import type { Asset } from './Asset';
import { ASSET_TYPE_LABELS, isPlaceableType } from './AssetTypes';
import { containerReaches } from './container';
import type { ObjectHolder, Project } from './Project';

/**
 * Why `asset` cannot be placed into `holder`, or '' when it can. A drag needs the answer while
 * it hovers, `PlaceAssetCommand` needs it at the drop; both ask here so the preview cannot
 * promise a placement the command then refuses.
 */
export function placementRejection(project: Project, holder: ObjectHolder, asset: Asset): string {
  // A pattern or a sound is dragged out of the panel for a song (#334), and may pass over a scene.
  if (!isPlaceableType(asset.type))
    return `A ${ASSET_TYPE_LABELS[asset.type].toLowerCase()} cannot be placed into a scene`;
  if (asset.type === 'container' && containerReaches(project, asset, holder.id))
    return `${asset.name} cannot contain ${holder.name}: that nests forever`;
  if (asset.type === 'composition' && holder.type === 'composition')
    return 'A composition cannot be placed into a composition';
  return '';
}