import type { CanvasNode } from "@/types/canvas";

export type PendingCanvasAgentTarget = {
  nodeId?: string | null;
  requestedAt?: number | null;
};

const DEFAULT_PENDING_TARGET_MAX_AGE_MS = 10 * 60 * 1000;

function normalizeNodeId(value: unknown) {
  return typeof value === "string" ? value.trim() : "";
}

export function resolvePendingCanvasAgentTargetNode(params: {
  nodes: CanvasNode[];
  pendingTarget?: PendingCanvasAgentTarget | null;
  now?: number;
  maxAgeMs?: number;
  isEligibleNode?: (node: CanvasNode) => boolean;
}) {
  const nodeId = normalizeNodeId(params.pendingTarget?.nodeId);
  if (!nodeId) return null;

  const requestedAt = Number(params.pendingTarget?.requestedAt || 0);
  const now = Number(params.now ?? Date.now());
  const maxAgeMs = Math.max(
    0,
    Number(params.maxAgeMs ?? DEFAULT_PENDING_TARGET_MAX_AGE_MS)
  );
  if (
    Number.isFinite(requestedAt) &&
    requestedAt > 0 &&
    Number.isFinite(now) &&
    now - requestedAt > maxAgeMs
  ) {
    return null;
  }

  const node = params.nodes.find((item) => item.id === nodeId) || null;
  if (!node) return null;
  if (params.isEligibleNode && !params.isEligibleNode(node)) return null;
  return node;
}

export function mergePendingCanvasAgentTargetNodeIds(params: {
  selectedNodeIds: string[];
  pendingTargetNodeId?: string | null;
  maxItems?: number;
}) {
  const maxItems = Math.max(1, Number(params.maxItems || 20));
  return Array.from(
    new Set(
      [
        ...params.selectedNodeIds,
        normalizeNodeId(params.pendingTargetNodeId),
      ].filter(Boolean)
    )
  ).slice(0, maxItems);
}