// The reactive room a page shows: the seat this browser holds (or the
// gallery), the table, the talk, and the game's view. It knows the game only
// through GameSpec.

import { game } from '$lib/game';
import { SPECTATOR, type SeatId, type TableOptions } from '$lib/game/spec';
import type { Input, State } from '$lib/game';
import { makeApi, rememberSeat, watchRoom, type HeldSeat } from './client';
import { markTalkSeen } from './talk';
import type { RoomView } from './view';

export const api = makeApi<State, Input>();
export const NAME_MAX = 24;
const NAME_KEY = '__SLUG__:name';

export function playerName(): string {
	try {
		return localStorage.getItem(NAME_KEY) ?? '';
	} catch {
		return '';
	}
}

export function rememberName(raw: string): void {
	const name = raw.trim().slice(0, NAME_MAX);
	try {
		if (name) localStorage.setItem(NAME_KEY, name);
		else localStorage.removeItem(NAME_KEY);
	} catch {
		// The name still applies to this visit.
	}
}

/** "Ysolde", "Ysolde and Grey", "Ysolde, Grey and Ormund". */
function listText(names: string[]): string {
	if (names.length <= 1) return names[0] ?? '';
	return `${names.slice(0, -1).join(', ')} and ${names[names.length - 1]}`;
}

export class Room {
	view = $state<RoomView<State>>(null!);
	token: string;
	connected = $state(false);
	error = $state('');
	/** A move is on its way to the server. */
	sending = $state(false);

	constructor(view: RoomView<State>, token: string) {
		this.view = view;
		this.token = token;
	}

	me = $derived(this.view.me);
	roomId = $derived(this.view.roomId);
	/** Watching from the gallery, with no seat at the table. */
	spectating = $derived(this.view.me === SPECTATOR);
	started = $derived(this.view.state !== null);
	state = $derived(this.view.state);
	isHost = $derived(!this.spectating && this.view.host === this.view.me);
	others = $derived(this.view.seats.filter((s) => s.id !== this.me));
	/** Your move is in and the round waits on someone else. */
	moved = $derived(this.started && !this.view.over && !this.spectating && !this.view.waitingOn.includes(this.me));
	/** Names of the seats the round is waiting on, yours aside. */
	awaiting = $derived(this.view.waitingOn.filter((id) => id !== this.me).map((id) => this.nameOf(id)));
	awaitingText = $derived(listText(this.awaiting));
	/** A chair at the table is empty, held for someone or not. */
	seatEmpty = $derived(!this.started && this.view.seats.length < this.view.size);
	/** An empty chair not held for anyone: a stranger may sit. */
	seatUnheld = $derived(this.seatEmpty && this.view.seats.length + this.view.expected.length < this.view.size);

	nameOf(id: SeatId): string {
		return this.view.seats.find((s) => s.id === id)?.name ?? (this.view.state ? game.nameOf(this.view.state, id) : id);
	}

	apply(view: RoomView<State>): void {
		this.view = view;
		markTalkSeen(view.roomId, view.chat.length);
	}

	/** Fetch the view now, and keep fetching whenever the server says something changed. */
	connect(): () => void {
		const fetchView = () => (this.spectating ? api.watch(this.roomId) : api.view(this.roomId, this.token));
		const refresh = () => {
			fetchView()
				.then((v) => this.apply(v))
				.catch((e: Error) => (this.error = e.message));
		};
		return watchRoom(this.roomId, this.token, refresh, (open) => (this.connected = open));
	}

	private async act(fn: () => Promise<RoomView<State>>, failure: string): Promise<boolean> {
		this.error = '';
		try {
			this.apply(await fn());
			return true;
		} catch (e) {
			this.error = e instanceof Error ? e.message : failure;
			return false;
		}
	}

	begin(): Promise<boolean> {
		return this.act(() => api.begin(this.roomId, this.token), 'The game could not begin.');
	}

	addBot(): Promise<boolean> {
		return this.act(() => api.addBot(this.roomId, this.token), 'The bot could not be seated.');
	}

