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

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

// MQTT Broker settings
const char* mqtt_server = "test.mosquitto.org";
const int mqtt_port = 1883;
const char* mqtt_client_id = "";

// Pin definitions
#define DHT_PIN 4
#define DHT_TYPE DHT22
#define PIR_PIN 21
#define BUTTON_PIN 27
#define RELAY_LAMP_PIN 12
#define RELAY_PUMP_PIN 13
#define BUZZER_PIN 14
#define TRIG_PIN 5
#define ECHO_PIN 18


// Objects
DHT dht(DHT_PIN, DHT_TYPE);
WiFiClient espClient;
PubSubClient client(espClient);

// Variables
float temperature = 0;
float humidity = 0;
float waterLevel = 0;
bool motionDetected = false;
bool lampStatus = false;
bool pumpStatus = false;
bool alarmStatus = false;
bool buttonPressed = false;
bool lastButtonState = HIGH;
unsigned long lastMotionTime = 0;
unsigned long lastSensorRead = 0;
unsigned long lastPublish = 0;
const unsigned long MOTION_TIMEOUT = 20000; // 20 seconds
const unsigned long SENSOR_INTERVAL = 2000; // 2 seconds
const unsigned long PUBLISH_INTERVAL = 1000; // 1 second

// MQTT Topics
const char* TOPIC_TEMP = "smarthome/temperature";
const char* TOPIC_HUMIDITY = "smarthome/humidity";
const char* TOPIC_WATER_LEVEL = "smarthome/waterlevel";
const char* TOPIC_MOTION = "smarthome/motion";
const char* TOPIC_LAMP_STATUS = "smarthome/lamp/status";
const char* TOPIC_LAMP_CONTROL = "smarthome/lamp/control";
const char* TOPIC_PUMP_STATUS = "smarthome/pump/status";
const char* TOPIC_ALARM_STATUS = "smarthome/alarm/status";

void setup() {
  Serial.begin(115200);
  
  // Initialize pins
  pinMode(PIR_PIN, INPUT);
  pinMode(BUTTON_PIN, INPUT_PULLUP);
  pinMode(RELAY_LAMP_PIN, OUTPUT);
  pinMode(RELAY_PUMP_PIN, OUTPUT);
  pinMode(BUZZER_PIN, OUTPUT);
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  
  // Initialize outputs
  digitalWrite(RELAY_LAMP_PIN, LOW);
  digitalWrite(RELAY_PUMP_PIN, LOW);
  digitalWrite(BUZZER_PIN, LOW);
  
  // Initialize DHT sensor
  dht.begin();
  
  // Connect to WiFi
  setupWiFi();
  
  // Setup MQTT
  client.setServer(mqtt_server, mqtt_port);
  client.setCallback(mqttCallback);
  
  Serial.println("Smart Home System Started!");
}

void loop() {
  // Maintain MQTT connection
  if (!client.connected()) {
    reconnectMQTT();
  }
  client.loop();
  
  // Read sensors periodically
  if (millis() - lastSensorRead >= SENSOR_INTERVAL) {
    readSensors();
    lastSensorRead = millis();
  }
  
  // Check button press
  checkButton();
  
  // Check motion timeout
  checkMotionTimeout();
  
  // Control pump based on water level
  controlPump();
  
  // Control alarm
  controlAlarm();
  
  // Publish data periodically
  if (millis() - lastPublish >= PUBLISH_INTERVAL) {
    publishData();
    lastPublish = millis();
  }
  
  delay(50);
}

void setupWiFi() {
  delay(10);
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);
  
  WiFi.begin(ssid, password);
  
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  
  Serial.println("");
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
}

void reconnectMQTT() {
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    
    if (client.connect(mqtt_client_id)) {
      Serial.println("connected");
      // Subscribe to control topics
      client.subscribe(TOPIC_LAMP_CONTROL);
      Serial.println("Subscribed to lamp control topic");
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      delay(5000);
    }
  }
}

void mqttCallback(char* topic, byte* payload, unsigned int length) {
  Serial.print("Message arrived [");
  Serial.print(topic);
  Serial.print("] ");
  
  String message;
  for (int i = 0; i < length; i++) {
    message += (char)payload[i];
  }
  Serial.println(message);
  
  // Handle lamp control from dashboard
  if (String(topic) == TOPIC_LAMP_CONTROL) {
    if (message == "ON" || message == "1") {
      lampStatus = true;
      digitalWrite(RELAY_LAMP_PIN, HIGH);
      Serial.println("Lamp turned ON via MQTT");
    } else if (message == "OFF" || message == "0") {
      lampStatus = false;
      digitalWrite(RELAY_LAMP_PIN, LOW);
      Serial.println("Lamp turned OFF via MQTT");
    } else if (message == "TOGGLE") {
      toggleLamp();
    }
  }
}

void readSensors() {
  // Read DHT22 sensor
  float newTemp = dht.readTemperature();
  float newHumidity = dht.readHumidity();
  
  if (!isnan(newTemp) && !isnan(newHumidity)) {
    temperature = newTemp;
    humidity = newHumidity;
  }
  
