From 4b1e00d3aa313f5ce4d6844135ebebab7b556b32 Mon Sep 17 00:00:00 2001
From: Skyxim <me@skyxim.dev>
Date: Sun, 12 Mar 2023 12:08:16 +0800
Subject: [PATCH] chore: unified parse mixed string and array

---
 common/utils/slice.go      | 23 +++++++++++++++++++++++
 component/resolver/host.go | 38 +++++++++++++++++++-------------------
 config/config.go           | 23 +++++------------------
 3 files changed, 47 insertions(+), 37 deletions(-)

diff --git a/common/utils/slice.go b/common/utils/slice.go
index fa8eef9b..1b0fa494 100644
--- a/common/utils/slice.go
+++ b/common/utils/slice.go
@@ -1,5 +1,11 @@
 package utils
 
+import (
+	"errors"
+	"fmt"
+	"reflect"
+)
+
 func Filter[T comparable](tSlice []T, filter func(t T) bool) []T {
 	result := make([]T, 0)
 	for _, t := range tSlice {
@@ -9,3 +15,20 @@ func Filter[T comparable](tSlice []T, filter func(t T) bool) []T {
 	}
 	return result
 }
+
+func ToStringSlice(value any) ([]string, error) {
+	strArr := make([]string, 0)
+	switch reflect.TypeOf(value).Kind() {
+	case reflect.Slice, reflect.Array:
+		origin := reflect.ValueOf(value)
+		for i := 0; i < origin.Len(); i++ {
+			item := fmt.Sprintf("%v", origin.Index(i))
+			strArr = append(strArr, item)
+		}
+	case reflect.String:
+		strArr = append(strArr, fmt.Sprintf("%v", value))
+	default:
+		return nil, errors.New("value format error, must be string or array")
+	}
+	return strArr, nil
+}
diff --git a/component/resolver/host.go b/component/resolver/host.go
index 135d35db..0b98bd68 100644
--- a/component/resolver/host.go
+++ b/component/resolver/host.go
@@ -2,11 +2,11 @@ package resolver
 
 import (
 	"errors"
-	"fmt"
 	"math/rand"
 	"net/netip"
-	"reflect"
 	"strings"
+
+	"github.com/Dreamacro/clash/common/utils"
 )
 
 type HostValue struct {
@@ -19,27 +19,27 @@ func NewHostValue(value any) (HostValue, error) {
 	isDomain := true
 	ips := make([]netip.Addr, 0)
 	domain := ""
-	switch reflect.TypeOf(value).Kind() {
-	case reflect.Slice, reflect.Array:
-		isDomain = false
-		origin := reflect.ValueOf(value)
-		for i := 0; i < origin.Len(); i++ {
-			if ip, err := netip.ParseAddr(fmt.Sprintf("%v", origin.Index(i))); err == nil {
+	if valueArr, err := utils.ToStringSlice(value); err != nil {
+		return HostValue{}, err
+	} else {
+		if len(valueArr) > 1 {
+			isDomain=false
+			for _, str := range valueArr {
+				if ip, err := netip.ParseAddr(str); err == nil {
+					ips = append(ips, ip)
+				} else {
+					return HostValue{}, err
+				}
+			}
+		} else if len(valueArr) == 1 {
+			host := valueArr[0]
+			if ip, err := netip.ParseAddr(host); err == nil {
 				ips = append(ips, ip)
+				isDomain = false
 			} else {
-				return HostValue{}, err
+				domain = host
 			}
 		}
-	case reflect.String:
-		host := fmt.Sprintf("%v", value)
-		if ip, err := netip.ParseAddr(host); err == nil {
-			ips = append(ips, ip)
-			isDomain = false
-		} else {
-			domain = host
-		}
-	default:
-		return HostValue{}, errors.New("value format error, must be string or array")
 	}
 	if isDomain {
 		return NewHostValueByDomain(domain)
diff --git a/config/config.go b/config/config.go
index 778d56c5..b29144c4 100644
--- a/config/config.go
+++ b/config/config.go
@@ -9,7 +9,6 @@ import (
 	"net/netip"
 	"net/url"
 	"os"
-	"reflect"
 	"runtime"
 	"strconv"
 	"strings"
@@ -852,7 +851,7 @@ func parseHosts(cfg *RawConfig) (*trie.DomainTrie[resolver.HostValue], error) {
 							}
 						}
 					}
-					anyValue=ips
+					anyValue = ips
 				}
 			}
 			value, err := resolver.NewHostValue(anyValue)
@@ -988,24 +987,12 @@ func parseNameServerPolicy(nsPolicy map[string]any, preferH3 bool) (map[string][
 	policy := map[string][]dns.NameServer{}
 
 	for domain, server := range nsPolicy {
-		var (
-			nameservers []dns.NameServer
-			err         error
-		)
 
-		switch reflect.TypeOf(server).Kind() {
-		case reflect.Slice, reflect.Array:
-			origin := reflect.ValueOf(server)
-			servers := make([]string, 0)
-			for i := 0; i < origin.Len(); i++ {
-				servers = append(servers, fmt.Sprintf("%v", origin.Index(i)))
-			}
-			nameservers, err = parseNameServer(servers, preferH3)
-		case reflect.String:
-			nameservers, err = parseNameServer([]string{fmt.Sprintf("%v", server)}, preferH3)
-		default:
-			return nil, errors.New("server format error, must be string or array")
+		servers, err := utils.ToStringSlice(server)
+		if err != nil {
+			return nil, err
 		}
+		nameservers, err := parseNameServer(servers, preferH3)
 		if err != nil {
 			return nil, err
 		}