var http = require('http'),
    url  = require('url'),
    fs   = require('fs'),
    qs   = require('querystring');

http.createServer(function(req, res){

  if (req.method == 'POST') {
    var body = '';

    req.on('data', function (chunk) {
        body += chunk;
    });

    req.on('end', function (){
      var post = qs.parse(body);

      fs.readFile('tasks.json', function(err, data){
        if (err) throw err;
        var tasks = JSON.parse(data);

        switch (url.parse(req.url).pathname) {   // checking post destination {new task, edit task, complete task}
          case '/add':
            var newTask = {};
            newTask.id = post.id;
            newTask.text = post.text;
            newTask.lastupdate = post.lastupdate;
            newTask.complete = false;
            tasks.tasks.push(newTask);
            break;
          case '/edit':
            tasks.tasks[post.id] = {
              "id":post.id,
              "text":post.text,
              "lastupdate":post.lastupdate
            };
            break;
          case '/complete':
            tasks.tasks[post.id].complete = true;
        }

        fs.writeFile('tasks.json', JSON.stringify({tasks:tasks.tasks}), function(err, data){  // write changed
          if (err) throw err;
          res.writeHead(200, {"Content-type": "text/plain"});
          res.end('OK');
        });

      });

    });

  } else {
    switch (url.parse(req.url).pathname) {                             // checking mime type from request
      case '/':
        fs.readFile('index.html', function (err, data) {
          if (err) throw err;
          res.writeHead(200, {"Content-type": "text/html"});
          res.write(data);
          res.end();
        });
        break;
      case '/jquery-1.7.2.min.js':
        fs.readFile('jquery-1.7.2.min.js', function (err, data) {
          if (err) throw err;
          res.writeHead(200, {"Content-type": "text/javascript"});
          res.write(data);
          res.end();
        });
        break;
      case '/tasks.json':
        fs.readFile('tasks.json', function (err, data) {
          if (err) throw err;
          res.writeHead(200, {"Content-type": "text/plain"});
          res.end(data);
          res.end();
        });
        break;
      default:
        res.writeHead(404, {"Content-type": "text/plain"});
        res.end('Not found');
        res.end();
        break;
    }
  }
}).listen(3000);