  // Read ultrasonic sensor for water level
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  
  long duration = pulseIn(ECHO_PIN, HIGH);
  float distance = duration * 0.034 / 2; // Convert to cm
  
  // Convert distance to water level (assuming tank height is 300cm)
  waterLevel = 300 - distance;
  if (waterLevel < 0) waterLevel = 0;
  if (waterLevel > 300) waterLevel = 300;
  
  // Read PIR sensor
  bool currentMotion = digitalRead(PIR_PIN);
  if (currentMotion && !motionDetected) {
    motionDetected = true;
    lastMotionTime = millis();
    Serial.println("Motion detected!");
  } else if (currentMotion) {
    lastMotionTime = millis(); // Update last motion time
  }
  
  // Print sensor readings
  Serial.printf("Temp: %.1f°C, Humidity: %.1f%%, Water Level: %.1fcm, Motion: %s\n", 
                temperature, humidity, waterLevel, motionDetected ? "YES" : "NO");
}

void checkButton() {
  bool currentButtonState = digitalRead(BUTTON_PIN);
  
  if (currentButtonState == LOW && lastButtonState == HIGH) {
    // Button pressed (falling edge)
    delay(30); // Debounce
    if (digitalRead(BUTTON_PIN) == LOW) {
      toggleLamp();
      Serial.println("Button pressed - Lamp toggled");
    }
  }
  
  lastButtonState = currentButtonState;
}

void toggleLamp() {
  lampStatus = !lampStatus;
  digitalWrite(RELAY_LAMP_PIN, lampStatus ? HIGH : LOW);
  
  if (lampStatus) {
    lastMotionTime = millis(); // Reset motion timer when lamp is manually turned on
  }
  
  Serial.printf("Lamp %s\n", lampStatus ? "ON" : "OFF");
}

void checkMotionTimeout() {
  if (motionDetected && (millis() - lastMotionTime >= MOTION_TIMEOUT)) {
    motionDetected = false;
    if (lampStatus) {
      lampStatus = false;
      digitalWrite(RELAY_LAMP_PIN, LOW);
      Serial.println("No motion for 20s - Lamp turned OFF automatically");
    }
  }
}

void controlPump() {
  bool newPumpStatus = pumpStatus;
  
  if (waterLevel < 100) {
    newPumpStatus = true;
  } else if (waterLevel > 200) {
    newPumpStatus = false;
  }
  // Between 100-200cm: maintain current status
  
  if (newPumpStatus != pumpStatus) {
    pumpStatus = newPumpStatus;
    digitalWrite(RELAY_PUMP_PIN, pumpStatus ? HIGH : LOW);
    Serial.printf("Pump %s (Water level: %.1fcm)\n", pumpStatus ? "ON" : "OFF", waterLevel);
  }
}

void controlAlarm() {
  bool newAlarmStatus = (waterLevel > 200 && temperature > 30);
  
  if (newAlarmStatus != alarmStatus) {
    alarmStatus = newAlarmStatus;
    digitalWrite(BUZZER_PIN, alarmStatus ? HIGH : LOW);
    Serial.printf("Alarm %s (Water: %.1fcm, Temp: %.1f°C)\n", 
                  alarmStatus ? "ON" : "OFF", waterLevel, temperature);
  }
}

void publishData() {
  if (client.connected()) {
    // Publish sensor data
    client.publish(TOPIC_TEMP, String(temperature, 1).c_str());
    client.publish(TOPIC_HUMIDITY, String(humidity, 1).c_str());
    client.publish(TOPIC_WATER_LEVEL, String(waterLevel, 1).c_str());
    
    // Publish status data
    client.publish(TOPIC_MOTION, motionDetected ? "1" : "0");
    client.publish(TOPIC_LAMP_STATUS, lampStatus ? "1" : "0");
    client.publish(TOPIC_PUMP_STATUS, pumpStatus ? "1" : "0");
    client.publish(TOPIC_ALARM_STATUS, alarmStatus ? "1" : "0");
    
    // Publish JSON data for dashboard
    StaticJsonDocument<200> doc;
    doc["temperature"] = temperature;
    doc["humidity"] = humidity;
    doc["waterLevel"] = waterLevel;
    doc["motion"] = motionDetected;
    doc["lamp"] = lampStatus;
    doc["pump"] = pumpStatus;
    doc["alarm"] = alarmStatus;
    doc["timestamp"] = millis();
    
    String jsonString;
    serializeJson(doc, jsonString);
    client.publish("smarthome/data", jsonString.c_str());
  }
}