fix redirectHTTP middleware, add bypass.user_agents option

internal/net/gphttp/middleware/redirect_http.go

@@ -1,29 +1,51 @@
 package middleware
 
 import (
+	"net"
 	"net/http"
 	"strings"
 
 	"github.com/yusing/go-proxy/internal/common"
 	"github.com/yusing/go-proxy/internal/logging"
 )
 
-type redirectHTTP struct{}
+type redirectHTTP struct {
+	Bypass struct {
+		UserAgents []string
+	}
+}
 
 var RedirectHTTP = NewMiddleware[redirectHTTP]()
 
 // before implements RequestModifier.
-func (redirectHTTP) before(w http.ResponseWriter, r *http.Request) (proceed bool) {
+func (m *redirectHTTP) before(w http.ResponseWriter, r *http.Request) (proceed bool) {
 	if r.TLS != nil {
 		return true
 	}
+
+	if len(m.Bypass.UserAgents) > 0 {
+		ua := r.UserAgent()
+		for _, uaBypass := range m.Bypass.UserAgents {
+			if strings.Contains(ua, uaBypass) {
+				return true
+			}
+		}
+	}
+
 	r.URL.Scheme = "https"
-	host := r.Host
-	if i := strings.Index(host, ":"); i != -1 {
-		host = host[:i] // strip port number if present
+	host, _, err := net.SplitHostPort(r.Host)
+	if err != nil {
+		host = r.Host
 	}
-	r.URL.Host = host + ":" + common.ProxyHTTPSPort
-	logging.Debug().Str("url", r.URL.String()).Msg("redirect to https")
-	http.Redirect(w, r, r.URL.String(), http.StatusTemporaryRedirect)
-	return true
+
+	if common.ProxyHTTPSPort != "443" {
+		r.URL.Host = host + ":" + common.ProxyHTTPSPort
+	} else {
+		r.URL.Host = host
+	}
+
+	http.Redirect(w, r, r.URL.String(), http.StatusMovedPermanently)
+
+	logging.Debug().Str("url", r.URL.String()).Str("user_agent", r.UserAgent()).Msg("redirect to https")
+	return false
 }

internal/net/gphttp/middleware/redirect_http_test.go

@@ -14,7 +14,7 @@ func TestRedirectToHTTPs(t *testing.T) {
 		reqURL: types.MustParseURL("http://example.com"),
 	})
 	ExpectNoError(t, err)
-	ExpectEqual(t, result.ResponseStatus, http.StatusTemporaryRedirect)
+	ExpectEqual(t, result.ResponseStatus, http.StatusPermanentRedirect)
 	ExpectEqual(t, result.ResponseHeaders.Get("Location"), "https://example.com:"+common.ProxyHTTPSPort)
 }