// Including Libraries
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <DHTesp.h>
#include <WiFi.h>
#include <PubSubClient.h>
#include <WiFiClient.h>
#include <ESP32Servo.h> 
#include <NTPClient.h> 
#include <WiFiUdp.h> 
//#include <math.h>

//Defining Screen parameters
#define  SCREEN_WIDTH 128
#define  SCREEN_HEIGHT 64
#define  OLED_RESET -1
#define  SCREEN_ADDRESS 0x3C

//Defining pin arrangements
#define BUZZER 27
#define LED_alarm 14
#define LED_temp 13
#define button_cancel 34
#define button_ok 32
#define button_down 35
#define button_up 33
#define DHTpin 26
#define LDR 39
#define ServoPin 15

WiFiClient espClient;
PubSubClient mqttClient(espClient);
Servo myservo;  // create servo object to control a servo

//Defining NTP parameters
WiFiUDP ntpClient;
NTPClient timeClient(ntpClient);


//Declaring objects
DHTesp dhtsensor;
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

//Global variable
int hours = 0;
int minutes = 0;
int seconds = 0;
int time_offset = 0;
String time_now = "";
String temp_status = "";
String hum_status = "";

char TempAr[6];
char TempHu[6];
char Lightint[6];
char Clock[8];
char ShadeAngle[6];
float LDRvalue = 0.0;
float LDROutput = 0.0;
int ContFactor = 75;
int MinAngle = 30;
int ServoAngle = 0;

bool GUI_alarm_enabled = false;
bool alarm_enabled = false;
int n_alarms = 3;
int alarm_hours[] = {0, 0, 0};
int alarm_minutes[] = {0, 0, 0};
bool alarm_triggered[] = {false, false, false};
unsigned long GUI_Alarm_Time;

// Alarm tone for Buzzer
int n_notes = 5;
int C4 = 262;
int E4 = 330;
int notes[] = {C4,E4};

// Setting up the main menu
int current_menu = 0;
int max_menu = 4;
String menu[] = {"1 - Set\nTime Zone","2 - Set\nAlarm 1","3 - Set\nAlarm 2","4 - Set\nAlarm 3","5 - Remove\nAlarms"};


// Setup
void setup() {
  
  pinMode(BUZZER,OUTPUT);
  pinMode(LED_alarm,OUTPUT);
  pinMode(LED_temp,OUTPUT);
  pinMode(button_cancel,INPUT);
  pinMode(button_ok, INPUT);
  pinMode(button_down, INPUT);
  pinMode(button_up, INPUT);
  pinMode(DHTpin, INPUT);
  pinMode(LDR, INPUT);
  

  dhtsensor.setup(DHTpin,DHTesp::DHT22);
  SetupMQTT();
  myservo.attach(ServoPin); // Servo Motor pin settings

  Serial.begin(115200);
  

  //Check display functionality
  if (!display.begin(SSD1306_SWITCHCAPVCC, SCREEN_ADDRESS)) {
    Serial.println(F("SSD1306 allocation failed"));
    for(;;);
  }

  display.display();
  delay(1000);
  display.clearDisplay();
  print_text("Welcome to  Medibox!", 2, 20, 2);
  delay(1000);
  display.clearDisplay(); 

  WiFi.begin("Wokwi-GUEST", "", 6);
    while (WiFi.status() != WL_CONNECTED) {
    delay(250);
    display.clearDisplay();
    print_text("Connecting to Wi-FI..", 1, 20, 0);
  }

  display.clearDisplay();
  print_text("Wi-FI Connected..", 1, 20, 0);

  timeClient.begin();
  timeClient.setTimeOffset(19800); // +5.30hrs of offset is set. This can be change from the main menu upon requirement.
  
