#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <DHT.h>
#include <WiFi.h>
#include <PubSubClient.h>
#include <ArduinoJson.h>

// Pin & konfigurasi
#define DHTPIN     12
#define DHTTYPE    DHT22
#define LDR_PIN    34
#define BTN_MODE   14
#define RELAY_PIN  26
#define LED_PIN    27

// Konfigurasi WiFi
const char* ssid = "Wokwi-GUEST"; // default wokwi
const char* password = "";        

// Konfigurasi MQTT
const char* clientId = "clientId-KlvPo5xGXv";
const char* mqttServer = "mqtt-dashboard.com";
const int mqttPort = 1883;
const char* mqttUser = "";
const char* mqttPassword = "";

// MQTT Topics
const char* mqttTopicSensor = "magang/praktik/iot/sensor";     // Untuk mengirim data sensor
const char* mqttTopicControl = "magang/praktik/iot/control";   // Untuk menerima perintah
const char* mqttTopicStatus = "magang/praktik/iot/status";     // Untuk mengirim status relay

// Inisialisasi
DHT dht(DHTPIN, DHTTYPE);
Adafruit_SSD1306 display(128, 64, &Wire, -1);
WiFiClient wifiClient;
PubSubClient client(wifiClient);

// Variabel global
int mode = 1;
int thresholdTemp = 30;
unsigned long lastDebounce = 0;
unsigned long lastSerialPrint = 0;
unsigned long lastMqttPublish = 0;
String inputString = "";

void setup() {
  Serial.begin(115200);
  connectToWiFi();
  client.setServer(mqttServer, mqttPort);
  client.setCallback(mqttCallback);

  dht.begin();

  pinMode(BTN_MODE, INPUT_PULLUP);
  pinMode(RELAY_PIN, OUTPUT);
  pinMode(LED_PIN, OUTPUT);
  digitalWrite(RELAY_PIN, LOW);

  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
  display.clearDisplay();
}

void loop() {
  // Cek koneksi MQTT
  if (!client.connected()) {
    reconnectMQTT();
  }
  client.loop();

  // Tombol ganti mode
  if (digitalRead(BTN_MODE) == LOW && millis() - lastDebounce > 300) {
    mode++;
    if (mode > 3) mode = 1;
    lastDebounce = millis();
  }

  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);

  switch (mode) {
    case 1: showSensorData(); break;
    case 2: showRelayStatus(); break;
    case 3: showThresholdControl(); break;
  }

  display.display();

  // Tampilkan data ke Serial setiap 5 detik
  if (millis() - lastSerialPrint > 5000) {
    printToSerial();
    lastSerialPrint = millis();
  }

  // Kirim data sensor ke MQTT setiap 10 detik
  if (millis() - lastMqttPublish > 10000) {
    publishSensorData();
    lastMqttPublish = millis();
  }

  // Terima command dari Serial Monitor
  readSerialCommand();

  delay(200);
}

void showSensorData() {
  float temp = dht.readTemperature();
  float hum  = dht.readHumidity();
  float voltage = analogRead(LDR_PIN) * (3.3 / 4095.0);
  float resistance = (3.3 - voltage) * 10000 / voltage;
  float lux = 500 / (resistance / 1000); // estimasi lux

  display.setCursor(0, 0);
  display.println("Mode 1: Sensor");
  display.print("Temp: "); display.print(temp); display.println(" C");
  display.print("Hum : "); display.print(hum); display.println(" %");
  display.print("Lux : "); display.println(lux);
  display.println("MQTT: Connected");

  if (temp > thresholdTemp) {
    digitalWrite(RELAY_PIN, HIGH);
    digitalWrite(LED_PIN, HIGH);
    display.println("Relay ON");
  } else {
    digitalWrite(RELAY_PIN, LOW);
    digitalWrite(LED_PIN, LOW);
    display.println("Relay OFF");
  }
}

void showRelayStatus() {
  float temp = dht.readTemperature();

  display.setCursor(0, 0);
  display.println("Mode 2: Relay");
  bool state = digitalRead(RELAY_PIN);
  display.print("Relay: ");
  display.println(state ? "ON" : "OFF");
  display.println("Control via MQTT:");
  display.println("on / off");

