feat: implement asset refresh scheduling for playlists - #499

This pull request refactors how playlist manifest URL refreshes are handled, moving the refresh logic from the backend to the frontend. The player now schedules a manifest refetch before the signed URL expires, ensuring uninterrupted playback without relying on backend event listeners or actions. Several backend files and tests related to the old refresh mechanism are removed, and new frontend logic and tests are added to handle the refresh process.

Frontend: Manifest Refresh Scheduling

• Added scheduleAssetRefresh and cancelAssetRefresh to usePlaylist, which schedule and cancel a timer to reload the playlist before the manifest URL expires. The timer uses the new asset_refresh_in property from the backend. (resources/js/composables/playlist.ts, resources/js/composables/playlist.tsR2-R22)
• Updated useShaka to call scheduleAssetRefresh when loading a playlist and cancelAssetRefresh on reset, ensuring the manifest is refreshed at the correct time during playback. (resources/js/composables/shaka.ts, [1] [2] [3] [4]
• Added comprehensive tests for the new refresh logic, including timer scheduling, cancellation, and ensuring reloads occur as expected. (resources/js/__tests__/composables/playlist.test.ts, [1] [2]

Backend: Supporting Data and Cleanup

• Added getUrlRefreshIn to the Playlist model and exposed it as asset_refresh_in in the API resource, providing the frontend with the correct refresh interval. (src/Domain/Playlists/Models/Playlist.php, [1]; src/App/Api/Playlists/Resources/PlaylistResource.php, [2]
• Removed the backend manifest refresh action, event listener, and related feature tests, as this logic is now handled on the frontend. (src/Domain/Playlists/Actions/RefreshPlaylistManifest.php, [1]; src/Domain/Playlists/Listeners/RefreshExpiringPlaylistManifest.php, [2]; tests/Feature/Playlist/RefreshPlaylistManifestTest.php, [3]; tests/Feature/Playlist/RefreshExpiringPlaylistManifestTest.php, [4]

Configuration and Documentation

• Updated the manifest refresh configuration comment for clarity, reflecting the new frontend-based approach. (config/playlists.php, config/playlists.phpL83-R85)

Testing

• Added unit tests for the new getUrlRefreshIn method to ensure correct calculation and clamping at zero. (tests/Feature/Playlist/PlaylistTest.php, tests/Feature/Playlist/PlaylistTest.phpR136-R153)

These changes simplify the manifest refresh flow, reduce backend complexity, and ensure the player always has a valid manifest URL for uninterrupted playback.