#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <DHT.h>

// LCD settings
LiquidCrystal_I2C lcd(0x27, 20, 4); // Adjust I2C address if necessary

// DHT22 settings
#define DHTPIN1 4 // Pin for the first DHT22 sensor
#define DHTPIN2 5 // Pin for the second DHT22 sensor
#define DHTTYPE DHT22
DHT dht1(DHTPIN1, DHTTYPE);
DHT dht2(DHTPIN2, DHTTYPE);

// TCRT5000, buzzer, and button pins
const int tcrt5000Pin = 2;          // Digital pin for TCRT5000
const int resetButtonPin = 3;       // Digital pin for reset button
const int pageSwitchButtonPin = 6;  // Digital pin for page switch button
const int buzzerPin = 7;            // Digital pin for the buzzer

int counter = 0;                    // Count detected events
bool previousState = HIGH;          // Previous state of the TCRT5000 sensor
bool currentPage = false;           // False = TCRT5000 page, True = DHT22 page

void setup() {
  // Initialize LCD
  lcd.init();
  lcd.backlight();

  // Initialize DHT22 sensors
  dht1.begin();
  dht2.begin();

  // Display initial TCRT5000 page
  showTCRT5000Page();

  // Initialize the pins
  pinMode(tcrt5000Pin, INPUT_PULLUP);
  pinMode(resetButtonPin, INPUT_PULLUP);      // Use internal pull-up resistor
  pinMode(pageSwitchButtonPin, INPUT_PULLUP); // Use internal pull-up resistor
  pinMode(buzzerPin, OUTPUT);                 // Buzzer pin as output
  digitalWrite(buzzerPin, LOW);               // Ensure buzzer is off initially
}

void loop() {
  // Read the current state of the TCRT5000 sensor
  bool currentState = digitalRead(tcrt5000Pin);

  // Detect a transition from HIGH to LOW (light to dark)
  if (previousState == HIGH && currentState == LOW) {
    counter++; // Increment the counter
    soundBuzzer(); // Sound the buzzer for 0.3 seconds at 1,000 Hz

    if (!currentPage) {
      updateTCRT5000Page();
    }
  }

  // Check if the reset button is pressed
  if (digitalRead(resetButtonPin) == LOW) {
    counter = 0; // Reset the counter
    if (!currentPage) {
      updateTCRT5000Page();
    }
    delay(200); // Debounce delay
  }

  // Check if the page switch button is pressed
  if (digitalRead(pageSwitchButtonPin) == LOW) {
    currentPage = !currentPage; // Toggle the page
    if (currentPage) {
      showDHT22Page();
    } else {
      showTCRT5000Page();
    }
    delay(200); // Debounce delay
  }

  // Update the DHT22 page if it's active
  if (currentPage) {
    updateDHT22Page();
  }

  // Update the previous state of the TCRT5000 sensor
  previousState = currentState;

  // Small delay to debounce inputs
  delay(50);
}

void showTCRT5000Page() {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("TCRT5000 Counter:");
  lcd.setCursor(0, 1);
  lcd.print("Count: ");
  lcd.setCursor(7, 1);
  lcd.print(counter);
}

void updateTCRT5000Page() {
  lcd.setCursor(7, 1);
  lcd.print("    "); // Clear old value
  lcd.setCursor(7, 1);
  lcd.print(counter);
}

void showDHT22Page() {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("S1: ");
  lcd.setCursor(0, 1);
  lcd.print("S2: ");
  lcd.setCursor(0, 2);
  lcd.print("Avg Temp: ");
  lcd.setCursor(0, 3);
  lcd.print("Avg Hum: ");
}

void updateDHT22Page() {
  // Read temperature and humidity from both DHT22 sensors
  float temp1 = dht1.readTemperature(true); // True for Fahrenheit
  float hum1 = dht1.readHumidity();
  float temp2 = dht2.readTemperature(true);
  float hum2 = dht2.readHumidity();

  // Calculate averages
  float avgTemp = (temp1 + temp2) / 2.0;
  float avgHum = (hum1 + hum2) / 2.0;

  // Update LCD without flickering
  lcd.setCursor(0, 0);
  lcd.print("S1: ");
  lcd.print(temp1, 1);
  lcd.print("F ");
  lcd.print(hum1, 1);
  lcd.print("%   "); // Overwrite leftover characters

  lcd.setCursor(0, 1);
  lcd.print("S2: ");
  lcd.print(temp2, 1);
  lcd.print("F ");
  lcd.print(hum2, 1);
  lcd.print("%   "); // Overwrite leftover characters

  lcd.setCursor(0, 2);
  lcd.print("Avg Temp: ");
  lcd.print(avgTemp, 1);
  lcd.print("F   ");

  lcd.setCursor(0, 3);
  lcd.print("Avg Hum: ");
  lcd.print(avgHum, 1);
  lcd.print("%   ");

  delay(1000); // Delay for real-time updates
}

void soundBuzzer() {
  tone(buzzerPin, 1000); // Generate a 1,000 Hz tone on the buzzer pin
  delay(300);            // Play the tone for 0.3 seconds
  noTone(buzzerPin);      // Stop the tone
}