feat(ux): Implement advanced reasoning view with progress tracking and refined Markdown rendering.

frontend/src/components/chat/ChatInterface.tsx

@@ -1,6 +1,7 @@
 import * as React from "react"
 import { MessageList } from "./MessageList"
 import { ChatInput } from "./ChatInput"
+import { ExecutionStatus } from "./ExecutionStatus"
 import { ChatService, type MessageResponse } from "@/services/chat"
 import { AlertCircle } from "lucide-react"
 import { Alert, AlertDescription, AlertTitle } from "@/components/ui/alert"
@@ -22,18 +23,17 @@ export function ChatInterface({
   const [isStreaming, setIsStreaming] = React.useState(false)
   const [error, setError] = React.useState<string | null>(null)
 
+  // Get steps from the currently active assistant message if streaming
+  const activeSteps = isStreaming && messages.length > 0 
+    ? messages[messages.length - 1].steps || [] 
+    : []
+
   // Sync messages if threadId or initialMessages changes
   React.useEffect(() => {
-    console.log("ChatInterface: Syncing messages", initialMessages)
     setMessages(initialMessages)
     setError(null)
   }, [threadId, initialMessages])
 
-  // Log messages changes for debugging
-  React.useEffect(() => {
-    console.log("ChatInterface: Messages state updated", messages)
-  }, [messages])
-
   const handleSendMessage = async (text: string) => {
     setError(null)
     setIsStreaming(true)
@@ -69,7 +69,7 @@ export function ChatInterface({
   return (
     <div className="flex flex-col h-full bg-background rounded-xl border shadow-lg overflow-hidden">
       {error && (
-        <Alert variant="destructive" className="m-4">
+        <Alert variant="destructive" className="m-4 shrink-0">
           <AlertCircle className="h-4 w-4" />
           <AlertTitle>Error</AlertTitle>
           <AlertDescription>{error}</AlertDescription>
@@ -77,6 +77,12 @@ export function ChatInterface({
       )}
       
       <MessageList messages={messages} />
+
+      {isStreaming && activeSteps.length > 0 && (
+        <div className="px-4 pb-4 shrink-0">
+          <ExecutionStatus steps={activeSteps} />
+        </div>
+      )}
       
       <ChatInput 
         onSendMessage={handleSendMessage} 

frontend/src/components/chat/ExecutionStatus.tsx

@@ -0,0 +1,64 @@
+import { cn } from "@/lib/utils"
+import { Loader2Icon, CheckCircle2Icon } from "lucide-react"
+
+interface ExecutionStatusProps {
+  steps: string[]
+  isComplete?: boolean
+  className?: string
+}
+
+const PHASE_CONFIG = [
+  { label: "Analyzing query...", match: "Query analysis complete." },
+  { label: "Generating strategic plan...", match: "Strategic plan generated." },
+  { label: "Writing analysis code...", match: "Analysis code generated." },
+  { label: "Performing data analysis...", match: "Data analysis and visualization complete." }
+]
+
+export function ExecutionStatus({ steps, isComplete, className }: ExecutionStatusProps) {
+  if (steps.length === 0) return null
+
+  // Calculate progress based on phase completion
+  const completedCount = PHASE_CONFIG.filter(p => steps.includes(p.match)).length
+  const totalPhases = PHASE_CONFIG.length
+  const progress = Math.min((completedCount / totalPhases) * 100, 100)
+
+  return (
+    <div className={cn("space-y-3 p-3 bg-muted/30 rounded-lg border border-border/50", className)}>
+      <div className="flex items-center justify-between gap-4">
+        <div className="flex-1 h-1.5 bg-muted rounded-full overflow-hidden">
+          <div 
+            className="h-full bg-primary transition-all duration-500 ease-out" 
+            style={{ width: `${isComplete ? 100 : progress}%` }}
+          />
+        </div>
+        <span className="text-[10px] font-medium tabular-nums opacity-60">
+          {isComplete ? "100%" : `${Math.round(progress)}%`}
+        </span>
+      </div>
+
+      <div className="space-y-1.5">
+        {steps.map((step, index) => {
+          const isLast = index === steps.length - 1
+          const isCompletionStep = PHASE_CONFIG.some(p => p.match === step)
+          
+          return (
+            <div 
+              key={index} 
+              className={cn(
+                "flex items-start gap-2 transition-all duration-300",
+                isLast && !isComplete ? "text-xs font-medium opacity-100" : "text-[10px] opacity-50"
+              )}
+            >
+              {isLast && !isComplete && !isCompletionStep ? (
+                <Loader2Icon className="h-3 w-3 mt-0.5 animate-spin text-primary" />
+              ) : (
+                <CheckCircle2Icon className="h-3 w-3 mt-0.5 text-primary opacity-80" />
+              )}
+              <span className="leading-tight">{step}</span>
+            </div>
+          )
+        })}
+      </div>
+    </div>
+  )
+}

