feat: persist default History API provider, selectable in Admin UI

packages/server-admin-ui/src/components/Sidebar/Sidebar.tsx

@@ -27,6 +27,7 @@ import {
 } from '../../store'
 import classNames from 'classnames'
 import { isOverrideDormantUnderGroups } from '../../utils/sourceGroups'
+import { useHistoryProviderUnavailable } from '../../hooks/useHistoryProviderStatus'
 import './Sidebar.css'
 import SidebarFooter from './../SidebarFooter/SidebarFooter'
 import SidebarForm from './../SidebarForm/SidebarForm'
@@ -158,6 +159,7 @@ export default function Sidebar({ location }: SidebarProps) {
   ).length
 
   const unconfiguredGnssCount = useUnconfiguredGnssSources().length
+  const historyProviderUnavailable = useHistoryProviderUnavailable()
 
   const items = useMemo((): NavItemData[] => {
     const appUpdates = appStore.updates.length
@@ -306,13 +308,17 @@ export default function Sidebar({ location }: SidebarProps) {
       })()
     ]
 
+    const historyProviderBadge: BadgeData | null = historyProviderUnavailable
+      ? { variant: 'warning', text: '!' }
+      : null
+
     if (isAdmin) {
       result.push(
         {
           name: 'Apps & Plugins',
           url: '/apps',
           icon: 'icon-basket',
-          badges: [updatesBadge, unconfiguredBadge],
+          badges: [updatesBadge, unconfiguredBadge, historyProviderBadge],
           children: [
             {
               name: 'Store',
@@ -322,7 +328,7 @@ export default function Sidebar({ location }: SidebarProps) {
             {
               name: 'Configuration',
               url: '/apps/configuration/-',
-              badge: unconfiguredBadge
+              badges: [unconfiguredBadge, historyProviderBadge]
             }
           ]
         },
@@ -432,7 +438,8 @@ export default function Sidebar({ location }: SidebarProps) {
     conflictCount,
     unconfiguredPriorityCount,
     overridesWithMissingSourcesCount,
-    unconfiguredGnssCount
+    unconfiguredGnssCount,
+    historyProviderUnavailable
   ])
 
   const [openDropdowns, setOpenDropdowns] = useState<Set<string>>(

packages/server-admin-ui/src/hooks/useHistoryProviderStatus.ts

@@ -0,0 +1,50 @@
+import { useState, useEffect } from 'react'
+import { usePlugins } from '../store'
+
+const PROVIDERS_PATH = '/signalk/v2/api/history/_providers'
+
+/**
+ * True when a default History API provider is configured but not
+ * currently registered (e.g. its plugin is disabled), so requests are
+ * served by a fallback. Re-checks whenever the plugin list changes,
+ * since providers register and unregister with plugin enable/disable.
+ */
+export function useHistoryProviderUnavailable(): boolean {
+  const plugins = usePlugins()
+  const [unavailable, setUnavailable] = useState(false)
+
+  useEffect(() => {
+    let cancelled = false
+    const check = async () => {
+      try {
+        const [providersRes, defaultRes] = await Promise.all([
+          fetch(PROVIDERS_PATH, { credentials: 'include' }),
+          fetch(`${PROVIDERS_PATH}/_default`, { credentials: 'include' })
+        ])
+        if (!providersRes.ok || !defaultRes.ok) {
+          return
+        }
+        const ids = Object.keys(
+          (await providersRes.json()) as Record<string, unknown>
+        )
+        const defaultBody = (await defaultRes.json()) as {
+          configured?: string
+        }
+        if (!cancelled) {
+          setUnavailable(
+            defaultBody.configured !== undefined &&
+              !ids.includes(defaultBody.configured)
+          )
+        }
+      } catch {
+        // status stays as-is; the badge is best-effort
+      }
+    }
+    check()
+    return () => {
+      cancelled = true
+    }
+  }, [plugins])
+
+  return unavailable
+}