.json(result);
    } catch (e) {
      console.error('Failed to parse JSON from Python script stdout:', e);
      console.error('Stdout:', stdoutData);
      res.status(500).json({
        error: 'Failed to parse response from Python script.',
        stdout: stdoutData,
      });
    }
  });
});

// Serve the main index.html for any other GET request to support client-side routing
if (fs.existsSync(staticPath)) {
    app.get('*', (req, res) => {
        res.sendFile(path.join(staticPath, 'index.html'));
      });
}


app.listen(port, () => {
  console.log(`Server listening on port ${port}`);
});