#include <WiFi.h>
#include <HTTPClient.h>

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

// ThingSpeak API
const char* server = "http://api.thingspeak.com/update";
String apiKey = "0LZPYNP254P5NJI2";

// Potentiometer pins
const int pot1Pin = 34;  // Simulates voltage
const int pot2Pin = 35;  // Simulates current

// Energy calculation
unsigned long lastMillis = 0;
float energy_kWh = 0.0;

void setup() {
  Serial.begin(115200);
  WiFi.begin(ssid, password);

  Serial.print("Connecting to WiFi");
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("\nConnected.");
  lastMillis = millis();
}

void loop() {
  // Read raw analog values
  int rawVolt = analogRead(pot1Pin);  // 0 - 4095
  int rawAmp = analogRead(pot2Pin);   // 0 - 4095

  // Map to realistic values
  float voltage = rawVolt * (300.0 / 4095.0);  // 0 - 300V
  float current = rawAmp * (20.0 / 4095.0);    // 0 - 20A

  // Power in kW
  float power_kW = (voltage * current) / 1000.0;

  // Time since last reading
  unsigned long now = millis();
  float deltaHours = (now - lastMillis) / 3600000.0;  // ms to hours
  lastMillis = now;

  // Energy in kWh
  energy_kWh += power_kW * deltaHours;

  // Output
  Serial.printf("Voltage: %.2f V, Current: %.2f A, Power: %.3f kW, Energy: %.5f kWh\n",
                voltage, current, power_kW, energy_kWh);

  // Send to ThingSpeak
  if (WiFi.status() == WL_CONNECTED) {
    HTTPClient http;
    String url = String(server) + "?api_key=" + apiKey +
                 "&field1=" + String(voltage) +
                 "&field2=" + String(current) +
                 "&field3=" + String(power_kW) +
                 "&field4=" + String(energy_kWh);

    http.begin(url);
    int httpCode = http.GET();
    if (httpCode > 0) {
      Serial.println("Data sent to ThingSpeak.");
    } else {
      Serial.printf("Failed to send: %s\n", http.errorToString(httpCode).c_str());
    }
    http.end();
  }

  delay(20000);  // Wait at least 15s for ThingSpeak
}