#pragma once

#include <mySD.h>

#include "data.h"

const int mySD_CS=13;
const int mySD_SCLK=14;
const int mySD_MISO=2;
const int mySD_MOSI=15;

/*
  we write fixed-length CSV lines because, at some point in the
  future, I may need to seek "10 measurements back" or something like
  that; also, it's easier to read
 */
//                      12345, 12345, 12345, 12345, 123456, 123456, 123456, 123456, 12345\n
const char csvHeader[]=" secs,   co2,  temp, humid,    pm1,  pm2.5,    pm4,   pm10,  batt\n";
const char csvFormat[]="% 5lu, % 5u, % 5.1f, % 5.1f, % 6.1f, % 6.1f, % 6.1f, % 6.1f, % 5.2f\n";
const size_t lineLength=66;

class DataLog {
private:
  File logfile;
  char line[100];
  uint8_t linesSinceLastFlush;
  uint8_t flushThreshold;
public:
  DataLog(uint8_t ft=4) : flushThreshold(ft) {}

  void start() {
    bool sdok=SD.begin(mySD_CS, mySD_MOSI, mySD_MISO, mySD_SCLK);
    Serial.print("# sdok: ");Serial.println(sdok);
    logfile = SD.open("quality.csv",FILE_WRITE);
    Serial.print("# file: ");Serial.println(logfile.name());
    uint32_t fileSize = logfile.size();
    logfile.seek(fileSize);
    if (fileSize == 0) {
      logfile.write((uint8_t*)csvHeader, lineLength);
    }                    
    linesSinceLastFlush=1;
  }

  void show(const SensorData *data) {
    snprintf(
             line, lineLength+1, // zero terminator!
             csvFormat,
             millis()/1000,

             data->co2,
             data->temperature,
             data->humidity,

             data->pm.mc_1p0,
             max(0.0f,data->pm.mc_2p5 - data->pm.mc_1p0),
             max(0.0f,data->pm.mc_4p0 - data->pm.mc_2p5),
             max(0.0f,data->pm.mc_10p0 - data->pm.mc_4p0),

             data->batteryVoltage
             );
    size_t written=logfile.write((uint8_t *)line,lineLength);
    Serial.print("# ");Serial.write(line);
    Serial.print("# written: ");Serial.println(written);
    if (++linesSinceLastFlush > flushThreshold) {
      logfile.flush();
      linesSinceLastFlush=0;

      Serial.println("# flushed");
    }
  }
};