/*
Simple basic example From ESP32/ESP8266 as Client to Nodejs as a server via TCP Protocol.
*/

//-----------  ESP32 as TCP Client----------------
// file .ino

#include "WiFi.h"
const char* ssid      = "SSID";
const char* password  = "password";
void setup() {
  Serial.begin(115200);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.println("Connecting to WiFi..");
  }
    Serial.println("");
    Serial.println("WiFi connected");
    Serial.println("IP address: ");
    Serial.println(WiFi.localIP());
}
 
void loop()
{
    const uint16_t port = 52275; // port TCP server
    const char * host = "192.168.1.19"; // ip or dns
    Serial.print("Connecting to ");
    Serial.println(host);
    // Use WiFiClient class to create TCP connections
    WiFiClient client;
    if (!client.connect(host, port)) {
        Serial.println("Connection failed.");
        Serial.println("Waiting 5 seconds before retrying...");
        delay(5000);
        return;
    }
    // This will send a request to the server
    //uncomment this line to send an arbitrary string to the server
    //client.print("Send this data to the server");
    //uncomment this line to send a basic document request to the server
    client.print("hello server im from esp");
  int maxloops = 0;
  //wait for the server's reply to become available
  while (!client.available() && maxloops < 1000)
  {
    maxloops++;
    delay(1); //delay 1 msec
  }
  if (client.available() > 0)
  {
    //read back one line from the server
    String line = client.readStringUntil('\r');
    Serial.println(line);
  }
  else
  {
    Serial.println("client.available() timed out ");
  }

    Serial.println("Closing connection.");
    client.stop();

    Serial.println("Waiting 5 seconds before restarting...");
    delay(5000);
}


// ------------------- NodeJS TCP server ------------------------------
// file.js

var net = require('net');
var textChunk = '';
var server = net.createServer(function(socket) {
	socket.write('callback server\r\n');
	socket.on('data', function(data){
		console.log(data);
		textChunk = data.toString('utf8');
		console.log('from server'+textChunk);
		socket.write(textChunk);
	});
});
server.listen(52275, '0.0.0.0');