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

// ===== WiFi Simulation (Wokwi) =====
const char* ssid = "Wokwi-GUEST";  // Wokwi WiFi simulation
const char* password = "";          // empty password

// ===== ThingSpeak HTTP =====
const char* server = "http://api.thingspeak.com/update";
const char* writeAPIKey = "5HD7ORL7KQ025ASW";  // Replace with your ThingSpeak API key

// ===== Pins & sensor max values =====
#define CURRENT_PIN 34
#define VOLTAGE_PIN 35
float maxCurrent = 5.0;   // 5A
float maxVoltage = 250.0; // 250V

// ===== Thresholds =====
float CURRENT_LIMIT = 3.0;      // Ampere
float VOLTAGE_LOW   = 200.0;    // Volt
float VOLTAGE_HIGH  = 240.0;    // Volt

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

  Serial.println("===== Smart Grid Node Simulation =====");

  // Connect WiFi (simulated in Wokwi)
  WiFi.begin(ssid, password);
  Serial.print("Connecting to WiFi...");
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("\nWiFi connected (simulated)");
}

void loop() {
  // ===== Read simulated sensors =====
  int rawCurrent = analogRead(CURRENT_PIN);
  int rawVoltage = analogRead(VOLTAGE_PIN);

  float current = (rawCurrent / 4095.0) * maxCurrent;
  float voltage = (rawVoltage / 4095.0) * maxVoltage;

  // ===== Check thresholds =====
  String status = "NORMAL";
  if(current > CURRENT_LIMIT){
    status = "OVER CURRENT";
  } else if(voltage < VOLTAGE_LOW){
    status = "UNDER VOLTAGE";
  } else if(voltage > VOLTAGE_HIGH){
    status = "OVER VOLTAGE";
  }

  // ===== Print to Serial =====
  Serial.print("Voltage: "); Serial.print(voltage,1); Serial.print(" V | ");
  Serial.print("Current: "); Serial.print(current,2); Serial.print(" A | ");
  Serial.print("Status: "); Serial.println(status);

  // ===== Simulate HTTP request to ThingSpeak =====
  if(WiFi.status() == WL_CONNECTED){
    HTTPClient http;
    String url = String(server) + "?api_key=" + writeAPIKey
                 + "&field1=" + String(voltage,1)
                 + "&field2=" + String(current,2);
    http.begin(url);
    int httpCode = http.GET();  // Simulated HTTP GET
    Serial.print("HTTP Response code (simulated): "); Serial.println(httpCode);
    http.end();
  }

  delay(15000); // ThingSpeak update limit = 15 seconds
}