#include <ESP8266WiFi.h>
#include <ESP8266mDNS.h>

bool useStaticIP = false;
#ifndef STASSID
  #define STASSID "DWI 2319"
  #define STAPSK  "*65S265u"
#endif

const char* ssid = STASSID;
const char* password = STAPSK;
String staticIP      = "192.168.0.100";
String staticGateway = "192.168.0.1";
String staticSubnet  = "255.255.255.0";
String staticDNS     = "192.168.0.1";
String mdnsPrefix    = "SMART-UPS"; //for fast access like http://smart-ups.local

static volatile bool wifiStarted = false;
static volatile uint32_t wifiNextCheckTick = 0;
static volatile bool wifiConnected = false;
static volatile bool wifiConnecting = false;
static volatile uint8_t wifiCurrentState = 0;
static volatile bool setWifiConfig = false;

static volatile uint8_t wifiSignalLevel = 0; //0=none, 1=low, 2=medium, 2=high

long rssi = -999;

void WiFiManagerRoutine() {
  int8_t wifiState = WiFi.status();
  bool isWifiConnected = wifiState == WL_CONNECTED;
  if (isWifiConnected) wifiConnecting = false;
  if (wifiConnected != isWifiConnected){
     setWifiConfig = true; //reset config on reconnect
     wifiConnected = isWifiConnected;
     if (wifiConnected) wifiCurrentState = 2; //connected
  }

  //wifi signal update
  rssi = WiFi.RSSI();
  if (rssi <= -80){
    wifiSignalLevel = 1;
  }else if (rssi > -80 && rssi <= -70){
    wifiSignalLevel = 2;
  }else if (rssi > -70 && rssi <= -60){
    wifiSignalLevel = 3;
  }else{
    wifiSignalLevel = 3;
  }
  
  if (!isWifiConnected){
    if (wifiState==WL_NO_SSID_AVAIL || wifiState==WL_CONNECT_FAILED || wifiState==WL_CONNECTION_LOST) {
      wifiConnecting = false;
      wifiCurrentState=0;
      wifiSignalLevel = 0;
    }
    
    if (!wifiStarted || (millis() - wifiNextCheckTick) >= 30000UL){ //check each 30seconds
      wifiStarted = true;
      Serial.print("Connecting to ");
      Serial.println(ssid);
      WiFi.setOutputPower(20.5);//set to max dbm for reliability (for highest RF power output, supply current ~ 80mA)
      //WiFi.setOutputPower(0);//(for lowest RF power output, supply current ~ 70mA)
      WiFi.mode(WIFI_STA);
      WiFi.begin(ssid, password);
      wifiNextCheckTick = millis(); //next 30 seconds check again
      wifiConnecting = true;
      wifiCurrentState = 1; //connecting
    }
  }else{
    if (!wifiStarted){
      wifiStarted = true;
      setWifiConfig = true;
    }
    if (setWifiConfig){
      //set connection on first time connected
      setWifiConfig = false;
      
      WiFi.setAutoReconnect(true);
      WiFi.persistent(true);
      
      if (useStaticIP){
        IPAddress ip, gateway, subnet, dns;
        bool b = ip.fromString(staticIP);
        b = gateway.fromString(staticGateway);
        b = subnet.fromString(staticSubnet);
        b = dns.fromString(staticDNS);
        WiFi.config(ip, gateway, subnet, dns);
      }
      
      Serial.print("Connected to ");
      Serial.println(ssid);
      Serial.print("IP address: ");
      Serial.println(WiFi.localIP());
      if (MDNS.begin(mdnsPrefix)) {
        Serial.print("MDNS responder started as ");
        Serial.print(mdnsPrefix);
        Serial.println(".local");
      }
    }

    MDNS.update();
    
  }
  
}