import type {
  IconComponent,
  NavItem,
  NavSection,
} from '../../lib/navigation/nav-model';

/** A flattened, navigable destination used by the command palette search. */
export interface SearchItem {
  label: string;
  to: string;
  icon: IconComponent;
  /** Section the destination belongs to (shown as a hint on the right). */
  group: string;
  /** A different Recomaze product: opened in a tab, never pushed at the router. */
  external?: boolean;
}

/** The group a destination falls under when its section has no title. */
const DEFAULT_GROUP = 'General';

/**
 * Flattens the nav tree into the list of navigable destinations for search.
 * Group headers are labels, not destinations, so only the entries under them
 * reach the palette.
 *
 * @param {NavSection[]} sections - Top nav sections
 * @param {NavItem[]} bottom - Utility nav items
 * @returns {SearchItem[]} Every leaf destination with a `to`
 */
export function flattenNav(
  sections: NavSection[],
  bottom: NavItem[]
): SearchItem[] {
  const destinations: SearchItem[] = [];
  const walk = (item: NavItem, group: string): void => {
    if (item.to) {
      destinations.push({
        label: item.label,
        to: item.to,
        icon: item.icon,
        group,
        external: item.external,
      });
    }
    item.children?.forEach(child => walk(child, group));
  };
  sections.forEach(section => {
    section.items.forEach(item => walk(item, section.title || DEFAULT_GROUP));
  });
  bottom.forEach(item => walk(item, DEFAULT_GROUP));
  return destinations;
}

/**
 * The destinations whose label or group contains what was typed; all of
 * them for a blank query.
 *
 * @param {SearchItem[]} items - Every destination
 * @param {string} query - What the merchant typed
 * @returns {SearchItem[]} The matches, in nav order
 */
export function searchNavItems(
  items: SearchItem[],
  query: string
): SearchItem[] {
  const normalizedQuery = query.trim().toLowerCase();
  if (!normalizedQuery) return items;
  return items.filter(
    item =>
      item.label.toLowerCase().includes(normalizedQuery) ||
      item.group.toLowerCase().includes(normalizedQuery)
  );
}