frontend/src/shared/api/resource-query.ts

import {
	type QueryClient,
	type QueryFunctionContext,
	useQueryClient,
	type UseQueryOptions,
} from "@tanstack/react-query";
import { useEffect } from "react";

import type { components, paths } from "./generated/schema";

import { useAuthenticatedQuery } from "./authenticated-query";
import { getAuthenticatedSessionSnapshot } from "./client";
import { ApiErrorCode, apiErrorCode, isApiErrorCode } from "./problem-details";

type InvestmentResourceMeta = components["schemas"]["InvestmentResourceMetaDto"];

type Resource = {
	[key: string]: unknown;
	data: unknown;
	meta: InvestmentResourceMeta;
	sync?: unknown;
};

type ResourcePath = {
	[P in keyof paths]: paths[P]["get"] extends {
		// eslint-disable-next-line @typescript-eslint/no-magic-numbers -- HTTP success response in the generated contract.
		responses: { 200: { content: { "application/json": Resource } } };
	} ? P : never;
}[keyof paths];

type ResourceQueryKey = readonly [
	"get",
	ResourcePath,
	{ params?: { path?: object; query?: { sync?: "observe" } } }?,
];

function invalidateResourceAccess(
	client: QueryClient,
	group: string,
	error: unknown,
) {
	const errorCode = apiErrorCode(error);
	if (
		[
			ApiErrorCode.Forbidden,
			ApiErrorCode.InvalidTbankToken,
			ApiErrorCode.NotFound,
			ApiErrorCode.TbankNotConnected,
		].every(code => !isApiErrorCode(errorCode, code))
	)
		return;

	const affected = {
		predicate: (cached: { meta?: Record<string, unknown> }) =>
			cached.meta?.accessGroup === group,
	};

	void client.cancelQueries(affected);
	for (const cached of client.getQueryCache().findAll(affected))
		cached.setState({
			data: undefined,
			dataUpdatedAt: 0,
			error: error as Error,
			fetchStatus: "idle",
			status: "error",
		});
}

// Keep endpoint and parameters intact. The generated queryFn accepts the
// optional sync mode even for a cache key originally created without init.
function observationKey<K extends readonly unknown[]>(key: K): K {
	const [method, path, init] = key as unknown as [
		string,
		string,
		{ params?: { path?: object; query?: object } }?,
	];

	return [method, path, {
		...init,
		params: { ...init?.params, query: { ...init?.params?.query, sync: "observe" } },
	}] as unknown as K;
}

// Observation changes transport mode, never the generated cache identity.
function useResourceQuery<
	T extends Resource,
	E = unknown,
	K extends readonly unknown[] = ResourceQueryKey,
>(
	options: UseQueryOptions<T, E, T, K>,
) {
	const client = useQueryClient();

	const group
		= typeof options.meta?.accessGroup === "string"
			? options.meta.accessGroup
			: undefined;

	const query = useAuthenticatedQuery(options);
	useEffect(() => {
		if (group) invalidateResourceAccess(client, group, query.error);
	}, [client, group, query.error]);

	const observe = async () => {
		const queryFunction = options.queryFn;
		if (
			typeof queryFunction !== "function"
			|| !query.isEnabled
			|| !getAuthenticatedSessionSnapshot()
		)
			return;
		// Cancellation is synchronous; start the replacement in the same boundary.
		void client.cancelQueries({ exact: true, queryKey: options.queryKey });

		return client.query({
			...options,
			queryFn: async (context: QueryFunctionContext<K>) => {
				const queryKey = observationKey(context.queryKey);

				return queryFunction({ ...context, queryKey });
			},
			retry: false,
			// Keep the cache envelope independent of observer projection.
			select: undefined,
			staleTime: 0,
		});
	};

	const data: T["data"] | undefined = query.data?.data;
	const meta: T["meta"] | undefined = query.data?.meta;

	// Project resource fields; refetch still returns the transport envelope.
	return {
		data: data ?? undefined,
		error: query.error,
		fetchStatus: query.fetchStatus,
		isEnabled: query.isEnabled,
		isError: query.isError,
		isFetching: query.isFetching,
		isLoading: query.isLoading,
		isPending: query.isPending,
		isSuccess: query.isSuccess,
		meta,
		observe,
		queryKey: options.queryKey,
		refetch: query.refetch,
		status: query.status,
		sync: query.data && "sync" in query.data ? query.data.sync : undefined,
	};
}

export {
	type InvestmentResourceMeta,
	useResourceQuery,
};