/**
 * The unattended worker for one instance, running in the signed-in desktop:
 *
 *   Vash (/ws/agent) ──follow──▶ osu!tourney: right team size, right room
 *   tosu ──live scores──▶ Vash;  tosu ──team names──▶ room confirmed
 *   Vash (/stream) ──Go live──▶ relay listening ──▶ OBS streams into it
 *   OBS: overlay over the captured tourney window, AMD hardware encoding
 *   relay ──▶ every destination + HLS recording on the Vash site
 *
 * It restarts whatever stops (OBS, tosu, osu!tourney, the relay), reports what
 * it is doing to Vash and to state.json, and stops cleanly when asked.
 */
import { existsSync } from 'node:fs';
import { mkdir, rm, writeFile } from 'node:fs/promises';
import { dirname, join } from 'node:path';
import { VashLink, type Follow } from '../link';
import { Obs } from '../obs';
import { Broadcaster, RtmpIngest } from '../relay';
import { TosuFeed } from '../tosu';
import { VashApi, type StreamConfig } from '../vash-api';
import {
	accessHeaders,
	layout,
	loadConfig,
	readJson,
	secret,
	VERSION,
	writeJson,
	type InstanceConfig,
	type Layout
} from './config';
import { authorized, callWorker, type Runtime } from './control';
import { WindowsDesktop, type Desktop, type SessionInfo } from './desktop';
import { acquireLock, lockOwner, releaseLock } from './lock';
import { fileLogger } from './log';
import { ObsScene } from './obs-control';
import { encoderFromLog, latestObsLog, OBS_ARGS, writeObsSettings } from './obs-files';
import { startAccessProxy } from './proxy';
import { Supervised, type Child } from './supervise';
import { normalModeFor, pickMainWindow, readSavedLogin, TourneyController } from './tourney';
import { startViewer } from './viewer';

export interface WorkerState {
	instance: string;
	version: string;
	pid: number;
	state: string;
	detail: string | null;
	updatedAt: string;
	startedAt: string;
	onAir: boolean;
	live: boolean;
	obsStreaming: boolean;
	relayReceiving: boolean;
	encoder: string | null;
	match: {
		id: string | null;
		title: string | null;
		lobbyId: number | null;
		roomName: string | null;
	} | null;
	tourney: { state: string; detail: string | null; verified: boolean };
	components: Record<string, unknown>;
	destinations: { label: string; state: string; error: string | null }[];
	vash: { connected: boolean; rejected: boolean; channel: string | null; lastError: string | null };
	desktop: SessionInfo | null;
	warnings: string[];
}

/** The same program, as a command line: the compiled exe, or bun + this script in development. */
export function selfCommand(...args: string[]) {
	const compiled =
		Bun.main.startsWith('B:/~BUN') || Bun.main.startsWith('/$bunfs') || Bun.main.includes('~BUN');
	return compiled ? [process.execPath, ...args] : [process.execPath, Bun.main, ...args];
}

const childOf = (process: import('bun').Subprocess): Child => ({
	pid: process.pid,
	exited: process.exited,
	kill: () => process.kill()
});

/** Stops every process whose program lives in this instance's folder. */
export async function stopInstanceProcesses(
	desktop: Desktop,
	paths: Layout,
	log: (...parts: unknown[]) => void
) {
	const processes = await desktop.processes(paths.dir);
	if (!processes.length) return 0;
	log(`Stopping ${processes.length} leftover process(es) of this instance`);
	return desktop.kill(processes.map((process) => process.pid));
}

