import { useCallback, useState } from "react";

import type { AppEntry } from "./menuEntries.js";

/**
 * Tracks the favorite state the user has changed while the menu is open.
 *
 * The changes are applied optimistically on top of the article rows and rolled
 * back if the handler rejects. The overrides are kept for the lifetime of the
 * menu, since the article list is only loaded the first time it is opened and
 * would otherwise show a stale state the second time around.
 */
export function useFavorites(onToggleFavorite?: (id: string, favorite: boolean) => void | Promise<unknown>) {
	let [overrides, setOverrides] = useState<Record<string, boolean>>({});

	let applyOverrides = useCallback(
		(entries: AppEntry[]) => {
			if (Object.keys(overrides).length === 0) return entries;

			return entries.map((entry) => (entry.id in overrides ? { ...entry, isFavorite: overrides[entry.id] } : entry));
		},
		[overrides],
	);

	let toggleFavorite = useCallback(
		async (id: string, favorite: boolean) => {
			setOverrides((current) => ({ ...current, [id]: favorite }));

			try {
				await onToggleFavorite?.(id, favorite);
			} catch (error) {
				console.error(error);
				setOverrides((current) => ({ ...current, [id]: !favorite }));
			}
		},
		[onToggleFavorite],
	);

	return { applyOverrides, toggleFavorite: onToggleFavorite ? toggleFavorite : undefined };
}