//ESP32 MQTT + Deep Sleep + Power Reset

//WiFi and MQTT
#include "WiFi.h"                                 //1
#include "PubSubClient.h"

const char* password = "****************";        //2
const char* ssid = "*************";                
#define mqtt_broker "192.168.2.103"               //3

WiFiClient espClient;                             //4
PubSubClient mqttClient(espClient);               

//Example Values:                                 //5
String val1= "Hello";
String val2= "World";
String val3= "Hey";
String val4= "ESP32";
char Buffer[5];                                   

//Deep Sleep
#include <Wire.h>                                 //6
#define DS3231RTC_I2C_ADDRESS 0x68
#define I2C_SDA 21                                  
#define I2C_SCL 22

//EEPROM
#include <EEPROM.h>                               //7
#define EEPROM_BYTES 2
#define WIFIRESETADDRESS 0
#define MQTTRESETADDRESS 1

//Restart
#define RestartPin 27                             //8

void setup(){
  Wire.begin(I2C_SDA, I2C_SCL);                   //9
  clearAlarm1();
  EEPROM.begin(EEPROM_BYTES);                     //10
  Serial.begin(115200);
  esp_sleep_enable_ext0_wakeup(GPIO_NUM_13,0);
  WiFiConnect();                                  //11
  MQTTConnect();  
  Serial.println("Transmitting data.");
  val1.toCharArray(Buffer, 6);                    //12
  mqttClient.publish("ESP32/Test1", Buffer);      //13
  delay(500);                                     //14
  val2.toCharArray(Buffer, 6);
  mqttClient.publish("ESP32/Test2", Buffer);
  delay(500);
  val3.toCharArray(Buffer, 4);
  mqttClient.publish("ESP32/Test3", Buffer);
  delay(500);
  val4.toCharArray(Buffer, 6);
  mqttClient.publish("ESP32/Test4", Buffer);
  Serial.println("Going into sleep mode");
  esp_deep_sleep_start();                         //15
}

void loop(){
  //Main loop is not going to be called.
}

void clearAlarm1(){                              
  Wire.beginTransmission(DS3231RTC_I2C_ADDRESS);
  Wire.write(0x0F);                               
  Wire.write(B00000000);                          
  Wire.endTransmission();
}

void WiFiConnect(){                                 //16
  byte WiFiResets = EEPROM.read(WIFIRESETADDRESS);  //17
  unsigned long Timer = millis()+1000;              //18
  Serial.print("Connecting with WiFi");
  WiFi.begin(ssid, password);                       //19
  unsigned long Timeout = millis()+30000;           //20
  while(WiFi.status() !=WL_CONNECTED){              //21
    
    if(millis()>Timer){                             //22
      Timer= millis()+1000;
      Serial.print(".");
    }
    
    if(millis()>Timeout){                           //23
      if(WiFiResets ==2){                           //24
        EEPROM.write(WIFIRESETADDRESS, 0);          
        EEPROM.commit();
        Serial.println();
        Serial.println("Could not connect to MQTT Broker 3 times. Going into deep sleep.");
        esp_deep_sleep_start();
      }
      else{                                         //25
        WiFiResets++;
        EEPROM.write(WIFIRESETADDRESS, WiFiResets);
        EEPROM.commit();
        Serial.println();
        Serial.println("Could not connect to MQTT Broker. Restarting MCU.");
        digitalWrite(RestartPin, HIGH);
      }
    }
  }
  EEPROM.write(WIFIRESETADDRESS, 0);                //26
  EEPROM.commit();
  Serial.println();
  Serial.println("Successfully connected to WiFi");
}

void MQTTConnect(){                                 //27
  byte MQTTResets = EEPROM.read(MQTTRESETADDRESS);
  unsigned long Timer = millis()+1000;
  Serial.print("Connecting with MQTT Broker");
  mqttClient.setServer(mqtt_broker, 1883);          //28
  mqttClient.connect("ESP32Client");                //29
  unsigned long Timeout = millis()+30000;
  while(!mqttClient.connected()){                   //30
    
    if(millis()>Timer){
      Timer= millis()+1000;
      Serial.print(".");
      mqttClient.connect("ESP32Client"); 
    }
    
    if(millis()>Timeout){
      if(MQTTResets ==2){
        EEPROM.write(MQTTRESETADDRESS, 0);
        EEPROM.commit();
        Serial.println();
        Serial.println("Could not connect to MQTT Broker 3 times. Going into deep sleep.");
        esp_deep_sleep_start();
      }
      else{
        MQTTResets++;
        EEPROM.write(MQTTRESETADDRESS, MQTTResets);
        EEPROM.commit();
        Serial.println();
        Serial.println("Could not connect to MQTT Broker. Restarting MCU.");
        digitalWrite(RestartPin, HIGH);
      }
    }
  }
  EEPROM.write(MQTTRESETADDRESS, 0);
  EEPROM.commit();
  Serial.println();
  Serial.println("Successfully connected to MQTT Broker");
}