package util

import (
	"strings"

	gp "github.com/mozillazg/go-pinyin"
)

var (
	fullArgs = func() gp.Args {
		a := gp.NewArgs()
		a.Style = gp.Normal
		a.Fallback = func(r rune, _ gp.Args) []string {
			return []string{strings.ToLower(string(r))}
		}
		return a
	}()
	initialArgs = func() gp.Args {
		a := gp.NewArgs()
		a.Style = gp.FirstLetter
		a.Fallback = func(r rune, _ gp.Args) []string {
			s := strings.ToLower(string(r))
			if s == "" {
				return nil
			}
			return []string{string(s[0])}
		}
		return a
	}()
)

// ToPinyin converts a Chinese name to full pinyin and initials.
// Non-Chinese characters are kept as-is (lowercased).
// Example: "茅台酒" → ("maotaijiu", "mtj")
func ToPinyin(s string) (full, initials string) {
	var fb, ib strings.Builder
	for _, row := range gp.Pinyin(s, fullArgs) {
		if len(row) > 0 {
			fb.WriteString(row[0])
		}
	}
	for _, row := range gp.Pinyin(s, initialArgs) {
		if len(row) > 0 {
			ib.WriteString(row[0])
		}
	}
	return fb.String(), ib.String()
}