Enhance DMS Greeter logic

core/cmd/dms/utils.go

@@ -3,6 +3,7 @@ package main
 import (
 	"fmt"
 	"os/exec"
+	"strings"
 )
 
 func commandExists(cmd string) bool {
@@ -24,3 +25,68 @@ func isArchPackageInstalled(packageName string) bool {
 	err := cmd.Run()
 	return err == nil
 }
+
+type systemdServiceState struct {
+	Name         string
+	EnabledState string
+	NeedsDisable bool
+	Exists       bool
+}
+
+// checkSystemdServiceEnabled returns (state, should_disable, error) for a systemd service
+func checkSystemdServiceEnabled(serviceName string) (string, bool, error) {
+	cmd := exec.Command("systemctl", "is-enabled", serviceName)
+	output, err := cmd.Output()
+
+	stateStr := strings.TrimSpace(string(output))
+
+	if err != nil {
+		knownStates := []string{"disabled", "masked", "masked-runtime", "not-found", "enabled", "enabled-runtime", "static", "indirect", "alias"}
+		isKnownState := false
+		for _, known := range knownStates {
+			if stateStr == known {
+				isKnownState = true
+				break
+			}
+		}
+
+		if !isKnownState {
+			return stateStr, false, fmt.Errorf("systemctl is-enabled failed: %w (output: %s)", err, stateStr)
+		}
+	}
+
+	shouldDisable := false
+	switch stateStr {
+	case "enabled", "enabled-runtime", "static", "indirect", "alias":
+		shouldDisable = true
+	case "disabled", "masked", "masked-runtime", "not-found":
+		shouldDisable = false
+	default:
+		shouldDisable = true
+	}
+
+	return stateStr, shouldDisable, nil
+}
+
+func getSystemdServiceState(serviceName string) (*systemdServiceState, error) {
+	state := &systemdServiceState{
+		Name:   serviceName,
+		Exists: false,
+	}
+
+	enabledState, needsDisable, err := checkSystemdServiceEnabled(serviceName)
+	if err != nil {
+		return nil, fmt.Errorf("failed to check enabled state: %w", err)
+	}
+
+	state.EnabledState = enabledState
+	state.NeedsDisable = needsDisable
+
+	if enabledState == "not-found" {
+		state.Exists = false
+		return state, nil
+	}
+
+	state.Exists = true
+	return state, nil
+}