import type { Channel } from '@/api/types';

export interface ChannelGroup {
  category: Channel | null;
  channels: Channel[];
}

/**
 * Группирует комнаты по категориям, сохраняя порядок `position`.
 * Невидимые комнаты (`can_view === false`) сервер обычно не присылает,
 * но если прислал — прячем их на клиенте.
 */
export function groupChannels(channels: Channel[]): ChannelGroup[] {
  const visible = channels
    .filter((channel) => channel.can_view !== false && channel.type !== 'category')
    .slice()
    .sort((left, right) => left.position - right.position);
  const categories = channels
    .filter((channel) => channel.type === 'category')
    .slice()
    .sort((left, right) => left.position - right.position);

  const groups: ChannelGroup[] = [];
  const uncategorized = visible.filter((channel) => channel.parent_id === undefined);
  if (uncategorized.length > 0) {
    groups.push({ category: null, channels: uncategorized });
  }
  for (const category of categories) {
    const children = visible.filter((channel) => channel.parent_id === category.id);
    if (children.length > 0) {
      groups.push({ category, channels: children });
    }
  }
  return groups;
}