// defines:
// variable ws (the websocket)
// variable wsReady (boolean)
// variable wsVerbose (boolean)
// wsSend(msg) (send a message when websocket is ready)
// wsOnMessage(function) (react to messages)
sclass HInitWebSocket {
  S wsVar = "ws";
  S onOpen;
  S readyMsg = "WebSocket ready!";
  bool handleEvals = true;
  
  S headStuff aka get() {
    ret hreconnectingWebSockets() + hscript([[
      var wsReady = false;
      var wsInitialMsgs = [];
      var wsMsgListeners = [];
      var wsVerbose = false;
      var wsURL = ((window.location.protocol === "https:") ? "wss://" : "ws://") + window.location.host
        + window.location.pathname + window.location.search;
        
      var ]] + wsVar + [[ = new ReconnectingWebSocket(wsURL);
      
      ]] + wsVar + [[.onopen = function(event) {
        wsReady = true;
        console.log(]] + jsQuote(readyMsg + " ") + [[+ wsURL);
        
        ws.onmessage = function(event) {
          wsMsgListeners.forEach(function(listener) {
            listener(event);
          });
        };

        wsInitialMsgs.forEach(function(msg) {
          if (wsVerbose) console.log("Sending initial msg: " + msg);
          ws.send(msg);
        });
        wsInitialMsgs = [];
        ]] + jsDropTrailingComments(onOpen) + [[ };
        
      ]] + wsVar + [[.onmessage = function(event) {
        ]] + unnull(onMessage) + [[
      };
      
      // send it now if ws is open already or when ws was opened
      function wsSend(msg) {
        if (wsReady) {
        wsInitialMsgs.push(msg);
          if (wsVerbose) console.log("Sending initial msg: " + msg);
          ws.send(msg);
        }
      }
      
      function wsOnMessage(f) {
        wsMsgListeners.push(f);      
      }
      
      ]] + (!handleEvals ? "" : "wsOnMessage(" + js_evalOnWebSocketMessage() + ");\n")
    );
  }
}