import 'dart:math';

final storageUnits = ["bytes", "KB", "MB", "GB"];

String convertBytesToReadableFormat(int bytes) {
  int storageUnitIndex = 0;
  while (bytes >= 1024 && storageUnitIndex < storageUnits.length - 1) {
    storageUnitIndex++;
    bytes = (bytes / 1024).round();
  }
  return bytes.toString() + " " + storageUnits[storageUnitIndex];
}

String formatBytes(int bytes, [int decimals = 2]) {
  if (bytes == 0) return '0 bytes';
  const k = 1024;
  final int dm = decimals < 0 ? 0 : decimals;
  final int i = (log(bytes) / log(k)).floor();
  return ((bytes / pow(k, i)).toStringAsFixed(dm)) + ' ' + storageUnits[i];
}

//shows 1st decimal only if less than 10GB & omits decimal if decimal is 0
num roundBytesUsedToGBs(int usedBytes, int freeSpace) {
  const tenGBinBytes = 10737418240;
  num bytesInGB = convertBytesToGBs(usedBytes);
  if ((usedBytes >= tenGBinBytes && freeSpace >= tenGBinBytes) ||
      bytesInGB % 1 == 0) {
    bytesInGB = bytesInGB.truncate();
  }
  return bytesInGB;
}

//Eg: 0.3 GB, 11.0 GB, 532.3 GB
num convertBytesToGBs(int bytes) {
  return num.parse((bytes / (pow(1024, 3))).toStringAsFixed(1));
}

int convertBytesToMBs(int bytes) {
  return (bytes / pow(1024, 2)).round();
}

//Eg: 1TB, 1.3TB, 2.9TB, 3TB
roundGBsToTBs(sizeInGBs) {
  final num sizeInTBs = num.parse((sizeInGBs / 1000).toStringAsFixed(1));
  if (sizeInTBs % 1 == 0) {
    return sizeInTBs.truncate();
  } else {
    return sizeInTBs;
  }
}