  if (temp > thresholdTemp) {
    digitalWrite(RELAY_PIN, HIGH);
    digitalWrite(LED_PIN, HIGH);
    display.println("Relay ON");
  } else {
    digitalWrite(RELAY_PIN, LOW);
    digitalWrite(LED_PIN, LOW);
    display.println("Relay OFF");
  }
}

void showThresholdControl() {
  float temp = dht.readTemperature();

  display.setCursor(0, 0);
  display.println("Mode 3: Threshold");
  display.print("Batas: "); display.print(thresholdTemp); display.println(" C");
  display.print("Suhu : "); display.print(temp); display.println(" C");

  if (temp > thresholdTemp) {
    digitalWrite(RELAY_PIN, HIGH);
    digitalWrite(LED_PIN, HIGH);
    display.println("Relay ON");
  } else {
    digitalWrite(RELAY_PIN, LOW);
    digitalWrite(LED_PIN, LOW);
    display.println("Relay OFF");
  }
}

void printToSerial() {
  float temp = dht.readTemperature();
  float hum = dht.readHumidity();
  float ldr = analogRead(LDR_PIN) * (3.3 / 4095.0);

  Serial.println("----- Sensor Data -----");
  Serial.print("Temp      : "); Serial.print(temp); Serial.println(" C");
  Serial.print("Humidity  : "); Serial.print(hum); Serial.println(" %");
  Serial.print("LDR       : "); Serial.println(ldr);
  Serial.print("Relay     : "); Serial.println(digitalRead(RELAY_PIN) ? "ON" : "OFF");
  Serial.print("Threshold : "); Serial.println(thresholdTemp);
  Serial.println("------------------------");
}

// Fungsi untuk mengirim data sensor ke MQTT
void publishSensorData() {
  float temp = dht.readTemperature();
  float hum = dht.readHumidity();
  float voltage = analogRead(LDR_PIN) * (3.3 / 4095.0);
  float resistance = (3.3 - voltage) * 10000 / voltage;
  float lux = 500 / (resistance / 1000);
  bool relayState = digitalRead(RELAY_PIN);

  // Membuat JSON untuk data sensor
  StaticJsonDocument<200> sensorDoc;
  sensorDoc["temperature"] = temp;
  sensorDoc["humidity"] = hum;
  sensorDoc["lux"] = lux;
  sensorDoc["relay_state"] = relayState;
  sensorDoc["threshold"] = thresholdTemp;
  sensorDoc["timestamp"] = millis();

  String sensorPayload;
  serializeJson(sensorDoc, sensorPayload);

  // Publish data sensor
  if (client.publish(mqttTopicSensor, sensorPayload.c_str())) {
    Serial.println("Data sensor berhasil dikirim ke MQTT");
    Serial.println("Payload: " + sensorPayload);
  } else {
    Serial.println("Gagal mengirim data sensor ke MQTT");
  }

  // Kirim status relay terpisah
  StaticJsonDocument<100> statusDoc;
  statusDoc["relay"] = relayState ? "ON" : "OFF";
  statusDoc["threshold"] = thresholdTemp;
  statusDoc["auto_mode"] = (mode == 3);

  String statusPayload;
  serializeJson(statusDoc, statusPayload);

  if (client.publish(mqttTopicStatus, statusPayload.c_str())) {
    Serial.println("Status berhasil dikirim ke MQTT");
  }
}

// Fungsi membaca perintah dari Serial Monitor
void readSerialCommand() {
  while (Serial.available()) {
    char c = Serial.read();
    if (c == '\n') {
      processSerialCommand(inputString);
      inputString = "";
    } else {
      inputString += c;
    }
  }
}

void processSerialCommand(String cmd) {
  cmd.trim();

  if (cmd.startsWith("threshold:")) {
    int val = cmd.substring(10).toInt();
    thresholdTemp = val;
    Serial.println("Threshold diubah ke: " + String(thresholdTemp));
  }
  else if (cmd == "on") {
    digitalWrite(RELAY_PIN, HIGH);
    Serial.println("Relay ON via Serial");
  }
  else if (cmd == "off") {
    digitalWrite(RELAY_PIN, LOW);
    Serial.println("Relay OFF via Serial");
  }
  else {
    Serial.println("Perintah tidak dikenali");
  }
}

