import type { TextureAsset, TextureFrame } from '../model/Asset';
import { findAsset, type Project } from '../model/Project';
import { findFrame } from '../model/texture';

export const NO_TEXTURE_LABEL = 'None';

const FRAME_SEPARATOR = ' / ';

export interface TextureChoice {
  /** Asset id for the whole picture, frame id for one cut-out of it. */
  id: string;
  label: string;
  asset: TextureAsset;
  /** Null for the whole-picture entry. */
  frame: TextureFrame | null;
}

/**
 * The texture's name, "Sheet / Frame" for a frame, "None" for the empty id, `<id>?` when it no
 * longer resolves – a dangling reference shows its id rather than passing for an empty field.
 */
export function textureRefLabel(project: Project | null, id: string): string {
  if (id === '') return NO_TEXTURE_LABEL;
  if (!project) return `${id}?`;
  const asset = findAsset(project, id);
  if (asset) return asset.type === 'texture' ? asset.name : `${id}?`;
  const found = findFrame(project, id);
  return found ? `${found.asset.name}${FRAME_SEPARATOR}${found.frame.name}` : `${id}?`;
}

/**
 * Everything a sprite may wear, in menu order: each texture followed by its own frames. Textures
 * are sorted by name so the order does not depend on upload time; frames keep creation order,
 * which for a sliced sheet is reading order.
 */
export function textureRefChoices(project: Project): TextureChoice[] {
  const textures = project.assets
    .filter((a): a is TextureAsset => a.type === 'texture')
    .sort((a, b) => a.name.localeCompare(b.name));
  const choices: TextureChoice[] = [];
  for (const asset of textures) {
    choices.push({ id: asset.id, label: asset.name, asset, frame: null });
    for (const frame of asset.frames)
      choices.push({
        id: frame.id,
        label: `${asset.name}${FRAME_SEPARATOR}${frame.name}`,
        asset,
        frame,
      });
  }
  return choices;
}