/** Runs until asked to stop. Tests pass a fake desktop; Windows uses the PowerShell helper. */
export async function runWorker(name: string, desktop?: Desktop): Promise<number> {
	const config = await loadConfig(name);
	const paths = layout(name);
	const log = fileLogger(paths.log);
	log(
		`vash-broadcast ${VERSION} worker starting for "${name}": ${config.server}, channel ${config.channel}`
	);
	const worker = new Worker(
		config,
		paths,
		log,
		desktop ?? new WindowsDesktop(paths.helperScript, log)
	);
	return worker.run();
}

class Worker {
	private desktop: Desktop;
	private api: VashApi;
	private link: VashLink;
	private tosu: TosuFeed;
	private tourney: TourneyController;
	private obs: Obs;
	private scene: ObsScene;
	private ingest: RtmpIngest;
	private broadcaster: Broadcaster;
	private obsProcess: Supervised;
	private tosuProcess: Supervised;
	private stopRequested = false;
	private stopping = false;
	private blockedBy: string | null = null;
	private stream: StreamConfig | null = null;
	private streamError: string | null = null;
	private session: SessionInfo | null = null;
	private follow: Follow | null = null;
	private obsLaunchedWith = '';
	private obsConnectedAt = 0;
	private obsConnecting = false;
	private obsStreaming = false;
	private lastStartStream = 0;
	private streamingSince = 0;
	private encoder: string | null = null;
	private warnings = new Set<string>();
	private startedAt = new Date();
	private controlToken = secret();
	private headers: Record<string, string>;
	private overlayUrl: string | null = null;

	constructor(
		private config: InstanceConfig,
		private paths: Layout,
		private log: (...parts: unknown[]) => void,
		desktop: Desktop
	) {
		this.headers = accessHeaders(config);
		this.desktop = desktop;
		this.api = new VashApi(config.server, config.channel, config.token, this.headers);
		this.tosu = new TosuFeed(
			`ws://127.0.0.1:${config.ports.tosu}/websocket/v2`,
			(frame) => this.link.sendScores(frame),
			log
		);
		this.link = new VashLink({
			server: config.server,
			channel: config.channel,
			token: config.token,
			headers: this.headers,
			log,
			onFollow: (follow) => {
				const changed =
					follow.matchId !== this.follow?.matchId || follow.lobbyId !== this.follow?.lobbyId;
				this.follow = follow;
				if (changed)
					log(
						follow.title
							? `Vash: now showing ${follow.title}${follow.lobbyId ? ` (mp/${follow.lobbyId})` : ''}`
							: 'Vash: nothing to show'
					);
				this.tourney.follow(follow);
			}
		});
		this.tourney = new TourneyController({
			osuDir: paths.osu,
			snapshots: paths.snapshots,
			height: config.tourneyHeight,
			windowTitle: `Vash osu!tourney (${config.name})`,
			desktop: this.desktop,
			tosu: this.tosu,
			log
		});
		this.obs = new Obs(`ws://127.0.0.1:${config.ports.obs}`, config.obsPassword);
		this.obs.onClose = (reason) => {
			log(`OBS websocket closed: ${reason}`);
			this.obsConnectedAt = 0;
			this.obsStreaming = false;
			this.scene.reset();
		};
		this.scene = new ObsScene(this.obs, log);
		this.ingest = new RtmpIngest({
			ffmpeg: paths.ffmpeg,
			host: '127.0.0.1',
			port: config.ports.ingest,
			key: config.ingestKey,
			log
		});
		this.broadcaster = new Broadcaster({
			api: this.api,
			ffmpeg: paths.ffmpeg,
			hlsDir: paths.hls,
			source: this.ingest,
			log
		});
		this.obsProcess = new Supervised('OBS', () => this.launchObs(), { log });
		this.tosuProcess = new Supervised(
			'tosu',
			() =>
				childOf(
					Bun.spawn([paths.tosuExe], {
						cwd: paths.tosu,
						stdout: 'ignore',
						stderr: 'ignore',
						windowsHide: true
					})
				),
			{ log }
		);
	}

