import { useState } from "react";
import { useParams } from "react-router";

import type { InvestmentResourceMeta } from "@/shared/api";

import {
	type BrokerageEvent,
	useBrokerageEvents,
} from "@/entities/brokerage-event";
import { useScreenSync } from "@/features/tbank-connection";
import {
	defaultPeriod,
	isValidPeriod,
	moscowDate,
	useInitialAvailability,
	useUrlPeriod,
} from "@/shared/lib";

type AccountEventsPageViewModel
	= | {
		canApply: boolean;
		draftPeriod: [null | string, null | string];
		events: BrokerageEvent[];
		maxDate: string;
		onApply: () => void;
		onPeriodChange: (value: [null | string, null | string]) => void;
		onPeriodPopoverOpen: () => void;
		onReset: () => void;
		partial?: boolean;
		source?: InvestmentResourceMeta;
		state: "loaded";
	}
	| { onReset: () => void; state: "error" }
	| { state: "loading" };

function useAccountEventsPageViewModel(): AccountEventsPageViewModel {
	const { accountId = "" } = useParams();

	const {
		from: appliedFrom,
		setParameters: setSearchParameters,
		to: appliedTo,
	} = useUrlPeriod();

	const [draftPeriod, setDraftPeriod] = useState<[
		null | string,
		null | string,
	]>([appliedFrom, appliedTo]);

	const [draftFrom, draftTo] = draftPeriod;

	const [maxDate, setMaxDate] = useState(() => moscowDate(new Date()));

	const scope = JSON.stringify([accountId, appliedFrom, appliedTo]);
	const [previousScope, setPreviousScope] = useState(scope);

	if (previousScope !== scope) {
		setPreviousScope(scope);
		setDraftPeriod([appliedFrom, appliedTo]);
	}

	const events = useBrokerageEvents(accountId, {
		...(appliedFrom && { from: appliedFrom }),
		...(appliedTo && { to: appliedTo }),
	});

	useScreenSync(
		{
			accountId,
			screen: "events",
			...(appliedFrom && { from: appliedFrom }),
			...(appliedTo && { to: appliedTo }),
		},
		[events],
	);

	const availability = useInitialAvailability({
		hasContent: !!events.data,
		identity: scope,
		isError: events.isError || events.meta?.lastAttempt.state === "failed",
		isFetching: events.isFetching,
	});

	if (availability === "loading" && events.isLoading)
		return { state: "loading" };

	const onReset = () => {
		setDraftPeriod([appliedFrom, appliedTo]);
		setSearchParameters({});
	};

	if ((events.isError || events.meta?.lastAttempt.state === "failed") && !events.data)
		return {
			onReset,
			state: "error",
		};
	if (!events.data)
		return availability === "unavailable"
			? { onReset, state: "error" }
			: { state: "loading" };

	return {
		canApply:
			(draftFrom !== appliedFrom || draftTo !== appliedTo)
			&& isValidPeriod(draftFrom, draftTo),
		draftPeriod,
		events: events.data.events,
		maxDate,
		onApply: () => {
			if (!isValidPeriod(draftFrom, draftTo)) return;
			setSearchParameters({
				...(draftFrom && { from: draftFrom }),
				...(draftTo && { to: draftTo }),
			});
		},
		onPeriodChange: value => setDraftPeriod(
			value[0] === null && value[1] === null ? defaultPeriod() : value,
		),
		onPeriodPopoverOpen: () => setMaxDate(moscowDate(new Date())),
		onReset,
		partial: events.meta?.completeness === "incomplete",
		source: events.meta,
		state: "loaded",
	};
}

export { type AccountEventsPageViewModel, useAccountEventsPageViewModel };