// Include libraries
#include <Wire.h>
#include <Adafruit_GFX.h>       
#include <Adafruit_SSD1306.h>
#include <DHTesp.h>

// Define OLED parameters
#define SCREEN_WIDTH 128     
#define SCREEN_HEIGHT 64     
#define OLED_RESET -1        
#define SCREEN_ADDRESS 0x3C

#define LED_1 14
#define Buzzer 12
#define PB_ok 35
#define PB_up 32
#define PB_down 33
#define PB_cancel 25
#define dht 26

Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

DHTesp dhtSensor;

// variables for time
int days = 0;
int hours = 0;
int minutes = 0;
int seconds = 0;
unsigned long timeNow = 0;
unsigned long timeLast = 0;

// variables for alarm
bool alarm_enabled = true;
int n_alarms = 2;
int alarm_hours[] = {0,1};
int alarm_minutes[] = {1,10};
bool alarm_triggered[] = {false, false};

// variables for buzzer
int n_notes = 8;
int C = 262;
int D = 294;
int E = 330;
int F = 349;
int G = 392;
int A = 440;
int B = 494;
int C_H = 523;
int notes[] = {C, D, E, F, G, A, B, C_H};

// variables for menu
int current_mode = 0;
int max_modes = 4;
String modes[] = {"1 - Set Time", "2 - Set Alarm 1", "3 - Set Alarm 2", "4 - Disable Alarms"};

/////////////////////////////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////////////////////////////

void setup(){

  pinMode(LED_1, OUTPUT);
  pinMode(Buzzer, OUTPUT);
  pinMode(PB_cancel, INPUT);
  pinMode(PB_ok, INPUT);
  pinMode(PB_up, INPUT);
  pinMode(PB_down, INPUT);
  Serial.begin(115200);

  dhtSensor.setup(dht, DHTesp :: DHT22);

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

  // Adafruit boot screen
  display.display();
  delay(1000);              
  display.clearDisplay();   

  print_line("Welcome to Medibox!", 0, 20, 2);
  delay(1000);
  display.clearDisplay();

}

/////////////////////////////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////////////////////////////

void loop(){
  update_time_with_check_alarm();
  if(digitalRead(PB_ok) == LOW){
    delay(200);
    go_to_menu();
  }
  check_temp();
}

/////////////////////////////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////////////////////////////


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


void print_time_now(void){
  display.clearDisplay();      // No need (check at last)
  print_line(String(days), 0, 0, 2);
  print_line(":", 20, 0, 2);
  print_line(String(hours), 30, 0, 2);
  print_line(":", 50, 0, 2);
  print_line(String(minutes), 60, 0, 2);
  print_line(":", 80, 0, 2);
  print_line(String(seconds), 90, 0, 2);
}


void update_time(){
  timeNow = millis()/1000;  // seconds passed from bootup
  seconds = timeNow - timeLast;

  if (seconds >= 60){
    minutes += 1;
    timeLast += 60;
  }
  if (minutes == 60){
    hours += 1;
    minutes = 0;
  }
  if (hours == 24){
    days += 1;
    hours = 0;
  }
}


void ring_alarm() {
  display. clearDisplay();
  print_line("Medicine Time!", 0, 0, 2);   
  digitalWrite(LED_1, HIGH);

  bool break_happened = false;
  while (break_happened == false && digitalRead(PB_cancel) == HIGH){
    for (int i = 0; i < n_notes; i++) {
      if (digitalRead(PB_cancel) == LOW){
        delay(200);
        break_happened = true;
        break;
      }
      tone(Buzzer, notes[i]);
      delay(500);
      noTone(Buzzer);
      delay(2);
    }
  }
  digitalWrite(LED_1, LOW);
  display.clearDisplay();     // No need (check at last)
}


void update_time_with_check_alarm(void) {
  display. clearDisplay();
  update_time();
  print_time_now();

  if (alarm_enabled == true) {
    for (int i = 0; i < n_alarms ; i++) { 
      if (alarm_triggered[i] == false && hours == alarm_hours[i] && minutes == alarm_minutes[i]) {
        ring_alarm();
        alarm_triggered[i] = true; 
      }
    }
  }
}


int button_pressed(){
  while (true) {
    if (digitalRead(PB_up) == LOW){
      delay(200);
      return PB_up;     // returns the pin number of PB_up
    }

    else if (digitalRead(PB_down) == LOW){
      delay(200);
      return PB_down;
    }

    else if (digitalRead(PB_ok) == LOW){
      delay(200);
      return PB_ok;
    }

    else if (digitalRead(PB_cancel) == LOW){
      delay(200);
      return PB_cancel;
    }
    update_time();    // to keep track of time when changing menu
  }
}  


void go_to_menu(){
  while (true){
    display.clearDisplay();
    print_line(modes[current_mode], 0, 0, 2);

