#include <WiFi.h>
#include <ThingSpeak.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <DHT.h>
#include <LiquidCrystal_I2C.h>

// ThingSpeak credentials
const char* ssid = "Wokwi-GUEST";
const char* pass = "vnkhdcnk";
WiFiClient client;
unsigned long myChannelNumber = 2753291; 
const char* myWriteAPIKey = "BKWC5O4V4QDGT1S8"; 

// OLED display setup
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
Adafruit_SSD1306 oled(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);

// DHT22 sensor setup
#define DHTPIN 4
#define DHTTYPE DHT22
DHT dht(DHTPIN, DHTTYPE);

// Ultrasonic sensor setup
#define TRIG_PIN 14
#define ECHO_PIN 27

// LCD setup
LiquidCrystal_I2C lcd(0x27, 16, 2);

// Other setup
int buzzer = 5;
float humidity, temperature;
int batteryLevel, batteryPercent;
long duration, distance;

void setup() {
  Serial.begin(9600);

  // Initialize WiFi
  WiFi.begin(ssid, pass);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("\nConnected to WiFi");

  // Initialize ThingSpeak
  ThingSpeak.begin(client);

  // Initialize sensors and displays
  dht.begin();
  lcd.init();
  lcd.backlight();

  if (!oled.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("Failed to start SSD1306 OLED"));
    while (1);
  }

  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(buzzer, OUTPUT);

  // Initial messages
  oled.clearDisplay();
  oled.setTextSize(2);
  oled.setCursor(15, 30);
  oled.println("Ready");
  oled.display();

  delay(2000); // Allow sensors to initialize
}

void loop() {
  // Read DHT22 values
  humidity = dht.readHumidity();
  temperature = dht.readTemperature();

  // Calculate distance using ultrasonic sensor
  distance = getDistanceInCentimeters();

  // Read battery level
  batteryLevel = analogRead(34);
  batteryPercent = map(batteryLevel, 0, 4095, 0, 100);

  // Display data on OLED
  oled.clearDisplay();
  oled.setTextSize(1.5);
  oled.setCursor(0, 0);
  oled.print("Temp: ");
  oled.print(temperature);
  oled.println(" C");
  oled.print("Hum: ");
  oled.print(humidity);
  oled.println(" %");
  oled.print("Dist: ");
  oled.print(distance);
  oled.println(" cm");
  oled.print("Batt: ");
  oled.print(batteryPercent);
  oled.println(" %");
  oled.display();

  // Display data on LCD
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Temp: ");
  lcd.print(temperature);
  lcd.print("C");
  lcd.setCursor(0, 1);
  lcd.print("Hum: ");
  lcd.print(humidity);
  lcd.print("%");

  // Trigger buzzer for abnormal conditions
  if (humidity >= 70 || temperature >= 30) {
    tone(buzzer, 1000, 500);
    delay(500);
  } else {
    noTone(buzzer);
  }

  // Update ThingSpeak
  ThingSpeak.setField(1, temperature);
  ThingSpeak.setField(2, humidity);
  ThingSpeak.setField(3, batteryPercent);
  ThingSpeak.setField(4, distance);
  int statusCode = ThingSpeak.writeFields(myChannelNumber, myWriteAPIKey);

  if (statusCode == 200) {
    Serial.println("ThingSpeak update successful");
  } else {
    Serial.println("ThingSpeak update failed: " + String(statusCode));
  }

  delay(15000); // ThingSpeak updates every 15 seconds
}

long getDistanceInCentimeters() {
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  duration = pulseIn(ECHO_PIN, HIGH);
  return (duration * 0.034 / 2);
}