Function assignLayers

apps/sim/lib/workflows/autolayout/core.ts:81–184

(
  blocks: Record<string, BlockState>,
  edges: Edge[],
  subflowDepths?: Map<string, number>
)

 * @param subflowDepths - Optional map of container block IDs to their internal depth (max layers inside)
 */
export function assignLayers(
  blocks: Record<string, BlockState>,
  edges: Edge[],
  subflowDepths?: Map<string, number>
): Map<string, GraphNode> {
  const nodes = new Map<string, GraphNode>()

  for (const [id, block] of Object.entries(blocks)) {
    nodes.set(id, {
      id,
      block,
      metrics: getBlockMetrics(block),
      incoming: new Set(),
      outgoing: new Set(),
      layer: 0,
      position: { ...block.position },
    })
  }

  const incomingEdgesMap = new Map<string, Edge[]>()
  for (const edge of edges) {
    if (!incomingEdgesMap.has(edge.target)) {
      incomingEdgesMap.set(edge.target, [])
    }
    incomingEdgesMap.get(edge.target)!.push(edge)
  }

  for (const edge of edges) {
    const sourceNode = nodes.get(edge.source)
    const targetNode = nodes.get(edge.target)

    if (sourceNode && targetNode) {
      sourceNode.outgoing.add(edge.target)
      targetNode.incoming.add(edge.source)
    }
  }

  const starterNodes = Array.from(nodes.values()).filter((node) => node.incoming.size === 0)

  if (starterNodes.length === 0 && nodes.size > 0) {
    const firstNode = Array.from(nodes.values())[0]
    starterNodes.push(firstNode)
    logger.warn('No starter blocks found, using first block as starter', { blockId: firstNode.id })
  }

  const inDegreeCount = new Map<string, number>()

  for (const node of nodes.values()) {
    inDegreeCount.set(node.id, node.incoming.size)
    if (starterNodes.includes(node)) {
      node.layer = 0
    }
  }

  const queue: string[] = starterNodes.map((n) => n.id)
  const processed = new Set<string>()

  while (queue.length > 0) {