implement backend health check and alert system

lightrag/api/graph_viewer_webui/src/App.tsx

@@ -1,12 +1,18 @@
 import ThemeProvider from '@/components/ThemeProvider'
+import BackendMessageAlert from '@/components/BackendMessageAlert'
 import { GraphViewer } from '@/GraphViewer'
+import { cn } from '@/lib/utils'
+import { useBackendState } from '@/stores/state'
 
 function App() {
+  const health = useBackendState.use.health()
+
   return (
-    <ThemeProvider defaultTheme="system" storageKey="lightrag-viewer-webui-theme">
-      <div className="h-screen w-screen">
+    <ThemeProvider>
+      <div className={cn('h-screen w-screen', !health && 'pointer-events-none')}>
         <GraphViewer />
       </div>
+      {!health && <BackendMessageAlert />}
     </ThemeProvider>
   )
 }

lightrag/api/graph_viewer_webui/src/GraphViewer.tsx

@@ -153,7 +153,7 @@ export const GraphViewer = () => {
         />
       </div>
 
-      <div className="bg-background/20 absolute bottom-2 left-2 flex flex-col rounded-xl border-2 backdrop-blur-lg">
+      <div className="bg-background/60 absolute bottom-2 left-2 flex flex-col rounded-xl border-2 backdrop-blur-lg">
         <Settings />
         <ZoomControl />
         <LayoutsControl />

lightrag/api/graph_viewer_webui/src/api/lightrag.ts

@@ -0,0 +1,97 @@
+import { backendBaseUrl } from '@/lib/constants'
+
+export type LightragNodeType = {
+  id: string
+  labels: string[]
+  properties: Record<string, any>
+}
+
+export type LightragEdgeType = {
+  id: string
+  source: string
+  target: string
+  type: string
+  properties: Record<string, any>
+}
+
+export type LightragGraphType = {
+  nodes: LightragNodeType[]
+  edges: LightragEdgeType[]
+}
+
+export type LightragStatus = {
+  status: 'healthy'
+  working_directory: string
+  input_directory: string
+  indexed_files: string[]
+  indexed_files_count: number
+  configuration: {
+    llm_binding: string
+    llm_binding_host: string
+    llm_model: string
+    embedding_binding: string
+    embedding_binding_host: string
+    embedding_model: string
+    max_tokens: number
+    kv_storage: string
+    doc_status_storage: string
+    graph_storage: string
+    vector_storage: string
+  }
+}
+
+export type LightragDocumentsScanProgress = {
+  is_scanning: boolean
+  current_file: string
+  indexed_count: number
+  total_files: number
+  progress: number
+}
+
+const checkResponse = (response: Response) => {
+  if (!response.ok) {
+    throw new Error(`${response.status} ${response.statusText} ${response.url}`)
+  }
+}
+
+export const queryGraphs = async (label: string): Promise<LightragGraphType> => {
+  const response = await fetch(backendBaseUrl + `/graphs?label=${label}`)
+  checkResponse(response)
+  return await response.json()
+}
+
+export const getGraphLabels = async (): Promise<string[]> => {
+  const response = await fetch(backendBaseUrl + '/graph/label/list')
+  checkResponse(response)
+  return await response.json()
+}
+
+export const checkHealth = async (): Promise<
+  LightragStatus | { status: 'error'; message: string }
+> => {
+  try {
+    const response = await fetch(backendBaseUrl + '/health')
+    if (!response.ok) {
+      return {
+        status: 'error',
+        message: `Health check failed. Service is currently unavailable.\n${response.status} ${response.statusText} ${response.url}`
+      }
+    }
+    return await response.json()
+  } catch (e) {
+    return {
+      status: 'error',
+      message: `${e}`
+    }
+  }
+}
+
+export const getDocuments = async (): Promise<string[]> => {
+  const response = await fetch(backendBaseUrl + '/documents')
+  return await response.json()
+}
+
+export const getDocumentsScanProgress = async (): Promise<LightragDocumentsScanProgress> => {
+  const response = await fetch(backendBaseUrl + '/documents/scan-progress')
+  return await response.json()
+}

lightrag/api/graph_viewer_webui/src/components/BackendMessageAlert.tsx

@@ -0,0 +1,22 @@
+import { Alert, AlertDescription, AlertTitle } from '@/components/ui/Alert'
+import { useBackendState } from '@/stores/state'
+import { AlertCircle } from 'lucide-react'
+
+const BackendMessageAlert = () => {
+  const health = useBackendState.use.health()
+  const message = useBackendState.use.message()
+  const messageTitle = useBackendState.use.messageTitle()
+
+  return (
+    <Alert
+      variant={health ? 'default' : 'destructive'}
+      className="absolute top-1/2 left-1/2 w-auto -translate-x-1/2 -translate-y-1/2 transform"
+    >
+      {!health && <AlertCircle className="h-4 w-4" />}
+      <AlertTitle>{messageTitle}</AlertTitle>
+      <AlertDescription>{message}</AlertDescription>
+    </Alert>
+  )
+}
+
+export default BackendMessageAlert

lightrag/api/graph_viewer_webui/src/components/GraphSearch.tsx

@@ -70,7 +70,7 @@ export const GraphSearchInput = ({
 
   return (
     <AsyncSelect
-      className="bg-background/20 w-52 rounded-xl border-1 opacity-60 backdrop-blur-lg transition-opacity hover:opacity-100"
+      className="bg-background/60 w-52 rounded-xl border-1 opacity-60 backdrop-blur-lg transition-opacity hover:opacity-100"
       fetcher={loadOptions}
       renderOption={OptionComponent}
       getOptionValue={(item) => item.id}

lightrag/api/graph_viewer_webui/src/components/PropertiesView.tsx

@@ -59,7 +59,7 @@ const PropertiesView = () => {
     return <></>
   }
   return (
-    <div className="bg-background/20 max-w-sm rounded-xl border-2 p-2 backdrop-blur-lg">
+    <div className="bg-background/80 max-w-sm rounded-xl border-2 p-2 backdrop-blur-lg">
       {currentType == 'node' ? (
         <NodePropertiesView node={currentElement as any} />
       ) : (

lightrag/api/graph_viewer_webui/src/components/Settings.tsx

@@ -7,6 +7,8 @@ import { useSettingsStore } from '@/stores/settings'
 
 import { SettingsIcon } from 'lucide-react'
 
