import { prisma } from '../prisma.js';

/**
 * Get user's favorite apps, ordered by position.
 */
export async function getUserFavorites(userId: string) {
	return prisma.userFavorite.findMany({
		where: { userId },
		orderBy: { order: 'asc' },
		include: {
			app: {
				include: {
					statuses: {
						orderBy: { checkedAt: 'desc' },
						take: 1
					}
				}
			}
		}
	});
}

/**
 * Add an app to user's favorites (append to end).
 */
export async function addFavorite(userId: string, appId: string) {
	// Check if already favorited
	const existing = await prisma.userFavorite.findUnique({
		where: { userId_appId: { userId, appId } }
	});
	if (existing) {
		throw new Error('App is already in favorites');
	}

	// Get the next order value
	const maxFav = await prisma.userFavorite.findFirst({
		where: { userId },
		orderBy: { order: 'desc' },
		select: { order: true }
	});
	const nextOrder = (maxFav?.order ?? -1) + 1;

	return prisma.userFavorite.create({
		data: {
			userId,
			appId,
			order: nextOrder
		},
		include: {
			app: true
		}
	});
}

/**
 * Remove an app from user's favorites.
 */
export async function removeFavorite(userId: string, appId: string) {
	const existing = await prisma.userFavorite.findUnique({
		where: { userId_appId: { userId, appId } }
	});
	if (!existing) {
		throw new Error('App is not in favorites');
	}

	await prisma.userFavorite.delete({
		where: { userId_appId: { userId, appId } }
	});
}

/**
 * Reorder user's favorites by setting order based on array position.
 */
export async function reorderFavorites(userId: string, favoriteIds: string[]) {
	const updates = favoriteIds.map((id, index) =>
		prisma.userFavorite.update({
			where: { id },
			data: { order: index }
		})
	);

	return prisma.$transaction(updates);
}