int countTen = 0;
unsigned long timeTen = 0;
int maxP = 0;
int minP = 1000;

const int trigPin = 32;
const int echoPin = 33;

//define sound speed in cm/uS
#define SOUND_SPEED 0.034
#define CM_TO_INCH 0.393701

long duration;
float distanceA = 0.0;
float distanceB = 0.0;

#include "FS.h"
#include "SD.h"
#include "SPI.h"

//This creates a file if it doesn't already exist or overwrites whatever is in the file
void writeFile(fs::FS &fs, const char * path, const char * message){
  Serial.printf("Writing file: %s\n", path);

  File file = fs.open(path, FILE_WRITE);
  if(!file){
    return;
  }
  if(file.print(message)){
  } 
  else {
  }
  file.close();
}

//This adds integers to the file
void appendFile(fs::FS &fs, const char * path, int message)
{
  Serial.printf("Appending to file: %s\n", path);

  File file = fs.open(path, FILE_APPEND);
  if(!file){
    //Serial.println("Failed to open file for appending");
    return;
  }
  if(file.print(message, DEC)){
    //Serial.println("Message appended");
  } 
  else {
    //Serial.println("Append failed");
  }
  file.close();
}

//This makes the file go to a new line
void newLine(fs::FS &fs, const char * path)
{
  Serial.printf("Going to a new line\n");

  File file = fs.open(path, FILE_APPEND);
  if(!file){
    return;
  }
  if(file.print('\n')){
  } 
  else {
  }
  file.close();
}

//This deletes a file
void deleteFile(fs::FS &fs, const char * path){
  Serial.printf("Deleting file: %s\n", path);
  if(fs.remove(path)){
    Serial.println("File deleted");
  } else {
    Serial.println("Delete failed");
  }
}

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT); 

  if(!SD.begin(5)){
    Serial.println("Card Mount Failed");
    while(1);
  }
  uint8_t cardType = SD.cardType();

  if(cardType == CARD_NONE){
    Serial.println("No SD card attached");
    while(1);
  }

  Serial.print("SD Card Type: ");
  if(cardType == CARD_MMC){
    Serial.println("MMC");
  } else if(cardType == CARD_SD){
    Serial.println("SDSC");
  } else if(cardType == CARD_SDHC){
    Serial.println("SDHC");
  } else {
    Serial.println("UNKNOWN");
  }

  uint64_t cardSize = SD.cardSize() / (1024 * 1024);
  Serial.printf("SD Card Size: %lluMB\n", cardSize);

  //Deletes file to prevent multiple copies and then creates a new one
  deleteFile(SD, "/results.txt");
  delay(100);
  writeFile(SD, "/results.txt", "Results: \n");
}

void loop() {
  // put your main code here, to run repeatedly:

  //Checks if the distance has changed i.e. someone has passed by
  if(distanceA < 145.0 || distanceA > 190.0)
  {
    Serial.println("Someone passed the sensor");
    //Marks down that someone has passed
    countTen++;
    delay(500);
    //This checks to see if the person is no longer standing in front of the sensor
    //It prevents counting someone who stands in front multiple times
    while(distanceA < 145.0 || distanceA > 190.0)
    {
      distanceA = 0;
      delay(200);
      Serial.println("Waiting");

        // Clears the trigPin
        digitalWrite(trigPin, LOW);
        delayMicroseconds(2);
        // Sets the trigPin on HIGH state for 10 micro seconds
        digitalWrite(trigPin, HIGH);
        delayMicroseconds(10);
        digitalWrite(trigPin, LOW);
        
        duration = pulseIn(echoPin, HIGH);
    
        // Reads the echoPin, returns the sound wave travel time in microseconds
        for(int i = 0; i < 5; i++)
        {
          distanceA = distanceA + (duration * SOUND_SPEED/2);
          delay(100);
         }
        
      distanceA = distanceA/5;
    }
  }
  
  //Gets the distance every half of a second
  // Calculate the distance
  for(int i = 0; i < 5; i++)
  {
    // Clears the trigPin
    digitalWrite(trigPin, LOW);
    delayMicroseconds(2);
    // Sets the trigPin on HIGH state for 10 micro seconds
    digitalWrite(trigPin, HIGH);
    delayMicroseconds(10);
    digitalWrite(trigPin, LOW);
  
    // Reads the echoPin, returns the sound wave travel time in microseconds
    duration = pulseIn(echoPin, HIGH);
    distanceA = distanceA + (duration * SOUND_SPEED/2);
    delay(100);
  }
  distanceA = distanceA/5;

  if(millis() > (timeTen + 600000))
  {
    //do every 10 minutes
    Serial.print(countTen);
    Serial.println(" people have passed.");

    //Checks if there is a new max or min
    if(countTen > maxP)
      maxP = countTen;
    else if(countTen < minP)
      minP = countTen;
      
    //Send count to SD card
    appendFile(SD, "/results.txt", countTen);
    newLine(SD, "/results.txt");
    
    countTen = 0;
    timeTen = millis();
  }

  if(Serial.available() > 0)
  {
    //Outputs a summary if I input s into the serial port
    char input = Serial.read();
    if(input == 's')
    {
      //Code to output max, min and summary
      Serial.print("The maximum people who passed in a 10 minute period is ");
      Serial.println(maxP);

      Serial.print("The minimum people who passed in a 10 minute period is ");
      Serial.println(minP);

      Serial.print("Time Elapsed: ");
      Serial.println(millis()/60000);
    }
  }
}