feat: add panel update functionality via web GUI (#4117)

* feat: add panel update functionality via web GUI

* feat: enhance panel update notifications in web GUI

* feat: implement panel update modal and enhance translation strings

* fix design

4 files changed, 234 insertions, 0 deletions

diff --git a/web/service/panel.go b/web/service/panel.go
index e4fb0c68..75f2f155 100644
--- a/web/service/panel.go
+++ b/web/service/panel.go
@@ -1,10 +1,19 @@
 package service
 
 import (
+	"encoding/json"
+	"fmt"
+	"net/http"
 	"os"
+	"os/exec"
+	"path/filepath"
+	"runtime"
+	"strconv"
+	"strings"
 	"syscall"
 	"time"
 
+	"github.com/mhsanaei/3x-ui/v2/config"
 	"github.com/mhsanaei/3x-ui/v2/logger"
 )
 
@@ -12,6 +21,13 @@ import (
 // It handles panel restart, updates, and system-level panel controls.
 type PanelService struct{}
 
+// PanelUpdateInfo contains the current and latest available panel versions.
+type PanelUpdateInfo struct {
+	CurrentVersion  string `json:"currentVersion"`
+	LatestVersion   string `json:"latestVersion"`
+	UpdateAvailable bool   `json:"updateAvailable"`
+}
+
 func (s *PanelService) RestartPanel(delay time.Duration) error {
 	p, err := os.FindProcess(syscall.Getpid())
 	if err != nil {
@@ -26,3 +42,161 @@ func (s *PanelService) RestartPanel(delay time.Duration) error {
 	}()
 	return nil
 }
+
+// GetUpdateInfo checks GitHub for the latest 3x-ui release.
+func (s *PanelService) GetUpdateInfo() (*PanelUpdateInfo, error) {
+	latest, err := fetchLatestPanelVersion()
+	if err != nil {
+		return nil, err
+	}
+	current := config.GetVersion()
+	return &PanelUpdateInfo{
+		CurrentVersion:  current,
+		LatestVersion:   latest,
+		UpdateAvailable: isNewerVersion(latest, current),
+	}, nil
+}
+
+// StartUpdate starts the official updater outside of the current web request.
+func (s *PanelService) StartUpdate() error {
+	if runtime.GOOS != "linux" {
+		return fmt.Errorf("panel web update is supported only on Linux installations")
+	}
+
+	bash, err := exec.LookPath("bash")
+	if err != nil {
+		return fmt.Errorf("bash is required to run the panel updater: %w", err)
+	}
+	curl, err := exec.LookPath("curl")
+	if err != nil {
+		return fmt.Errorf("curl is required to download the panel updater: %w", err)
+	}
+
+	mainFolder, serviceFolder := resolveUpdateFolders()
+	updateScript := fmt.Sprintf("set -o pipefail; %s -fLs https://raw.githubusercontent.com/MHSanaei/3x-ui/main/update.sh | %s", shellQuote(curl), shellQuote(bash))
+
+	if systemdRun, err := exec.LookPath("systemd-run"); err == nil {
+		unitName := fmt.Sprintf("x-ui-web-update-%d", time.Now().Unix())
+		cmd := exec.Command(systemdRun,
+			"--unit", unitName,
+			"--setenv", "XUI_MAIN_FOLDER="+mainFolder,
+			"--setenv", "XUI_SERVICE="+serviceFolder,
+			bash, "-lc", updateScript,
+		)
+		out, err := cmd.CombinedOutput()
+		if err != nil {
+			output := strings.TrimSpace(string(out))
+			if !strings.Contains(output, "System has not been booted with systemd") &&
+				!strings.Contains(output, "Failed to connect to bus") {
+				return fmt.Errorf("failed to start panel update job: %w: %s", err, output)
+			}
+			logger.Warning("systemd-run is unavailable, falling back to detached update process:", output)
+		} else {
+			logger.Infof("started panel update job via systemd-run unit %s", unitName)
+			return nil
+		}
+	}
+
+	cmd := exec.Command(bash, "-lc", updateScript)
+	cmd.Env = append(os.Environ(),
+		"XUI_MAIN_FOLDER="+mainFolder,
+		"XUI_SERVICE="+serviceFolder,
+	)
+	setDetachedProcess(cmd)
+	if err := cmd.Start(); err != nil {
+		return fmt.Errorf("failed to start panel update job: %w", err)
+	}
+	if err := cmd.Process.Release(); err != nil {
+		logger.Warning("failed to release panel update process:", err)
+	}
+	logger.Infof("started panel update job with pid %d", cmd.Process.Pid)
+	return nil
+}
+
+func fetchLatestPanelVersion() (string, error) {
+	client := &http.Client{Timeout: 10 * time.Second}
+	resp, err := client.Get("https://api.github.com/repos/MHSanaei/3x-ui/releases/latest")
