package mem

import (
	"fmt"
	"strings"

	"github.com/shirou/gopsutil/v3/mem"

	"go.fanir.de/statusline/config"
)

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

const binaryFactor = 1024

func HBin(a uint64, precision int) string {
	f := float64(a)
	var suffix string
	for _, suffix = range binarySuffixes {
		if f < binaryFactor {
			break
		}
		f /= binaryFactor
	}
	return fmt.Sprintf("%.*f%s", precision, f, suffix)
}

func Mem(format config.Format, absolute, percent bool) (string, error) {
	if !(absolute || percent) {
		return "", nil
	}

	v, err := mem.VirtualMemory()
	if err != nil {
		return "", err // FIXME
	}

	s := &strings.Builder{}
	if v.UsedPercent > 90 {
		fmt.Fprint(s, format.Warning, "[")
	} else {
		fmt.Fprint(s, format.Default, "[")
	}
	if absolute {
		fmt.Fprintf(s, "%s/%s", HBin(v.Used, 1), HBin(v.Total, 1))
		if percent {
			fmt.Fprint(s, " ")
		}
	}
	if percent {
		fmt.Fprintf(s, "%.0f%%", v.UsedPercent)
	}
	fmt.Fprint(s, "]")

	return s.String(), nil
}