frontend/src/components/chat/MessageBubble.tsx

@@ -24,26 +24,6 @@ export function MessageBubble({ message }: MessageBubbleProps) {
             : "bg-primary text-primary-foreground"
         )}
       >
-        {isAssistant && message.steps && message.steps.length > 0 && (
-          <div className="mb-3 space-y-1 border-b border-secondary-foreground/10 pb-2">
-            {message.steps.map((step, index) => {
-              const isLast = index === message.steps!.length - 1
-              return (
-                <div 
-                  key={index} 
-                  className={cn(
-                    "flex items-center gap-2 transition-all duration-300",
-                    isLast ? "text-xs font-medium opacity-80" : "text-[10px] opacity-40"
-                  )}
-                >
-                  <div className={cn("rounded-full bg-current", isLast ? "h-1 w-1" : "h-0.5 w-0.5")} />
-                  {step}
-                </div>
-              )
-            })}
-          </div>
-        )}
-
         <div className="break-words text-sm">
           {isAssistant ? (
             message.content ? (

frontend/src/services/chat.test.ts

@@ -22,14 +22,14 @@ describe("ChatService SSE Parsing", () => {
     const events = ChatService.parseSSEChunk(rawChunk)
     
     expect(events).toHaveLength(2)
-    expect(events[1].data.chunk).toBe(" World")
+    expect(events[1].data!.chunk).toBe(" World")
   })
 
   it("should parse encoded plots from executor node", () => {
     const rawChunk = `data: {"type": "on_chain_end", "name": "executor", "data": {"encoded_plots": ["base64data"]}}\n\n`
     const events = ChatService.parseSSEChunk(rawChunk)
     
-    expect(events[0].data.encoded_plots).toEqual(["base64data"])
+    expect(events[0].data!.encoded_plots).toEqual(["base64data"])
   })
 
   it("should identify the done event", () => {

frontend/src/services/chat.ts

@@ -10,13 +10,26 @@ export interface MessageResponse {
   steps?: string[] // reasoning steps
 }
 
+export interface ConversationResponse {
+  id: string
+  name: string
+  summary?: string
+  created_at: string
+  data_state: string
+}
+
 export interface ChatEvent {
   type: string
   name?: string
   node?: string
   data?: {
     chunk?: { content?: string }
-    output?: { messages?: { content: string }[] }
+    output?: { 
+      messages?: { content: string }[]
+      plots?: string[]
+      dfs?: Record<string, string>
+      summary?: string
+    }
     encoded_plots?: string[]
     message?: string
   }
@@ -47,7 +60,7 @@ export const ChatService = {
         if (!dataStr) continue
         
         try {
-          const event = JSON.parse(dataStr)
+          const event = JSON.parse(dataStr) as ChatEvent
           events.push(event)
         } catch (err) {
           console.error("Failed to parse SSE event JSON:", err, dataStr)
@@ -245,36 +258,37 @@ export const ChatService = {
           }
 
           activeMessages = this.updateMessagesWithEvent(activeMessages, event)
-          onMessageUpdate(activeMessages)
+          onMessageUpdate([...activeMessages])
         }
       }
-    } catch (err: any) {
+    } catch (err: unknown) {
       console.error("Streaming error:", err)
-      if (onError) onError(err.message || "Connection failed")
+      const message = err instanceof Error ? err.message : "Connection failed"
+      if (onError) onError(message)
     }
   },
 
