fix(bot): improve autoplay source diversity

CHANGELOG.md

@@ -15,6 +15,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Changed
 
 - **frontend shell/sidebar foundation**: strengthened the Lucky sidebar into a clearer guild command center with a more prominent active guild block, explicit readiness state, stronger nav grouping, and fuller active-route treatment while keeping route structure unchanged.
+- **autoplay diversity tuning**: autoplay recommendation scoring now penalizes same-source tracks more strongly, helping the queue favor varied sources without changing the existing hard caps that prevent refill starvation.
 
 ## [2.6.62] - 2026-04-04
 

packages/bot/src/utils/music/queueManipulation.spec.ts

@@ -65,6 +65,7 @@ type QueueMock = Partial<GuildQueue> & {
     addTrack: jest.Mock
     tracks: { size: number; toArray: jest.Mock }
     guild: { id: string }
+    history?: { tracks: { toArray: jest.Mock } }
 }
 
 function createQueueMock(overrides: Partial<QueueMock> = {}): QueueMock {
@@ -650,6 +651,145 @@ describe('queueManipulation.replenishQueue', () => {
         ).toContain('similar energy')
     })
 
+    it('prefers a different-source candidate when scores are otherwise close', async () => {
+        const queue = createQueueMock({
+            tracks: {
+                size: 0,
+                toArray: jest.fn().mockReturnValue([]),
+            },
+            history: {
+                tracks: {
+                    toArray: jest.fn().mockReturnValue([
+                        {
+                            title: 'History Song 1',
+                            author: 'Same Artist',
+                            url: 'https://example.com/history-1',
+                        },
+                        {
+                            title: 'History Song 2',
+                            author: 'Different Artist',
+                            url: 'https://example.com/history-2',
+                        },
+                    ]),
+                },
+            },
+            currentTrack: {
+                title: 'Alpha Beta Gamma Delta',
+                author: 'Current Artist',
+                url: 'https://example.com/current-diversity',
+                source: 'youtube',
+            } as unknown as Track,
+            player: {
+                search: jest.fn().mockResolvedValue({
+                    tracks: [
+                        {
+                            title: 'Alpha Beta Gamma Delta Remix',
+                            author: 'Same Artist',
+                            url: 'https://example.com/same-source',
+                            source: 'youtube',
+                        },
+                        {
+                            title: 'Unrelated Fresh Cut',
+                            author: 'Different Artist',
+                            url: 'https://example.com/different-source',
+                            source: 'spotify',
+                        },
+                    ],
+                }),
+            },
+        })
+
+        await replenishQueue(queue as unknown as GuildQueue)
+
+        const firstAdded = queue.addTrack.mock.calls[0]?.[0] as Track
+
+        expect(firstAdded).toEqual(
+            expect.objectContaining({
+                url: 'https://example.com/different-source',
+                source: 'spotify',
+                metadata: expect.objectContaining({
+                    recommendationReason:
+                        expect.stringContaining('source variety'),
+                }),
+            }),
+        )
+    })
+
+    it('still selects three tracks when only one source is viable', async () => {
+        const queue = createQueueMock({
+            tracks: {
+                size: 5,
+                toArray: jest.fn().mockReturnValue([
+                    {
+                        title: 'Queued Song 1',
+                        author: 'Queued Artist 1',
+                        url: 'https://example.com/queued-1',
+                    },
+                    {
+                        title: 'Queued Song 2',
+                        author: 'Queued Artist 2',
+                        url: 'https://example.com/queued-2',
+                    },
+                    {
+                        title: 'Queued Song 3',
+                        author: 'Queued Artist 3',
+                        url: 'https://example.com/queued-3',
+                    },
+                    {
+                        title: 'Queued Song 4',
+                        author: 'Queued Artist 4',
+                        url: 'https://example.com/queued-4',
+                    },
+                    {
+                        title: 'Queued Song 5',
+                        author: 'Queued Artist 5',
+                        url: 'https://example.com/queued-5',
+                    },
+                ]),
+            },
+            currentTrack: {
+                title: 'Current Track',
+                author: 'Current Artist',
+                url: 'https://example.com/current-cap',
+                source: 'youtube',
+            } as unknown as Track,
+            player: {
+                search: jest.fn().mockResolvedValue({
+                    tracks: [
+                        {
+                            title: 'Viable One',
+                            author: 'Artist 1',
+                            url: 'https://example.com/viable-1',
+                            source: 'youtube',
+                        },
+                        {
+                            title: 'Viable Two',
+                            author: 'Artist 2',
+                            url: 'https://example.com/viable-2',
+                            source: 'youtube',
+                        },
+                        {
+                            title: 'Viable Three',
+                            author: 'Artist 3',
+                            url: 'https://example.com/viable-3',
+                            source: 'youtube',
+                        },
+                        {
+                            title: 'Viable Four',
+                            author: 'Artist 4',
+                            url: 'https://example.com/viable-4',
+                            source: 'youtube',
+                        },
+                    ],
+                }),
+            },
+        })
+
+        await replenishQueue(queue as unknown as GuildQueue)
+
+        expect(queue.addTrack).toHaveBeenCalledTimes(3)
+    })
+
     it('collects lastfm seed tracks and searches for recommendations', async () => {
         getLastFmSeedTracksMock.mockResolvedValueOnce([
             { artist: 'Radiohead', title: 'Paranoid Android' },

packages/bot/src/utils/music/queueManipulation.ts

@@ -702,7 +702,7 @@ function calculateRecommendationScore(
         score -= 0.25
     }
     if (candidate.source === currentTrack.source) {
-        score -= 0.15
+        score -= 0.25
     } else if (candidate.source) {
         reasons.push('source variety')
     }