#include <WiFi.h>
#include <HTTPClient.h>
#include <ArduinoJson.h> // Make sure to install the ArduinoJson library

const int relayPin = 17; // Relay control pin
const int buttonPin = 22; // Push button pin
const int enablePin = 21; // Enable button pin
const int triggerPin = 18; // Trigger pin for ultrasonic sensor
const int echoPin = 5; // Echo pin for ultrasonic sensor

bool relayState = false; // Initial state of the relay
unsigned long relayOnDuration = 5000; // Duration to keep the relay ON (in milliseconds)
unsigned long relayOnStartTime = 0; // Variable to store the time when the relay was turned ON
bool relayTimerActive = false; // Flag to check if the relay timer is active

void setup() {
  Serial.begin(9600);
  
  // Connect to Wi-Fi
  WiFi.begin("Wokwi-GUEST", ""); // Replace with your Wi-Fi credentials
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.println("Connecting to WiFi...");
  }
  Serial.println("Connected to WiFi");

  pinMode(relayPin, OUTPUT); // Set relay pin as OUTPUT
  pinMode(buttonPin, INPUT_PULLUP); // Set button pin as INPUT with internal pull-up
  pinMode(enablePin, INPUT_PULLUP); // Set enable pin as INPUT with internal pull-up
  pinMode(triggerPin, OUTPUT); // Set trigger pin as OUTPUT
  pinMode(echoPin, INPUT); // Set echo pin as INPUT

  digitalWrite(relayPin, relayState ? HIGH : LOW); // Initialize relay state
}

void sendRelayStateToServer(bool state) {
  if (WiFi.status() == WL_CONNECTED) {
    HTTPClient http;
    http.begin("https://emslte.arkaautomaations.com/teltonika_test.php"); // Replace with your server URL
    http.addHeader("Content-Type", "application/json");

    // Create a JSON object
    StaticJsonDocument<200> jsonDoc;
    jsonDoc["relayState"] = state ? "ON" : "OFF";

    // Serialize JSON to string
    String jsonString;
    serializeJson(jsonDoc, jsonString);

    // Send HTTP POST request
    int httpResponseCode = http.POST(jsonString);

    if (httpResponseCode > 0) {
      String response = http.getString();
      Serial.println("Response: " + response);
    } else {
      Serial.print("Error on sending POST: ");
      Serial.println(httpResponseCode);
    }

    http.end(); // Free resources
  } else {
    Serial.println("WiFi not connected");
  }
}

float readUltrasonicDistance() {
  // Trigger the ultrasonic sensor
  digitalWrite(triggerPin, LOW);
  delayMicroseconds(2);
  digitalWrite(triggerPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(triggerPin, LOW);

  // Read the echo pin
  long duration = pulseIn(echoPin, HIGH);
  float distance = (duration * 0.0343) / 2; // Convert to cm
  return distance;
}

void controlRelayBasedOnDistance(float distance) {
  const float minHeight = 80.0; // Minimum height in cm
  const float maxHeight = 350.0; // Maximum height in cm

  if (distance < minHeight) {
    if (!relayState) {
      relayState = true; // Set relay state to ON
      digitalWrite(relayPin, HIGH); // Update relay state
      Serial.println("Relay is now: ON (Distance below minimum)");
      sendRelayStateToServer(relayState); // Send state to server
    }
  } else if (distance > maxHeight) {
    if (relayState) {
      relayState = false; // Set relay state to OFF
      digitalWrite(relayPin, LOW); // Update relay state
      Serial.println("Relay is now: OFF (Distance above maximum)");
      sendRelayStateToServer(relayState); // Send state to server
    }
  }
}

void loop() {
  static bool lastButtonState = HIGH; // Last button state
  bool currentButtonState = digitalRead(buttonPin); // Read current button state

  // Read distance from ultrasonic sensor
  float distance = readUltrasonicDistance();
  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.println(" cm");
  delay(10000);

  // Control relay based on distance
  controlRelayBasedOnDistance(distance);
}
  //