fix(sub): add content disposition for subscriptions

sub/subHandler.go

@@ -1,6 +1,10 @@
 package sub
 
 import (
+	"fmt"
+	"net/url"
+	"strings"
+
 	"github.com/alireza0/s-ui/logger"
 	"github.com/alireza0/s-ui/service"
 
@@ -75,4 +79,33 @@ func (s *SubHandler) addHeaders(c *gin.Context, headers []string) {
 	c.Writer.Header().Set("Subscription-Userinfo", headers[0])
 	c.Writer.Header().Set("Profile-Update-Interval", headers[1])
 	c.Writer.Header().Set("Profile-Title", headers[2])
+	c.Writer.Header().Set("Content-Disposition", contentDispositionHeader(headers[2]))
+}
+
+func contentDispositionHeader(name string) string {
+	filename := strings.TrimSpace(name)
+	if filename == "" {
+		filename = "subscription"
+	}
+
+	return fmt.Sprintf("attachment; filename=\"%s\"; filename*=UTF-8''%s", asciiSafeFilename(filename), url.PathEscape(filename))
+}
+
+func asciiSafeFilename(filename string) string {
+	var builder strings.Builder
+	for _, r := range filename {
+		switch {
+		case r == '"' || r == '\\':
+			builder.WriteByte('_')
+		case r >= 0x20 && r <= 0x7e:
+			builder.WriteRune(r)
+		}
+	}
+
+	fallback := strings.TrimSpace(builder.String())
+	if fallback == "" {
+		return "subscription"
+	}
+
+	return fallback
 }

sub/subHandler_test.go

@@ -0,0 +1,62 @@
+package sub
+
+import (
+	"net/http/httptest"
+	"testing"
+
+	"github.com/gin-gonic/gin"
+)
+
+func TestAddHeadersPreservesSubscriptionHeadersAndAddsContentDisposition(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+	recorder := httptest.NewRecorder()
+	context, _ := gin.CreateTestContext(recorder)
+
+	handler := &SubHandler{}
+	handler.addHeaders(context, []string{
+		"upload=1; download=2; total=3; expire=4",
+		"12",
+		"phj233_vpn",
+	})
+
+	headers := recorder.Header()
+	tests := map[string]string{
+		"Subscription-Userinfo":   "upload=1; download=2; total=3; expire=4",
+		"Profile-Update-Interval": "12",
+		"Profile-Title":           "phj233_vpn",
+		"Content-Disposition":     "attachment; filename=\"phj233_vpn\"; filename*=UTF-8''phj233_vpn",
+	}
+
+	for key, want := range tests {
+		if got := headers.Get(key); got != want {
+			t.Fatalf("header %s = %q, want %q", key, got, want)
+		}
+	}
+}
+
+func TestContentDispositionHeaderUsesSubscriptionNameWithoutExtension(t *testing.T) {
+	got := contentDispositionHeader("phj233_vpn")
+	want := "attachment; filename=\"phj233_vpn\"; filename*=UTF-8''phj233_vpn"
+
+	if got != want {
+		t.Fatalf("contentDispositionHeader() = %q, want %q", got, want)
+	}
+}
+
+func TestContentDispositionHeaderEscapesUTF8Name(t *testing.T) {
+	got := contentDispositionHeader("蓝胖云 LanPangYun")
+	want := "attachment; filename=\"LanPangYun\"; filename*=UTF-8''%E8%93%9D%E8%83%96%E4%BA%91%20LanPangYun"
+
+	if got != want {
+		t.Fatalf("contentDispositionHeader() = %q, want %q", got, want)
+	}
+}
+
+func TestContentDispositionHeaderFallsBackWhenNameIsEmpty(t *testing.T) {
+	got := contentDispositionHeader(" ")
+	want := "attachment; filename=\"subscription\"; filename*=UTF-8''subscription"
+
+	if got != want {
+		t.Fatalf("contentDispositionHeader() = %q, want %q", got, want)
+	}
+}