worktimeBot/internal/bot/sanitize.go

package bot

import (
	"strings"
	"unicode"
)

const maxNoteLength = 500
const maxUsernameLength = 64

// SanitizeNote cleans user-provided note text: trims whitespace, limits length,
// and removes control characters (keeps newlines).
func SanitizeNote(s string) string {
	s = strings.TrimSpace(s)
	if len(s) > maxNoteLength {
		s = s[:maxNoteLength]
	}
	return strings.Map(func(r rune) rune {
		if r == '\n' || r == '\t' || r == ' ' {
			return r
		}
		if unicode.IsControl(r) {
			return -1
		}
		return r
	}, s)
}

// SanitizeDisplayName cleans a display name (username) for safe rendering.
func SanitizeDisplayName(s string) string {
	s = strings.TrimSpace(s)
	if len(s) > maxUsernameLength {
		s = s[:maxUsernameLength]
	}
	return strings.Map(func(r rune) rune {
		if unicode.IsControl(r) {
			return -1
		}
		return r
	}, s)
}