	private async launchObs(): Promise<Child> {
		const stream = this.stream;
		const settings = {
			websocketPort: this.config.ports.obs,
			websocketPassword: this.config.obsPassword,
			width: stream?.width ?? 1920,
			height: stream?.height ?? 1080,
			fps: stream?.fps ?? 60,
			bitrateKbps: stream?.bitrateKbps ?? 6000,
			encoder: this.config.encoder,
			ingestUrl: this.ingest.url,
			ingestKey: this.config.ingestKey
		};
		await writeObsSettings(this.paths.obsConfig, settings);
		// Started before Vash answered: restart once the channel's real settings are known.
		this.obsLaunchedWith = this.videoKey(stream) || 'defaults';
		this.scene.reset();
		const process = Bun.spawn([this.paths.obsExe, ...OBS_ARGS], {
			cwd: dirname(this.paths.obsExe),
			stdout: 'ignore',
			stderr: 'ignore'
		});
		this.log(
			`OBS started (${settings.width}×${settings.height} ${settings.fps} fps, ${settings.bitrateKbps} kbps, ${settings.encoder})`
		);
		return childOf(process);
	}

	/** OBS must restart (while off air) when these change. */
	private videoKey(stream: StreamConfig | null) {
		return stream ? `${stream.width}x${stream.height}@${stream.fps}/${stream.bitrateKbps}` : '';
	}

	async run(): Promise<number> {
		const { paths, config, log } = this;
		const server = Bun.serve({
			hostname: '127.0.0.1',
			port: config.ports.control,
			fetch: async (request) => {
				if (!authorized(request, this.controlToken))
					return new Response('Forbidden', { status: 403 });
				const url = new URL(request.url);
				if (url.pathname === '/status') return Response.json(this.state());
				if (url.pathname === '/stop' && request.method === 'POST') {
					this.stopRequested = true;
					return Response.json({ ok: true });
				}
				if (url.pathname === '/snapshot' && request.method === 'POST')
					return Response.json(await this.snapshot());
				return new Response('Not found', { status: 404 });
			}
		});
		const runtime: Runtime = {
			pid: process.pid,
			watchdogPid: Number(process.env.VASH_WATCHDOG_PID) || null,
			port: config.ports.control,
			token: this.controlToken,
			startedAt: this.startedAt.toISOString(),
			version: VERSION
		};
		await writeJson(paths.runtime, runtime);
		process.on('SIGTERM', () => (this.stopRequested = true));
		process.on('SIGINT', () => (this.stopRequested = true));

		// Leftovers of a crashed run would hold ports and windows; this instance's only.
		await stopInstanceProcesses(this.desktop, paths, log).catch((err) => log('Cleanup:', err));

		let proxy: ReturnType<typeof startAccessProxy> | null = null;
		if (config.access) {
			proxy = startAccessProxy({
				port: config.ports.proxy,
				upstream: config.server,
				headers: this.headers,
				log
			});
			log(`Overlay proxy for Cloudflare Access on 127.0.0.1:${config.ports.proxy}`);
		}

		this.link.start();
		this.tosu.start();
		// Sleep or a switched-off display would stop capture in the middle of a match.
		await this.desktop.stayAwake(true).catch((err) => log('Could not keep the PC awake:', err));

		let tick = 0;
		while (!this.stopRequested) {
			tick++;
			try {
				await this.step(tick);
			} catch (err) {
				log('Worker step failed:', err);
			}
			await this.writeState();
			await Bun.sleep(1000);
		}
		await this.shutdown();
		proxy?.stop(true);
		server.stop(true);
		return 0;
	}

	private async step(tick: number) {
		const { paths, config, log } = this;

		// One osu!tourney + tosu stack per PC.
		if (this.blockedBy !== null || tick === 1) {
			const lock = await acquireLock(paths.lock, config.name);
			if (!lock.ok) {
				if (this.blockedBy !== lock.owner.instance)
					log(
						`Waiting: instance "${lock.owner.instance}" runs osu!tourney on this PC (pid ${lock.owner.pid})`
					);
				this.blockedBy = lock.owner.instance;
				// A holder whose worker has not answered for a minute is gone (its pid was reused).
				const answering = await this.ownerAnswers(lock.owner.instance);
				if (answering) this.silentSince = 0;
				else if (!this.silentSince) this.silentSince = Date.now();
				else if (Date.now() - this.silentSince > 60_000) {
					log(
						`Instance "${lock.owner.instance}" holds the tourney lock but does not answer; taking over`
					);
					await rm(paths.lock, { force: true });
					this.silentSince = 0;
				}
				this.link.report(this.report());
				await Bun.sleep(4000);
				return;
			}
			if (this.blockedBy) log('The tourney stack is free; starting');
			this.blockedBy = null;
		}

