#include <WiFi.h>
#include <WiFiClient.h>
#include <PubSubClient.h>
#include <ArduinoJson.h>

#define MAX_CHARACTER 50
#define MQTT_SERVER "0.tcp.ap.ngrok.io"

// Declaration of ultrasonic sensor pins
#define trigPin 13
#define echoPin 12

// Declaration of WiFi parameters
char ssid[] = "Wokwi-GUEST";
char pass[] = "";

// Declaration of MQTT server parameters
char mqtt_topic[] = "airpdam";
int mqtt_port = 14204;

WiFiClient espClient;
PubSubClient client(espClient);

// Initialization of variables
int kondisiAir = 0;

// Declaration of WiFi setup function
void setupWifi() {
  Serial.print("Connecting [ ");
  Serial.print(ssid);
  Serial.println(" ]");

  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, pass);

  while (WiFi.status() != WL_CONNECTED) {
    delay(5000);
    Serial.print(".");
  }

  randomSeed(micros());
  Serial.println("");
  Serial.print("Connected to ");
  Serial.println(ssid);
  Serial.print("IP address: ");
  Serial.println(WiFi.localIP());
  Serial.println("");
}

// Check MQTT server connection function
void setupMqtt() {
  while (!client.connected()) {
    Serial.println("Loading MQTT");

    String idClient = "client-";
    idClient += String(random(0xffff), HEX);

    if (client.connect(idClient.c_str())) {
      Serial.println("MQTT connected");
      Serial.println();

      client.publish(mqtt_topic, "Device connected...");
      client.publish(mqtt_topic, " ");
    } else {
      Serial.print("Failed: ");
      Serial.print(client.state());
      Serial.println(" Retrying...");
      delay(5000);
    }
  }
}

// Setup function
void setup() {
  Serial.begin(115200);

  setupWifi();
  client.setServer(MQTT_SERVER, mqtt_port);

  if (!client.connected()) {
    setupMqtt();
  }

  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
}

// Ultrasonic sensor function
void sensor() {
  // Send ultrasonic signal
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  // Receive ultrasonic wave reflection time
  unsigned long duration = pulseIn(echoPin, HIGH);

  // Calculate distance based on reflection time
  kondisiAir = duration * 0.034 / 2;

  // Display data on Serial Monitor
  Serial.print("Kandungan pH Air: ");
  Serial.println(kondisiAir);

  // Example logic based on kondisiAir value
  if (kondisiAir > 15 && kondisiAir < 25) {
    Serial.println("Condition: BERSIH");
  } else if (kondisiAir < 15) {
    Serial.println("Condition: ASAM");
  } else if (kondisiAir > 25) {
    Serial.println("Condition: BASA");
}
}

// Main program loop
void loop() {
  client.loop();
  sensor();

  Serial.println("--------------------------------------------------------------");
  StaticJsonDocument<300> doc;

  doc["Kandungan pH Air"] = kondisiAir;

  // Example logic based on ultrasonic kondisiAir
  if (kondisiAir > 15 && kondisiAir < 25) {
    doc["Kondisi Air"] = "BERSIH";
  } else if (kondisiAir < 15) {
    doc["Kondisi Air"] = "ASAM";
  } else if (kondisiAir > 25) {
    doc["Kondisi Air"] = "BASA";
  }

  String out;
  serializeJson(doc, out);
  char json[out.length() + 1];
  out.toCharArray(json, out.length() + 1);

  // Send data to MQTT server
  client.publish(mqtt_topic, json);
  client.publish(mqtt_topic, "---------------");
  delay(5000);
}