#include <WiFi.h>
#include <HTTPClient.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>

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

// ThingSpeak API
const char* server = "http://api.thingspeak.com/update";
const char* apiKey = "J3LP8C8RJ4BV1G2O";

// I2C LCD setup: Address 0x27, 20 columns, 4 rows
LiquidCrystal_I2C lcd(0x27, 20, 4);

// Sensor input pins (simulated)
#define VOLTAGE_PIN 34
#define CURRENT_PIN 35
#define TEMP_PIN 32

// Output pins
#define GREEN_LED 4
#define YELLOW_LED 5
#define RED_LED 18
#define BUZZER 19

// Thresholds
const float VOLTAGE_WARNING = 230.0;
const float VOLTAGE_FAULT = 240.0;
const float CURRENT_WARNING = 10.0;
const float CURRENT_FAULT = 15.0;
const float TEMP_WARNING = 50.0;
const float TEMP_FAULT = 60.0;

unsigned long lastDataSentTime = 0;
bool displayDataSent = false;

void setup() {
  // Initialize serial monitor
  Serial.begin(115200);

  // Initialize LCD
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("Initializing.......");
  delay(2000);
  lcd.clear();

  lcd.setCursor(0, 0);
  lcd.print("Smart Grid System");
  delay(2000);
  lcd.clear();

  // Initialize LEDs and buzzer
  pinMode(GREEN_LED, OUTPUT);
  pinMode(YELLOW_LED, OUTPUT);
  pinMode(RED_LED, OUTPUT);
  pinMode(BUZZER, OUTPUT);

  // Connect to WiFi
  lcd.setCursor(0, 0);
  lcd.print("Connecting to WiFi");
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
    lcd.setCursor(0, 1);
    lcd.print(".");
  }
  Serial.println("\nWiFi connected!");
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("WiFi Connected!");
  delay(2000);
}

void loop() {
  // Simulate sensor readings (replace with real values if available)
  float voltage = analogRead(VOLTAGE_PIN) * (250.0 / 4095.0);
  float current = analogRead(CURRENT_PIN) * (20.0 / 4095.0);
  float temperature = analogRead(TEMP_PIN) * (100.0 / 4095.0);

  // Debug: Print sensor values
  Serial.printf("Voltage: %.1f V, Current: %.1f A, Temperature: %.1f C\n", voltage, current, temperature);

  // Update LCD rows
  lcd.setCursor(0, 0);
  lcd.printf("V: %.1fV C: %.1fA", voltage, current);
  lcd.setCursor(0, 1);
  lcd.printf("T: %.1fC ", temperature);

  // Fault detection and LED/buzzer control
  bool isBuzzerOn = false;
  String alertMessage = "System Normal"; // Default message
  if (voltage > VOLTAGE_FAULT || current > CURRENT_FAULT || temperature > TEMP_FAULT) {
    digitalWrite(RED_LED, HIGH);
    digitalWrite(YELLOW_LED, LOW);
    digitalWrite(GREEN_LED, LOW);
    digitalWrite(BUZZER, HIGH);
    isBuzzerOn = true;
    alertMessage = "CRITICAL ALERT!"; // Critical alert
  } else if (voltage > VOLTAGE_WARNING || current > CURRENT_WARNING || temperature > TEMP_WARNING) {
    digitalWrite(YELLOW_LED, HIGH);
    digitalWrite(GREEN_LED, LOW);
    digitalWrite(RED_LED, LOW);
    digitalWrite(BUZZER, LOW);
    isBuzzerOn = false;
    alertMessage = "Warning Detected!"; // Warning alert
  } else {
    digitalWrite(GREEN_LED, HIGH);
    digitalWrite(YELLOW_LED, LOW);
    digitalWrite(RED_LED, LOW);
    digitalWrite(BUZZER, LOW);
    isBuzzerOn = false;
  }

  // Display buzzer status and alert message
  lcd.setCursor(9, 1);
  lcd.print(isBuzzerOn ? "Buzzer:ON " : "Buzzer:OFF");
  lcd.setCursor(0, 2); // Fourth row
  lcd.print(alertMessage);

  // Send data to ThingSpeak
  if (WiFi.status() == WL_CONNECTED) {
    HTTPClient http;
    String url = String(server) + "?api_key=" + apiKey +
                 "&field1=" + String(voltage) +
                 "&field2=" + String(current) +
                 "&field3=" + String(temperature);
    http.begin(url.c_str());
    int httpCode = http.GET();
    if (httpCode > 0) {
      Serial.println("Data sent to ThingSpeak!");
      lcd.setCursor(0, 3);
      lcd.print("Data Sent to TS!");
      displayDataSent = true;
      lastDataSentTime = millis();
    } else {
      Serial.println("Error sending data to ThingSpeak!");
    }
    http.end();
  } else {
    Serial.println("WiFi disconnected!");
  }

  // Clear "Data Sent" message after 2 seconds
  if (displayDataSent && (millis() - lastDataSentTime > 2000)) {
    lcd.setCursor(0, 2);
    lcd.print("                    "); // Clear line
    displayDataSent = false;
  }

  delay(20000); // Limit updates to every 20 seconds
}