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

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

// MQTT Configuration
const char* mqttServer = "broker.emqx.io";
const int mqttPort = 1883;
const char* mqttUsername = "emqx";
const char* mqttPassword = "public";

// Library
DHT dht(14, DHT22); // DHT 11 Declaration

#define LdrPin 34
#define soilMoisturePin 15
int soilMoistureValue;

const int RELAY_PIN = 16;

float calculateBrightness(int ldrRawValue) {
  const float gamma = 0.7;
  const float rl10 = 50;

  // Convert LDR raw value to a 0-1023 scale
  ldrRawValue = map(ldrRawValue, 4095, 0, 1024, 0);

  // Convert LDR raw value to voltage
  float voltage = ldrRawValue / 1024.0 * 5.0;

  // Calculate resistance based on voltage and known resistor values
  float resistance = 2000 * voltage / (1 - voltage / 5);

  // Calculate brightness using the given formula
  float brightness = pow(rl10 * 1e3 * pow(10, gamma) / resistance, (1 / gamma));

  return brightness;
}

WiFiClient espClient;
PubSubClient client(espClient);

void setup() {
  Serial.begin(9600);

  // Starting DHT11 scanning
  dht.begin();

  pinMode(RELAY_PIN, OUTPUT);

  // Connect to Wi-Fi
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.println("Connecting to WiFi...");
  }
  Serial.println("Connected to WiFi");

  // Connect to MQTT broker
  client.setServer(mqttServer, mqttPort);
  if (client.connect("ESP32Client", mqttUsername, mqttPassword)) {
    Serial.println("Connected to MQTT broker");
  } else {
    Serial.println("Connection to MQTT broker failed");
  }
}

void loop() {
  float h = dht.readHumidity();
  float t = dht.readTemperature();
  float hic = dht.computeHeatIndex(t, h, false);

  int ldrRawValue = analogRead(LdrPin);
  float brightness = calculateBrightness(ldrRawValue);

  soilMoistureValue = analogRead(soilMoisturePin);

  Serial.print(F("Humidity: "));
  Serial.print(h);
  Serial.print(F("% Temperature: "));
  Serial.print(t);
  Serial.println(" *C ");
  client.publish("humidity_topic", String(h).c_str());

  Serial.print("Brightness: ");
  Serial.print(brightness);
  Serial.println(" lux ");
  client.publish("emqx/brightnessxx", String(brightness).c_str());

  Serial.print("Soil Moisture: ");
  Serial.print(soilMoistureValue);
  Serial.println(" cm ");
  client.publish("soil_moisture_topic", String(soilMoistureValue).c_str());

  if (soilMoistureValue >= 75 && soilMoistureValue <= 150) {
    digitalWrite(RELAY_PIN, HIGH);
    Serial.println("Relay: ON");
    client.publish("relay_status_topic", "ON");
  } else {
    digitalWrite(RELAY_PIN, LOW);
    Serial.println("Relay: OFF");
    client.publish("relay_status_topic", "OFF");
  }

  delay(2000);
}