    int pressed = button_pressed();
    if (pressed == PB_up){
      delay(200);
      current_mode += 1;
      if (current_mode > max_modes-1){    // or current_mode = current_mode % max_modes
        current_mode = 0;
      }
    }
    else if (pressed == PB_down){
      delay(200);
      current_mode -= 1;
      if (current_mode < 0){
        current_mode = max_modes-1;
      }
    }
    else if (pressed == PB_ok){
      delay(200);
      run_mode(current_mode);
    }
    else if (pressed == PB_cancel){
      delay(200);
      break;
    }
  }
}


void run_mode(int mode){     // mode = current_mode from go_to_menu
  if (mode == 0){
    set_time();
  }
  else if (mode == 1 || mode == 2){
    set_alarm(mode - 1);
  }
  else if(mode == 3){
    alarm_enabled = false;     // both alarms will be disabled
    display.clearDisplay();
    print_line("Alarm disabled", 0, 0, 2);
    delay(1000);
  }
}


void set_time(){

  int temp_hours = hours;       // to change the global variable only after the setting is done
  while (true){
    display.clearDisplay();
    print_line("Enter hours: " + String(temp_hours), 0, 0, 2);

    int pressed = button_pressed(); 
    if (pressed == PB_up){
      delay(200);
      temp_hours += 1;
      if (temp_hours > 23){    // or temp_hours = temp_hours % 24
        temp_hours = 0;
      }
    }
    else if (pressed == PB_down){
      delay(200);
      temp_hours -= 1;
      if (temp_hours < 0){
        temp_hours = 23;
      }
    }
    else if (pressed == PB_ok){
      delay(200);
      hours = temp_hours;
      break;
    }
    else if (pressed == PB_cancel){
      delay(200);
      break;
    }
  }

  int temp_minutes = minutes;
  while (true){
    display.clearDisplay();
    print_line("Enter minutes: " + String(temp_minutes), 0, 0, 2);

    int pressed = button_pressed();     // not needed, already declared in hours setting
    if (pressed == PB_up){
      delay(200);
      temp_minutes += 1;
      if (temp_minutes > 59){    // or temp_minutes = temp_minutes % 60
        temp_minutes = 0;
      }
    }
    else if (pressed == PB_down){
      delay(200);
      temp_minutes -= 1;
      if (temp_minutes < 0){
        temp_minutes = 59;
      }
    }
    else if (pressed == PB_ok){
      delay(200);
      minutes = temp_minutes;
      break;
    }
    else if (pressed == PB_cancel){
      delay(200);
      break;
    }
  }

  display.clearDisplay();
  print_line("Time is set", 0, 0, 2);
  delay(1000);
}


void set_alarm(int alarm){    // alarm = mode-1 = current_mode

  int temp_hours = alarm_hours[alarm];
  while (true){
    display.clearDisplay();
    print_line("Enter hours: " + String(temp_hours), 0, 0, 2);

    int pressed = button_pressed(); 
    if (pressed == PB_up){
      delay(200);
      temp_hours += 1;
      if (temp_hours > 23){    // or temp_hours = temp_hours % 24
        temp_hours = 0;
      }
    }
    else if (pressed == PB_down){
      delay(200);
      temp_hours -= 1;
      if (temp_hours < 0){
        temp_hours = 23;
      }
    }
    else if (pressed == PB_ok){
      delay(200);
      alarm_hours[alarm] = temp_hours;
      break;
    }
    else if (pressed == PB_cancel){
      delay(200);
      break;
    }
  }

  int temp_minutes = alarm_minutes[alarm];
  while (true){
    display.clearDisplay();
    print_line("Enter minute: " + String(temp_minutes), 0, 0, 2);

    int pressed = button_pressed();
    if (pressed == PB_up){
      delay(200);
      temp_minutes += 1;
      if (temp_minutes > 59){    // or temp_minutes = temp_minutes % 60
        temp_minutes = 0;
      }
    }
    else if (pressed == PB_down){
      delay(200);
      temp_minutes -= 1;
      if (temp_minutes < 0){
        temp_minutes = 59;
      }
    }
    else if (pressed == PB_ok){
      delay(200);
      alarm_minutes[alarm] = temp_minutes;
      break;
    }
    else if (pressed == PB_cancel){
      delay(200);
      break;
    }
  }

  display.clearDisplay();
  if (alarm == 0){
    print_line("Alarm 1 is set", 0, 0, 2);
  }
  else if (alarm == 1){
    print_line("Alarm 2 is set", 0, 0, 2);
  }
  delay(1000);
}


void check_temp(){
  TempAndHumidity data = dhtSensor.getTempAndHumidity();
  if (data.temperature > 35){
    display.clearDisplay();
    print_line("TEMP HIGH", 0, 30, 1);
    delay(500);
  }
  else if (data.temperature < 25){
    display.clearDisplay();
    print_line("TEMP LOW", 0, 30, 1);
    delay(500);
  }
  if (data.humidity > 40){
    display.clearDisplay();
    print_line("HUMIDITY HIGH", 0, 40, 1);
    delay(500);
  }
  else if (data.humidity < 20){
    display.clearDisplay();
    print_line("HUMIDITY LOW", 0, 40, 1);
    delay(500);
  }
}