#include <Arduino.h>
#include <WiFiManager.h>
#include <ArduinoWebsockets.h>

WiFiManager wifiManager;

using namespace websockets;
WebsocketsClient client;

static const char SERVER[] = "ws://192.168.1.149"; // my laptop's IP

void onMessageCallback(WebsocketsMessage message) {
    Serial.print("Got Message: ");
    Serial.println(message.data());
}

void onEventsCallback(WebsocketsEvent event, String data) {
    if(event == WebsocketsEvent::ConnectionOpened) {
        Serial.println("Connnection Opened");
    } else if(event == WebsocketsEvent::ConnectionClosed) {
        Serial.println("Connnection Closed");
    } else if(event == WebsocketsEvent::GotPing) {
        Serial.println("Got a Ping!");
    } else if(event == WebsocketsEvent::GotPong) {
        Serial.println("Got a Pong!");
    }
}

void setup()
{
  Serial.begin(115200);
  wifiManager.autoConnect();

  // Setup Callbacks
  client.onMessage(onMessageCallback);
  client.onEvent(onEventsCallback);
  client.connect(SERVER);

  client.send("Hello");
  client.ping();
}

void loop()
{
  client.send(String(millis()));
  client.poll();
  delay(500);
}

$ sudo nc -l 80 -vvvv
Listening on [0.0.0.0] (family 0, port 80)
Connection from espressif 62507 received!
GET / HTTP/1.1
Host: 192.168.1.149
Upgrade: websocket
Connection: Upgrade
Sec-WebSocket-Key: MDEyMzQ1Njc4OWFiY2RlZg==
Sec-WebSocket-Version: 13

sudo websocat -s 80 -vvvv
Listening on ws://127.0.0.1:80/
[INFO  websocat::lints] Auto-inserting the line mode
[DEBUG websocat] Done third phase of interpreting options.
[DEBUG websocat] Done fourth phase of interpreting options.
[DEBUG websocat] Preparation done. Now actually starting.
[INFO  websocat::sessionserve] Serving Message2Line(WsServer(TcpListen(V4(127.0.0.1:80)))) to BroadcastReuser(Line2Message(Stdio)) with Options { websocket_text_mode: true, websocket_protocol: None, websocket_reply_protocol: None, udp_oneshot_mode: false, unidirectional: false, unidirectional_reverse: false, exit_on_eof: true, oneshot: false, unlink_unix_socket: false, exec_args: [], ws_c_uri: "ws://0.0.0.0/", linemode_strip_newlines: false, linemode_strict: false, origin: None, custom_headers: [], custom_reply_headers: [], websocket_version: None, websocket_dont_close: false, one_message: false, no_auto_linemode: false, buffer_size: 65536, broadcast_queue_len: 16, read_debt_handling: Warn, linemode_zero_terminated: false, restrict_uri: None, serve_static_files: [], exec_set_env: false, reuser_send_zero_msg_on_disconnect: false, process_zero_sighup: false, process_exit_sighup: false, socks_destination: None, auto_socks5: None, socks5_bind_script: None, tls_domain: None, tls_insecure: false, max_parallel_conns: None, ws_ping_interval: None, ws_ping_timeout: None }

*WM: [1] AutoConnect 
*WM: [2] ESP32 event handler enabled 
*WM: [2] Connecting as wifi client... 
*WM: [1] STA static IP:
*WM: [2] setSTAConfig static ip not set 
*WM: [3] WIFI station disconnect 
*WM: [1] Connecting to saved AP: XXXXXXXX
*WM: [3] Using Password: XXXXXXXX
*WM: [3] WiFi station enable 
*WM: [1] connectTimeout not set, ESP waitForConnectResult... 
*WM: [2] Connection result: WL_CONNECTED
*WM: [3] lastconxresult: WL_CONNECTED
*WM: [1] AutoConnect: SUCCESS 
*WM: [1] STA IP Address: 192.168.1.29
[E][WiFiClient.cpp:282] setOption(): fail on fd 54, errno: 22, "Invalid argument"
[E][WiFiClient.cpp:365] write(): fail on fd 54, errno: 104, "Connection reset by peer"
Guru Meditation Error: Core  1 panic'ed (LoadProhibited). Exception was unhandled.
Core 1 register dump:
PC      : 0x4012d2c0  PS      : 0x00060830  A0      : 0x8012d721  A1      : 0x3ffb1b90  
A2      : 0x00000000  A3      : 0x3ffb1bef  A4      : 0x00000001  A5      : 0x00000001  
A6      : 0x00000000  A7      : 0xffffffa7  A8      : 0x00000000  A9      : 0x00000000  
A10     : 0x00000000  A11     : 0x3ffc8dcc  A12     : 0x00000000  A13     : 0x00000001  
A14     : 0x00060e20  A15     : 0x00000000  SAR     : 0x00000004  EXCCAUSE: 0x0000001c  
EXCVADDR: 0x00000008  LBEG    : 0x4000c2e0  LEND    : 0x4000c2f6  LCOUNT  : 0xffffffff  

Backtrace: 0x4012d2c0:0x3ffb1b90 0x4012d71e:0x3ffb1bb0 0x40173692:0x3ffb1be0 0x400dc65b:0x3ffb1c10 0x400dc2e6:0x3ffb1c30 0x400dcefa:0x3ffb1d70 0x400d20ad:0x3ffb1f60 0x400e0abf:0x3ffb1fb0 0x4008b015:0x3ffb1fd0

Rebooting...