package util

import (
	"fmt"
	"strings"
)

func HumanSize(size int64) string {
	const unit = 1024
	if size < unit {
		return fmt.Sprintf("%d B", size)
	}
	div, exp := int64(unit), 0
	for n := size / unit; n >= unit; n /= unit {
		div *= unit
		exp++
	}
	return fmt.Sprintf("%.1f %cB",
		float64(size)/float64(div),
		"KMGTPE"[exp],
	)
}

func SafeFilename(name string) string {
	name = strings.TrimSpace(name)

	out := make([]rune, 0, len(name))
	for _, r := range name {
		// block control chars (incl CR/LF/TAB), DEL, quotes, backslash
		if r < 32 || r == 127 || r == '"' || r == '\\' {
			continue
		}
		out = append(out, r)
	}
	if len(out) == 0 {
		return "file"
	}
	// optional: cap length
	if len(out) > 200 {
		out = out[:200]
	}
	return string(out)
}