#include <WiFi.h>

#include "SSD1306.h" // alias for `#include "SSD1306Wire.h"

// jfs Wemos lolin32
// jfs Heltec WiFi kit 32 (weisses Board)
// #define HELTEC
#define DEBUG

// Initialize the OLED display using Wire library
#ifdef HELTEC
SSD1306  display(0x3c, 4, 15);
#else
SSD1306  display(0x3c, 5, 4);
#endif

#define MSG 50 // Maximale Länge der Nachricht

//WiFiServer server(6969); // Server hört auf Port 8088
const char* server = "192.168.2.61"; // IP-Adresse des Node-RED-Servers
const int port = 6969; // Port
unsigned long previousMillis = 0; // Letzter Update-Zeitstempel
const long interval = 1000;       // Sende-Intervall in ms

//// WIFI
const int mxSize=4;
String ssids[mxSize] ={"GAST","pipanet","FRITZ!Box Gastzugang","WLAN-DE8245"};
String ssidp[mxSize] = {"passatvr6","passatvr6","praxis123","4955065570896956"};
boolean conok =false;

void netfound(int i){
     display.clear();
     display.setColor(BLACK);
     display.fillRect(0, 0, 128, 10);
     display.setColor(WHITE);
     display.drawString(0,0,String(i));
     display.drawString(20,0,"networks found");
     display.display(); 
}

boolean init_wifi(){
    boolean ok = false;
    WiFi.mode(WIFI_STA);
    WiFi.disconnect();
    delay(100);
    int n = WiFi.scanNetworks();
    Serial.println("scan done");
    if (n == 0) {
        Serial.println("no networks found");
        netfound(0);
    } else {
        Serial.print(n);
        Serial.println(" networks found");
        netfound(n);        
        for (int i = 0; i < n; ++i) {
            for (int p=0;p<mxSize;p++){
              if (WiFi.SSID(i).equals(ssids[p])){
                String pp = ssidp[p];
                String ss = WiFi.SSID(i);
                WiFi.begin(ss.c_str(), pp.c_str());
                i=n;
                ok = true;
              }
            }
            delay(10);
        }
    }     
    return ok;
}  
///// WIFI


void setup() {
  // test
  adcAttachPin(25);
  analogSetClockDiv(1); // 1338mS
  analogSetPinAttenuation(26,ADC_0db);
  
  // put your setup code here, to run once:
#ifdef HELTEC
  pinMode(16,OUTPUT); digitalWrite(16, LOW); delay(50); digitalWrite(16, HIGH);
#endif 
  Serial.begin(115200); 
  display.init();
  display.flipScreenVertically();
  display.clear();
  display.drawString(0, 0, "Starting...");
  display.display();
  while (!init_wifi()){
    delay(200);  
  }
  display.drawString(0, 10, "Connecting to WiFi...");
  display.display();
  while (WiFi.status() != WL_CONNECTED) {
      delay(500);
      Serial.print(".");
  }
  display.drawString(0, 20, "\nWiFi connected, IP address: "); 
  display.drawString(0, 30, WiFi.localIP().toString());
  //server.begin(); // server starten
  display.display();
  }

void loop() {
  //String msg = ""; 
  // Nachricht// Auf einen neuen Client warten
  //WiFiClient client1 = serverin.available();
  //uint8_t data[MSG];
  //if (client1) {
  //Serial.println("New client");
  // Prüfen, ob Client verbunden
  // while (client1.connected()) {
  //  if (client1.available()) {
  //    int len = client1.read(data, MSG);
  //    if (len < MSG) data[len] = '\0';
  //    else data[MSG] = '\0';
  //    Serial.print("Clients message: ");
  //    msg = (char*)data;
  //    Serial.println(msg);
  //    client1.stop();
  //    }
  // }
  //}
  //unsigned long currentMillis = millis();
  //if (currentMillis - previousMillis >= interval) {
   // previousMillis = currentMillis;
    //Serial.print("Connecting to ");
    //Serial.println(server);
    //WiFiClient client; // Für TCP-Connection
    //if (!client.connect(server, port)) {
    //  Serial.println("Connection failed");
    //  return;
    //}
    int analogValue = analogRead(36);// Messwerterfassung
    //Serial.println(analogValue);
    //client.println(analogValue); // Sende Daten zum Server
   // client.stop();// Schließe TCP-Verbindung
  //}
   
  
  double volt2 = ReadVoltage(25)*127000/27000;
  double volt1 = ReadVoltage0dB(26);
  Serial.print(volt2,1);
  Serial.print("   ");
  Serial.println(volt1);
  display.clear();
  display.drawString(0, 10, WiFi.localIP().toString());
  display.drawString(0,20,"Volt 1 "+String(volt1));
  display.drawString(0,30,"Volt 2 "+String(volt2));
  display.display();
  delay(100);
}


// test
double ReadVoltage0dB(byte pin){
  double reading = analogRead(pin); // Reference voltage is 3v3 so maximum reading is 3v3 = 4095 in range 0 to 4095
  if(reading < 1 || reading > 4095) return 0;
  return reading/4095;
}
double ReadVoltage(byte pin){
  double reading = analogRead(pin); // Reference voltage is 3v3 so maximum reading is 3v3 = 4095 in range 0 to 4095
  if(reading < 1 || reading > 4095) return 0;
  // return -0.000000000009824 * pow(reading,3) + 0.000000016557283 * pow(reading,2) + 0.000854596860691 * reading + 0.065440348345433;
  return -0.000000000000016 * pow(reading,4) + 0.000000000118171 * pow(reading,3)- 0.000000301211691 * pow(reading,2)+ 0.001109019271794 * reading + 0.034143524634089;
} // Added an improved polynomial, use either, comment out as required