-  async listConversations() {
-    const response = await api.get("/conversations")
+  async listConversations(): Promise<ConversationResponse[]> {
+    const response = await api.get<ConversationResponse[]>("/conversations")
     return response.data
   },
 
-  async createConversation(name: string = "New Conversation") {
-    const response = await api.post("/conversations", { name })
+  async createConversation(name: string = "New Conversation"): Promise<ConversationResponse> {
+    const response = await api.post<ConversationResponse>("/conversations", { name })
     return response.data
   },
 
-  async renameConversation(conversationId: string, name: string) {
-    const response = await api.patch(`/conversations/${conversationId}`, { name })
+  async renameConversation(conversationId: string, name: string): Promise<ConversationResponse> {
+    const response = await api.patch<ConversationResponse>(`/conversations/${conversationId}`, { name })
     return response.data
   },
 
-  async deleteConversation(conversationId: string) {
+  async deleteConversation(conversationId: string): Promise<void> {
     await api.delete(`/conversations/${conversationId}`)
   },
 
-  async getMessages(conversationId: string) {
-    const response = await api.get(`/conversations/${conversationId}/messages`)
+  async getMessages(conversationId: string): Promise<MessageResponse[]> {
+    const response = await api.get<MessageResponse[]>(`/conversations/${conversationId}/messages`)
     return response.data
   }
 }

frontend/src/services/chat_history.test.ts

@@ -1,9 +1,10 @@
 import { describe, it, expect, vi, beforeEach } from "vitest"
 import api from "./api"
 import { ChatService } from "./chat"
+import { AxiosResponse } from "axios"
 
 vi.mock("./api")
-const mockedApi = api as any
+const mockedApi = vi.mocked(api)
 
 describe("ChatService History Management", () => {
   beforeEach(() => {
@@ -12,7 +13,7 @@ describe("ChatService History Management", () => {
 
   it("should list conversations", async () => {
     const mockData = [{ id: "c1", name: "Conv 1" }]
-    mockedApi.get.mockResolvedValueOnce({ data: mockData })
+    mockedApi.get.mockResolvedValueOnce({ data: mockData } as AxiosResponse)
     
     const result = await ChatService.listConversations()
     expect(mockedApi.get).toHaveBeenCalledWith("/conversations")
@@ -21,7 +22,7 @@ describe("ChatService History Management", () => {
 
   it("should create a conversation", async () => {
     const mockData = { id: "c2", name: "New Conv" }
-    mockedApi.post.mockResolvedValueOnce({ data: mockData })
+    mockedApi.post.mockResolvedValueOnce({ data: mockData } as AxiosResponse)
     
     const result = await ChatService.createConversation("New Conv")
     expect(mockedApi.post).toHaveBeenCalledWith("/conversations", { name: "New Conv" })
@@ -30,7 +31,7 @@ describe("ChatService History Management", () => {
 
   it("should rename a conversation", async () => {
     const mockData = { id: "c1", name: "Renamed" }
-    mockedApi.patch.mockResolvedValueOnce({ data: mockData })
+    mockedApi.patch.mockResolvedValueOnce({ data: mockData } as AxiosResponse)
     
     const result = await ChatService.renameConversation("c1", "Renamed")
     expect(mockedApi.patch).toHaveBeenCalledWith("/conversations/c1", { name: "Renamed" })
@@ -38,7 +39,7 @@ describe("ChatService History Management", () => {
   })
 
   it("should delete a conversation", async () => {
-    mockedApi.delete.mockResolvedValueOnce({})
+    mockedApi.delete.mockResolvedValueOnce({} as AxiosResponse)
     
     await ChatService.deleteConversation("c1")
     expect(mockedApi.delete).toHaveBeenCalledWith("/conversations/c1")
@@ -46,7 +47,7 @@ describe("ChatService History Management", () => {
 
   it("should fetch messages", async () => {
     const mockData = [{ id: "m1", content: "Hi" }]
-    mockedApi.get.mockResolvedValueOnce({ data: mockData })
+    mockedApi.get.mockResolvedValueOnce({ data: mockData } as AxiosResponse)
     
     const result = await ChatService.getMessages("c1")
     expect(mockedApi.get).toHaveBeenCalledWith("/conversations/c1/messages")