#include <SoftwareSerial.h>
SoftwareSerial esp8266(3, 2); // RX | TX

#define DEBUG true

int ERROR_PIN = 7;
int OK_PIN = 6;

char serialbuffer[600];//serial buffer for request url
const String ssid = "heimnetzlannet";
const String pw = "77041084";

int state = 0;

void setup()
{
  delay(1000);
  /**
  // init leds
  pinMode(ERROR_PIN, OUTPUT);
  pinMode(OK_PIN, OUTPUT);

  state = 0;

  digitalWrite(ERROR_PIN, HIGH);
  digitalWrite(OK_PIN, LOW);
  /**/
  // init ports
  Serial.begin(9600);
  Serial.println("initializing esp8266 port...");
  esp8266.begin(9600);
  delay(400);
  // init WIFI
  /**/
  while(!esp8266.available())
  {
    Serial.print("...");
    delay(300);
  }
  Serial.println();
  Serial.println("FINISH esp8266 initializing!");
  //
  /**
  digitalWrite(ERROR_PIN, LOW);
  digitalWrite(OK_PIN, HIGH);
  state = 1;
  /**/
  /**/
  // Setup connection
  sendData("print(wifi.sta.getip())\r\n",2000,DEBUG);
  sendData("wifi.setmode(wifi.STATION)\r\n",1000,DEBUG);
  //sendData("AT+CWMODE=1\r\n",2000,DEBUG);
  //sendData("AT+RST\r\n",3000,DEBUG);
  //sendData("AT+CWLAP\r\n",6000,DEBUG);
  sendData("wifi.sta.config(\"" + ssid + "\",\""+ pw +"\")\r\n",4000,DEBUG);
  sendData("print(wifi.sta.getip())\r\n",4000,DEBUG);

  delay(2000);
  // test output
  Createconnection("");
  /**/
  /**/
}

void loop()
{
  if (esp8266.available())
  {
    char c = esp8266.read() ;
    Serial.print(c);
    /**
    if(state == 0)
    {
      state = 1;
      digitalWrite(ERROR_PIN, LOW);
      digitalWrite(OK_PIN, HIGH);
    }
    /**/
  }
  else
  {
    /**
    if(state > 0)
    {
      state = 0;
      digitalWrite(ERROR_PIN, HIGH);
      digitalWrite(OK_PIN, LOW);
    }
    /**/
  }
  if (Serial.available())
  {
    char c = Serial.read();
    esp8266.print(c);
  }
}

//////////////////////////////////////////////////////////////////////////////
char* sendData(String command, const int timeout, boolean debug)
{
  String response = "";
  int idx = 0;
  esp8266.print(command); // send the read character to the esp8266
  long int time = millis();
  while( (time+timeout) > millis())
  {
    while(esp8266.available())
    {
      // The esp has data so display its output to the serial window
      char c = esp8266.read(); // read the next character.
      serialbuffer[idx] = c;
      //response+=c;
      idx++;
    }
  }
  serialbuffer[idx] = '\0';
  if(debug)
  {
    Serial.print(serialbuffer);
  }
  return serialbuffer;
}
//////////////////////////////////////////////////////////////////////////////////
String Createconnection(String url)
{
  String tmpCreateConnection = "conn=net.createConnection(net.TCP, false)\r\n";
  String tmpReceive = "conn:on(\"receive\", function(conn, pl) print(pl) end)\r\n";
  String tmpConnect = "conn:connect(80,\"121.41.33.127\")\r\n";
  String tmpSend = "conn:send(\"GET / HTTP/1.1\r\nHost: www.nodemcu.com\r\nConnection: keep-alive\r\nAccept: */*\r\n\r\n\")";
  sendData(tmpCreateConnection, 4000, DEBUG);
  sendData(tmpReceive, 4000, DEBUG);
  sendData(tmpConnect, 4000, DEBUG);
  sendData(tmpSend, 15000, DEBUG);
  WebRequest("");
}
//////////////////////////////////////////////////////////////////////////////////
String WebRequest(String url)
{
  //conn:send("GET / HTTP/1.1\r\nHost: www.nodemcu.com\r\nConnection: keep-alive\r\nAccept: */*\r\n\r\n")
  String tmpGET = "conn:send(\"GET / HTTP/1.1\r\n";
  String tmpHost = "Host: www.nodemcu.com\r\n";
  String tmpConnection = "Connection: keep-alive\r\n";
  String tmpAccept = "Accept: */*\r\n\r\n\")\r\n";
  sendData(tmpGET, 1500, DEBUG);
  sendData(tmpHost, 1500, DEBUG);
  sendData(tmpConnection, 1500, DEBUG);
  sendData(tmpAccept, 6000, DEBUG);
}