// Copyright 2026 Alibaba Group
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package helpers

import (
	"strings"
	"unicode"
)

// NormalizeSkillName converts free-form skill names to a stable dash-case key.
func NormalizeSkillName(input string) string {
	s := strings.TrimSpace(strings.ToLower(input))
	if s == "" {
		return ""
	}

	var out []rune
	for _, r := range s {
		switch {
		case unicode.IsLetter(r) || unicode.IsDigit(r):
			out = append(out, r)
		case unicode.IsSpace(r) || r == '-' || r == '_':
			if len(out) > 0 && out[len(out)-1] != '-' {
				out = append(out, '-')
			}
		}
	}

	for len(out) > 0 && out[len(out)-1] == '-' {
		out = out[:len(out)-1]
	}
	return string(out)
}