#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

  column ranges and sizes:
  * secs: up to ~36 hours = 130000, unsigned: 6 characters
  * co2: up to ~4000, unsigned: 4 characters
  * temp: -20.0 … +40.0, signed: 5 characters
  * humid: 0.0 … 100.0, unsigned: 5 characters
  * pm*: 0.0 … 9999.9, unsigned: 6 characters
  * batt: 3.00 … 4.30, unsigned: 4 characters
 */
//                      123456, 1234, 12345, 12345, 123456, 123456, 123456, 123456, 1234\n
const char csvHeader[]="  secs,  co2,  temp, humid,    pm1,  pm2.5,    pm4,   pm10, batt\n";
const char csvFormat[]="% 6lu, % 4u, % 5.1f, %5.1f, %6.1f, %6.1f, %6.1f, %6.1f, %4.2f\n";
const size_t lineLength=65;

const char defaultFilename[] = "quality.csv";

class DataLog {
private:
  File logfile;
  const char *filename;
  char line[100];
  uint8_t linesSinceLastFlush;
  uint8_t flushThreshold;

  void openFile() {
    logfile = SD.open(filename,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;
    }
    else {
      linesSinceLastFlush=0;
    }
  }
public:
  DataLog(uint8_t ft=4, const char *fn=defaultFilename) :
    filename(fn),
    flushThreshold(ft)
  {}

  void start() {
    bool sdok=SD.begin(mySD_CS, mySD_MOSI, mySD_MISO, mySD_SCLK);
    Serial.print("# sdok: ");Serial.println(sdok);
    openFile();
  }

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

             data->co2,
             data->temperature,
             max(0.0f,data->humidity),

             max(0.0f,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),

             max(0.0f,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");
    }
  }

  bool serialCommand(const String &tag, const String &command) {
    if (command == "logcat") {
      Serial.print(tag);Serial.println(" begin");

      uint8_t buffer[1024];
      logfile.flush();
      int remaining = logfile.position();
      logfile.seek(0);
      while (remaining > 0) {
        int bytesRead = logfile.read(buffer, 1024);
        Serial.write(buffer, bytesRead);
        remaining -= bytesRead;
      }

      Serial.print(tag);Serial.println(" end");

      return true;
    }
    else if (command == "logwipe") {
      logfile.close();
      // ugh, why is it `remove(char*)`??
      SD.remove(const_cast<char*>(filename));
      openFile();
      Serial.print(tag);Serial.println(" wiped");
    }

    return false;
  }
};