  

}

// main loop
void loop() {

  if (!mqttClient.connected()) {
    connectToBroker();
  }

  if (digitalRead(button_ok) == LOW){
     delay(200);
     go_to_menu();
  }

  mqttClient.loop();
  check_alarm_and_temp_hum();
  print_time_temp_hum();
  Update_Lightintensity();
  Shade_Control();

}


// Checking alarm time with current time
void check_alarm_and_temp_hum(){
  update_time();
  
  if (alarm_enabled){
     for(int i=0; i<n_alarms; i++){
       if(alarm_triggered[i] == false && alarm_hours[i] == hours && alarm_minutes[i] == minutes){
      ring_alarm();
      alarm_triggered[i] = true;
      }

     }
  }

  if (GUI_alarm_enabled) {
    
    update_time();
    unsigned long Current_Time = timeClient.getEpochTime();
    
    if (Current_Time > GUI_Alarm_Time) {
      myservo.detach();
      ring_alarm();
      GUI_alarm_enabled = false;
      myservo.attach(ServoPin);
    }
  }
  update_temp_and_hum();
  
}


// Time update trough NTP
void update_time(void){
  timeClient.update();
  
  hours = timeClient.getHours();
  minutes = timeClient.getMinutes();
  seconds = timeClient.getSeconds();

  char TimeArray [8]; //Char Array for store converted two digits numbers
  sprintf (TimeArray, "%02u:%02u:%02u\n", timeClient.getHours(), timeClient.getMinutes(), timeClient.getSeconds()); //Converting hours, miniutes and seconds for two digits numbers
   
  time_now = String(TimeArray); // Assinged value of present time
  
  mqttClient.publish("239958U-Clock", TimeArray);

}

// Obtaining temperature and humidity data
void update_temp_and_hum(){
  TempAndHumidity data = dhtsensor.getTempAndHumidity();
  
  String(data.temperature, 2).toCharArray(TempAr, 6);
  String(data.humidity, 2).toCharArray(TempHu, 6);

  mqttClient.publish("239958U-Temp-Data", TempAr);
  mqttClient.publish("239958U-Hum-Data", TempHu);

  if(data.temperature > 32){
    temp_status = "High";
    digitalWrite(LED_temp, HIGH);
  }

  else if(data.temperature < 26){
    temp_status = "Low";
    digitalWrite(LED_temp, HIGH);
  }

  else if(26 <= data.temperature <= 32){
    temp_status = "Ok";
    
  }
  
  if(data.humidity > 80){
    hum_status = "High";
    digitalWrite(LED_temp, HIGH);
  }
  
  else if(data.humidity < 60){
    hum_status = "Low";
    digitalWrite(LED_temp, HIGH);
  }

  else if(60 <= data.humidity <= 80){
    hum_status = "Ok";
    
  }
  
  if((data.humidity >= 60 && data.humidity <= 80) && (data.temperature >= 26 && data.temperature <= 32)){
    digitalWrite(LED_temp, LOW);
  }    
}

// Main Screen with time and environment data
void print_time_temp_hum() {
    display.clearDisplay();
    print_text(time_now + "\n\nTemp " + temp_status + "\nHum " + hum_status, 2, 0, 15);
  }


// Displying texts 
void print_text(String text, int text_size , int row, int column){
  display.setTextSize(text_size);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(column,row);
  display.println(text);
  display.display();
}

//Alarm ringing with tone
void ring_alarm() {
  display.clearDisplay();
  print_text(" Medicine\n   time!", 2, 15, 0);

  digitalWrite(LED_alarm, HIGH);
 
  while(digitalRead(button_cancel) == HIGH) {
   
    tone(BUZZER, notes[0]);
    delay(500);
    noTone(BUZZER);
    delay(50);
    tone(BUZZER, notes[1]);
    delay(200);
    noTone(BUZZER);
    delay(50);
    
  }

  if(digitalRead(button_cancel) == LOW){
    delay(200);
    digitalWrite(LED_alarm, LOW);
      
  }
    
}

// Function to check any button press
int wait_for_button_press(){
  while(true){
    if(digitalRead(button_ok) == LOW){
      delay(200);
      return button_ok;
    }
    else if(digitalRead(button_up) == LOW){
      delay(200);
      return button_up;
    }
    else if(digitalRead(button_down) == LOW){
      delay(200);
      return button_down;
    }
    else if(digitalRead(button_cancel) == LOW){
      delay(200);
      return button_cancel;
    }
  
