#include <Arduino.h>
#include <FS.h>                   //this needs to be first, or it all crashes and burns...
#include <LittleFS.h>
#include <string>
#include <ESP8266WiFi.h>          //https://github.com/esp8266/Arduino
#include <PubSubClient.h>
#include <Ticker.h>

#define BUILTIN_LED D15
#define TRIGGER_PIN    D7 
#define START_STOP_PIN D6



void reconnect();
void setup_wifi();
void datenSave(int wert);
int readDaten();
int saveKorektur(float wert);
float readKorectur();
void verifyFingerprint();
void callback(char* topic1, byte* payload, unsigned int length);
void pulse_pin(uint8_t pin);

WiFiClientSecure espClient;
PubSubClient client(espClient);

#include<mess_htu21.h>

#include <mess_BMP280.h>

#include <mess_Ub.h>

#include <messADS1115.h>

#include <mcp9808.h>


const char* ssid = STASSID;
const char* password = STAPSK;
String hostname = NAME;

const char *MyIP = KMYIP;
IPAddress ip;
IPAddress gateway;
IPAddress subnet(255, 255, 255, 0);
IPAddress dns; 
IPAddress secondaryDNS(8, 8, 8, 8);


const char* mqtt_fprint = "a3:44:1d:aa:6e:e5:c7:55:02:20:98:ea:9b:df:1a:42:a2:f3:e3:0d";
const char* mqtt_user =   "mqtt";
const char* mqtt_pass =   "fische";

const unsigned long interval  = TINTERVAL * 60000000LU; // Minuten * Mikrosekunden für Sleep Mode
const unsigned long intervalLowBatt = TLOWBATT * 60000000LU; // Minuten * Mikrosekunden für Sleep Mode, Akku entladen
const unsigned long stoerung  = TERROR * 60000000LU; // Minuten * Mikrosekunden für Sleep Mode

unsigned long previousMillis = 0;

long deviceId;
char sID[16];
char clientName[30];
unsigned long startTime;
unsigned long endTime;
char topic[100];
char topic_1[50];
char topicWert[20];
char msg[20];
int SystemStatus;



void setup() {
  pinMode(TRIGGER_PIN, OUTPUT);
  pinMode(START_STOP_PIN, OUTPUT);
  digitalWrite(TRIGGER_PIN, HIGH);
  digitalWrite(START_STOP_PIN, LOW);
  pulse_pin(TRIGGER_PIN);      // ==> 1
  Serial.begin(74880);
  while ( !Serial ) delay(100);   // wait for native usb
  Serial.println(F("BMP280 Sensor event test"));
  Serial.println("HTU21D-F test");
  startTime = millis();
  WiFi.mode( WIFI_OFF );
  WiFi.forceSleepBegin();
  pulse_pin(TRIGGER_PIN);      // ==> 1
  Serial.println();
  //Serial.println("Testpunkt 1");
  /* if (!LittleFS.begin()) {
    Serial.println("LittleFS mount failed");
    delay(5000);
    return;
  } */
  //Serial.println("Testpunkt 2");
  /* Dir dir = LittleFS.openDir("/data");
  while (dir.next()) {
    Serial.print(dir.fileName());
    if(dir.fileSize()) {
        File f = dir.openFile("r");
        Serial.println(f.size());
    }
  } */
  //Serial.println("Testpunkt 3");
  Serial.println();
  Serial.println();
  Serial.println();
  //SystemStatus = readDaten();
  //korectur = readKorectur();
  //Serial.print("Korektur: "); Serial.println(korectur,6);
  pinMode(BUILTIN_LED, OUTPUT);     // Initialize the BUILTIN_LED pin as an output
  //digitalWrite(BUILTIN_LED, LOW);
  //digitalWrite(BUILTIN_LED, HIGH);
  //Serial.print("STATUS (Systemmeldung): "); Serial.println(SystemStatus);
  #if (MQTT == 0)
  init_HTU21();
  Init_BMP280();
  //initADS();
  //init_MCP9808();
  #endif
  AKKU = getBattery();  // ca. 170 ms
  // ca. 280 ms
  if (F_HTU_21D == true){
    read_HTU21D();
  }
  read_BMP_280();
  //MessungADS();
  setup_wifi();  // ca. 4,5 s
  // ca. 12ms
  // ---------------------------------
  // Status ändern !!! 0
  //datenSave(0);
  // ---------------------------------
  //digitalWrite(BUILTIN_LED, HIGH);
  deviceId = ESP.getChipId();
  sprintf(sID, "%010ld", deviceId);
  Serial.print("ID: \t\t"); Serial.println(deviceId);
  
