// Dependencies declaration & setup

// fs is for working with files, aka the JSON file we want to use to store our labels data
const fs = require('fs');

// express is for setting up the server and make it works when users do their things in the browser
const express = require('express');
const app = express();
const path = require('path');

// the port is setted in the etc/nginx/sites-enabled under the location /collecting-labels
const port = 3124;

// express middleware for working with JSON between the server (this) and the client (all the things in the public folder)
app.use(express.urlencoded({ extended: true }));
app.use(express.json());

// serves the contents of the public folder as static resources
// i.e. then you can access it using https://hub.xpub.nl/soupboat/collecting-labels as root
app.use('/collecting-labels', express.static('public'))


// we dont need this now because express automatically uses the index.html file in the /public folder
// (still need to understand how to get a notification when someone connects, but maybe it is just a callbac to the app.use function of line 19whe 

// app.get('/collecting-labels', function(req, res) {
//       res.sendFile(path.join(__dirname, 'public', 'index.html'));
//       console.log('Someone connected!')
// });


// when a post request is made to the https://hub.xpub.nl/soupboat/collecting-labels url this function starts
app.post('/collecting-labels', function(req, res) {  

    // with fs we read the file labels.json inside the public folder 
    // it is there because we then use the same file in the client for drawing all the labels stored in the server
    // don't know if it is a good idea or not tho
    // for now oke
    
    // also: we need to check that the contents of the post request is what we want aka a label object, structured as we want ecc 
    // and not some other random thing, otherwise everything will break
    
    fs.readFile('public/labels.json', function(err, data) {
     if (err) throw err;
     // parse a JSON out of the labels.json file      
     let storage = JSON.parse(data)
     
     // insert the req.body (aka our label object) to the labels array present inside the labels.json file
     storage.labels.push(req.body)
     
     // overwrite the labels.json file with all the data
     // this will not be efficient in the long term, but then we may switch to a proper database and not this scissor and glue thing 
     fs.writeFile('public/labels.json', JSON.stringify(storage), (err)=>{
         if (err) throw err;
         console.log('Data written to file');})
    })
    
    // reply to the client 
    // TODO: sayng oke everything worked nice
    // for now it just echoes the incoming data
    res.send(req.body)
});


    // listen to the port we defined at the beginning aka wait for clients to connect there
app.listen(port, function() {
  console.log(`🧶  → Collecting Labels on port ${port}!`)
});