		if (tick % 2 === 1) this.session = await this.desktop.session().catch(() => null);

		if (tick % 5 === 1) {
			try {
				const stream = await this.api.stream();
				// OBS on this PC loads the overlay itself; behind Access, through the local proxy.
				if (config.access)
					stream.overlayUrl = stream.overlayUrl.replace(
						/^https?:\/\/[^/]+/,
						`http://127.0.0.1:${config.ports.proxy}`
					);
				this.stream = stream;
				this.streamError = null;
			} catch (err) {
				if (this.streamError !== (err as Error).message) log('Vash stream settings:', err);
				this.streamError = (err as Error).message;
			}
		}

		// Programs: tosu and OBS always; osu!tourney once Vash said what to show (or after 15 s).
		await this.tosuProcess.ensure();
		if (
			this.stream &&
			this.obsLaunchedWith &&
			this.obsLaunchedWith !== this.videoKey(this.stream) &&
			!this.broadcaster.onAir
		) {
			log('Channel video settings changed; restarting OBS');
			await this.stopObs();
		}
		await this.obsProcess.ensure();
		await this.connectObs();

		if (this.follow || Date.now() - this.startedAt.getTime() > 15_000)
			if (tick % 2 === 0) await this.tourney.tick(this.session);

		if (this.obs.connected && this.stream && tick % 3 === 0) {
			const window = this.tourney.window;
			await this.scene
				.reconcile({
					canvas: { width: this.stream.width, height: this.stream.height },
					fps: this.stream.fps,
					overlayUrl: this.stream.overlayUrl,
					capture: window
						? {
								title: `Vash osu!tourney (${config.name})`,
								className: window.className,
								exe: 'osu!.exe'
							}
						: null,
					showGameplay: this.tourney.state === 'spectating',
					ingest: { server: this.ingest.url, key: config.ingestKey }
				})
				.catch((err) => log('OBS scene:', err));
		}

		// On and off air, following the channel's Go live switch.
		if (this.stream && tick % 5 === 1)
			await this.broadcaster.apply(this.stream).catch((err) => log('Broadcast:', err));
		await this.broadcaster.tick();
		await this.syncObsStream();
		this.link.report(this.report());
	}

	private silentSince = 0;

	private async ownerAnswers(instance: string) {
		try {
			return !!(await callWorker(layout(instance).runtime, '/status'));
		} catch {
			return false;
		}
	}

	private async connectObs() {
		if (!this.obsProcess.running || this.obs.connected || this.obsConnecting) return;
		this.obsConnecting = true;
		try {
			await this.obs.connect();
			this.obsConnectedAt = Date.now();
			this.log('OBS websocket connected');
			const encoder = await this.scene.profileEncoder().catch(() => null);
			if (this.config.encoder === 'amd' && encoder && encoder !== 'amd')
				this.warn(
					`OBS switched the encoder to ${encoder}: the AMD hardware encoder is not available (see OBS's log)`
				);
		} catch (err) {
			const upFor = Date.now() - this.obsProcess.startedAt;
			if (upFor > 90_000) {
				this.log(
					`OBS is running but its websocket does not answer (${(err as Error).message}); restarting OBS`
				);
				await this.stopObs();
			}
		} finally {
			this.obsConnecting = false;
		}
	}

