package mutex

import (
	"fmt"
	"strings"
)

const maxMutexLength = 64

func sanitizeName(name string) (string, error) {
	trimmed := strings.TrimSpace(name)
	if trimmed == "" {
		return "", fmt.Errorf("empty mutex name")
	}

	var builder strings.Builder
	for _, r := range trimmed {
		if (r >= 'a' && r <= 'z') || (r >= 'A' && r <= 'Z') || (r >= '0' && r <= '9') || r == '-' || r == '_' || r == '.' {
			builder.WriteRune(r)
		}
	}

	sanitized := builder.String()
	if sanitized == "" {
		return "", fmt.Errorf("mutex name has no valid characters")
	}

	if len(sanitized) > maxMutexLength {
		sanitized = sanitized[:maxMutexLength]
	}

	return sanitized, nil
}