{
  "context": "Tests whether the agent implements efficient async image loading in a UICollectionView using ImageIO downsampling (or byPreparingThumbnail), correct cell-reuse Task cancellation, NSCache costed by decoded bytes, UICollectionView.CellRegistration stored as a property, and UICollectionViewDiffableDataSource with stable UUIDs.",
  "type": "weighted_checklist",
  "checklist": [
    {
      "name": "ImageIO downsampling",
      "description": "Uses CGImageSourceCreateThumbnailAtIndex (from ImageIO framework) OR byPreparingThumbnail(ofSize:) — does NOT use UIImage(contentsOfFile:)/UIImage(named:) followed by a separate resize/draw step",
      "max_score": 14
    },
    {
      "name": "Display-size thumbnail",
      "description": "The thumbnail is requested or created at the cell's display size (e.g. cell bounds or a fixed pixel dimension), not at the full original image resolution",
      "max_score": 10
    },
    {
      "name": "Task cancellation in prepareForReuse",
      "description": "PhotoCell overrides prepareForReuse and cancels the image-loading Task (calls task.cancel() or similar) inside that override",
      "max_score": 14
    },
    {
      "name": "Image cleared in prepareForReuse",
      "description": "prepareForReuse sets the image view's image to nil (or clears it) before cancellation",
      "max_score": 8
    },
    {
      "name": "Identity check before setting image",
      "description": "After the async load completes, the code verifies the cell still corresponds to the same photo (e.g. checks a stored URL, ID, or tag) before assigning the image to the image view — preventing stale images in recycled cells",
      "max_score": 12
    },
    {
      "name": "NSCache cost = decoded bytes",
      "description": "When inserting into NSCache, the cost argument is computed from pixel dimensions × 4 (e.g. width * height * 4 or cgImage.bytesPerRow * cgImage.height), NOT from data.count or file size",
      "max_score": 10
    },
    {
      "name": "CellRegistration stored property",
      "description": "UICollectionView.CellRegistration is stored as a property (e.g. lazy var or let) on the view controller or data source — it is NOT created inside the cell provider closure",
      "max_score": 10
    },
    {
      "name": "DiffableDataSource with UUID identifiers",
      "description": "Uses UICollectionViewDiffableDataSource keyed by UUID (or another stable scalar ID), not by the full model struct",
      "max_score": 10
    },
    {
      "name": "No string-based cell dequeue",
      "description": "Does NOT use register(_:forCellWithReuseIdentifier:) or dequeueReusableCell(withReuseIdentifier:for:) — uses dequeueConfiguredReusableCell(using:for:item:) from CellRegistration instead",
      "max_score": 12
    }
  ]
}