package router

import (
	"strings"
	"unicode"

	"golang.org/x/text/unicode/norm"
)

// NormalizeMatchText derives a lossy lexical matching view from raw ingress text.
// The result is intended ONLY for consumers that explicitly opt into
// case-insensitive, whitespace-collapsed matching. It must not be used for
// user-visible text, entity identity, quoted content, free-form arguments,
// or persisted utterances without proving the transformation is safe for
// that consumer.
//
// Pipeline: TrimSpace → Unicode NFKC → lowercase → collapse Unicode whitespace.
// Does NOT fold ё→е, strip punctuation, strip wake words, rewrite numbers,
// or invoke morphology.
func NormalizeMatchText(in string) string {
	out := strings.TrimSpace(in)
	out = norm.NFKC.String(out)
	out = strings.ToLower(out)
	// Collapse runs of Unicode whitespace (including non-breaking space,
	// thin space, ideographic space, etc.) to a single ASCII space.
	out = strings.Join(strings.FieldsFunc(out, func(r rune) bool {
		return unicode.IsSpace(r)
	}), " ")
	return out
}