  }
}

// Accessing menu from buttons
void go_to_menu(){
  while(digitalRead(button_cancel) == HIGH){
    display.clearDisplay();
    print_text(menu[current_menu], 2, 0, 0);

    int pressed = wait_for_button_press();

    if(pressed == button_up){
      delay(200);
      current_menu += 1;
      if(current_menu > 4){
        current_menu = 0;
      }
    }
    else if(pressed == button_down){
      delay(200);
      current_menu -= 1;
      if(current_menu < 0){
        current_menu = 4;
      }
    }

    else if(pressed == button_ok){
      delay(200);
      run_mode(current_menu);
      current_menu = 0;
      break;
    }

    else if(pressed == button_cancel){
      delay(200);
      //configTime(time_offset, UTC_OFFSET_DST, NTP_SERVER); //Update time to avoid time error while using the menu 
      break;
    }
  }

}

// Menu selection
void run_mode(int current_menu){
  if(current_menu == 0){
    set_time_offset();
  }

  else if(current_menu == 1 || current_menu==2 || current_menu==3){
    set_alarm(current_menu - 1) ;
    alarm_enabled = true;
  }

  else if(current_menu == 4){
  alarm_enabled = false;
  display.clearDisplay();
  print_text("Alarms\ndisabled!", 2, 0, 0);
  delay(1000);
  }
}

// Menu for set Time Zone
void set_time_offset() {
  int temp_hour = 0;

  while (true) {
    display.clearDisplay();
    print_text("UTC Hour\noffset:" + String(temp_hour), 2, 0, 0);

    int pressed = wait_for_button_press();

    if (pressed == button_up) {
      delay(200);
      temp_hour += 1;
      if (temp_hour > 12) {
        temp_hour = 0;
      }
    }

    else if (pressed == button_down) {
      delay(200);
      temp_hour -= 1;
      if (temp_hour < -12) {
        temp_hour = 0;
      }
    }
    else if (pressed == button_ok) {
      delay(200);
      time_offset = temp_hour * 3600;
      break;  
    }
    
    else if (pressed == button_cancel) {
      delay(200);
      break;
    }

    }

  int temp_minute = 0;

    while (true) {
      display.clearDisplay();
      print_text("UTC Minute\noffset:" + String(temp_minute), 2, 0, 0);

      int pressed = wait_for_button_press();
      if (pressed == button_up) {
        delay(200);
        temp_minute += 15;
        if (temp_minute > 45) {
          temp_minute = 0;
        }
      }

      else if (pressed == button_down) {
        delay(200);
        temp_minute -= 15;
        if (temp_minute < -45) {
          temp_minute = 0;
        }
      }
        
      else if (pressed == button_ok) {
        delay(200);
        time_offset = time_offset + (temp_minute * 60);
        Serial.println(time_offset);
        display.clearDisplay();
        print_text("Time Zone\nis set!", 2, 0, 0);
        delay(1000);
        //configTime(time_offset, UTC_OFFSET_DST, NTP_SERVER); //Update time to avoid time error while using the menu 
        
        timeClient.setTimeOffset(time_offset); // Set Offset
        timeClient.update(); //Update time to avoid time error while using the menu 
        break;
      }
    
      else if (pressed == button_cancel) {
        delay(200);
        break;
      }
  }
  
}

// Menu for setting alarms
void set_alarm(int alarm){
  int temp_hour = hours;
  while(true){
    display.clearDisplay();
    print_text("Enter\nhour :" + String(temp_hour), 2, 0, 2);

    int pressed = wait_for_button_press();

    if(pressed == button_up){
      delay(200);
      temp_hour += 1;
     if(temp_hour > 23){
      temp_hour = 0;
      }
    }

    else if(pressed == button_down){
      delay(200);
      temp_hour -= 1;
      if(temp_hour < 0){
      temp_hour = 23;
      }
    }

    else if(pressed == button_ok){
      delay(200);
      alarm_hours[alarm] = temp_hour;
      break;
    }

