export interface CompoundMemberLike {
  id: number;
  parentStructure?: number | { id: number } | null;
  constructionStatus?: string | null;
  storageUsedKg?: number | null;
  storageCapacityKg?: number | null;
}

export function compoundParentId(member: CompoundMemberLike): number | null {
  const parent = member.parentStructure;
  if (parent === null || parent === undefined) return null;
  return typeof parent === "object" ? parent.id : parent;
}

export function isOperationalMember(member: CompoundMemberLike): boolean {
  return (member.constructionStatus ?? "complete") === "complete";
}

/**
 * Compound storage pooling: the hub's totals cover itself plus its operational
 * children. Building or awaiting-materials children contribute nothing yet. An
 * uncapped member (null capacity) makes the whole compound uncapped.
 */
export function aggregateCompoundStorage(
  hub: CompoundMemberLike,
  children: CompoundMemberLike[],
): { storageUsedKg: number; storageCapacityKg: number | null } {
  let used = hub.storageUsedKg ?? 0;
  let capacity: number | null = hub.storageCapacityKg ?? null;
  for (const child of children) {
    if (!isOperationalMember(child)) continue;
    used += child.storageUsedKg ?? 0;
    const childCap = child.storageCapacityKg;
    if (childCap === null || childCap === undefined) capacity = null;
    else if (capacity !== null) capacity += childCap;
  }
  return { storageUsedKg: used, storageCapacityKg: capacity };
}