Avoid starting config flow and show alert dialog early if single config entry only

src/data/integration.ts

@@ -43,6 +43,7 @@ export interface IntegrationManifest {
     | "cloud_push"
     | "local_polling"
     | "local_push";
+  single_config_entry?: boolean;
 }
 export interface IntegrationSetup {
   domain: string;

src/data/integrations.ts

@@ -11,6 +11,7 @@ export interface Integration {
   iot_class?: string;
   supported_by?: string;
   is_built_in?: boolean;
+  single_config_entry?: boolean;
 }
 
 export interface Integrations {

src/panels/config/integrations/dialog-add-integration.ts

@@ -54,6 +54,7 @@ import {
   AddIntegrationDialogParams,
   showYamlIntegrationDialog,
 } from "./show-add-integration-dialog";
+import { getConfigEntries } from "../../../data/config_entries";
 
 export interface IntegrationListItem {
   name: string;
@@ -67,6 +68,7 @@ export interface IntegrationListItem {
   cloud?: boolean;
   is_built_in?: boolean;
   is_add?: boolean;
+  single_config_entry?: boolean;
 }
 
 @customElement("dialog-add-integration")
@@ -208,6 +210,7 @@ class AddIntegrationDialog extends LitElement {
             supported_by: integration.supported_by,
             is_built_in: supportedIntegration.is_built_in !== false,
             cloud: supportedIntegration.iot_class?.startsWith("cloud_"),
+            single_config_entry: integration.single_config_entry,
           });
         } else if (
           !("integration_type" in integration) &&
@@ -572,6 +575,27 @@ class AddIntegrationDialog extends LitElement {
       return;
     }
 
+    if (integration.single_config_entry) {
+      const configEntries = await getConfigEntries(this.hass, {
+        domain: integration.domain,
+      });
+      if (configEntries.length > 0) {
+        this.closeDialog();
+        showAlertDialog(this, {
+          title: this.hass.localize(
+            "ui.panel.config.integrations.config_flow.single_config_entry_title"
+          ),
+          text: this.hass.localize(
+            "ui.panel.config.integrations.config_flow.single_config_entry",
+            {
+              integration_name: integration.name,
+            }
+          ),
+        });
+        return;
+      }
+    }
+
     if (integration.config_flow) {
       this._createFlow(integration.domain);
       return;

src/panels/config/integrations/ha-config-integration-page.ts

@@ -1286,6 +1286,26 @@ class HaConfigIntegrationPage extends SubscribeMixin(LitElement) {
   }
 
   private async _addIntegration() {
+    if (this._manifest?.single_config_entry) {
+      const entries = this._domainConfigEntries(
+        this.domain,
+        this._extraConfigEntries || this.configEntries
+      );
+      if (entries.length > 0) {
+        await showAlertDialog(this, {
+          title: this.hass.localize(
+            "ui.panel.config.integrations.config_flow.single_config_entry_title"
+          ),
+          text: this.hass.localize(
+            "ui.panel.config.integrations.config_flow.single_config_entry",
+            {
+              integration_name: this._manifest.name,
+            }
+          ),
+        });
+        return;
+      }
+    }
     showAddIntegrationDialog(this, {
       domain: this.domain,
     });

src/panels/config/integrations/ha-config-integrations-dashboard.ts

@@ -29,7 +29,7 @@ import "../../../components/ha-fab";
 import "../../../components/ha-icon-button";
 import "../../../components/ha-svg-icon";
 import "../../../components/search-input";
-import { ConfigEntry } from "../../../data/config_entries";
+import { ConfigEntry, getConfigEntries } from "../../../data/config_entries";
 import { getConfigFlowInProgressCollection } from "../../../data/config_flow";
 import { fetchDiagnosticHandlers } from "../../../data/diagnostics";
 import {
@@ -658,6 +658,24 @@ class HaConfigIntegrationsDashboard extends SubscribeMixin(LitElement) {
     const integration = findIntegration(integrations, domain);
 
     if (integration?.config_flow) {
+      if (integration.single_config_entry) {
+        const configEntries = await getConfigEntries(this.hass, { domain });
+        if (configEntries.length > 0) {
+          showAlertDialog(this, {
+            title: this.hass.localize(
+              "ui.panel.config.integrations.config_flow.single_config_entry_title"
+            ),
+            text: this.hass.localize(
+              "ui.panel.config.integrations.config_flow.single_config_entry",
+              {
+                integration_name: integration.name,
+              }
+            ),
+          });
+          return;
+        }
+      }
+
       // Integration exists, so we can just create a flow
       const localize = await this.hass.loadBackendTranslation(
         "title",

src/translations/en.json

@@ -3978,7 +3978,9 @@
             "missing_matter": "To add a {brand} device, you first need the {integration} integration and {supported_hardware_link}. Do you want to proceed with the setup of {integration}?",
             "matter_mobile_app": "You need to use the Home Assistant Companion app on your mobile phone to commission Matter devices.",
             "supported_hardware": "supported hardware",
-            "proceed": "Proceed"
+            "proceed": "Proceed",
+            "single_config_entry_title": "This integration allows only one configuration",
+            "single_config_entry": "{integration_name} supports only one configuration. Adding additional ones is not needed."
           }
         },
         "users": {