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

const int sampleWindow = 1000;                              // Sample window width in mS (50 mS = 20Hz)
unsigned int sample;
unsigned int signalMax = 0;                            //minimum value
unsigned int signalMin = 4096;                         //maximum value
int db = 0;
unsigned int seconds = 0;
int sumTotal = 0;
int sum10mins = 0;
int average10mins = 0;
int averageTotal = 0;
int lowestReading = 2000;
int highestReading = 0;

void setup() {
  Serial.begin(115200);
  pinMode(32,INPUT);

  //check if the card is connected
  if(!SD.begin()){
        Serial.println("Card Mount Failed");
        return;
    }

  //opne the file and clear it and format it
  File data = SD.open("/data.txt", FILE_WRITE);
  File data10mins = SD.open("/data10mins.txt", FILE_WRITE);
  data.printf("Loudness(dB)\n");
  data10mins.printf("AverageLoundness10mins(dB),AverageLoundnessTotal(dB),LowestLoundness(dB),HighestLoudness(dB)\n");
  //save the file and close it
  data.close();
  data10mins.close();
}

void loop() {
  unsigned long startMillis= millis();                   // Start of sample window
  float peakToPeak = 0;                                  // peak-to-peak level
                                                          // collect data for 50 mS
  while (millis() - startMillis < sampleWindow)
  {
    sample = analogRead(32);                    //get reading from microphone
    if (sample < 2048)                                  // toss out spurious readings
    {
        if (sample > signalMax)
        {
          signalMax = sample;                           // save just the max levels
        }
        else if (sample < signalMin)
        {
          signalMin = sample;                           // save just the min levels
        }
    }
  }
 
  peakToPeak = signalMax - signalMin;                    // max - min = peak-peak amplitude
  
  //maps the values to the decible scale
  db = map(peakToPeak,100,250,40,80);
  //open the files
  File data = SD.open("/data.txt",FILE_APPEND);
  File data10mins = SD.open("/data10mins.txt",FILE_APPEND);
  //print the value to serial monitor
  Serial.printf("%d\n",db);
  //print the value to the file
  data.printf("%d\n",db);

  //update the tracker variables
  seconds++;
  sumTotal += db;
  sum10mins += db;

  //saving the lowest value
  if(db<lowestReading){
    lowestReading = db;
  } 

  //saving the highest value
  if(db>highestReading){
    highestReading = db;
  }

  if(seconds%600 == 0){
    //calculates 10min average
    average10mins = sum10mins/600;
    //calculates total average
    averageTotal = sumTotal/seconds;
    //prints to the file
    data10mins.printf("%d,%d,%d,%d\n",average10mins,averageTotal,lowestReading,highestReading);
    //prints to the serial
    Serial.printf("%d,%d,%d,%d\n",average10mins,averageTotal,lowestReading,highestReading);
    //resets the values back to original
    sum10mins = 0;
    lowestReading = 2000;
    highestReading = 0;
  }

  //saving the file
  data.close();
  data10mins.close();

  //refreshes the max and min
  signalMax = 0;
  signalMin = 4095;
}