#include <DHTesp.h>
#include <WiFi.h>
#include <ThingSpeak.h>
#define LED_PIN 5

const char* ssid = "wokwi-GUEST";
const char* pass = "";
WiFiClient client;
const unsigned long MyChannelNumber = 2610006;
const char* myWriteAPIKey = "00CX68E242G06109";

DHTesp dhtSensor;
const int dhtPin = 27;
const int trig = 17;
const int echo = 16;

void setup() {
  Serial.begin(115200);
  pinMode(echo, INPUT);
  pinMode(trig, OUTPUT);
  pinMode(LED_PIN, OUTPUT);
  dhtSensor.setup(dhtPin, DHTesp::DHT22);
  
  WiFi.mode(WIFI_STA);
  ThingSpeak.begin(client);
  connectToWiFi();
}

void loop() {
  TempAndHumidity data = dhtSensor.getTempAndHumidity();
  float distance = getDistance();
  
  Serial.print("Humidity: ");
  Serial.print(data.humidity);
  Serial.print(" Temperature: ");
  Serial.print(data.temperature);
  Serial.print(" Distance = ");
  Serial.println(distance);

  ThingSpeak.setField(1, distance);
  ThingSpeak.setField(2, data.temperature);
  ThingSpeak.setField(3, data.humidity);

  if(data.temperature <=20 && data.humidity<=20)
  {
    digitalWrite(LED_PIN, HIGH);
}
else
{
  digitalWrite(LED_PIN, LOW);
}
  int statusCode = ThingSpeak.writeFields(MyChannelNumber, myWriteAPIKey);
  if (statusCode == 200) {
    Serial.println("Channel updated successfully.");
  } else {
    Serial.print("Problem writing data. HTTP error code: ");
    Serial.println(statusCode);
  }
  
  delay(15000); 
}

float getDistance() {
  digitalWrite(trig, LOW);
  delayMicroseconds(2);
  digitalWrite(trig, HIGH);
  delay(10);
  digitalWrite(trig, LOW);
  
  unsigned long duration = pulseIn(echo, HIGH);
  float distance = duration * 0.034 / 2;
  
  // Optional: Add a check to ensure distance is within a reasonable range
  if (distance < 0 || distance > 400) {
    distance = -1; // Invalid distance
  }
  
  return distance;
}

void connectToWiFi() {
  Serial.print("Attempting to connect to WiFi");
  WiFi.begin(ssid, pass);
  
  unsigned long startTime = millis();
  unsigned long timeout = 300000; // 300 seconds timeout
  
  while (WiFi.status() != WL_CONNECTED) {
    if (millis() - startTime > timeout) {
      Serial.println("Failed to connect to WiFi.");
      return;
    }
    Serial.print(".");
    delay(500);
  }
  
  Serial.println("\nConnected to WiFi");
}