  // ca. 5 s
  espClient.setFingerprint(mqtt_fprint); 
  client.setServer(mqtt_server, mqtt_port);
  client.setCallback(callback);
  //----------
  
}

void loop() {
  unsigned long Pause = 0;
  if (!client.connected()) {
    reconnect();
  }
  //client.loop();
  int currentMillis = millis();
  if (currentMillis - previousMillis >= 10000) {
    previousMillis = currentMillis;
    read_HTU21D();
    read_BMP_280();
    //valTemp = getTemperature_MCP9808();
    dtostrf(AKKU,8,2,ADSData.Akku);
    sprintf(topic, "%s%s%s", "hjk/devices/", hostname.c_str(), "/telemetry/battery" );
    client.publish(topic, ADSData.Akku, true);
    #if(MQTT == 0)
    M2M_HTU21D(hostname.c_str());
    M2M_BMP280(hostname.c_str());
    M2M_Temperatur_MCP9808(hostname.c_str());
    #endif
    long int Feldstaerke = WiFi.RSSI();
    sprintf(msg,"%ld", Feldstaerke);
    sprintf(topic, "%s%s%s", "hjk/devices/", hostname.c_str(), "/telemetry/RSSI" );
    client.publish(topic, msg, true);
    client.loop();
    delay(500);
    digitalWrite(BUILTIN_LED, HIGH);
    /* ESP.deepSleep(5e6);
    delay(100); */
    endTime = millis();
    if (AKKU < MinimalSpannung){
      // ---------------------------------
      // Status ändern !!! -5
      datenSave(-5);
      // ---------------------------------
      Pause = intervalLowBatt -((endTime - startTime) * 1000); // Pause ca. 60 Minuten
      Serial.println("AKKU entladen!");
    }
    else{
      Pause = interval -((endTime - startTime) * 1000);      // Pause ca. 15 Minuten
    }
    if(Pause <=0){
      Pause = 1;
    }
    //ESP.restart();
    Serial.print("Ich gehe für ca. "); Serial.print((Pause/1000/1000/60)+1); Serial.println( " Minuten schlafen.");
    //ESP.deepSleep(Pause, WAKE_RF_DISABLED); // Pause  
    digitalWrite(START_STOP_PIN, !LOW);
    #if (DEBUG == 1)
    ESP.deepSleep(10e6);
    #else
    ESP.deepSleep(Pause);
    #endif
    
    delay(100); 
  }
}

void setup_wifi() {

  long ErrCount = 0;

  delay(10);
  // We start by connecting to a WiFi network
  Serial.println();
  Serial.print("Connecting to ");
  Serial.print(ssid);
  Serial.print(" ");

  WiFi.forceSleepWake();
  delay( 1 );
  WiFi.persistent( false );
  WiFi.mode( WIFI_STA );
  //WiFi.setHostname(hostname.c_str()); //define hostname
  WiFi.hostname(hostname.c_str());
  WiFi.mode( WIFI_STA );
  if (!ip.fromString(MyIP)) { // try to parse into the IPAddress
    Serial.println("UnParsable IP");
    }
  if (!dns.fromString(DNS)) { // try to parse into the IPAddress
    Serial.println("UnParsable DNS");
    }
  if (!gateway.fromString(GATEWAY)) { // try to parse into the IPAddress
    Serial.println("UnParsable GATEWAY");
    }
  //WiFi.config( ip, dns, gateway, subnet );
  if (!WiFi.config(ip, gateway, subnet, dns, secondaryDNS))
  {
    Serial.println("STA Failed to configure");
  }

