Feature: add filter option to proxy group (#2518)

adapter/outboundgroup/parser.go

@@ -3,6 +3,7 @@ package outboundgroup
 import (
 	"errors"
 	"fmt"
+	"regexp"
 
 	"github.com/Dreamacro/clash/adapter/outbound"
 	"github.com/Dreamacro/clash/adapter/provider"
@@ -29,6 +30,7 @@ type GroupCommonOption struct {
 	Interval   int      `group:"interval,omitempty"`
 	Lazy       bool     `group:"lazy,omitempty"`
 	DisableUDP bool     `group:"disable-udp,omitempty"`
+	Filter     string   `group:"filter,omitempty"`
 }
 
 func ParseProxyGroup(config map[string]any, proxyMap map[string]C.Proxy, providersMap map[string]types.ProxyProvider) (C.ProxyAdapter, error) {
@@ -45,14 +47,25 @@ func ParseProxyGroup(config map[string]any, proxyMap map[string]C.Proxy, provide
 		return nil, errFormat
 	}
 
-	groupName := groupOption.Name
+	var (
+		groupName = groupOption.Name
+		filterReg *regexp.Regexp
+	)
 
-	providers := []types.ProxyProvider{}
+	if groupOption.Filter != "" {
+		f, err := regexp.Compile(groupOption.Filter)
+		if err != nil {
+			return nil, fmt.Errorf("%s: invalid filter regex: %w", groupName, err)
+		}
+		filterReg = f
+	}
 
 	if len(groupOption.Proxies) == 0 && len(groupOption.Use) == 0 {
 		return nil, fmt.Errorf("%s: %w", groupName, errMissProxy)
 	}
 
+	providers := []types.ProxyProvider{}
+
 	if len(groupOption.Proxies) != 0 {
 		ps, err := getProxies(proxyMap, groupOption.Proxies)
 		if err != nil {
@@ -94,7 +107,12 @@ func ParseProxyGroup(config map[string]any, proxyMap map[string]C.Proxy, provide
 		if err != nil {
 			return nil, fmt.Errorf("%s: %w", groupName, err)
 		}
-		providers = append(providers, list...)
+		if filterReg != nil {
+			pd := provider.NewFilterableProvider(groupName, list, filterReg)
+			providers = append(providers, pd)
+		} else {
+			providers = append(providers, list...)
+		}
 	}
 
 	var group C.ProxyAdapter