#include "HX711.h"
#include <LiquidCrystal.h>
#include <Wire.h>
#include <RTClib.h>
#include <EEPROM.h>

#define calibration_factor -7050.0 // This value is obtained using the SparkFun_HX711_Calibration sketch
#define LOADCELL_DOUT_PIN  3
#define LOADCELL_SCK_PIN  2

HX711 scale;
const float EMPTY_THRESHOLD = 5.0; // Adjust this value based on the weight of an empty container (in grams)

int pushVal = 0;                           
int val;
int val2;
int addr = 0;

RTC_DS3231 rtc;

const int rs = 12, en = 11, d4 = 5, d5 = 4, d6 = 3, d7 = 2; // LCD pins
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);

#define getWellsoon 0                                           
#define HELP_SCREEN 1
#define TIME_SCREEN 2

int pushpressed = 0;
const int ledPin =  LED_BUILTIN; // Buzzer and LED pin
int ledState = LOW;
int Signal = 0;
int buzz = 13;                                     
int push1state, push2state, push3state, stopinState = 0;     
int push1Flag, push2Flag, Push3Flag = false; // Push button flags 
int push1pin = 9;
int push2pin = 8;
int push3pin = 7;
int stopPin = A0;
int screens = 0; // Screen to show
int maxScreen = 2; // Screen count
bool isScreenChanged = true;

long previousMillis = 0;           
long interval = 500; // Buzzing interval
unsigned long currentMillis;

long previousMillisLCD = 0; // For LCD screen update
long intervalLCD = 2000; // Screen cycling interval
unsigned long currentMillisLCD;

// Set Reminder Change Time
int buzz8amHH = 8; // HH - hours
int buzz8amMM = 00; // MM - Minute
int buzz8amSS = 00; // SS - Seconds

int buzz2pmHH = 14; // HH - hours
int buzz2pmMM = 00; // MM - Minute
int buzz2pmSS = 00; // SS - Seconds

int buzz8pmHH = 20; // HH - hours
int buzz8pmMM = 00; // MM - Minute
int buzz8pmSS = 00; // SS - Seconds

int nowHr, nowMin, nowSec; // To show current mm, hh, ss

void gwsMessage() { // Print get well soon message
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Stay Healthy :)"); // Give some cheers
  lcd.setCursor(0, 1);
  lcd.print("Get Well Soon :)"); // Wish
}

void helpScreen() { // Function to display 1st screen on LCD
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Press Buttons");
  lcd.setCursor(0, 1);
  lcd.print("for Reminder...!");
}

void timeScreen() { // Function to display Date and time on LCD screen
  DateTime now = rtc.now(); // Take RTC time and print on display
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Time:");
  lcd.setCursor(6, 0);
  lcd.print(nowHr = now.hour(), DEC);
  lcd.print(":");
  lcd.print(nowMin = now.minute(), DEC);
  lcd.print(":");
  lcd.print(nowSec = now.second(), DEC);
  lcd.setCursor(0, 1);
  lcd.print("Date: ");
  lcd.print(now.day(), DEC);
  lcd.print("/");
  lcd.print(now.month(), DEC);
  lcd.print("/");
  lcd.print(now.year(), DEC);
}

void setup() {
  Serial.begin(9600); // Start serial debugging
  if (!rtc.begin()) { // Check if RTC is connected 
    Serial.println("Couldn't find RTC");
    while (1);
  }
  if (rtc.lostPower()) {
    Serial.println("RTC lost power, lets set the time!");
  }
  rtc.adjust(DateTime(2019, 1, 10, 7, 59, 30)); // Manual time set

  lcd.begin(16, 2);
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Welcome To"); // Print a message at startup
  lcd.setCursor(0, 1);
  lcd.print("SMART PILL");
  delay(2000);  // Display welcome message for 2 seconds
  lcd.clear();

  pinMode(push1pin, INPUT); // Define push button pins type
  pinMode(push2pin, INPUT);
  pinMode(push3pin, INPUT);
  pinMode(stopPin, INPUT);
  pinMode(ledPin, OUTPUT);
  delay(200);
  Serial.println(EEPROM.read(addr));
  val2 = EEPROM.read(addr); // Read previously saved value of push button to start from where it was left previously
  switch (val2) {
    case 1:
      Serial.println("Set for 1/day");
      push1state = 1;
      push2state = 0;
      push3state = 0;
      pushVal = 1;
      break;
    case 2:
      Serial.println("Set for 2/day");
      push1state = 0;
      push2state = 1;
      push3state = 0;
      pushVal = 2;
      break;
    case 3:
      Serial.println("Set for 3/day");
      push1state = 0;
      push2state = 0;
      push3state = 1;
      pushVal = 3;
      break;
  }

  // Load Cell Setup
  scale.begin(LOADCELL_DOUT_PIN, LOADCELL_SCK_PIN);
  scale.set_scale(calibration_factor); // This value is obtained by using the SparkFun_HX711_Calibration sketch
  scale.tare(); // Assuming there is no weight on the scale at startup, reset the scale to 0

  Serial.println("Readings:");
}

void loop() {
  // Load Cell Reading
  float weight = scale.get_units() * 453.592; // Convert lbs to grams (1 lb = 453.592 grams)
  Serial.print("Reading: ");
  Serial.print(weight, 1); // Display weight in grams
  Serial.println(" g");

  if (weight < EMPTY_THRESHOLD) {
    Serial.println("Warning: The container is empty or nearly empty!");
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Container Empty!");
    delay(2000);
    lcd.clear();
  }

