import type { Node, Edge } from '@xyflow/react';
import type { DiagramDocument, DiagramEdge, DiagramNode, NodeKind } from './types';

/**
 * React Flow's runtime Node/Edge carry UI-only fields (measured, selected,
 * dragging, zIndex, ...). Only this subset gets persisted.
 */
export function serializeDocument(nodes: Node[], edges: Edge[]): DiagramDocument {
  return {
    nodes: nodes.map(
      (node): DiagramNode => ({
        id: node.id,
        type: (node.type ?? 'task') as NodeKind,
        position: { x: node.position.x, y: node.position.y },
        data: node.data as DiagramNode['data'],
      }),
    ),
    edges: edges.map(
      (edge): DiagramEdge => ({
        id: edge.id,
        source: edge.source,
        target: edge.target,
        type: edge.type,
        data: edge.data as DiagramEdge['data'],
      }),
    ),
  };
}

export function debounce<Args extends unknown[]>(fn: (...args: Args) => void, delayMs: number) {
  let timer: ReturnType<typeof setTimeout> | undefined;
  return (...args: Args) => {
    if (timer) clearTimeout(timer);
    timer = setTimeout(() => fn(...args), delayMs);
  };
}