package utils

import (
	"io/fs"
	"path/filepath"
	"strconv"
	"strings"

	"github.com/pkg/errors"
)

var sizeSuffixes = [...]string{"B", "KiB", "MiB", "GiB", "TiB"}

// ConvertFileSize converts size in bytes down to biggest units it represents.
// Returns converted size, unit and, a concatenation of size and unit
func ConvertFileSize(size int64) (float64, string, string) {
	var idx int
	var fSize float64 = float64(size)

	for idx = 0; fSize >= 1024; fSize /= 1024 {
		idx++
	}

	fSizeStr := strconv.FormatFloat(fSize, 'f', 3, 64)
	fSizeStr = strings.TrimRight(fSizeStr, "0")
	fSizeStr = strings.TrimSuffix(fSizeStr, ".")

	return fSize, sizeSuffixes[idx], strings.Join([]string{fSizeStr, sizeSuffixes[idx]}, " ")
}

func DirectorySize(path string) (dirSz int64, err error) {
	err = filepath.Walk(path, func(_ string, info fs.FileInfo, err error) error {
		if err != nil {
			return errors.Wrapf(err, "failed to compute %s directory size", path)
		}

		dirSz += info.Size()

		return nil
	})

	if err != nil {
		return 0, err
	}

	return dirSz - 4096, nil
}