  // Medicine Reminder Logic
  push1(); // Call to set once/day 
  push2(); // Call to set twice/day 
  push3(); // Call to set thrice/day 

  if (pushVal == 1) { // If push button 1 pressed then remind at 8am
    at8am(); // Function to start buzzing at 8am 
  }
  else if (pushVal == 2) { // If push button 2 pressed then remind at 8am and 8pm
    at8am();                                            
    at8pm(); // Function to start buzzing at 8pm
  }
  else if (pushVal == 3) { // If push button 3 pressed then remind at 8am, 2pm, and 8pm
    at8am();
    at2pm(); // Function to start buzzing at 2pm
    at8pm();
  }

  currentMillisLCD = millis(); // Start millis for LCD screen switching at defined interval of time
  push1state = digitalRead(push1pin); // Start reading all push button pins
  push2state = digitalRead(push2pin);
  push3state = digitalRead(push3pin);
  stopinState = digitalRead(stopPin);

  stopPins(); // Call to stop buzzing
  changeScreen(); // Screen cycle function

  delay(1000); // Delay to prevent spamming the Serial monitor
}

void push1() { // Function to set reminder once/day 
  if (push1state == 1) {
    push1state = 0;
    push2state = 0;
    push3state = 0;
    EEPROM.write(addr, 1);
    Serial.print("Push1 Written: "); Serial.println(EEPROM.read(addr)); // For debugging
    pushVal = 1; // Save the state of push button-1 
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Reminder set ");
    lcd.setCursor(0, 1);
    lcd.print("for Once/day !");
    delay(1200);
    lcd.clear();
  }
}

void push2() { // Function to set reminder twice/day
  if (push2state == 1) {
    push2state = 0;
    push1state = 0;
    push3state = 0;
    EEPROM.write(addr, 2);
    Serial.print("Push2 Written: "); Serial.println(EEPROM.read(addr));
    pushVal = 2;
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Reminder set ");
    lcd.setCursor(0, 1);
    lcd.print("for Twice/day !");
    delay(1200);
    lcd.clear();
  }
}

void push3() { // Function to set reminder thrice/day
  if (push3state == 1) {
    push3state = 0;
    push1state = 0;
    push2state = 0;
    EEPROM.write(addr, 3);
    Serial.print("Push3 Written: "); Serial.println(EEPROM.read(addr));
    pushVal = 3;
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Reminder set ");
    lcd.setCursor(0, 1);
    lcd.print("for Thrice/day !");
    delay(1200);
    lcd.clear();
  }
}

void stopPins() { // Function to stop buzzing when user pushes stop push button
  if (stopinState == 1) {
    pushpressed = 1;
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Take Medicine  ");
    lcd.setCursor(0, 1);
    lcd.print("with Warm Water");
    delay(1200);
    lcd.clear();
  }
}

void startBuzz() { // Function to start buzzing when time reaches the defined interval
  if (pushpressed == 0) {
    Serial.println("pushpressed is false in blink");
    unsigned long currentMillis = millis();
    if (currentMillis - previousMillis >= interval) {
      previousMillis = currentMillis; // Save the last time you blinked the LED
      Serial.println("Start Buzzing");
      if (ledState == LOW) { // If the LED is off, turn it on and vice-versa:
        ledState = HIGH;
      } else {
        ledState = LOW;
      }
      digitalWrite(ledPin, ledState);
    }
  } else if (pushpressed == 1) {
    Serial.println("pushpressed is true");
    ledState = LOW;
    digitalWrite(ledPin, ledState);
  }
}

void at8am() { // Function to start buzzing at 8am
  DateTime now = rtc.now();
  if (int(now.hour()) >= buzz8amHH) {
    if (int(now.minute()) >= buzz8amMM) {
      if (int(now.second()) > buzz8amSS) {
        startBuzz();
      }
    }
  }
}

void at2pm() { // Function to start buzzing at 2pm
  DateTime now = rtc.now();
  if (int(now.hour()) >= buzz2pmHH) {
    if (int(now.minute()) >= buzz2pmMM) {
      if (int(now.second()) > buzz2pmSS) {
        startBuzz();
      }
    }
  }
}

void at8pm() { // Function to start buzzing at 8pm
  DateTime now = rtc.now();
  if (int(now.hour()) >= buzz8pmHH) {
    if (int(now.minute()) >= buzz8pmMM) {
      if (int(now.second()) > buzz8pmSS) {
        startBuzz();
      }
    }
  }
}

void changeScreen() { // Function for Screen Cycling
  if (currentMillisLCD - previousMillisLCD > intervalLCD) { // Save the last time you changed the display
    previousMillisLCD = currentMillisLCD;
    screens++;
    if (screens > maxScreen) {
      screens = 0; // All screens over -> start from 1st
    }
    isScreenChanged = true;
  }

  if (isScreenChanged) { // Only update the screen if the screen is changed
    isScreenChanged = false; // Reset for next iteration
    switch (screens) {
      case getWellsoon:
        gwsMessage(); // Get well soon message
        break;
      case HELP_SCREEN:              
        helpScreen(); // Instruction screen
        break;
      case TIME_SCREEN:
        timeScreen(); // To print date and time
        break;
      default:
        break;
    }
  }
}