import {
	type BrokerageAccountCard,
	brokerageAccountCards,
	useBrokerageAccounts,
} from "@/entities/brokerage-account";
import { useScreenSync } from "@/features/tbank-connection";
import {
	ApiErrorCode,
	apiErrorCode,
	isApiErrorCode,
	readRetry,
} from "@/shared/api";
import { useInitialAvailability } from "@/shared/lib";

type AccountsPageReadRetry = ReturnType<typeof readRetry>;

type AccountsPageViewModel
	= | {
		accounts: BrokerageAccountCard[];
		meta: NonNullable<ReturnType<typeof useBrokerageAccounts>["meta"]>;
		readRetry: AccountsPageReadRetry;
		state: "loaded";
	}
	| { code?: string; readRetry: AccountsPageReadRetry; state: "error" }
	| { state: "empty" }
	| { state: "loading" };

function isAccountsAccessFailure(code?: string) {
	return isApiErrorCode(code, ApiErrorCode.InvalidTbankToken)
		|| isApiErrorCode(code, ApiErrorCode.TbankNotConnected);
}

function useAccountsPageVm(): AccountsPageViewModel {
	const accounts = useBrokerageAccounts();
	useScreenSync({ screen: "accounts" }, [accounts]);

	const code = apiErrorCode(accounts.error);
	const retry = readRetry([accounts]);
	const isAccessFailure = isAccountsAccessFailure(code);

	const hasResult = !!accounts.data
		&& !!accounts.meta
		&& !(accounts.meta.completeness === "incomplete" && accounts.data.length === 0);

	const availability = useInitialAvailability({
		hasContent: hasResult,
		identity: "accounts",
		isError: accounts.isError || accounts.meta?.lastAttempt.state === "failed",
		isFetching: accounts.isFetching,
	});

	if (isAccessFailure)
		return { code, readRetry: retry, state: "error" as const };

	if (!hasResult || !accounts.data)
		return availability === "unavailable"
			? { code, readRetry: retry, state: "error" as const }
			: { state: "loading" as const };

	if (accounts.data.length === 0)
		return {
			state: "empty" as const,
		};

	const meta = accounts.meta;
	if (!meta) return { state: "loading" as const };

	return {
		accounts: brokerageAccountCards(accounts.data, meta.dependencies),
		meta,
		readRetry: retry,
		state: "loaded" as const,
	};
}

export { useAccountsPageVm };