    else if(pressed == button_cancel){
      delay(200);
      break;
    }
  }

  int temp_minute = minutes;
  while(true){
    display.clearDisplay();
    print_text("Enter\nminute :" + String(temp_minute), 2, 0, 0);

    int pressed = wait_for_button_press();

    if(pressed == button_up){
      delay(200);
      temp_minute += 1;
      if(temp_minute > 59){
      temp_minute = 0;
      }
    }
    else if(pressed == button_down){
      delay(200);
      temp_minute -= 1;
      if(temp_minute < 0){
      temp_minute = 59;
      }
    }

    else if(pressed == button_ok){
      delay(200);
      alarm_minutes[alarm] = temp_minute;
      display.clearDisplay();
      print_text("Alarm is\nset!", 2, 0, 0);
      alarm_enabled = true;
      alarm_triggered[alarm] = false;
      delay(1000);
      break;
    }

    else if(pressed == button_cancel){
      delay(200);
      break;
    }
  }
 
 
}

// MQTT Setup
void SetupMQTT() {

  mqttClient.setServer("test.mosquitto.org", 1883);
  mqttClient.setCallback(ReceiveCallback);
  
}

// Connection to MQTT and subscribe for topics
void connectToBroker() {

  while (!mqttClient.connected()) {
    Serial.print("Attempting MQTT connection..."); 
    
    if (mqttClient.connect("ESP32-239958U")) {
    Serial.println("connected");
    mqttClient.subscribe("239958U-Min_Angle");
    mqttClient.subscribe("239958U-Cont_Factor");
    mqttClient.subscribe("239958U-Alarm");
    } else {
    Serial.print("failed ");
    Serial.print(mqttClient.state());
    delay(5000);
    }
  }

}

// Reading messages from the MQTT Server
void ReceiveCallback(char* topic, byte* payload, unsigned int length) {
  Serial.print("Message arrived [");
  Serial.print(topic);
  Serial.print("] ");

  char mqttCharAr[length];
  for (int i = 0; i < length; i++) {
    mqttCharAr[i] = (char)payload[i];
  }

  if (strcmp(topic, "239958U-Min_Angle") == 0) {
      MinAngle = atoi(mqttCharAr);
      Serial.print("[");
      Serial.print(MinAngle);//print the minimum angle
      Serial.print("]");
      Serial.println();
      delay(200);
  } else if (strcmp(topic, "239958U-Cont_Factor") == 0) {
      ContFactor = atoi(mqttCharAr);
      Serial.print("[");
      Serial.print(ContFactor);//print the control fcator
      Serial.print("]");
      Serial.println();
      delay(200);
  } else if (strcmp(topic, "239958U-Alarm") == 0) {

    if (mqttCharAr[0] == 'N') {
        GUI_alarm_enabled = false;
        
    } else {
        GUI_alarm_enabled = true;
        GUI_Alarm_Time = atol(mqttCharAr);
        Serial.print("[");
        Serial.print(GUI_Alarm_Time);//print the Alarm time from Epoch in Seconds
        Serial.print("]");
        Serial.println();
        delay(200);
    }
  }
}



// Transfering LDR Data to Dashboard
void Update_Lightintensity() {

  LDRvalue = analogRead(LDR);
  LDROutput = map(LDRvalue, 4063, 32, 0, 100);
  LDROutput = round(LDROutput);;
  String(LDROutput/100, 2).toCharArray(Lightint, 6);
  mqttClient.publish("239958U-Lightintensity", Lightint);

}

void Shade_Control() {

  ServoAngle = round(MinAngle + (180 - MinAngle) * LDROutput/100 * ContFactor/100);
  myservo.write(ServoAngle);
  
  String(ServoAngle).toCharArray(ShadeAngle, 6);
  mqttClient.publish("239958U-Shade", ShadeAngle);
  Serial.print("[");
  Serial.print(ServoAngle);//print the Alarm time from Epoch in Seconds
  Serial.print("]");
  Serial.println();
  delay(200);

}