// ingestion/internal/wiki/slug.go
package wiki

import (
	"strings"
	"unicode"
)

// Slug converts a title to a kebab-case slug suitable for wiki filenames.
// Rules: lowercase, spaces/hyphens/underscores → hyphens, strip everything else.
func Slug(title string) string {
	var b strings.Builder
	prevHyphen := true // start true to trim leading hyphens
	for _, r := range strings.ToLower(title) {
		switch {
		case r == ' ' || r == '-' || r == '_':
			if !prevHyphen {
				b.WriteRune('-')
				prevHyphen = true
			}
		case unicode.IsLetter(r) || unicode.IsDigit(r):
			b.WriteRune(r)
			prevHyphen = false
			// all other characters (apostrophes, colons, dots, etc.) are dropped
		}
	}
	return strings.TrimRight(b.String(), "-")
}