+import * as Api from '@/api/lightrag'
+
 /**
  * Component that displays a checkbox with a label.
  */
@@ -95,6 +97,13 @@ export default function Settings() {
             onCheckedChange={setShowEdgeLabel}
             label="Show Edge Label"
           />
+          <Button
+            onClick={async () => {
+              console.log(Api.checkHealth())
+            }}
+          >
+            Test Api
+          </Button>
         </div>
       </PopoverContent>
     </Popover>

lightrag/api/graph_viewer_webui/src/components/ui/Alert.tsx

@@ -0,0 +1,49 @@
+import * as React from 'react'
+import { cva, type VariantProps } from 'class-variance-authority'
+
+import { cn } from '@/lib/utils'
+
+const alertVariants = cva(
+  'relative w-full rounded-lg border px-4 py-3 text-sm [&>svg+div]:translate-y-[-3px] [&>svg]:absolute [&>svg]:left-4 [&>svg]:top-4 [&>svg]:text-foreground [&>svg~*]:pl-7',
+  {
+    variants: {
+      variant: {
+        default: 'bg-background text-foreground',
+        destructive:
+          'border-destructive/50 text-destructive dark:border-destructive [&>svg]:text-destructive'
+      }
+    },
+    defaultVariants: {
+      variant: 'default'
+    }
+  }
+)
+
+const Alert = React.forwardRef<
+  HTMLDivElement,
+  React.HTMLAttributes<HTMLDivElement> & VariantProps<typeof alertVariants>
+>(({ className, variant, ...props }, ref) => (
+  <div ref={ref} role="alert" className={cn(alertVariants({ variant }), className)} {...props} />
+))
+Alert.displayName = 'Alert'
+
+const AlertTitle = React.forwardRef<HTMLParagraphElement, React.HTMLAttributes<HTMLHeadingElement>>(
+  ({ className, ...props }, ref) => (
+    <h5
+      ref={ref}
+      className={cn('mb-1 leading-none font-medium tracking-tight', className)}
+      {...props}
+    />
+  )
+)
+AlertTitle.displayName = 'AlertTitle'
+
+const AlertDescription = React.forwardRef<
+  HTMLParagraphElement,
+  React.HTMLAttributes<HTMLParagraphElement>
+>(({ className, ...props }, ref) => (
+  <div ref={ref} className={cn('text-sm [&_p]:leading-relaxed', className)} {...props} />
+))
+AlertDescription.displayName = 'AlertDescription'
+
+export { Alert, AlertTitle, AlertDescription }

lightrag/api/graph_viewer_webui/src/hooks/useLightragGraph.tsx

@@ -3,6 +3,8 @@ import { useCallback, useEffect, useState } from 'react'
 import { randomColor } from '@/lib/utils'
 import * as Constants from '@/lib/constants'
 import { useGraphStore, RawGraph } from '@/stores/graph'
+import { queryGraphs } from '@/api/lightrag'
+import { useBackendState } from '@/stores/state'
 
 const validateGraph = (graph: RawGraph) => {
   if (!graph) {
@@ -46,8 +48,14 @@ export type NodeType = {
 export type EdgeType = { label: string }
 
 const fetchGraph = async (label: string) => {
-  const response = await fetch(`/graphs?label=${label}`)
-  const rawData = await response.json()
+  let rawData: any = null
+
+  try {
+    rawData = await queryGraphs(label)
+  } catch (e) {
+    useBackendState.getState().setErrorMessage(`${e}`, 'Query Graphs Error!')
+    return null
+  }
 
   let rawGraph = null
 

lightrag/api/graph_viewer_webui/src/lib/constants.ts

@@ -1,5 +1,7 @@
 import { ButtonVariantType } from '@/components/ui/Button'
 
+export const backendBaseUrl = ''
+
 export const controlButtonVariant: ButtonVariantType = 'ghost'
 
 export const labelColorDarkTheme = '#B2EBF2'

lightrag/api/graph_viewer_webui/src/stores/state.ts

@@ -0,0 +1,41 @@
+import { create } from 'zustand'
+import { createSelectors } from '@/lib/utils'
+import { checkHealth } from '@/api/lightrag'
+
+interface BackendState {
+  health: boolean
+  message: string | null
+  messageTitle: string | null
+
+  check: () => Promise<boolean>
+  clear: () => void
+  setErrorMessage: (message: string, messageTitle: string) => void
+}
+
+const useBackendStateStoreBase = create<BackendState>()((set) => ({
+  health: true,
+  message: null,
+  messageTitle: null,
+
+  check: async () => {
+    const health = await checkHealth()
+    if (health.status === 'healthy') {
+      set({ health: true, message: null, messageTitle: null })
+      return true
+    }
+    set({ health: false, message: health.message, messageTitle: 'Backend Health Check Error!' })
+    return false
+  },
+
+  clear: () => {
+    set({ health: true, message: null, messageTitle: null })
+  },
+
+  setErrorMessage: (message: string, messageTitle: string) => {
+    set({ health: false, message, messageTitle })
+  }
+}))
+
+const useBackendState = createSelectors(useBackendStateStoreBase)
+
+export { useBackendState }