#include <WiFi.h>
#include <ThingSpeak.h>

const char* ssid = "Wokwi-GUEST"; 
const char* password = ""; 
WiFiClient client;
unsigned long myChannelNumber =  2728330;
const char * myWriteAPIKey = "BVRID7VTYVC2DDAL";

const int ldrPin = 36;
const int relayPin = 23;
const int trigPin = 5;
const int echoPin = 18;
int ldrValue = 0;
int threshold = 500;
long duration, distance;

void setup() {
  Serial.begin(115200);
  pinMode(ldrPin, INPUT);
  pinMode(relayPin, OUTPUT);
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  digitalWrite(relayPin, LOW);

  connectToWiFi();
  ThingSpeak.begin(client);
}

void loop() {
  ldrValue = analogRead(ldrPin);
  Serial.print("LDR Value: ");
  Serial.println(ldrValue);

  // Ultrasonic sensor code
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  duration = pulseIn(echoPin, HIGH);
  distance = (duration / 2) / 29.1;
  Serial.print("Distance: ");
  Serial.println(distance);

  if (ldrValue < threshold || distance < 100) {
    digitalWrite(relayPin, HIGH);
  } else {
    digitalWrite(relayPin, LOW);
  }

  ThingSpeak.setField(1, ldrValue);
  ThingSpeak.setField(2, distance);

  int x = ThingSpeak.writeFields(myChannelNumber, myWriteAPIKey);
  if (x == 200) {
    Serial.println("Channel update successful.");
  } else {
    Serial.println("Problem updating channel. HTTP error code " + String(x));
  }

  delay(20000);
}

void connectToWiFi() {
  WiFi.begin(ssid, password);
  Serial.print("Connecting to WiFi");

  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.print(".");
  }

  Serial.println("\nConnected to WiFi");
}