/* Self-Defense Cane Prototype for People with Vision Impairments
Group 2
12 STEM - Hipparchus
Chelsea Raine M. Baguio
Josephine Joy L. Bandola
Alex Roderick M. Bue Jr.
Justin Raeburn A. Dy
Angela B. Nunez
Jasmine Dianne R. Young
*/




#include <TinyGPS++.h>
#include <SoftwareSerial.h>

// Function prototypes
void triggerSensor(int echoPin);
void sendSMS(const char *phoneNumber, const char *message);
void readGPS();

// GPS module configuration
static const int GPS_RXPin = 11, GPS_TXPin = 12;
static const uint32_t GPSBaud = 9600;
TinyGPSPlus gps;
SoftwareSerial gpsSerial(GPS_RXPin, GPS_TXPin);

// Ultrasonic sensor configuration
int trigPin = 13;     
int echo1 = 5;
int buzzer1 = 2;
int buzzer2 = 3;
int buzzer3 = 4;
long duration, duration2, duration3, cm1, cm2, cm3, cm;

// GSM module configuration
static const int GSM_RXPin = 9, GSM_TXPin = 10;
SoftwareSerial gsmSerial(GSM_RXPin, GSM_TXPin);

const int buttonPin = 8; // Button for sending GSM
const int ultbutton = 7; // Button for ultrasonic

// Variables to store GPS location
float savedLongitude = 0.0;
float savedLatitude = 0.0;

void setup()
{
  Serial.begin(9600);
  gpsSerial.begin(GPSBaud);
  gsmSerial.begin(9600);
  pinMode(buttonPin, INPUT_PULLUP);
  pinMode(ultbutton, INPUT_PULLUP);

  pinMode(trigPin, OUTPUT);
  pinMode(echo1, INPUT);

  pinMode(buzzer1, OUTPUT);
  pinMode(buzzer2, OUTPUT);
  pinMode(buzzer3, OUTPUT);
}

void loop()
{
  readGPS(); // Read GPS data
  if (digitalRead(ultbutton) == LOW)
  {
  // Trigger Sensor 1
  triggerSensor(echo1);
  duration = pulseIn(echo1, HIGH);
  cm1 = (duration / 2) * 0.03436426116838487972508591065292;

  // Determine the shortest distance
  cm = cm1;

  // Print the distances and the shortest distance
  Serial.println("Distance from Sensor 1: " + String(cm1) + "cm");
  Serial.println("Shortest Distance: " + String(cm) + "cm");

  // Determine how many buzzers
  if (cm <= 50)
  {
    Serial.println(" 3 buzzers");
    digitalWrite(buzzer1, HIGH);
    digitalWrite(buzzer2, HIGH);
    digitalWrite(buzzer3, HIGH);
  }
  else if (cm <= 100)
  {
    Serial.println(" 2 buzzers");
    digitalWrite(buzzer1, HIGH);
    digitalWrite(buzzer2, HIGH);
    digitalWrite(buzzer3, LOW);
  }
  else if (cm <= 150)
  {
    Serial.println(" 1 buzzer");
    digitalWrite(buzzer1, HIGH);
    digitalWrite(buzzer2, LOW);
    digitalWrite(buzzer3, LOW);
  }
  else
  {
    Serial.println(" No buzzer");
    digitalWrite(buzzer1, LOW);
    digitalWrite(buzzer2, LOW);
    digitalWrite(buzzer3, LOW);
  }
  }
  else
  {
    digitalWrite(buzzer1, LOW);
    digitalWrite(buzzer2, LOW);
    digitalWrite(buzzer3, LOW);
  }
  if (digitalRead(buttonPin) == LOW)
  {
    Serial.println("Button Pressed - Saving GPS Location...");

    Serial.print("Saved Longitude: ");
    Serial.println(savedLongitude, 6);
    Serial.print("Saved Latitude: ");
    Serial.println(savedLatitude, 6);

    // Convert float values to strings
    char latString[10];
    char lonString[10];
    dtostrf(savedLatitude, 6, 4, latString);
    dtostrf(savedLongitude, 6, 4, lonString);

    Serial.println("Sending SMS...");
    char message[160];
    sprintf(message, "Ms./Mr. Yanyan Young feels endangered. Please contact them immediately. Check their location here: %s,%s", lonString, latString);

    sendSMS("+639291740535", message);

    delay(5000); // Delay to avoid multiple SMS on a single button press
  }
}

void triggerSensor(int echoPin)  // Setting for ultrasonic sensor (turn on or off)
{
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  pinMode(echoPin, INPUT);
}

void sendSMS(const char *phoneNumber, const char *message)
{
  Serial.println("Sending SMS...");
  gsmSerial.println("AT+CMGF=1");
  delay(1000);

  char command[30];
  sprintf(command, "AT+CMGS=\"%s\"", phoneNumber);
  gsmSerial.println(command);
  delay(1000);

  gsmSerial.println(message);
  delay(1000);

  gsmSerial.println((char)26); // End the SMS with Ctrl+Z
  delay(1000);
  Serial.println("SMS Sent");
}

void readGPS()
{
  gpsSerial.listen();
  
  while (gpsSerial.available() > 0)
  {
    if (gps.encode(gpsSerial.read()))
    {
      if (gps.location.isValid())
      {

        // Save GPS location to variables
        savedLongitude = gps.location.lng();
        savedLatitude = gps.location.lat();
      }
    }
  }
}