	/** Send a bot away before the game begins; only the host may. */
	unseat(seat: SeatId): Promise<boolean> {
		return this.act(() => api.unseat(this.roomId, this.token, seat), 'The bot could not be sent away.');
	}

	/** Out of the game, with the bots playing on: play the rest at once. */
	hurry(): Promise<boolean> {
		return this.act(() => api.hurry(this.roomId, this.token), 'The table did not hear you.');
	}

	/** This seat's ranking of the table's choices, best first, before the game begins. */
	rank(ranking: string[]): Promise<boolean> {
		return this.act(() => api.rank(this.roomId, this.token, ranking), 'Your ranking was not kept.');
	}

	/** Talk to the whole table, or, naming seats, to them alone. */
	say(text: string, to?: SeatId[]): Promise<boolean> {
		if (this.spectating) return Promise.resolve(false);
		return this.act(() => api.say(this.roomId, this.token, text, to), 'The table did not hear you.');
	}

	/** A word from the gallery, signed; only when the host has let the gallery talk. */
	sayFromGallery(name: string, text: string): Promise<boolean> {
		if (!this.spectating) return Promise.resolve(false);
		return this.act(() => api.sayFromGallery(this.roomId, name, text), 'The table did not hear you.');
	}

	/** Host only: let the Peanut Gallery talk at this table, or hush it. */
	setGalleryTalk(on: boolean): Promise<boolean> {
		return this.act(() => api.setGalleryTalk(this.roomId, this.token, on), 'The gallery could not be told.');
	}

	/** Call the keeper of the site to a held seat; their phone rings. */
	callKeeper(): Promise<boolean> {
		return this.act(() => api.challenge(this.roomId, this.token), 'The keeper could not be called.');
	}

	/** A finished table opens another with the same company; the caller is seated as its host. */
	async rematch(): Promise<string> {
		const next = await api.rematch(this.roomId, this.token);
		if (next.created && next.seat && next.token) rememberSeat(next.roomId, { seat: next.seat, token: next.token });
		return next.roomId;
	}

	/** A phrase that brings this seat to another device, good for ten minutes. */
	transfer(): Promise<{ phrase: string; expiresAt: number }> {
		return api.transfer(this.roomId, this.token);
	}

	async submit(input: Input): Promise<boolean> {
		this.sending = true;
		try {
			return await this.act(() => api.turn(this.roomId, this.token, input, this.view.resolved), 'The move did not reach the server.');
		} finally {
			this.sending = false;
		}
	}

	/** Open a table on the server, seated as its host; it begins when the host says. */
	static async create(name: string, size: number, options?: TableOptions): Promise<Room> {
		const seated = await api.create(name, size, options);
		rememberSeat(seated.view.roomId, { seat: seated.seat, token: seated.token });
		return new Room(seated.view, seated.token);
	}

	/** A room with a bot seated and the game begun, so a solo game is a ledger like any other. */
	static async createWithBot(name: string, options?: TableOptions): Promise<Room> {
		const seated = await api.create(name, 2, options);
		rememberSeat(seated.view.roomId, { seat: seated.seat, token: seated.token });
		const view = await api.addBot(seated.view.roomId, seated.token);
		// A table that asks for rankings waits in the lobby for the player's; the rest begin at once.
		if (game.rankable?.(view.options)) return new Room(view, seated.token);
		return new Room(await api.begin(seated.view.roomId, seated.token), seated.token);
	}

	static async join(roomId: string, name: string): Promise<Room> {
		const seated = await api.join(roomId, name);
		rememberSeat(roomId, { seat: seated.seat, token: seated.token });
		return new Room(seated.view, seated.token);
	}

	/** Return to a seat this browser already holds. */
	static async resume(roomId: string, held: HeldSeat): Promise<Room> {
		return new Room(await api.view(roomId, held.token), held.token);
	}

	/** Take a place in the Peanut Gallery: watch a table with no seat and no voice. */
	static async watch(roomId: string): Promise<Room> {
		return new Room(await api.watch(roomId), '');
	}
}