server.mjs

import express from 'express';
const app = express();
app.use(express.static('static'));
app.listen(3000, () => console.log('Sound Board running on http://localhost:3000'));

const VALID_REGEX = /^[a-zA-ZöäüÖÄÜß0-9\s_-]+$/; // Regex Check aus dem Frontend

function setResponseAndStatus(res, data, status) {
  res.type('application/json');
  res.status(status);
  res.send(JSON.stringify(data));
}

function validateRequest(data, requiredFields = ['projectName', 'fileName', 'date', 'importance', 'audioBuffer']) {
  for (const field of requiredFields) {
    if (!data.hasOwnProperty(field) || data[field] === '') {
      return `Property '${field}' is required and mustn't be empty!`;
    }
  }

  if (
    data.hasOwnProperty('projectName') &&
    (!VALID_REGEX.test(data.projectName) || data.projectName.length < 3 || data.projectName.length > 25)
  )
    return 'Project name contains invalid characters! Only letters, numbers, spaces, underscores and hyphens allowed. And the project name should contain between 3 and 25 characters!';

  if (
    data.hasOwnProperty('fileName') &&
    (!VALID_REGEX.test(data.fileName) || data.fileName.length < 3 || data.fileName.length > 25)
  )
    return 'File name contains invalid characters! Only letters, numbers, spaces, underscores and hyphens allowed. And the file name should contain between 3 and 25 characters!';

  if (
    data.hasOwnProperty('importance') &&
    (!Number.isInteger(data.importance) || data.importance < 1 || data.importance > 5)
  ) {
    return 'Importance must be an integer value between 1 and 5';
  }
  if (data.hasOwnProperty('date') && (isNaN(Date.parse(data.date)) || new Date(data.date) > Date.now()))
    return 'The date property is invald!';
  if (data.hasOwnProperty('audioBuffer') && !/^[A-Za-z0-9+/]*={0,2}$/.test(data.audioBuffer))
    return 'Invalid audio data';

  return null;
}

app.post('/save', async function (req, res) {
  try {
    const body = JSON.parse(req.body.toString('utf-8'));
    const error = validateRequest(body);

    if (error != null) {
      setResponseAndStatus(res, {error: error}, 400);
      return;
    }

    const sound = {
      projectName: body.projectName,
      fileName: body.fileName,
      date: body.date,
      importance: body.importance,
      location: body.location,
      audioBuffer: body.audioBuffer
    };

    // TODO -> IndexedDB
    const collection = db.collection('sounds');
    await collection.insertOne(sound);
    res.cookie('lastUsedProject', body.projectName);
    const result = {
      message: 'Sound saved successfully',
      fileName: body.fileName,
      projectName: body.projectName,
      timestamp: new Date().toISOString()
    };
    res.send(JSON.stringify(result));
  } catch (error) {
    console.error('Error saving sound:', error);
    res.status(500);
    res.type('application/json');
    res.send(
      JSON.stringify({
        error: 'Server error while saving sound',
        message: error.message
      })
    );
  }
});

app.get('/project-names', async function (req, res) {
  try {
    // TODO -> IndexedDB
    const projects = await db.collection('sounds').distinct('projectName');
    const lastUsedProject = req.cookies.lastUsedProject || null;
    res.json({
      projects: projects.filter(p => p),
      lastUsedProject: lastUsedProject || null
    });
  } catch (error) {
    console.error('Database error:', error);
    res.status(500).json({error: 'Server error'});
  }
});

app.get('/projects', async function (req, res) {
  try {
    // TODO -> IndexedDB
    const projectName = req.query.projectName?.toString().trim();
    if (projectName && projectName.length > 30) return res.status(400).json({error: 'Project name is too long!'});
    const sounds = await db
      .collection('sounds')
      .find(projectName ? {projectName} : {})
      .toArray();

    res.json({
      selectedProject: projectName || 'all',
      sounds: sounds,
      numSounds: sounds.length
    });
  } catch (error) {
    console.error('Database error:', error);
    res.status(500).json({error: 'Server error'});
  }
});

export default app;