  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
    ErrCount ++;
    if (ErrCount >= MaxErrCount){
      // ---------------------------------
      // Status ändern !!! -1
      datenSave(-1);
      // ---------------------------------
      endTime = millis();
      unsigned long Pause = stoerung -((endTime - startTime) * 1000); // Pause
      Serial.println();
      Serial.println("STÖRUNG WiFi.");
      Serial.print("Ich gehe für ca. "); Serial.print(Pause/1000/1000/60); Serial.println( " Minuten schlafen.");
      ESP.deepSleep(Pause, WAKE_NO_RFCAL); // Pause  
      delay(100);
      }
    }
  Serial.println(" WiFi connected");
  Serial.print("IP address: \t");
  Serial.print(WiFi.localIP()); Serial.print("\tRESSI: "); Serial.println(WiFi.RSSI());
  /* delay(2000);
  ESP.deepSleep(2e6, WAKE_RF_DEFAULT);
  delay(100); */
} 

void callback(char* topic1, byte* payload, unsigned int length)
{
  Serial.print("Message arrived [");
  Serial.print(topic1);
  Serial.print("] ");
  for (unsigned int i = 0; i < length; i++) {
    msg[i] = (char)payload[i];
  }
  msg[length] = '\0';
  Serial.println(msg);
  if(strcmp(topic1, topic_1)== 0){
    Serial.print(msg);
    Serial.println();
    korectur = atof(msg);
    Serial.print("Korektur:\t");Serial.println(korectur, 8);
    int er = saveKorektur(korectur);
    if (er != 0){
      Serial.println("Daten konnten nicht gespeichert werden.");
    }
    float test = readKorectur();
    Serial.print("Korektur:\t");Serial.println(test, 8);
  }
}

void reconnect() {
  // Loop until we're reconnected
  sprintf(clientName, "%s%s", "ESP8266Client", sID);
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    verifyFingerprint();
    // Attempt to connect
    if (client.connect(clientName)) {
      Serial.println("connected");
      // Once connected, publish an announcement...
      client.publish("outTopic", "hello world");
      // ... and resubscribe
      client.subscribe("inTopic");
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      // Wait 5 seconds before retrying
      delay(5000);
      ESP.restart();
    }
  }
}

void datenSave(int wert){
  File k = LittleFS.open("/status.txt", "w");
  if(!k){
    Serial.println("file open failed");
  }
  k.println(wert);
  k.close();
}

int readDaten()
{
  int Error;
  File k = LittleFS.open("/status.txt", "r");
  if(!k){
    Serial.println("file open failed");
    Error = -10;
  }else{
    String data = k.readString();
    Error = data.toInt();  
    k.close();
  }
  return Error;
}

int saveKorektur(float wert){
  int Error = 0;
  File k = LittleFS.open("/Korektur.txt", "w");
  if(!k){
    Serial.println("file open failed");
    Error = -1;
  }else{
    k.println(String(wert,8));
    k.close();
  }
  return Error;
}

float readKorectur(){
  float Korektur;
  File k = LittleFS.open("/Korektur.txt", "r");
  if(!k){
    Serial.println("file open failed");
    Korektur = 1.00;
  }else{
    String data = k.readString();
    Korektur = data.toFloat();  
    k.close();
  }
  return Korektur;
}

void verifyFingerprint() {
  unsigned long Pause = 0;
  if(client.connected() || espClient.connected()) return; //Already connected
  
  Serial.print("\n\tChecking TLS @ ");
  Serial.print(mqtt_server);
  Serial.print("...");
  
  if (!espClient.connect(mqtt_server, mqtt_port)) {
    //Serial.println("\n\tConnection failed. Rebooting.");
    Serial.println("\n\tConnection failed.");
    Serial.flush();
    //blink.detach();
    //blink.attach(0.05, flip);
    //delay(5000);
    endTime = millis();
    Pause = stoerung -((endTime - startTime) * 1000);      // Pause ca. 15 Minuten
    Serial.print("\tIch gehe für "); Serial.print((Pause/1000/1000/60)+1); Serial.println( " Minuten schlafen.");
    ESP.deepSleep(Pause, WAKE_RF_DISABLED); // Pause  
    delay(500);   
  }
  espClient.stop();
  delay(100);
}
void pulse_pin(uint8_t pin)
{
  digitalWrite(pin, LOW);
  delay(1);
  digitalWrite(pin, HIGH);	
}