#include <DHT.h>
#include <LiquidCrystal.h>
#include <TimeLib.h>
#include <ArduinoJson.h>
#include <pitches.h>

// Pin Definitions
#define DHT_PIN 2
#define PHOTORESISTOR_PIN A0
#define PIR_PIN 3
#define RED_LED_PIN 4
#define GREEN_LED_PIN 5
#define BLUE_LED_PIN 6
#define BUZZER_PIN 7
#define LCD_RS 8
#define LCD_EN 9
#define LCD_D4 10
#define LCD_D5 11
#define LCD_D6 12
#define LCD_D7 13
#define BUTTON_PIN A1

// Constants
#define DHT_TYPE DHT22
#define TEMP_HIGH 30
#define TEMP_LOW 20
#define DARK_THRESHOLD 300
#define LCD_UPDATE_INTERVAL 1000
#define SERIAL_UPDATE_INTERVAL 10000
#define MOTION_TIMEOUT 30000
#define ALARM_DURATION 3000
#define BUTTON_DEBOUNCE_DELAY 200

// Global variables
DHT dht(DHT_PIN, DHT_TYPE);
LiquidCrystal lcd(LCD_RS, LCD_EN, LCD_D4, LCD_D5, LCD_D6, LCD_D7);

float temperature = 0;
float humidity = 0;
int lightLevel = 0;
bool motionDetected = false;
unsigned long lastLCDUpdate = 0;
unsigned long lastSerialUpdate = 0;
unsigned long lastMotionTime = 0;
unsigned long alarmStartTime = 0;
unsigned long lastButtonPress = 0;
bool alarmActive = false;
bool lcdBacklightOn = true;
int displayMode = 0;
bool nightMode = false;

void setup() {
  Serial.begin(9600);
  dht.begin();
  lcd.begin(16, 2);
  lcd.print("Initializing...");
  
  pinMode(PIR_PIN, INPUT);
  pinMode(RED_LED_PIN, OUTPUT);
  pinMode(GREEN_LED_PIN, OUTPUT);
  pinMode(BLUE_LED_PIN, OUTPUT);
  pinMode(BUZZER_PIN, OUTPUT);
  pinMode(BUTTON_PIN, INPUT_PULLUP);
  
  // Set initial time (10:00 PM for testing night mode)
  setTime(22, 0, 0, 1, 1, 2023);
  
  delay(2000);
  lcd.clear();
}

void loop() {
  readSensors();
  checkButton();
  updateLCD();
  updateLEDs();
  checkAlarm();
  sendSerialData();
  checkPowerSaving();
  updateNightMode();
}

void readSensors() {
  temperature = dht.readTemperature();
  humidity = dht.readHumidity();
  lightLevel = analogRead(PHOTORESISTOR_PIN);
  motionDetected = digitalRead(PIR_PIN) == HIGH;
  if (motionDetected) {
    lastMotionTime = millis();
  }
}

void checkButton() {
  if (digitalRead(BUTTON_PIN) == LOW && millis() - lastButtonPress > BUTTON_DEBOUNCE_DELAY) {
    displayMode = (displayMode + 1) % 3;  // Cycle through 3 display modes
    lastButtonPress = millis();
  }
}

void updateLCD() {
  if (millis() - lastLCDUpdate >= LCD_UPDATE_INTERVAL) {
    lcd.clear();
    lcd.setCursor(0, 0);
    
    switch (displayMode) {
      case 0:  // Temperature and Humidity
        lcd.print("Temp: ");
        lcd.print(temperature, 1);
        lcd.print("C");
        lcd.setCursor(0, 1);
        lcd.print("Humidity: ");
        lcd.print(humidity, 1);
        lcd.print("%");
        break;
      case 1:  // Light and Motion
        lcd.print("Light: ");
        lcd.print(lightLevel);
        lcd.setCursor(0, 1);
        lcd.print("Motion: ");
        lcd.print(motionDetected ? "Detected" : "None");
        break;
      case 2:  // Time and Mode
        lcd.print("Time: ");
        lcd.print(formatTime(now()));
        lcd.setCursor(0, 1);
        lcd.print("Mode: ");
        lcd.print(nightMode ? "Night" : "Day");
        break;
    }
    
    lastLCDUpdate = millis();
  }
}

void updateLEDs() {
  digitalWrite(RED_LED_PIN, temperature > TEMP_HIGH);
  digitalWrite(GREEN_LED_PIN, temperature >= TEMP_LOW && temperature <= TEMP_HIGH);
  digitalWrite(BLUE_LED_PIN, temperature < TEMP_LOW);
}

void checkAlarm() {
  Serial.print(motionDetected);
  Serial.print(lightLevel<DARK_THRESHOLD);
  Serial.print(alarmActive);
  Serial.println(nightMode);
  if (motionDetected && lightLevel < DARK_THRESHOLD && !alarmActive &&nightMode) {
    alarmActive = true;
    alarmStartTime = millis();
    tone(BUZZER_PIN, 1000);
  }
  
  if (alarmActive && (millis() - alarmStartTime >= ALARM_DURATION || nightMode)) {
    alarmActive = false;
    noTone(BUZZER_PIN);
  }
}

void sendSerialData() {
  if (millis() - lastSerialUpdate >= SERIAL_UPDATE_INTERVAL) {
    // Serial.print("Temperature: ");
    // Serial.print(temperature);
    // Serial.print("C, Humidity: ");
    // Serial.print(humidity);
    // Serial.print("%, Light: ");
    // Serial.print(lightLevel);
    // Serial.print(", Motion: ");
    // Serial.print(motionDetected ? "Detected" : "Not Detected");
    // Serial.print(", Mode: ");
    // Serial.println(nightMode ? "Night" : "Day");

    StaticJsonDocument<200> doc;
    doc["temperature"] = temperature;
    doc["humidity"] = humidity;
    doc["lightLevel"] = lightLevel;
    doc["motionDetected"] = motionDetected;

    char buffer[200];
    serializeJson(doc, buffer);
    Serial.println(buffer);
    
    lastSerialUpdate = millis();
  }
}

void checkPowerSaving() {
  if (millis() - lastMotionTime >= MOTION_TIMEOUT) {
    if (lcdBacklightOn) {
      lcdBacklightOn = false;
      lcd.noDisplay();
    }
  } else {
    if (!lcdBacklightOn) {
      lcdBacklightOn = true;
      lcd.display();
    }
  }
}

void updateNightMode() {
  int currentHour = hour(now());
  nightMode = (currentHour >= 22 || currentHour < 6);
}

String formatTime(time_t t) {
  char buffer[9];
  sprintf(buffer, "%02d:%02d:%02d", hour(t), minute(t), second(t));
  return String(buffer);
}