// These are the pins your MicroSD Card Adapter and BME680 will be connected to.
// These pins are specific and should not change. You do not need to worry
// about why these are the pins, just connect them as listed.
// MOSI - pin 11
// MISO - pin 12
// CLK  - pin 13
#include <SPI.h>
#include <SD.h>
#include <Adafruit_Sensor.h>
#include "Adafruit_BME680.h"

// ************************************************** NEEDS EDITING **************************************************
// This is the CS pin that the SD Logger is connected to
const int SDLoggerChipSelect = ??;

// This is the CS pin that the BME680 is connected to
const int BMEchipSelect = ??;

// These are the pins your accelerometer lines are connected to
const int xAccelPin = A?;
const int yAccelPin = A?;
const int zAccelPin = A?;

// This is the pin your TMP36 is connected to 
const int tmpPin = A?;

// This is the pin your voltage divider is connected to
const int vDivPin = A?;

// Ohms, R1 = sum of all resistances between Vin and Vout
const float R1 = ???;

// Ohms, R2 = sum of all resistances between Vout and GND
const float R2 = ???;

const float tmpSlope        = ?;
const float tmpIntercept    = ?;

const float xAccelSlope     = ?;
const float xAccelIntercept = ?;
const float yAccelSlope     = ?;
const float yAccelIntercept = ?;
const float zAccelSlope     = ?;
const float zAccelIntercept = ?;

// true to print, false for no serial monitor
bool serialPrint = ???;
// ************************************************** END EDITING **************************************************

void setup() {
  if (serialPrint) {
    Serial.begin(9600);
    while (!Serial) { /* wait for Serial */ }
  }

  if(serialPrint)
    Serial.print(F("Initializing SD card..."));

  // See if the card is present and can be initialized:
  if (!SD.begin(SDLoggerChipSelect)) {
    if(serialPrint)
      Serial.println("Card failed, or not present");
    // don't do anything more:
    while (1);
  }
  if(serialPrint)
    Serial.println("SD card initialized!");

    // --- Find next available file name, like "datalog1.csv", "datalog2.csv" ---
  int fileIndex = 1;
  while (true) {
    // Format candidate
    snprintf(dataFileName, sizeof(dataFileName), "datalog%d.csv", fileIndex);
    
    // Use this filename if it doesn't exist
    if (!SD.exists(dataFileName)) {
      break;  // Filename chosen
    }
    fileIndex++;  // Increment and try the next number
  }

  // Now, before we actually start reading data, we need to write the header to the file.
  // Open the file. Note that only one file can be open at a time,
  // so you have to close this one before opening another.
  File dataFile = SD.open(dataFileName, FILE_WRITE);
  if (dataFile) {
      dataFile.println(header);
      dataFile.close();
      if (serialPrint) {
        Serial.print(F("Created file: "));
        Serial.println(dataFileName);
      }
  } 
  else {
      if (serialPrint) {
        Serial.print(F("Error1: Can't open "));
        Serial.println(dataFileName);
      }
  }

  // Initialize the BME and check if it's connected
  if (!bme.begin()) {
      if(serialPrint)
        Serial.println(F("Could not find a valid BME680 sensor, check wiring!"));
      while (1);
  }
  if(serialPrint)
    Serial.println(F("BME680 initialization OK!"));

  // *************** BME680 CONFIGURATION ***************
  bme.setTemperatureOversampling(BME680_OS_2X); // 2 samples for temperature oversampling
  bme.setHumidityOversampling(BME680_OS_2X);    // 2 samples for humidity oversampling
  bme.setPressureOversampling(BME680_OS_4X);    // 4 samples for pressure oversampling
  bme.setIIRFilterSize(BME680_FILTER_SIZE_1);   // Filter size for pressure & temperature, set to 0 for OFF

  // If you want to utilize the gas heater, a common setting is 320 C, 150 ms (320, 150)
  bme.setGasHeater(0, 0); // Gas heater settings: 0 C, 0 ms, DISABLED
  // *************** END OF BME680 CONFIGURATION ***************
  if(serialPrint)
    Serial.println(F("Setup complete!"));
}

void loop() {
  unsigned long currentTime = millis();
  bool bmeOk = bme.performReading();

  // Placeholder values for BME680
  float bme_temperature = NAN;
  float humidity        = NAN;
  float pressure        = NAN;

  if (!bmeOk) {
    if (serialPrint)
      Serial.println(F("**BME680 Read Failed**"));
    delay(10);
  } else {
    // Gather BME680 values
    bme_temperature  = bme.temperature; // °C
    humidity         = bme.humidity;    // %
    pressure         = bme.pressure;    // Pa
  }

  float vDivVal      = analogRead(vDivPin);
  float vDivVoltage  = (vDivVal * 5.0 / 1023.0) * ((R1 + R2) / R2);

  float tmpV         = analogRead(tmpPin) * 5.0 / 1023.0;
  float tmp          = (tmpSlope * tmpV) + tmpIntercept;

  float xAccelV      = analogRead(xAccelPin) * 5.0 / 1023.0;
  float xAccel       = (xAccelSlope * xAccelV) + xAccelIntercept;

  float yAccelV      = analogRead(yAccelPin) * 5.0 / 1023.0;
  float yAccel       = (yAccelSlope * yAccelV) + yAccelIntercept;

  float zAccelV      = analogRead(zAccelPin) * 5.0 / 1023.0;
  float zAccel       = (zAccelSlope * zAccelV) + zAccelIntercept;

  // Now let's make a nice string to write to the file.
  // This is a comma-separated values (CSV) file, so we need to separate each value with a comma.
  String dataString = "";
  dataString += String(millis());
  dataString += ",";
  dataString += String(vDivVoltage);    
  dataString += ",";
  dataString += String(tmp);            
  dataString += ",";
  dataString += String(bme_temperature);
  dataString += ",";
  dataString += String(pressure);       
  dataString += ",";
  dataString += String(humidity);       
  dataString += ",";
  dataString += String(xAccel);         
  dataString += ",";
  dataString += String(yAccel);         
  dataString += ",";
  dataString += String(zAccel);  

  // Write to SD card using unique filename
  File dataFile = SD.open(dataFileName, FILE_WRITE);
  if (dataFile) {
    dataFile.println(dataString);
    dataFile.close();
  } 
  else {
    if (serialPrint) {
      Serial.print(F("Error2: Can't open "));
      Serial.println(dataFileName);
    }
  }
  if (serialPrint)
    Serial.println(dataString);

  unsigned long elapsed = millis() - currentTime;
  unsigned long delayTime = (1000 - (elapsed % 1000)) % 1000;
  delay(delayTime);
}