# Vibe Coding Design Docs: Workspace/Artifact Split-Screen Pattern

## 1. Context & Objective
The goal is to implement a UI/UX pattern similar to **Claude Artifacts** or **Gemini Deep Research**. When a specific complex task is triggered (e.g., "Project Planning Skill"), the single-column chat interface should smoothly transition into a split-screen layout:
- **Left Panel (35%)**: Conversational context, CoT (Chain of Thought) traces, tool calls, and user input.
- **Right Panel (65%)**: A dedicated "Workspace" or "Artifact" rendering area to display long-form content (Markdown, code, diagrams) generated by the Agent's skills.

Crucially, this system must support **Reflexion/Iterative generation**. The user can comment on the generated artifact in the left panel, and the agent should update the artifact in the right panel based on the feedback.

---

## 2. Frontend Implementation Guide (React + Vite + Tailwind)

### 2.1 State Management (State & Types)
Extend the existing frontend state to track the workspace status and content.

```typescript
// 1. Extend the StreamEvent type to support UI control and artifact streaming
type StreamEvent = {
  type: 
    | "thought" 
    | "tool_call" 
    | "tool_result" 
    | "message"          // Standard chat message
    | "error"
    | "workspace_start"  // Trigger right panel open
    | "workspace_delta"  // Streaming text for the right panel
    | "workspace_end";   // Streaming completed
  content: string;
  step?: number;
  tool_name?: string;
  workspace_title?: string; // Optional title for the artifact
};

// 2. Add Workspace State (Can be added to useReducer or a separate useState)
type WorkspaceState = {
  isOpen: boolean;
  title: string;
  content: string;
  isGenerating: boolean;
};
```

### 2.2 SSE Parsing Logic
Modify the `onEvent` handler inside `streamChat` to intercept `workspace_*` events.
- When `workspace_start` arrives: Set `workspace.isOpen = true`, clear previous content, set `isGenerating = true`.
- When `workspace_delta` arrives: Append text to `workspace.content`. Do **not** append this text to the left-panel chat history to avoid redundancy.
- When `workspace_end` arrives: Set `isGenerating = false`.

### 2.3 Layout & UI Re-architecture
Refactor the root `<div>` of `PlanningAgent.tsx` to handle dynamic flex layouts. Use Tailwind's transition utilities for smooth scaling.

```tsx
<div className="flex h-full w-full overflow-hidden bg-surface">
  
  {/* Left Panel: Chat & Controls */}
  <div 
    className={`flex flex-col h-full transition-all duration-300 ease-in-out ${
      workspace.isOpen ? 'w-[35%] border-r border-border min-w-[350px]' : 'w-full max-w-5xl mx-auto'
    }`}
  >
      {/* Existing Message List & Input Area */}
  </div>

  {/* Right Panel: Workspace / Deep Research Output */}
  {workspace.isOpen && (
    <div className="w-[65%] h-full flex flex-col bg-surface-muted transition-opacity duration-300 animate-fade-in">
       {/* Header */}
       <div className="h-14 border-b border-border flex items-center px-6 justify-between bg-white">
          <h3 className="font-semibold text-txt flex items-center gap-2">
            <IconDocument /> {workspace.title || 'Project Planning Document'}
          </h3>
          {workspace.isGenerating && (
             <span className="text-sm text-magenta animate-pulse flex items-center gap-1">
               <Spinner /> Generating...
             </span>
          )}
       </div>
       {/* Markdown Content Area */}
       <div className="flex-1 overflow-y-auto p-8 prose prose-slate max-w-none">
          <ReactMarkdown remarkPlugins={[remarkGfm]} rehypePlugins={[rehypeRaw]}>
            {workspace.content}
          </ReactMarkdown>
       </div>
    </div>
  )}
</div>
```

---

## 3. Backend Implementation Guide (Agent / ReAct Loop)

The backend agent requires structural changes to understand the "Artifact" concept, emit correct SSE events, and maintain the artifact in its memory for iterative edits.

### 3.1 Tool / Skill Definition
When defining the `Project Planning Skill` for the LLM, clearly state its output behavior so the LLM knows *when* to use it.
- **Tool Description**: `use_planning_workspace`: "Invoke this tool to generate, structure, or update a major project planning document. The output will be rendered in a dedicated UI workspace."

### 3.2 Context Injection (Memory for Reflexion)
To allow the user to say *"extend the testing phase to 2 weeks"*, the LLM **must know what is currently in the right panel**.
- **Before sending the prompt to the LLM**, query the database/session for the current Artifact state.
- **Prompt Assembly**:
  ```text
  [System Prompt / ReAct Instructions]
  ...
  
  [Current Workspace Artifact (if exists)]
  <workspace>
  # Project Plan
  1. Dev Phase: 1 week
  2. Testing Phase: 1 week
  </workspace>

  [Chat History]
  User: extend the testing phase to 2 weeks.
  ```

### 3.3 Streaming Control (Hijacking the Stream)
Within the ReAct execution loop, when the Agent decides to execute the `Project Planning Skill`:
1. The Backend normally streams `thought` or `tool_call` events.
2. Upon entering the specific Skill execution, the backend emits `{"type": "workspace_start", "workspace_title": "Update: Project Plan"}`.
3. As the LLM (or a sub-agent) generates the Markdown schema, the backend maps these tokens to `workspace_delta` events and flushes them to the frontend.
4. (CRITICAL) Do **not** send these tokens as `message` or `final` chat events. The chat bubble should only say something like: *"I have updated the project plan in the workspace area."*
5. Save the final generated Markdown text into the session memory as the `Current Artifact` for future context injection.

---

## 4. Work Flow Summary (For LLM context generation)

1. `User` sends prompt: "Plan the new feature".
2. `Agent` thinks (`type: thought`), decides to use `Project Planning Skill` (`type: tool_call`).
3. `Agent` emits `{"type": "workspace_start"}`.
4. `Frontend` expands right panel (65% width).
5. `Agent` streams `{"type": "workspace_delta", "content": "..."}`.
6. `Frontend` live-renders Markdown in the right panel.
7. `Agent` finishes, saves artifact to backend session.
8. `User` reads right panel, types in left panel: "Change point 2".
9. `Agent` receives Left Panel history + Right Panel Artifact Content.
10. `Agent` updates document, streaming new `workspace_delta`. Frontend live-updates the right panel.