/*
 * @Descripttion:敏感词
 * @version:
 * @Author: Neo,Huang
 * @Date: 2021-04-17 11:04:16
 * @LastEditors: Neo,Huang
 * @LastEditTime: 2021-08-06 14:12:44
 */
package sensitive

import (
	"bufio"
	"fmt"
	"io"
	"os"
	"strings"
)

type Null struct{}

var sensitiveWord = make(map[string]interface{})
var Set = make(map[string]Null)

const InvalidWords = " ,~,!,@,#,$,%,^,&,*,(,),_,-,+,=,?,<,>,.,—,，,。,/,\\,|,《,》,？,;,:,：,',‘,；,“,"

var InvalidWord = make(map[string]Null) //无效词汇，不参与敏感词汇判断直接忽略

// 初始化
func InitDFA() {
	words := strings.Split(InvalidWords, ",")
	for _, v := range words {
		InvalidWord[v] = Null{}
	}

	f, err := os.Open("sensitive/words.txt")
	if err != nil {
		return
	}
	defer f.Close()

	buff := bufio.NewReader(f)
	for {
		line, err := buff.ReadString('\n')

		if err != nil || io.EOF == err {
			break
		}
		line = strings.TrimSpace(line)

		Set[line] = Null{}
	}

	AddSensitiveToMap(Set)
}

//生成违禁词集合
func AddSensitiveToMap(set map[string]Null) {
	for key := range set {
		str := []rune(key)
		nowMap := sensitiveWord
		for i := 0; i < len(str); i++ {
			if _, ok := nowMap[string(str[i])]; !ok { //如果该key不存在，
				thisMap := make(map[string]interface{})
				thisMap["isEnd"] = false
				nowMap[string(str[i])] = thisMap
				nowMap = thisMap
			} else {
				nowMap = nowMap[string(str[i])].(map[string]interface{})
			}
			if i == len(str)-1 {
				nowMap["isEnd"] = true
			}
		}

	}
}
func GetSensitiveMap() map[string]interface{} {
	return sensitiveWord
}

//敏感词汇转换为*
func ChangeSensitiveWords(txt string, sensitive map[string]interface{}) (word string) {
	str := []rune(txt)
	nowMap := sensitive
	start := -1
	tag := -1
	for i := 0; i < len(str); i++ {
		if _, ok := InvalidWord[(string(str[i]))]; ok || string(str[i]) == "," {
			continue
		}
		if thisMap, ok := nowMap[string(str[i])].(map[string]interface{}); ok {
			tag++
			if tag == 0 {
				start = i
			}
			isEnd, _ := thisMap["isEnd"].(bool)
			if isEnd {
				for y := start; y < i+1; y++ {
					str[y] = 42
				}
				nowMap = sensitive
				start = -1
				tag = -1

			} else {
				nowMap = nowMap[string(str[i])].(map[string]interface{})
			}

		} else {
			if start != -1 {
				i = start
			}
			nowMap = sensitive
			start = -1
			tag = -1
		}
	}

	return string(str)
}

// 敏感词检查
func CheckSensitive(txt string, sensitive map[string]interface{}) string {
	str := []rune(txt)
	nowMap := sensitive
	start := -1
	tag := -1
	for i := 0; i < len(str); i++ {
		// 跳过无效字符
		if _, ok := InvalidWord[(string(str[i]))]; ok || string(str[i]) == "," {
			continue
		}
		if thisMap, ok := nowMap[string(str[i])].(map[string]interface{}); ok {
			tag++
			if tag == 0 {
				start = i
			}
			isEnd, _ := thisMap["isEnd"].(bool)
			if isEnd {
				sensi := ""
				for y := start; y < i+1; y++ {
					sensi += string(str[y])
				}
				fmt.Printf("敏感词:%s\n", sensi)
				return "false"
			} else {
				nowMap = nowMap[string(str[i])].(map[string]interface{})
			}

		} else {
			if start != -1 {
				i = start
			}
			nowMap = sensitive
			start = -1
			tag = -1
		}
	}
	return "true"
}