	/** OBS streams into the relay while on air, and not otherwise. */
	private async syncObsStream() {
		if (!this.obs.connected) {
			this.obsStreaming = false;
			return;
		}
		const status = await this.scene.streaming().catch(() => null);
		if (!status) return;
		const was = this.obsStreaming;
		this.obsStreaming = status.outputActive;
		if (this.obsStreaming && !was) {
			this.streamingSince = Date.now();
			this.encoder = null;
		}
		const wanted =
			this.broadcaster.onAir &&
			this.ingest.running &&
			Date.now() - this.ingest.listeningSince > 1500;
		if (wanted && !status.outputActive && Date.now() - this.lastStartStream > 10_000) {
			this.lastStartStream = Date.now();
			this.log('Starting the OBS stream into the relay');
			await this.scene.startStream().catch((err) => this.log('OBS StartStream:', err));
		} else if (!this.broadcaster.onAir && status.outputActive) {
			this.log('Stopping the OBS stream');
			await this.scene.stopStream().catch((err) => this.log('OBS StopStream:', err));
		}
		// Which encoder actually runs, from OBS's own log, a few seconds into the stream.
		if (this.obsStreaming && !this.encoder && Date.now() - this.streamingSince > 5000) {
			const found = encoderFromLog(await latestObsLog(this.paths.obsConfig));
			this.encoder =
				found === 'amd'
					? 'AMD AMF (hardware)'
					: found === 'x264'
						? 'x264 (software)'
						: (found ?? 'unknown');
			this.log(`OBS encoder in use: ${this.encoder}`);
			if (this.config.encoder === 'amd' && found !== 'amd')
				this.warn(`Streaming with ${this.encoder}, not the AMD hardware encoder`);
		}
	}

	private warn(message: string) {
		if (this.warnings.has(message)) return;
		this.warnings.add(message);
		this.log(`Warning: ${message}`);
	}

	private async stopObs() {
		this.obs.close();
		this.obsConnectedAt = 0;
		await this.obsProcess.stop(async (child) => {
			await this.desktop.close(child.pid);
		});
	}

	/** The one state shown on the site and in `vash-broadcast status`. */
	private overall(): { state: string; detail: string | null } {
		if (this.stopping) return { state: 'stopping', detail: null };
		if (this.blockedBy)
			return {
				state: 'blocked',
				detail: `Instance "${this.blockedBy}" is running osu!tourney on this PC`
			};
		if (this.link.rejected)
			return {
				state: 'error',
				detail: 'Vash refused the agent token; run setup again with a new token'
			};
		if (this.streamError && !this.stream)
			return { state: 'error', detail: `Cannot reach Vash: ${this.streamError}` };
		const tourney = this.tourney.state;
		if (tourney === 'login-required')
			return { state: 'login-required', detail: this.tourney.detail };
		if (!this.obs.connected)
			return {
				state: this.obsProcess.restarts ? 'reconnecting' : 'starting',
				detail: this.obsProcess.lastExit ? `OBS ${this.obsProcess.lastExit}` : 'starting OBS'
			};
		if (this.broadcaster.onAir && !this.obsStreaming && Date.now() - this.lastStartStream > 20_000)
			return { state: 'reconnecting', detail: 'On air, but OBS is not streaming into the relay' };
		if (tourney === 'stopped')
			return { state: 'starting', detail: 'waiting for Vash to say what to show' };
		const map: Record<string, string> = {
			starting: 'starting',
			'desktop-locked': 'desktop-locked',
			idle: 'idle',
			'waiting-for-lobby': 'waiting-for-lobby',
			selecting: 'selecting',
			spectating: 'spectating',
			error: 'error'
		};
		return { state: map[tourney] ?? 'error', detail: this.tourney.detail };
	}

	private report() {
		const { state, detail } = this.overall();
		return {
			state,
			detail,
			onAir: this.broadcaster.onAir && this.obsStreaming,
			encoder: this.encoder,
			instance: this.config.name,
			version: VERSION
		};
	}