+	if err != nil {
+		return "", err
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		return "", fmt.Errorf("GitHub API returned status %d: %s", resp.StatusCode, resp.Status)
+	}
+
+	var release Release
+	if err := json.NewDecoder(resp.Body).Decode(&release); err != nil {
+		return "", err
+	}
+	if release.TagName == "" {
+		return "", fmt.Errorf("latest panel release tag is empty")
+	}
+	return release.TagName, nil
+}
+
+func resolveUpdateFolders() (string, string) {
+	mainFolder := os.Getenv("XUI_MAIN_FOLDER")
+	if mainFolder == "" {
+		if exePath, err := os.Executable(); err == nil {
+			mainFolder = filepath.Dir(exePath)
+		}
+	}
+	if mainFolder == "" {
+		mainFolder = "/usr/local/x-ui"
+	}
+
+	serviceFolder := os.Getenv("XUI_SERVICE")
+	if serviceFolder == "" {
+		serviceFolder = "/etc/systemd/system"
+	}
+	return mainFolder, serviceFolder
+}
+
+func isNewerVersion(latest string, current string) bool {
+	cmp, ok := compareVersionStrings(latest, current)
+	if !ok {
+		return normalizeVersionTag(latest) != normalizeVersionTag(current)
+	}
+	return cmp > 0
+}
+
+func compareVersionStrings(a string, b string) (int, bool) {
+	aParts, okA := parseVersionParts(a)
+	bParts, okB := parseVersionParts(b)
+	if !okA || !okB {
+		return 0, false
+	}
+	for i := 0; i < len(aParts); i++ {
+		if aParts[i] > bParts[i] {
+			return 1, true
+		}
+		if aParts[i] < bParts[i] {
+			return -1, true
+		}
+	}
+	return 0, true
+}
+
+func parseVersionParts(version string) ([3]int, bool) {
+	var result [3]int
+	parts := strings.Split(normalizeVersionTag(version), ".")
+	if len(parts) != 3 {
+		return result, false
+	}
+	for i, part := range parts {
+		n, err := strconv.Atoi(part)
+		if err != nil {
+			return result, false
+		}
+		result[i] = n
+	}
+	return result, true
+}
+
+func normalizeVersionTag(version string) string {
+	return strings.TrimPrefix(strings.TrimSpace(version), "v")
+}
+
+func shellQuote(value string) string {
+	return "'" + strings.ReplaceAll(value, "'", "'\\''") + "'"
+}
diff --git a/web/service/panel_other.go b/web/service/panel_other.go
new file mode 100644
index 00000000..53295c10
--- /dev/null
+++ b/web/service/panel_other.go
@@ -0,0 +1,7 @@
+//go:build !linux
+
+package service
+
+import "os/exec"
+
+func setDetachedProcess(cmd *exec.Cmd) {}
diff --git a/web/service/panel_test.go b/web/service/panel_test.go
new file mode 100644
index 00000000..44e9ba34
--- /dev/null
+++ b/web/service/panel_test.go
@@ -0,0 +1,41 @@
+package service
+
+import "testing"
+
+func TestIsNewerVersion(t *testing.T) {
+	cases := []struct {
+		latest  string
+		current string
+		want    bool
+	}{
+		{"v2.9.4", "2.9.3", true},
+		{"v2.10.0", "2.9.9", true},
+		{"v2.9.3", "2.9.3", false},
+		{"v2.9.2", "2.9.3", false},
+		{"v3.0.0", "2.9.3", true},
+	}
+
+	for _, tc := range cases {
+		if got := isNewerVersion(tc.latest, tc.current); got != tc.want {
+			t.Fatalf("isNewerVersion(%q, %q) = %v, want %v", tc.latest, tc.current, got, tc.want)
+		}
+	}
+}
+
+func TestCompareVersionStringsRejectsUnexpectedFormats(t *testing.T) {
+	if _, ok := compareVersionStrings("latest", "2.9.3"); ok {
+		t.Fatal("expected non-semver latest tag to be rejected")
+	}
+	if _, ok := compareVersionStrings("v2.9", "2.9.3"); ok {
+		t.Fatal("expected short version to be rejected")
+	}
+}
+
+func TestShellQuote(t *testing.T) {
+	if got := shellQuote("/usr/bin/curl"); got != "'/usr/bin/curl'" {
+		t.Fatalf("unexpected quote result: %s", got)
+	}
+	if got := shellQuote("/tmp/a'b"); got != "'/tmp/a'\\''b'" {
+		t.Fatalf("unexpected quote result with single quote: %s", got)
+	}
+}
diff --git a/web/service/panel_unix.go b/web/service/panel_unix.go
new file mode 100644
index 00000000..13d2237c
--- /dev/null
+++ b/web/service/panel_unix.go
@@ -0,0 +1,12 @@
+//go:build linux
+
+package service
+
+import (
+	"os/exec"
+	"syscall"
+)
+
+func setDetachedProcess(cmd *exec.Cmd) {
+	cmd.SysProcAttr = &syscall.SysProcAttr{Setsid: true}
+}