feat: enhance discovery, vibe sessions, and library enrichment

frontend/src/services/vibeService.ts

@@ -1,4 +1,5 @@
 import api from './api';
+import axios from 'axios';
 import type { Track } from '../types';
 
 // A candidate from the v2 recommendation plan. The plan is stored server-side
@@ -21,6 +22,13 @@ export interface VibeNextResponse {
   planRemaining: number;
 }
 
+export type VibeBatchStatus = 'complete' | 'exhausted' | 'failed';
+
+export interface VibeBatchResult {
+  tracks: Track[];
+  status: VibeBatchStatus;
+}
+
 export type VibeFeedbackAction = 'completed' | 'skipped' | 'promoted' | 'disliked';
 
 // V2 recommendation engine. The backend stores the plan in Redis (2h TTL) and
@@ -35,16 +43,16 @@ export const vibeService = {
   // GET /api/v2/vibe/next -> { track, explanation, planRemaining }
   // Returns one track at a time, shifting the server-side plan.
   // 404 if no active plan — caller should handle gracefully.
-  async next(): Promise<VibeNextResponse> {
-    const res = await api.get<VibeNextResponse>('/v2/vibe/next');
+  async next(sessionId: string): Promise<VibeNextResponse> {
+    const res = await api.get<VibeNextResponse>('/v2/vibe/next', { params: { sessionId } });
     return res.data;
   },
 
   // POST /api/v2/vibe/feedback { trackId, action } -> { status, planRemaining }
   // Action 'promoted' also calls addFavorite; 'disliked' also calls dislikeTrack.
   // Triggers replan of the remaining plan.
-  async feedback(trackId: string, action: VibeFeedbackAction): Promise<{ status: string; planRemaining: number }> {
-    const res = await api.post<{ status: string; planRemaining: number }>('/v2/vibe/feedback', { trackId, action });
+  async feedback(trackId: string, action: VibeFeedbackAction, sessionId?: string): Promise<{ status: string; planRemaining: number }> {
+    const res = await api.post<{ status: string; planRemaining: number }>('/v2/vibe/feedback', { trackId, action, sessionId });
     return res.data;
   },
 
@@ -58,16 +66,23 @@ export const vibeService = {
 
 // Fetch N tracks from the v2 plan sequentially. Each call to /next shifts the
 // server-side plan, so calls must be sequential (not parallel). Stops early on
-// 404 (plan exhausted or expired).
-export async function fetchNextBatch(count: number): Promise<Track[]> {
+// 409/VIBE_PLAN_EXHAUSTED is a normal terminal condition. A missing/replaced
+// session is intentionally reported as a failure so callers can preserve the
+// current playback state rather than pretending the plan completed cleanly.
+export async function fetchNextBatch(count: number, sessionId: string): Promise<VibeBatchResult> {
   const tracks: Track[] = [];
   for (let i = 0; i < count; i++) {
     try {
-      const { track } = await vibeService.next();
+      const { track } = await vibeService.next(sessionId);
       tracks.push(track);
-    } catch {
-      break;
+    } catch (error) {
+      return {
+        tracks,
+        status: axios.isAxiosError(error) && error.response?.status === 409 &&
+          (error.response.data as { code?: string } | undefined)?.code === 'VIBE_PLAN_EXHAUSTED'
+          ? 'exhausted' : 'failed',
+      };
     }
   }
-  return tracks;
+  return { tracks, status: 'complete' };
 }