	state(): WorkerState {
		const { state, detail } = this.overall();
		const follow = this.follow;
		return {
			instance: this.config.name,
			version: VERSION,
			pid: process.pid,
			state,
			detail,
			updatedAt: new Date().toISOString(),
			startedAt: this.startedAt.toISOString(),
			onAir: this.broadcaster.onAir,
			live: !!this.stream?.live,
			obsStreaming: this.obsStreaming,
			relayReceiving: this.ingest.receiving,
			encoder: this.encoder,
			match: follow
				? {
						id: follow.matchId,
						title: follow.title,
						lobbyId: follow.lobbyId,
						roomName: follow.roomName
					}
				: null,
			tourney: {
				state: this.tourney.state,
				detail: this.tourney.detail,
				verified: this.tourney.verified
			},
			components: {
				obs: { ...this.obsProcess.status(), websocket: this.obs.connected },
				tosu: {
					...this.tosuProcess.status(),
					connected: this.tosu.connected,
					players: this.tosu.fresh()?.clients.length ?? 0,
					frameAt: this.tosu.latestAt ? new Date(this.tosu.latestAt).toISOString() : null
				},
				scores: {
					players: this.link.scores.players,
					sentAt: this.link.scores.sentAt ? new Date(this.link.scores.sentAt).toISOString() : null,
					acceptedAt: this.link.scores.acceptedAt
						? new Date(this.link.scores.acceptedAt).toISOString()
						: null
				},
				relay: {
					listening: this.ingest.running,
					receiving: this.ingest.receiving,
					recording: this.broadcaster.recording
				}
			},
			destinations: this.broadcaster
				.destinations()
				.map(({ label, state, error }) => ({ label, state, error })),
			vash: {
				connected: this.link.connected,
				rejected: this.link.rejected,
				channel: this.link.channelName,
				lastError: this.streamError
			},
			desktop: this.session,
			warnings: [...this.warnings]
		};
	}

	private lastStateWrite = 0;
	private async writeState(force = false) {
		if (!force && Date.now() - this.lastStateWrite < 2000) return;
		this.lastStateWrite = Date.now();
		await writeJson(this.paths.state, this.state()).catch(() => {});
	}

	/** Saves what OBS outputs and what the tourney window shows, for checking from SSH. */
	private async snapshot() {
		const stamp = new Date().toISOString().replace(/[:.]/g, '-');
		await mkdir(this.paths.snapshots, { recursive: true });
		const files: string[] = [];
		const errors: string[] = [];
		if (this.obs.connected) {
			try {
				const file = join(this.paths.snapshots, `${stamp}-obs-output.png`);
				await writeFile(file, await this.scene.screenshot());
				files.push(file);
			} catch (err) {
				errors.push(`OBS: ${(err as Error).message}`);
			}
		} else errors.push('OBS is not connected');
		const window = this.tourney.window;
		if (window) {
			try {
				const file = join(this.paths.snapshots, `${stamp}-tourney-window.png`);
				await this.desktop.capture({
					x: window.clientX,
					y: window.clientY,
					width: window.clientWidth,
					height: window.clientHeight,
					path: file
				});
				files.push(file);
			} catch (err) {
				errors.push(`Tourney window: ${(err as Error).message}`);
			}
		} else errors.push('No osu!tourney window');
		const panel = join(this.paths.snapshots, 'tourney-panel.png');
		if (existsSync(panel)) files.push(panel, join(this.paths.snapshots, 'tourney-panel.json'));
		return { files, errors };
	}

	private async shutdown() {
		const { log, paths } = this;
		this.stopping = true;
		log('Stopping');
		this.link.report(this.report());
		await this.writeState(true);
		if (this.obs.connected && this.obsStreaming) await this.scene.stopStream().catch(() => {});
		await this.broadcaster.stop().catch((err) => log('Going off air:', err));
		await this.tourney.stop().catch((err) => log('Stopping osu!tourney:', err));
		await this.stopObs().catch(() => {});
		await this.tosuProcess.stop();
		this.tosu.stop();
		this.link.stop();
		await stopInstanceProcesses(this.desktop, paths, log).catch(() => {});
		this.desktop.stop();
		await releaseLock(paths.lock);
		await writeJson(paths.state, { ...this.state(), state: 'stopped', detail: null }).catch(
			() => {}
		);
		await rm(paths.runtime, { force: true });
		log('Stopped');
	}
}

