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

const char* WIFI_SSID = "Wokwi-GUEST";
const char* WIFI_PASS = "";
const char* MQTT_SERVER = "test.mosquitto.org";
const uint16_t MQTT_PORT = 1883;

const char* TOPIC_SET   = "home/room1/led/set";
const char* TOPIC_STATE = "home/room1/led/state";
const char* TOPIC_LDR   = "home/room1/ldr/value";

#define LED_PIN 2
#define LDR_PIN 34

WiFiClient espClient;
PubSubClient mqtt(espClient);

bool ledOn = false;
bool blinkMode = false;
unsigned long lastBlink = 0;
unsigned long lastLdrPublish = 0;

// =========================
// Hàm xuất trạng thái LED
// =========================
void publishState(bool retain = true) {
  mqtt.publish(TOPIC_STATE, ledOn ? "ON" : "OFF", retain);
}

// =========================
// Đảo lại logic bật/tắt LED
// =========================
void setLed(bool on) {
  ledOn = on;
  digitalWrite(LED_PIN, on ? LOW : HIGH); // đảo logic: LOW = sáng, HIGH = tắt
  publishState(true);
}

// =========================
void onMqttMessage(char* topic, byte* payload, unsigned int length) {
  String msg;
  for (unsigned int i = 0; i < length; i++) msg += (char)payload[i];
  msg.trim(); msg.toUpperCase();

  if (String(topic) == TOPIC_SET) {
    if (msg == "ON") {
      blinkMode = false;
      setLed(true);  // ON → sáng
    } 
    else if (msg == "OFF") {
      blinkMode = false;
      setLed(false); // OFF → tắt
    } 
    else if (msg == "TOGGLE") {
      blinkMode = false;
      setLed(!ledOn);
    }
    else if (msg == "BLINK") {
      blinkMode = true;
      Serial.println("LED BLINK MODE");
    }
  }
}

// =========================
void wifiConnect() {
  WiFi.mode(WIFI_STA);
  WiFi.setSleep(false);
  Serial.print("Connecting WiFi: ");
  Serial.println(WIFI_SSID);
  WiFi.begin(WIFI_SSID, WIFI_PASS);

  int retry = 0;
  while (WiFi.status() != WL_CONNECTED && retry < 30) {
    delay(500);
    Serial.print(".");
    retry++;
  }
  if (WiFi.status() == WL_CONNECTED) {
    Serial.print("\nWiFi OK, IP: ");
    Serial.println(WiFi.localIP());
  } else {
    Serial.println("\nWiFi FAILED.");
  }
}

// =========================
void mqttReconnect() {
  while (!mqtt.connected()) {
    String cid = "ESP32-" + String((uint32_t)ESP.getEfuseMac(), HEX);
    if (mqtt.connect(cid.c_str())) {
      mqtt.subscribe(TOPIC_SET);
      publishState(true);
    } else {
      delay(2000);
    }
  }
}

// =========================
void setup() {
  Serial.begin(115200);
  pinMode(LED_PIN, OUTPUT);
  digitalWrite(LED_PIN, HIGH); // khởi đầu tắt đèn (vì LOW = sáng)

  wifiConnect();
  mqtt.setServer(MQTT_SERVER, MQTT_PORT);
  mqtt.setCallback(onMqttMessage);
}

// =========================
void loop() {
  if (WiFi.status() != WL_CONNECTED) wifiConnect();
  if (!mqtt.connected()) mqttReconnect();
  mqtt.loop();

  unsigned long now = millis();
  if (now - lastLdrPublish > 1000) {
    int lightVal = analogRead(LDR_PIN);
    Serial.print("LDR: ");
    Serial.println(lightVal);

    char msg[16];
    snprintf(msg, sizeof(msg), "%d", lightVal);
    mqtt.publish(TOPIC_LDR, msg);

    // ⚙️ Khi sáng thì tắt đèn, khi tối thì bật đèn
    if (lightVal > 1500) {
      setLed(true);   // Tối → sáng
    } else {
      setLed(false);  // Sáng → tắt
    }

    lastLdrPublish = now;
  }

  if (blinkMode) {
    if (now - lastBlink > 500) {
      ledOn = !ledOn;
      digitalWrite(LED_PIN, ledOn ? LOW : HIGH); // Đảo logic luôn ở đây
      lastBlink = now;
    }
  }
}