package util

import (
	"bytes"
	"strings"
	"unicode"

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

func PinyinFirstLetterUpper(hans string) string {
	if hans == "" {
		return ""
	}

	py := getPinyin(hans)
	return processPolyphones(hans, py)
}

func getPinyin(hans string) string {
	a := pinyin.NewArgs()
	a.Style = pinyin.FIRST_LETTER
	a.Heteronym = true

	pys := pinyin.Pinyin(hans, a)

	var buffer bytes.Buffer

	for _, py := range pys {
		buffer.WriteString(strings.ToUpper(py[0]))
	}

	return buffer.String()
}

var polyphoneDict = map[string][2]rune{
	"阿": [2]rune{'A', 'E'},
	"参": [2]rune{'C', 'S'},
	"长": [2]rune{'C', 'Z'},
	"术": [2]rune{'S', 'Z'},
}

// 处理多音字，目前只支持一个汉字两个多音字的处理
func processPolyphones(src, py string) string {
	srcRune := []rune(src)
	keywordIndex := map[int][2]rune{}

	for i, r := range srcRune {
		if _, ok := polyphoneDict[string(r)]; ok {
			keywordIndex[i] = polyphoneDict[string(r)]
		}
	}

	if len(keywordIndex) == 0 {
		return py
	}

	pyRune := []rune(py)
	pyRuneReplaced := make([]rune, len(pyRune))

	for i, r := range pyRune {
		pyRuneReplaced[i] = r

		if rs, ok := keywordIndex[i]; ok {
			for _, pr := range rs {
				if r != pr {
					pyRuneReplaced[i] = pr
					break
				}
			}
		}
	}

	if len(pyRuneReplaced) > 0 {
		pyRune = append(pyRune, ',')
		pyRune = append(pyRune, pyRuneReplaced...)
	}

	return string(pyRune)
}

//是否是字母字符串
func IsLetter(s string) bool {
	for _, r := range s {
		if !unicode.IsLetter(r) {
			return false
		}
	}
	return true
}