/**
 * tosu (https://github.com/tosuapp/tosu) reads the osu! tourney client's
 * memory and serves it over a websocket. We need each spectated player's
 * live score, and how far through the map they are.
 */

export interface TosuClientScore {
	osuId: number;
	name: string;
	score: number;
	/** Percent. */
	accuracy: number;
	combo: number;
	failed: boolean;
}

export interface TosuFrame {
	/** 1 idle, 2 waiting for clients, 3 playing, 4 results (tosu's ipcState). */
	ipcState: number | null;
	beatmapId: number | null;
	/** 0–1 through the map. */
	progress: number | null;
	clients: TosuClientScore[];
}

/** Picks what Vash needs out of one tosu v2 message. Returns null outside tourney mode. */
export function parseTosu(message: unknown): TosuFrame | null {
	const root = message as {
		tourney?: {
			ipcState?: number;
			clients?: {
				user?: { id?: number; name?: string };
				play?: {
					score?: number;
					accuracy?: number;
					failed?: boolean;
					combo?: { current?: number };
				};
			}[];
		};
		beatmap?: { id?: number; time?: { live?: number; firstObject?: number; lastObject?: number } };
	};
	if (!root?.tourney || !Array.isArray(root.tourney.clients)) return null;
	const time = root.beatmap?.time;
	const span =
		time && time.lastObject != null && time.firstObject != null
			? time.lastObject - time.firstObject
			: 0;
	return {
		ipcState: root.tourney.ipcState ?? null,
		beatmapId: root.beatmap?.id ?? null,
		progress:
			span > 0 && time?.live != null
				? Math.max(0, Math.min(1, (time.live - time.firstObject!) / span))
				: null,
		clients: root.tourney.clients
			.filter((client) => (client.user?.id ?? 0) > 0)
			.map((client) => ({
				osuId: client.user!.id!,
				name: client.user?.name ?? '',
				score: client.play?.score ?? 0,
				accuracy: client.play?.accuracy ?? 0,
				combo: client.play?.combo?.current ?? 0,
				failed: client.play?.failed ?? false
			}))
	};
}