#include "DHT.h"
#include <WiFi.h>

#define DHTPIN 15
#define DHTTYPE DHT22
#define LED_PIN 2
#define BUTTON_PIN 18

DHT dht(DHTPIN, DHTTYPE);

const char* ssid = "Wokwi-GUEST";
const char* password = "";

const char* host = "api.thingspeak.com";
String writeAPIKey = "P4O58DHHM9F1P6SM";
unsigned long channelID = 3334586; // kept for reference

WiFiClient client;
bool systemOn = false;

void setup() {
  Serial.begin(115200);
  pinMode(LED_PIN, OUTPUT);
  pinMode(BUTTON_PIN, INPUT_PULLUP);
  dht.begin();

  Serial.print("Connecting to WiFi");
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

  Serial.println("\nWiFi connected!");
  Serial.println("Revision Lab: Smart Temperature Indicator");
}

void loop() {
  systemOn = (digitalRead(BUTTON_PIN) == LOW);

  float temp = dht.readTemperature();
  float hum = dht.readHumidity();

  if (isnan(temp) || isnan(hum)) {
    Serial.println("Sensor error!");
    delay(2000);
    return;
  }

  Serial.print("Temperature: ");
  Serial.print(temp);
  Serial.println(" °C");

  Serial.print("Humidity: ");
  Serial.print(hum);
  Serial.println(" %");

  if (systemOn && temp > 30.0) {
  digitalWrite(LED_PIN, HIGH);
  Serial.println("Uploading to ThingSpeak...");

  if (client.connect(host, 80)) {
    String url = "/update?api_key=" + writeAPIKey +
                 "&field1=" + String(temp) +
                 "&field2=" + String(hum);

    client.print(String("GET ") + url + " HTTP/1.1\r\n" +
                 "Host: " + host + "\r\n" +
                 "Connection: close\r\n\r\n");

    String response = "";
    while (client.connected() || client.available()) {
      if (client.available()) {
        response += client.readStringUntil('\n');
      }
    }

    client.stop();

    if (response.indexOf("200 OK") >= 0) {
      Serial.println("Upload successful!");
    } else {
      Serial.println("Upload failed!");
    }

  } else {
    Serial.println("Upload failed!");
  }

} else {
  digitalWrite(LED_PIN, LOW);
}

delay(15000);
}