# Error Resolution Log

## Fixed Issues (2023)

### ScreenCaptureKit API Updates
1. SCContentFilter Initialization
   - Fixed by using correct initializer and parameters:
     ```swift
     SCContentFilter(display: display, excludingWindows: [])
     ```
   - Using SCDisplay object directly (not displayID)
   - Correct parameter name: excludingWindows
   - Removed incorrect parameters (includingWindows/exceptingWindows)

2. Stream Output Type
   - Fixed type inference issue by explicit declaration:
     ```swift
     let outputType: SCStreamOutputType = .screen
     try stream.addStreamOutput(self, type: outputType, ...)
     ```
   - Ensures proper type resolution for .screen member

### Required Imports
- Added necessary framework imports:
  * CoreMedia
  * AVFoundation
  * ScreenCaptureKit
  * CoreGraphics
  * AppKit
  * Foundation

### Window Capture Strategy
1. Window Detection
   - Precise window identification:
     ```swift
     let bundleID = window.owningApplication?.bundleIdentifier ?? ""
     let isChessApp = bundleID == "com.chess.iphone"
     let hasValidSize = window.frame.width > 100 && window.frame.height > 100
     return isChessApp && window.isOnScreen && hasValidSize
     ```
   - Multiple validation checks:
     * Exact bundle ID match
     * Window is currently on screen
     * Window has valid dimensions
   - Handles iOS apps running on Mac properly

2. Capture Method
   - Implemented continuous capture:
     ```swift
     // Start once
     try await screenCapture.startCapture()
     
     // Process frames continuously
     while !Task.isCancelled {
         if let image = screenCapture.getCurrentImage() {
             try await processImage(image)
         }
         try await Task.sleep(nanoseconds: 100_000_000)
     }
     ```
   - Maintains single active stream
   - Eliminates capture flickering
   - Proper cleanup on stop

### Thread Safety and Async Handling
1. Main Actor Isolation
   - Added @MainActor to ViewModel class:
     ```swift
     @MainActor
     class ScreenCaptureViewModel: ObservableObject
     ```
   - Ensures all @Published property updates happen on main thread
   - Proper thread safety for SwiftUI bindings

2. Async Operation Handling
   - Optimized async/await usage:
     ```swift
     // Only use await for truly async operations
     try await screenCapture.startCapture()
     try await Task.sleep(nanoseconds: 100_000_000)
     ```
   - Removed unnecessary await keywords:
     * Non-async error handling
     * UI state updates
     * Image processing
   - Proper @MainActor usage for thread safety

3. Task and Error Handling
   - Improved task cancellation:
     ```swift
     captureLoop: while !Task.isCancelled {
         do {
             // Process frame
         } catch is CancellationError {
             break captureLoop
         } catch {
             // Continue capturing on non-critical errors
             await handleCaptureError(error)
         }
     }
     ```
   - Proper error recovery:
     * Continues on board detection failures
     * Shows error state without stopping
     * Clears errors on successful detection
   - Clean error state on stop:
     ```swift
     captureError = nil  // Clear any error when stopping
     ```
   - Proper cleanup on task exit

## Technical Notes
- Resource Management:
  * Shared CIContext to prevent command queue exhaustion:
    ```swift
    private static let shared = CIContext()
    private var context: CIContext { Self.shared }
    ```
  * Prevents "Command queue creation failed" errors
  * Reduces Metal resource usage
  * Proper cleanup on task completion

- Using correct SCContentFilter API with proper parameter names
- Proper type safety throughout the implementation:
  * Proper Vision framework result handling:
     ```swift
     guard let observations = request.results,
           !observations.isEmpty else {
         return nil
     }
     
     let bestObservation = observations[0]
     ```
  * No unnecessary type casting
  * Safe array access
  * Proper optional handling
- Appropriate framework dependencies
- Follows current ScreenCaptureKit best practices