#include "DHT.h"
#include <Servo.h>

// Pin Definitions
#define DHT_PIN        2
#define PIR_PIN        3
#define LED_PIN        4
#define SERVO_PIN      7

// DHT Sensor Type
#define DHT_TYPE       DHT22

// Debug Mode (set to 1 for debug messages, 0 to disable)
#define DEBUG_MODE     0

// Delay Times (in milliseconds)
#define TEMP_HUMIDITY_DELAY   1000
#define PIR_DELAY             1000
#define SERVO_MOVE_DELAY      500

DHT dht(DHT_PIN, DHT_TYPE);  // Initialize DHT sensor
Servo servo;                 // Initialize Servo

void readDHT();
void readPIR();
void setServo(uint8_t angle);

void setup() {
  pinMode(PIR_PIN, INPUT);   // Set PIR pin as input
  pinMode(LED_PIN, OUTPUT);  // Set LED pin as output
  Serial.begin(9600);        // Begin serial communication at 9600 baud rate
  
  dht.begin();               // Initialize the DHT sensor
  servo.attach(SERVO_PIN);   // Attach the servo to the specified pin
  Serial.println(F("IoT-Based Home Monitoring System"));
}

void loop() {
  readDHT();  // Read temperature and humidity
  readPIR();  // Read PIR sensor value
#if DEBUG_MODE
  setServo(90);  // Move servo to 90 degrees for testing
  setServo(0);   // Move servo back to 0 degrees for testing
#endif
}

void readDHT() {
  float temperature = dht.readTemperature(); // Read temperature
  float humidity = dht.readHumidity();       // Read humidity

  // Check if any reads failed and exit early (to try again)
  if (isnan(temperature) || isnan(humidity)) {
#if DEBUG_MODE
    Serial.println(F("Failed to read from DHT sensor!"));
#endif
    return;
  }

  Serial.print("a");
  Serial.println(temperature);
  delay(TEMP_HUMIDITY_DELAY);

  Serial.print("b");
  Serial.println(humidity);
  delay(TEMP_HUMIDITY_DELAY);

#if DEBUG_MODE
  Serial.print(F("Humidity: "));
  Serial.print(humidity);
  Serial.print(F("%  Temperature: "));
  Serial.print(temperature);
  Serial.println(F("°C"));
  delay(SERVO_MOVE_DELAY);
#endif
}

void readPIR() {
  bool pir_value = digitalRead(PIR_PIN); // Read PIR sensor value
  Serial.print("c");
  if (pir_value) {
    Serial.println(1);
#if DEBUG_MODE
    Serial.println(F("Motion triggered!"));
#endif
  } else {
    Serial.println(0);
  }
  digitalWrite(LED_PIN, pir_value); // Set LED based on PIR value
  delay(PIR_DELAY);
#if DEBUG_MODE
  delay(SERVO_MOVE_DELAY);
#endif
}

void setServo(uint8_t angle) {
  servo.write(angle); // Move servo to the specified angle
#if DEBUG_MODE
  delay(SERVO_MOVE_DELAY);
#endif
}

void serialEvent() {
  while (Serial.available()) {
    char sensor_id = Serial.read(); // Read sensor ID
    int value = Serial.parseInt();  // Parse the integer value
    if (Serial.read() == char(13)) { // Check for carriage return
      if (sensor_id == 'd') setServo(value); // Set servo position if sensor ID is 'd'
    }
  }
}