/** Launches osu!tourney under Wine and selects a room from its control panel. */
import { readFile, writeFile } from 'node:fs/promises';
import { dirname, join } from 'node:path';
import type { Subprocess } from 'bun';

interface Word {
	line: string;
	text: string;
	x: number;
	y: number;
	w: number;
	h: number;
}

export const plain = (value: string) =>
	value
		.normalize('NFKD')
		.toLowerCase()
		.replace(/[^\p{L}\p{N}]/gu, '');

/** OCR is imperfect, so require both team names on one control-panel line. */
export function findRoom(tsv: string, roomName: string): { x: number; y: number } | null {
	const names = [...roomName.matchAll(/\(([^)]+)\)/g)].map((match) => plain(match[1]));
	if (names.length !== 2 || names.some((name) => !name)) return null;
	const words: Word[] = tsv
		.split('\n')
		.slice(1)
		.map((row) => row.split('\t'))
		.filter((row) => row.length >= 12 && row[0] === '5' && Number(row[10]) >= 30)
		.map((row) => ({
			line: row.slice(1, 5).join(':'),
			text: row.slice(11).join(''),
			x: Number(row[6]),
			y: Number(row[7]),
			w: Number(row[8]),
			h: Number(row[9])
		}));
	const lines = new Map<string, Word[]>();
	for (const word of words) lines.set(word.line, [...(lines.get(word.line) ?? []), word]);
	for (const line of lines.values()) {
		const normalized = plain(line.map((word) => word.text).join(''));
		if (!normalized.includes(`vash${names[0]}vs${names[1]}`)) continue;
		const left = Math.min(...line.map((word) => word.x));
		const right = Math.max(...line.map((word) => word.x + word.w));
		const top = Math.min(...line.map((word) => word.y));
		const bottom = Math.max(...line.map((word) => word.y + word.h));
		return { x: Math.round((left + right) / 2), y: Math.round((top + bottom) / 2) };
	}
	return null;
}

/** tournament.cfg with our keys replaced and anything else osu! wrote kept. */
export function tournamentConfig(
	existing: string,
	options: { teamSize: number; height: number; acronym?: string }
) {
	const lines = existing
		.split(/\r?\n/)
		.filter((line) => !/^\s*(TeamSize|acronym|Height)\s*=/i.test(line));
	return [
		...lines.filter(Boolean),
		`TeamSize = ${options.teamSize}`,
		`acronym = ${options.acronym ?? 'VASH'}`,
		`Height = ${options.height}`,
		''
	].join('\n');
}

export class Tourney {
	private process: Subprocess | null = null;
	private size = 0;
	private startedAt = 0;
	private readonly exe: string;
	private readonly directory: string;
	private readonly display: string;
	private readonly width: number;
	private readonly height: number;

	constructor(exe: string, options: { display: string; width: number; height: number }) {
		this.exe = exe;
		this.directory = dirname(exe);
		this.display = options.display;
		this.width = options.width;
		this.height = options.height;
	}

	/** Config must be written while osu! is closed; a size change restarts it. */
	async ensure(teamSize: number) {
		if (!Number.isInteger(teamSize) || teamSize < 1 || teamSize > 8)
			throw new Error(`Unsupported team size ${teamSize}`);
		if (this.size === teamSize && this.process?.exitCode == null) return false;
		if (this.process) {
			this.process.kill();
			await Bun.spawn(['wineserver', '-k'], { stdout: 'ignore', stderr: 'ignore' }).exited;
			await this.process.exited;
			this.process = null;
		}
		const configPath = join(this.directory, 'tournament.cfg');
		const existing = await readFile(configPath, 'utf8').catch(() => '');
		await writeFile(configPath, tournamentConfig(existing, { teamSize, height: this.height }));
		this.process = Bun.spawn(['wine', this.exe], {
			cwd: this.directory,
			env: { ...process.env, DISPLAY: this.display },
			stdout: 'ignore',
			stderr: 'ignore'
		});
		this.size = teamSize;
		this.startedAt = Date.now();
		return true;
	}

	async select(roomName: string): Promise<boolean> {
		if (!this.process || this.process.exitCode != null || Date.now() - this.startedAt < 10_000)
			return false;
		const capture = Bun.spawn(
			[
				'ffmpeg',
				'-hide_banner',
				'-loglevel',
				'error',
				'-f',
				'x11grab',
				'-video_size',
				`${this.width}x200`,
				'-i',
				`${this.display}+0,${this.height}`,
				'-frames:v',
				'1',
				'-f',
				'image2pipe',
				'-vcodec',
				'png',
				'pipe:1'
			],
			{ stdout: 'pipe', stderr: 'ignore' }
		);
		const png = new Uint8Array(await new Response(capture.stdout).arrayBuffer());
		if ((await capture.exited) !== 0 || !png.length) return false;
		const ocr = Bun.spawn(['tesseract', 'stdin', 'stdout', 'tsv'], {
			stdin: 'pipe',
			stdout: 'pipe',
			stderr: 'ignore'
		});
		ocr.stdin.write(png);
		ocr.stdin.end();
		const result = await new Response(ocr.stdout).text();
		if ((await ocr.exited) !== 0) return false;
		const point = findRoom(result, roomName);
		if (!point) return false;
		return (
			(await Bun.spawn(
				['xdotool', 'mousemove', String(point.x), String(this.height + point.y), 'click', '1'],
				{ env: { ...process.env, DISPLAY: this.display }, stdout: 'ignore', stderr: 'ignore' }
			).exited) === 0
		);
	}

	stop() {
		this.process?.kill();
	}
}