#include <ESP8266WebServer.h>
#include <WiFiClient.h>
#include <ESP8266WiFi.h>

const char* ssid = "mathematics";
const char* password = "fzbyj8r7pdEk";

ESP8266WebServer server(7000);

String page = "";
String txt = "";
String txx = "";

void setup() {

  delay(1000);
  Serial.begin(115200);
  WiFi.begin(ssid, password);
  Serial.println("");

  // wait for connection
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");  
  }
  Serial.print("connected to ");
  Serial.println(ssid);
  Serial.print("ip: ");
  Serial.println(WiFi.localIP());
    server.on("/txt.txt", []() {
    server.send(200, "text/html", txt);
    });
    server.on("/", []() {
      page = "<h1>txx [  ] -</h1> <p id=\"txt\">""</p>\r\n";
      page += "<script>\r\n";
      page += "var x = setInterval(function() {loadData(\"txt.txt\",updateData)}, 1000);\r\n";
      page += "   function loadData(url, callback){\r\n";
      page += "   var xhttp = new XMLHttpRequest();\r\n";
      page += "   xhttp.onreadystatechange = function(){\r\n";
      page += "     if(this.readyState == 4 && this.status == 200){\r\n";
      page += "       callback.apply(xhttp);\r\n";
      page += "     }\r\n";
      page += "   };\r\n";
      page += "xhttp.open(\"GET\", url, true);\r\n";
      page += "xhttp.send();\r\n";
      page += "}\r\n";
      page += "function updateData(){\r\n";
      page += " document.getElementById(\"txt\").innerHTML = this.responseText;\r\n";
      page += "}\r\n";
      page += "</script>\r\n";
      server.send(200, "text/html", page);
    });

  server.begin();
  Serial.println("started");
}

void loop() {

   while (Serial.available() == 0) {} 
   String txx = Serial.readStringUntil('\n');
   txt = txx;
   Serial.println(txt);
   server.handleClient();
}