1  # Playback State Duplication Issue
 2  
 3  ## Problem
 4  
 5  The current codebase has a design issue where video playback state is managed in multiple places:
 6  
 7  1. The VideoController maintains a `playbackState` object
 8  2. The UIManager needs to know about playback state to update the UI
 9  3. The InteractionHandler needs to know about playback state to handle user interactions
10  4. The VideoSwitcher needs to know about playback state to handle video switching
11  
12  This duplication leads to synchronization issues and makes the code harder to maintain.
13  
14  ## Impact
15  
16  - Playback state may become inconsistent across components
17  - UI may not accurately reflect the actual playback state
18  - User interactions may be handled incorrectly based on playback state
19  - Difficult to debug due to state being spread across multiple components
20  
21  ## Current Implementation
22  
23  Currently, we're using events to synchronize playback state across components:
24  
25  1. VideoController publishes events like PLAYBACK_STARTED, PLAYBACK_PAUSED, PLAYBACK_ENDED
26  2. Other components subscribe to these events to update their internal state
27  3. Components query their local state to make decisions
28  
29  This approach works but is fragile and error-prone.
30  
31  ## Recommended Solution
32  
33  For future refactoring:
34  
35  1. **Single Source of Truth**: Keep playback state only in the VideoController
36  2. **Dependency Injection**: Inject the VideoController into components that need it
37  3. **Observer Pattern**: Components observe the VideoController for state changes
38  4. **No Local Copies**: Components should not maintain their own copies of the state
39  
40  ## Implementation Notes
41  
42  - The VideoController already has a `playbackState` object that could be exposed through getter methods
43  - Components should call methods like `isPlaying()`, `getCurrentTime()`, etc. directly on the VideoController
44  - Events should still be emitted for UI updates, but state should be queried from the VideoController
45  - This would simplify the code and reduce the risk of state inconsistencies