// ── Watchdog ────────────────────────────────────────────────────────────

/**
 * What the scheduled task runs. It restarts the worker if it crashes (with
 * backoff) and exits when the worker stops on purpose. The request file says
 * whether this start is the worker, the one-time sign-in, or a diagnosis.
 */
export async function runTask(name: string): Promise<number> {
	const paths = layout(name);
	const log = fileLogger(paths.log);
	const request = await readJson<{ mode: string; at: number }>(paths.request);
	await rm(paths.request, { force: true });
	const mode = request && Date.now() - request.at < 5 * 60_000 ? request.mode : 'run';
	if (mode === 'login') return runSignIn(name);
	if (mode === 'doctor') return runDesktopDoctor(name);

	const owner = await lockOwner(paths.lock);
	const runtime = await readJson<Runtime>(paths.runtime);
	if (runtime && owner?.pid === runtime.pid) {
		log('The worker is already running; not starting another');
		return 0;
	}
	let failures = 0;
	for (;;) {
		const started = Date.now();
		const child = Bun.spawn(selfCommand('worker', '--instance', name), {
			stdout: 'ignore',
			stderr: 'pipe',
			env: { ...process.env, VASH_WATCHDOG_PID: String(process.pid) },
			windowsHide: true
		});
		let stderr = '';
		void (async () => {
			for await (const chunk of child.stderr)
				stderr = (stderr + new TextDecoder().decode(chunk)).slice(-2000);
		})();
		const code = await child.exited;
		if (code === 0) return 0;
		if (Date.now() - started > 10 * 60_000) failures = 0;
		const wait = Math.min(60_000, 2000 * 2 ** failures++);
		log(
			`Worker exited with ${code}${stderr ? `: ${stderr.trim().split('\n').slice(-3).join(' ')}` : ''}; restarting in ${Math.round(wait / 1000)}s`
		);
		if (existsSync(paths.request)) return 0;
		await Bun.sleep(wait);
	}
}

// ── One-time sign-in ────────────────────────────────────────────────────

export interface SignInState {
	state: 'starting' | 'waiting' | 'closing' | 'done' | 'failed';
	message: string;
	port: number;
	token: string;
	username: string | null;
	updatedAt: string;
}

async function runSignIn(name: string): Promise<number> {
	const config = await loadConfig(name);
	const paths = layout(name);
	const log = fileLogger(paths.log);
	const desktop = new WindowsDesktop(paths.helperScript, log);
	const token = secret();
	let finish = false;
	let state: SignInState = {
		state: 'starting',
		message: 'Starting osu!…',
		port: config.ports.viewer,
		token,
		username: null,
		updatedAt: new Date().toISOString()
	};
	const set = async (next: Partial<SignInState>) => {
		state = { ...state, ...next, updatedAt: new Date().toISOString() };
		await writeJson(paths.login, state);
	};
	log('One-time sign-in: starting osu! normally');
	await stopInstanceProcesses(desktop, paths, log).catch(() => {});
	const restore = await normalModeFor(paths.osu);
	const viewer = startViewer({
		port: config.ports.viewer,
		token,
		desktop,
		scratch: paths.snapshots,
		title: `Vash broadcast sign-in (${name})`,
		status: () => ({
			message: state.message,
			done: state.state === 'done' || state.state === 'failed'
		}),
		onFinish: () => (finish = true)
	});
	await mkdir(paths.snapshots, { recursive: true });
	try {
		Bun.spawn([paths.osuExe], { cwd: paths.osu, stdout: 'ignore', stderr: 'ignore' });
		await set({
			state: 'waiting',
			message:
				'osu! is starting (a fresh installation downloads its files first). Sign in with the spectator account, tick Remember username and Remember password, then press Finish.'
		});
		const deadline = Date.now() + 45 * 60_000;
		while (!finish && Date.now() < deadline) {
			await Bun.sleep(1000);
			const window = pickMainWindow(await desktop.windows(paths.osu).catch(() => []));
			if (window && state.message.startsWith('osu! is starting'))
				await desktop.focus(window.hwnd).catch(() => false);
		}
		await set({ state: 'closing', message: 'Closing osu! so it saves the login…' });
		for (const process of await desktop.processes(paths.osu))
			await desktop.close(process.pid).catch(() => 0);
		for (
			let waited = 0;
			waited < 20_000 && (await desktop.processes(paths.osu)).length;
			waited += 1000
		)
			await Bun.sleep(1000);
		await stopInstanceProcesses(desktop, paths, log).catch(() => {});
		await restore();
		const login = await readSavedLogin(paths.osu);
		if (login.saved) {
			await set({
				state: 'done',
				username: login.username,
				message: `Signed in as ${login.username}; the login is saved.`
			});
			log(`One-time sign-in done: ${login.username}`);
		} else {
			await set({
				state: 'failed',
				message: finish
					? 'osu! did not save a login. Run vash-broadcast login again and tick Remember username and Remember password.'
					: 'The sign-in timed out after 45 minutes.'
			});
		}
	} catch (err) {
		await restore().catch(() => {});
		await set({ state: 'failed', message: (err as Error).message });
	} finally {
		await Bun.sleep(3000);
		viewer.stop(true);
		desktop.stop();
	}
	return 0;
}

