package human

import (
	"fmt"
	"strings"
	"time"
)

func Size(size int64) string {
	if size < 0 {
		return "-" + Size(-size)
	}

	if size < 1024 {
		return "0 B"
	}

	units := []string{"KB", "MB", "GB", "TB", "PB", "EB"}
	div := int64(1024)
	exp := 0

	for i := 1; i < len(units); i++ {
		nextDiv := div * 1024
		if size < nextDiv {
			break
		}
		div = nextDiv
		exp = i
	}

	value := float64(size) / float64(div)
	if value == float64(int64(value)) {
		return fmt.Sprintf("%.0f %s", value, units[exp])
	}
	return fmt.Sprintf("%.2f %s", value, units[exp])
}

func Duration(d time.Duration) string {
	if d < 0 {
		return "-" + Duration(-d)
	}

	totalSeconds := int64(d.Seconds())
	days := totalSeconds / 86400
	hours := (totalSeconds % 86400) / 3600
	minutes := (totalSeconds % 3600) / 60
	seconds := totalSeconds % 60
	nanos := d.Nanoseconds() % int64(time.Second)

	var parts []string
	if days > 0 {
		parts = append(parts, fmt.Sprintf("%dd", days))
	}
	if hours > 0 {
		parts = append(parts, fmt.Sprintf("%dh", hours))
	}
	if minutes > 0 {
		parts = append(parts, fmt.Sprintf("%dm", minutes))
	}

	if nanos > 0 {
		secWithNanos := float64(seconds) + float64(nanos)/1e9
		parts = append(parts, fmt.Sprintf("%.2fs", secWithNanos))
	} else if seconds > 0 {
		parts = append(parts, fmt.Sprintf("%ds", seconds))
	} else if len(parts) == 0 {
		return "0s"
	}

	return strings.Join(parts, " ")
}