// Fungsi untuk menghubungkan ke WiFi
void connectToWiFi() {
  Serial.print("Connecting to WiFi...");
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.print(".");
  }
  Serial.println("Connected to WiFi!");
  Serial.print("IP Address: ");
  Serial.println(WiFi.localIP());
}

// Fungsi untuk menghubungkan ke MQTT Broker
void reconnectMQTT() {
  while (!client.connected()) {
    Serial.print("Connecting to MQTT...");
    
    if (client.connect(clientId, mqttUser, mqttPassword)) {
      Serial.println("Connected to MQTT!");
      
      // Subscribe ke topic control untuk menerima perintah
      client.subscribe(mqttTopicControl);
      Serial.println("Subscribed to: " + String(mqttTopicControl));
      
    } else {
      Serial.print("Failed, rc=");
      Serial.print(client.state());
      delay(5000);
    }
  }
}

// Callback untuk menerima pesan MQTT
void mqttCallback(char* topic, byte* payload, unsigned int length) {
  // Convert payload to string
  String message = "";
  for (int i = 0; i < length; i++) {
    message += (char)payload[i];
  }
  
  Serial.println("Pesan MQTT diterima:");
  Serial.println("Topic: " + String(topic));
  Serial.println("Message: " + message);

  // Parse JSON message
  StaticJsonDocument<200> doc;
  DeserializationError error = deserializeJson(doc, message);

  if (error) {
    Serial.println("Error parsing JSON, mencoba perintah teks biasa...");
    
    // Jika bukan JSON, coba sebagai perintah teks biasa
    message.trim();
    message.toLowerCase();
    
    if (message == "on") {
      digitalWrite(RELAY_PIN, HIGH);
      digitalWrite(LED_PIN, HIGH);
      Serial.println("Relay ON via MQTT");
      publishStatusUpdate();
    }
    else if (message == "off") {
      digitalWrite(RELAY_PIN, LOW);
      digitalWrite(LED_PIN, LOW);
      Serial.println("Relay OFF via MQTT");
      publishStatusUpdate();
    }
    else {
      Serial.println("Perintah MQTT tidak dikenali: " + message);
    }
    return;
  }

  // Process JSON commands
  if (doc.containsKey("relay")) {
    String relayCmd = doc["relay"];
    relayCmd.toLowerCase();
    
    if (relayCmd == "on") {
      digitalWrite(RELAY_PIN, HIGH);
      digitalWrite(LED_PIN, HIGH);
      Serial.println("Relay ON via MQTT JSON");
    }
    else if (relayCmd == "off") {
      digitalWrite(RELAY_PIN, LOW);
      digitalWrite(LED_PIN, LOW);
      Serial.println("Relay OFF via MQTT JSON");
    }
    publishStatusUpdate();
  }

  if (doc.containsKey("threshold")) {
    int newThreshold = doc["threshold"];
    if (newThreshold > 0 && newThreshold < 100) {
      thresholdTemp = newThreshold;
      Serial.println("Threshold diubah via MQTT ke: " + String(thresholdTemp));
      publishStatusUpdate();
    }
  }

  if (doc.containsKey("mode")) {
    int newMode = doc["mode"];
    if (newMode >= 1 && newMode <= 3) {
      mode = newMode;
      Serial.println("Mode diubah via MQTT ke: " + String(mode));
    }
  }
}

// Fungsi untuk mengirim update status setelah perubahan
void publishStatusUpdate() {
  StaticJsonDocument<150> statusDoc;
  statusDoc["relay"] = digitalRead(RELAY_PIN) ? "ON" : "OFF";
  statusDoc["threshold"] = thresholdTemp;
  statusDoc["mode"] = mode;
  statusDoc["updated"] = "via_mqtt";

  String statusPayload;
  serializeJson(statusDoc, statusPayload);

  client.publish(mqttTopicStatus, statusPayload.c_str());
  Serial.println("Status update dikirim: " + statusPayload);
}