import { findAsset, type Project } from './Project';
import { textOf } from './Properties';

/** Mirrors `FontStore::isValidName` on the server, where the name is derived from the bytes. */
const FILE_PATTERN = /^[a-f0-9]{64}\.(ttf|otf|woff|woff2)$/;

export function isFontFile(name: string): boolean {
  return FILE_PATTERN.test(name);
}

/**
 * The CSS family a file is registered under. Derived from the content-addressed name, so the same
 * bytes are always one family and two uploads of one typeface cannot fight over a name – the name
 * inside the font is never used for this, only for the asset's label.
 */
export function fontFamilyOf(file: string): string {
  return `gm-font-${file.slice(0, 16)}`;
}

/**
 * Whether the face a `font` property points at is drawn smoothed, the font asset's Filter row the
 * way it is a texture's. The editor's own typeface, and a dangling id, are smooth.
 */
export function fontSmoothOf(project: Project, id: string): boolean {
  const asset = id === '' ? undefined : findAsset(project, id);
  return asset?.type !== 'font' || textOf(asset.props.filter ?? 'linear') !== 'nearest';
}

/** The file a `font` property points at, empty when the id is unset or no longer resolves. */
export function fontFileOf(project: Project, id: string): string {
  if (id === '') return '';
  const asset = findAsset(project, id);
  return asset?.type === 'font' ? asset.file : '';
}