/*
 * @Name:
 * @Descripttion:
 * @Warning:
 * @version:
 * @Author: moo
 * @Date: 2021-01-09 14:03:49
 * @LastEditors: moo
 * @LastEditTime: 2021-05-19 17:51:09
 */
package utils

import (
	"html"
	"regexp"
	"strings"
	"unicode/utf8"
)

func StringSub(s string, length int) string {
	var size, n int
	for i := 0; i < length && n < len(s); i++ {
		_, size = utf8.DecodeRuneInString(s[n:])
		n += size
	}

	return s[:n]
}

func StringLen(s string) int {
	return utf8.RuneCountInString(s)
}

func TrimHtml(sHtml string) string {
	src := html.UnescapeString(sHtml)
	//将HTML标签全转换成小写
	re, _ := regexp.Compile("\\<[\\S\\s]+?\\>")
	src = re.ReplaceAllStringFunc(src, strings.ToLower)
	//去除STYLE
	re, _ = regexp.Compile("\\<style[\\S\\s]+?\\</style\\>")
	src = re.ReplaceAllString(src, "")
	//去除SCRIPT
	re, _ = regexp.Compile("\\<script[\\S\\s]+?\\</script\\>")
	src = re.ReplaceAllString(src, "")
	//去除所有尖括号内的HTML代码，并换成换行符
	re, _ = regexp.Compile("\\<[\\S\\s]+?\\>")
	// src = re.ReplaceAllString(src, "\n")
	src = re.ReplaceAllString(src, " ")
	//去除连续的换行符
	re, _ = regexp.Compile("\\s{2,}")
	// src = re.ReplaceAllString(src, "\n")
	src = re.ReplaceAllString(src, "")
	return strings.TrimSpace(src)
}

func TrimHtmlDesc(sHtml string, iLen int) string {
	var iRtnLen int = 0
	iTrimLen := StringLen(sHtml)

	if iTrimLen > iLen+50 {
		iTrimLen = iLen + 50
	} else if iTrimLen > iLen {
		iTrimLen = iLen
	}

	stripped := TrimHtml(StringSub(sHtml, iTrimLen))
	iRtnLen = StringLen(stripped)
	if iRtnLen > iLen {
		iRtnLen = iLen
	}
	return StringSub(stripped, iRtnLen)
}