#include <Wire.h>
#include <MPU6050.h>

MPU6050 mpu;
// usage of ESP32 over aurdino nano is this has inbuilt wifi and bluetooth 
// Potentiometer is being used for alcohol detection and once the sample is taken and 
// that is greater than the thereshold value it detects that person consumed alcohol
const int alcoholPin = 34;   // Analog pin for ESP32
const int buzzerPin = 19;    // Buzzer pin
const int ledPin = 18;       // LED pin
const int threshold_value = 400; // Alcohol level threshold value

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

  pinMode(buzzerPin, OUTPUT);
  pinMode(ledPin, OUTPUT);

  // Initialize accelerometer to detect the movement of the helmet
  Wire.begin(21, 22); // SDA is connected to GPIO21 and SCL is being connected to  GPIO22
  mpu.initialize();
  if (!mpu.testConnection()) {
    Serial.println("Accelerometer connection failed!");
  } else {
    Serial.println("Accelerometer connected successfully!");
  }
}

void loop() {
  int alcohol_Value = analogRead(alcoholPin);  // Read potentiometer value (simulating alcohol level)

  // Getting accelerometer data
  int16_t ax, ay, az;
  mpu.getAcceleration(&ax, &ay, &az);

  // we are checking the value given by the potentiometer as the value given by alcohol 
  // detector. Basically when the person who has consumed alcohol breathes near the sensor 
  //the value increases significantly from 200 to 800 so we kept threshold value as 400
  //so that if the value greater than 400 says that the person is consumed alchohol 
  // and this sends the message that the rider can not start the bike and this also sends 
  // data to stop the bike to bike sensors provdied in the bike using bluetooth.
  if (alcohol_Value > threshold_value) {
    Serial.println("Alcohol detected! Preventing bike start.");
    digitalWrite(ledPin, HIGH);  // Turn on LED
    digitalWrite(buzzerPin, HIGH);  // Sound buzzer
    sendBluetoothSignal("Stop");  // Send "Stop" command via Bluetooth
    delay(1000);
  }
  // Helmet detection:
  //the helmet will be idle until we take and place it in head. during this process we displace that
  //and keep in head and tilt that due to that its position changes and movement will be 
  //greater than the threshold value . if so we say that the person is wearing helmet and 
  //if the movement is less than threshold we consider that helmet is moved just from 
  //one place to another and not wore by the rider.
  //if the person wears helmet the engine is allow to start and this information is given to bike sensor using bluetooth
  else if (abs(ax) < 1000 && abs(ay) < 1000 && abs(az) < 1000) {
    Serial.println("Helmet not worn! Preventing bike start.");
    digitalWrite(ledPin, HIGH);  // Turn on LED
    digitalWrite(buzzerPin, HIGH);  // Sound buzzer
    sendBluetoothSignal("Stop");  // Send "Stop" command via Bluetooth
    delay(1000);
  } else {
    // Both helmet worn and no alcohol detected the rider is safe to ride the bike and 
    //the information to start the bike will pass to the bike sensor using bluetooth.
    Serial.println("Helmet worn and no alcohol detected.");
    digitalWrite(ledPin, LOW);  // Turn off LED
    digitalWrite(buzzerPin, LOW);  // Turn off buzzer
    sendBluetoothSignal("Start");  // Send "Start" command via Bluetooth
  }

  delay(250); 
}

// Bluetooth communication via Serial Monitor
void sendBluetoothSignal(String command) {
  Serial.println(command);  
}