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

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

// MQTT Broker
const char* mqtt_server = "broker.hivemq.com";

WiFiClient espClient;
PubSubClient client(espClient);
// Chân kết nối
const int PIR_PIN = 13;
const int RED_LED_PIN = 14;
const int RELAY_PIN = 18;       // Điều khiển máy bơm (relay)
const int GREEN_LED_PIN = 253;  // LED2 (mô phỏng máy bơm)
const int TRIG_PIN = 37;
const int ECHO_PIN = 38;

// Các biến
bool motionDetected = false;

// Hàm đo khoảng cách siêu âm
long readUltrasonicCM() {
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);

  long duration = pulseIn(ECHO_PIN, HIGH, 30000); // timeout 30ms
  long distance = duration * 0.034 / 2;
  return distance;
}

void setup_wifi() {
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) delay(500);
  Serial.println("WiFi connected");
}

void reconnect() {
  while (!client.connected()) {
    if (client.connect("room1_device")) {
      client.publish("campus/room1/led", "offline"); // khởi tạo trạng thái
    } else {
      delay(1000);
    }
  }
}

void setup() {
  Serial.begin(115200);

  // Cấu hình chân
  pinMode(PIR_PIN, INPUT);
  pinMode(RED_LED_PIN, OUTPUT);
  pinMode(RELAY_PIN, OUTPUT);
  pinMode(GREEN_LED_PIN, OUTPUT);
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);

  // Khởi tạo trạng thái
  digitalWrite(RED_LED_PIN, LOW);
  digitalWrite(RELAY_PIN, LOW);
  digitalWrite(GREEN_LED_PIN, LOW);

  //wifi
  Serial.begin(115200);
  pinMode(PIR_PIN, INPUT);
  pinMode(RED_LED_PIN, OUTPUT);

  setup_wifi();
  client.setServer(mqtt_server, 1883);
}

void loop() {
  
  if (!client.connected()) reconnect();
  client.loop();

  bool motion = digitalRead(PIR_PIN);
  if (motion) digitalWrite(RED_LED_PIN, HIGH);
  else digitalWrite(RED_LED_PIN, LOW);

  // Publish trạng thái PIR & đèn
  client.publish("campus/room1/pir", motion ? "1" : "0");
  client.publish("campus/room1/led", motion ? "1" : "0");

  delay(500);
  // --- 1. Đọc PIR ---
  motionDetected = digitalRead(PIR_PIN);

  if (motionDetected) {
    digitalWrite(RED_LED_PIN, HIGH);  // Bật đèn đỏ
  } else {
    digitalWrite(RED_LED_PIN, LOW);   // Tắt đèn đỏ
  }

  // --- 2. Đọc siêu âm để điều khiển máy bơm ---
  long distanceCM = readUltrasonicCM();
  Serial.print("Distance: "); Serial.print(distanceCM); Serial.println(" cm");

  if (distanceCM >= 200) {
    digitalWrite(RELAY_PIN, HIGH);       // Relay bật → bật LED xanh (mô phỏng máy bơm)
    digitalWrite(GREEN_LED_PIN, HIGH);
  } else {
    digitalWrite(RELAY_PIN, LOW);        // Relay tắt → tắt LED xanh
    digitalWrite(GREEN_LED_PIN, LOW);
  }

  delay(500); // Delay 0.5s để ổn định đọc cảm biến
}