import type { BrokerageOperation } from "@/entities/broker-operation";
import type {
	BrokerageEvent,
	BrokerageEventsPreviewState,
} from "@/entities/brokerage-event";
import type { IncomeSummary } from "@/entities/income";
import type { InvestmentResourceMeta } from "@/shared/api";

const RECENT_EVENTS_LIMIT = 5;

type AccountPageIncomeSummary
	= | {
		state: "empty"
			| "loading"
			| "partial";
		to: string;
	}
	| { state: "error"; to: string }
	| {
		state: "loaded";
		summary: IncomeSummary;
		to: string;
	}
	;

type AccountPageRecentEvents = BrokerageEventsPreviewState;

type AccountPageRecentOperations
	= | {
		items: BrokerageOperation[];
		lastSuccessfulAt?: null | string;
		refreshError?: boolean;
		stale?: boolean;
		state: "loaded" | "partial";
		to: string;
		totalVisible?: boolean;
	}
	| {
		state: "empty"
			| "error"
			| "loading";
		to: string;
	};

type PreviewResource<T> = {
	data?: T;
	isError: boolean;
	meta?: Pick<InvestmentResourceMeta,
	"availability"
	| "completeness"
	| "freshness"
	| "lastAttempt"
	| "lastSuccessfulAt"
	>;
};

function toIncomeSummary(
	accountId: string | undefined,
	income: PreviewResource<IncomeSummary>,
): AccountPageIncomeSummary {
	const to = `/accounts/${accountId}/income`;
	if (!income.data && !income.isError && income.meta?.lastAttempt.state !== "failed")
		return { state: "loading", to };
	if (income.meta?.completeness === "incomplete") return { state: "partial", to };
	if (!income.data && (income.isError || income.meta?.lastAttempt.state === "failed"))
		return { state: "error", to };
	if (!income.data?.totalsByCurrency.length) return { state: "empty", to };

	return {
		state: "loaded",
		summary: income.data,
		to,
	};
}

function toRecentEvents(
	accountId: string | undefined,
	events: PreviewResource<{ events: BrokerageEvent[] }>,
): AccountPageRecentEvents {
	const to = `/accounts/${accountId}/events`;
	if (!events.data && !events.isError && events.meta?.lastAttempt.state !== "failed")
		return { state: "loading", to };
	if (events.meta?.completeness === "incomplete")
		return {
			items: events.data?.events.slice(0, RECENT_EVENTS_LIMIT) ?? [],
			state: "partial",
			to,
			totalVisible: false,
		};
	if (!events.data && (events.isError || events.meta?.lastAttempt.state === "failed"))
		return { state: "error", to };
	const items = events.data?.events.slice(0, RECENT_EVENTS_LIMIT) ?? [];
	if (items.length === 0) return { state: "empty", to };

	return {
		items,
		state: "loaded",
		to,
		totalVisible: events.meta?.completeness === "complete",
	};
}

function toRecentOperations(
	accountId: string | undefined,
	operations: PreviewResource<{ items: BrokerageOperation[] }>,
): AccountPageRecentOperations {
	const to = `/accounts/${accountId}/operations`;
	if (
		!operations.data
		&& !operations.isError
		&& operations.meta?.lastAttempt.state !== "failed"
	)
		return { state: "loading", to };
	if (operations.meta?.completeness === "incomplete")
		return {
			items: operations.data?.items ?? [],
			state: "partial",
			to,
			totalVisible: false,
		};
	if (
		!operations.data
		&& (operations.isError || operations.meta?.lastAttempt.state === "failed")
	)
		return { state: "error", to };
	if (!operations.data?.items.length) return { state: "empty", to };

	return {
		items: operations.data.items,
		lastSuccessfulAt: operations.meta?.lastSuccessfulAt,
		refreshError:
			operations.isError || operations.meta?.lastAttempt.state === "failed",
		stale: operations.meta?.freshness === "stale",
		state: "loaded",
		to,
		totalVisible: operations.meta?.completeness === "complete",
	};
}

export { toIncomeSummary, toRecentEvents, toRecentOperations };
export type {
	AccountPageIncomeSummary,
	AccountPageRecentEvents,
	AccountPageRecentOperations,
};