import { useQueryClient } from "@tanstack/react-query";
import { useParams } from "react-router";
import type { BrokerageOperation } from "@/entities/broker-operation";
import { useBrokerageOperations } from "@/entities/broker-operation";
import {
	type BrokerageAccount,
	brokerageAccountsQueryKey,
} from "@/entities/brokerage-account";
import {
	type BrokerageEvent,
	useBrokerageEvents,
} from "@/entities/brokerage-event";
import type { Portfolio } from "@/entities/portfolio";
import {
	formatMoney,
	formatShare,
	instrumentLogoUrl,
	portfolioErrorCode,
	usePortfolio,
} from "@/entities/portfolio";

type PositionSectionKind = "stocks" | "bonds" | "other";
type AccountPageReturnTone = "positive" | "negative";

type AccountPagePosition = Portfolio["positions"][number] & {
	shareText: string | null;
	returnText: string | null;
	returnTone?: AccountPageReturnTone;
	logoSrc: string | null;
};

type AccountPagePositionSection = {
	kind: PositionSectionKind;
	wide: boolean;
	positions: AccountPagePosition[];
};

type AccountPageRecentOperations =
	| {
			state: "loading" | "error" | "empty";
			to: string;
	  }
	| {
			state: "loaded";
			to: string;
			items: BrokerageOperation[];
	  };

type AccountPageRecentEvents =
	| {
			state: "loading" | "error" | "empty";
			to: string;
	  }
	| {
			state: "loaded";
			to: string;
			items: BrokerageEvent[];
	  };

type AccountPageContent = {
	account?: BrokerageAccount;
	accountId?: string;
	refreshing: boolean;
	refreshError: boolean;
	retry: () => void;
	recentOperations: AccountPageRecentOperations;
	recentEvents: AccountPageRecentEvents;
};

type AccountPageLoadedViewModel = AccountPageContent & {
	state: "loaded";
	portfolio: Portfolio;
	positionSections: AccountPagePositionSection[];
};

type AccountPageEmptyViewModel = AccountPageContent & {
	state: "empty";
};

type AccountPageViewModel =
	| { state: "loading" }
	| { state: "error"; code?: string; retry: () => void }
	| AccountPageEmptyViewModel
	| AccountPageLoadedViewModel;

function useAccountPageViewModel(): AccountPageViewModel {
	const { accountId } = useParams();
	const portfolio = usePortfolio(accountId);
	const operations = useBrokerageOperations(accountId, {
		limit: 5,
	});
	const events = useBrokerageEvents(accountId);
	const account = useQueryClient()
		.getQueryData<BrokerageAccount[]>(brokerageAccountsQueryKey)
		?.find((item) => item.id === accountId);
	const recentOperations = toRecentOperations(accountId, operations);
	const recentEvents = toRecentEvents(accountId, events);
	if (!portfolio.data) {
		if (portfolio.isError)
			return {
				state: "error" as const,
				code: portfolioErrorCode(portfolio.error),
				retry: () => portfolio.refetch(),
			};
		return { state: "loading" as const };
	}
	const refresh = {
		refreshing: portfolio.isFetching,
		refreshError: portfolio.isError,
		retry: () => portfolio.refetch(),
	};
	if (!portfolio.data.positions.length && !portfolio.data.cashBalances.length)
		return {
			state: "empty" as const,
			account,
			accountId,
			recentOperations,
			recentEvents,
			...refresh,
		};
	return {
		state: "loaded" as const,
		account,
		accountId,
		portfolio: portfolio.data,
		positionSections: toAccountPagePositionSections(portfolio.data),
		recentOperations,
		recentEvents,
		...refresh,
	};
}

function toRecentOperations(
	accountId: string | undefined,
	operations: ReturnType<typeof useBrokerageOperations>,
): AccountPageRecentOperations {
	const to = `/accounts/${accountId}/operations`;
	if (operations.isLoading) return { state: "loading", to };
	if (operations.isError) return { state: "error", to };
	if (!operations.data?.items.length) return { state: "empty", to };
	return { state: "loaded", to, items: operations.data.items };
}

function toRecentEvents(
	accountId: string | undefined,
	events: ReturnType<typeof useBrokerageEvents>,
): AccountPageRecentEvents {
	const to = `/accounts/${accountId}/events`;
	if (events.isLoading) return { state: "loading", to };
	if (events.isError) return { state: "error", to };
	const items = events.data?.events.slice(0, 5) ?? [];
	if (!items.length) return { state: "empty", to };
	return { state: "loaded", to, items };
}

function toAccountPagePositionSections(
	portfolio: Portfolio,
): AccountPagePositionSection[] {
	const denominators = new Map<string, number>();
	for (const position of portfolio.positions) {
		if (!position.currentValue) continue;
		const currency = position.currentValue.currency;
		denominators.set(
			currency,
			(denominators.get(currency) ?? 0) + Number(position.currentValue.value),
		);
	}
	const stocks = toSection("stocks", true, portfolio, denominators);
	const bonds = toSection("bonds", true, portfolio, denominators);
	const other = toSection("other", false, portfolio, denominators);
	return [stocks, bonds, other].filter(
		(section) => section.positions.length > 0,
	);
}

function toSection(
	kind: PositionSectionKind,
	wide: boolean,
	portfolio: Portfolio,
	denominators: Map<string, number>,
): AccountPagePositionSection {
	return {
		kind,
		wide,
		positions: portfolio.positions
			.filter((position) => {
				if (kind === "stocks") return position.type === "STOCK";
				if (kind === "bonds") return position.type === "BOND";
				return position.type !== "STOCK" && position.type !== "BOND";
			})
			.map((position) => toPosition(position, denominators, wide)),
	};
}

function toPosition(
	position: Portfolio["positions"][number],
	denominators: Map<string, number>,
	wide: boolean,
): AccountPagePosition {
	const returnValue = position.absoluteReturn
		? Number(position.absoluteReturn.value)
		: null;
	const returnTone =
		returnValue === null || returnValue === 0
			? undefined
			: returnValue > 0
				? "positive"
				: "negative";
	return {
		...position,
		shareText: position.currentValue?.currency
			? formatShare(position.currentValue, {
					currency: position.currentValue.currency,
					value: String(denominators.get(position.currentValue.currency) ?? 0),
				})
			: null,
		returnText: position.absoluteReturn
			? `${wide && returnValue !== null && returnValue > 0 ? "+" : ""}${formatMoney(position.absoluteReturn)}`
			: null,
		returnTone,
		logoSrc: wide ? instrumentLogoUrl(position.logoName) : null,
	};
}

export {
	type AccountPagePosition,
	type AccountPagePositionSection,
	type AccountPageRecentEvents,
	type AccountPageRecentOperations,
	toAccountPagePositionSections,
	useAccountPageViewModel,
};