Function prepareContainerDimensions

apps/sim/lib/workflows/autolayout/utils.ts:656–748

(
  blocks: Record<string, BlockState>,
  edges: Edge[],
  layoutFn: LayoutFunction,
  horizontalSpacing: number,
  verticalSpacing: number,
  gridSize?: number
)

 * @param gridSize - Optional grid size for snap-to-grid
 */
export function prepareContainerDimensions(
  blocks: Record<string, BlockState>,
  edges: Edge[],
  layoutFn: LayoutFunction,
  horizontalSpacing: number,
  verticalSpacing: number,
  gridSize?: number
): void {
  const { children } = getBlocksByParent(blocks)

  // Build dependency graph to process nested containers bottom-up
  const containerIds = Array.from(children.keys())
  const containerDepth = new Map<string, number>()

  // Calculate nesting depth for each container
  for (const containerId of containerIds) {
    let depth = 0
    let currentId: string | undefined = containerId
    while (currentId) {
      const block: BlockState | undefined = blocks[currentId]
      const parentId: string | undefined = block?.data?.parentId
      currentId = parentId
      if (currentId) depth++
    }
    containerDepth.set(containerId, depth)
  }

  // Sort containers by depth (deepest first) for bottom-up processing
  const sortedContainerIds = containerIds.sort((a, b) => {
    const depthA = containerDepth.get(a) ?? 0
    const depthB = containerDepth.get(b) ?? 0
    return depthB - depthA
  })

  // Process each container, laying out its children to determine dimensions
  for (const containerId of sortedContainerIds) {
    const container = blocks[containerId]
    if (!container) continue

    const childIds = children.get(containerId) ?? []
    const layoutChildIds = filterLayoutEligibleBlockIds(childIds, blocks)

    if (layoutChildIds.length === 0) {
      // Empty container - use default dimensions
      container.data = {
        ...container.data,
        width: CONTAINER_DIMENSIONS.DEFAULT_WIDTH,
        height: CONTAINER_DIMENSIONS.DEFAULT_HEIGHT,
      }
      container.layout = {
        ...container.layout,
        measuredWidth: CONTAINER_DIMENSIONS.DEFAULT_WIDTH,
        measuredHeight: CONTAINER_DIMENSIONS.DEFAULT_HEIGHT,
      }
      continue
    }

    // Build subset of blocks and edges for this container's children