// Student Name: Muhammad Afeeq Zhikri Bin Zamzuri
// Student ID: 52224122134

#include <WiFi.h>
#include <HTTPClient.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

#define SCREEN_WIDTH 128 // OLED width, in pixels
#define SCREEN_HEIGHT 64 // OLED height, in pixels

// OLED display object connected to I2C
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire);

// WiFi credentials
const char* ssid = "Wokwi-GUEST";
const char* password = "";

// ThingSpeak API information
const char* server = "https://api.thingspeak.com";
const char* apiKey = "CDJEFTTGRAFUMV67"; // Replace with your ThingSpeak Write API Key

void setup() {
  Serial.begin(115200);

  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("SSD1306 allocation failed"));
    for (;;);
  }

  display.clearDisplay();
  display.setTextColor(WHITE);

  WiFi.begin(ssid, password);
  Serial.print("Connecting to WiFi");
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.print(".");
  }
  Serial.println("\nWiFi connected!");
}

void sendDataToThingSpeak() {
  if (WiFi.status() == WL_CONNECTED) {
    HTTPClient http;
    String url = String(server) + "/update?api_key=" + apiKey;
    http.begin(url);
    int httpCode = http.GET();

    if (httpCode > 0) {
      Serial.println("Data sent to ThingSpeak successfully!");
    } else {
      Serial.print("Error sending data: ");
      Serial.println(http.errorToString(httpCode).c_str());
    }

    http.end();
  } else {
    Serial.println("WiFi not connected! Unable to send data.");
  }
}

void loop() {
  static unsigned long lastSendTime = 0;

  if (millis() - lastSendTime >= 10000) { // Send data every 10 seconds
    sendDataToThingSpeak();
    lastSendTime = millis();
  }

  display.clearDisplay();
  display.setTextSize(1);
  display.setCursor(0, 0);
  display.print("Sending data...");
  display.display();
}