import { RatingType as RatingTypeSchema } from '@generated/types';
import { Descendant, Text } from 'slate';
import { IdentityContext } from './identity';

export function ensureIdentity(
  identity: IdentityContext['identity']
): asserts identity is NonNullable<IdentityContext['identity']> {
  if (identity == null) throw new Error('Unauthorized.');
}

export function countWords(descendants: Descendant[]): number {
  let wordCount = 0;

  function traverse(nodes: Descendant[]) {
    for (const node of nodes) {
      if (Text.isText(node)) {
        const words = node.text.trim().split(/\s+/).filter(Boolean);
        wordCount += words.length;
      } else if ('children' in node) {
        traverse(node.children);
      }
    }
  }

  traverse(descendants);
  return wordCount;
}

export function ensureRatingType(value: string): asserts value is RatingTypeSchema {
  if (value === RatingTypeSchema.Up) return;
  if (value === RatingTypeSchema.Down) return;

  throw new Error('Invalid rating type');
}