// ── Diagnosis inside the desktop ─────────────────────────────────────────

async function runDesktopDoctor(name: string): Promise<number> {
	const paths = layout(name);
	const log = fileLogger(paths.log);
	const desktop = new WindowsDesktop(paths.helperScript, log);
	const checks: { name: string; ok: boolean; detail: string }[] = [];
	const check = async (label: string, run: () => Promise<string>) => {
		try {
			checks.push({ name: label, ok: true, detail: await run() });
		} catch (err) {
			checks.push({ name: label, ok: false, detail: (err as Error).message });
		}
	};
	await check('Desktop session', async () => {
		const session = await desktop.session();
		if (session.inputDesktop !== 'Default')
			throw new Error(
				`The desktop is locked or on a secure screen (${session.inputDesktop ?? 'no input desktop'}); rooms cannot be clicked`
			);
		if (session.sessionId !== session.consoleSessionId)
			throw new Error(
				`This session (${session.sessionId}) is not the one on the PC's screen (${session.consoleSessionId}); a disconnected Remote Desktop session has no display`
			);
		return `unlocked, ${session.screenWidth}×${session.screenHeight}, idle ${Math.round(session.idleMs / 1000)}s`;
	});
	await check('Screen capture', async () => {
		await mkdir(paths.snapshots, { recursive: true });
		const file = join(paths.snapshots, 'doctor-screen.jpg');
		const size = await desktop.capture({
			x: 0,
			y: 0,
			width: 640,
			height: 360,
			path: file,
			format: 'jpeg'
		});
		return `captured ${size.width}×${size.height} to ${file}`;
	});
	await check('Windows OCR', async () => {
		const ready = await desktop.ocrReady();
		return `language ${ready.language}, images up to ${ready.maxDimension} px`;
	});
	await check('osu!tourney window', async () => {
		const windows = await desktop.windows(paths.osu);
		return windows.length
			? windows
					.map((window) => `"${window.title}" ${window.clientWidth}×${window.clientHeight}`)
					.join('; ')
			: 'osu! is not running (normal while the worker is stopped)';
	});
	await check('AMD encoder in OBS log', async () => {
		const log = await latestObsLog(paths.obsConfig);
		if (!log) return 'no OBS log yet; start the worker once';
		const lines = log
			.split(/\r?\n/)
			.filter((line) => /amf|AMD|encoder/i.test(line))
			.slice(0, 12);
		return lines.join(' | ') || 'no encoder lines in the latest OBS log';
	});
	desktop.stop();
	await writeJson(paths.doctor, { at: new Date().toISOString(), checks });
	return 0;
}