/**
 * preview.ts: render the Matrix welcome screen outside omp.
 *
 *   npx tsx scripts/preview.ts
 *
 * Ctrl+C to quit. Useful for tuning the config file without restarting omp.
 * It reads the same config as the extension, so what you see here is what omp
 * will show.
 *
 * IMPORTANT: everything below runs only when this file is the process entry
 * point. omp's extension loader imports every `.ts` file it finds in a scanned
 * extensions directory *before* it decides whether the module exports a valid
 * factory, so a module with top-level side effects takes over the terminal and
 * can kill the host process on import. Keep this file inert when imported.
 */
import { pathToFileURL } from "node:url";

import { loadConfig } from "../config.js";
import { MatrixWelcome, type WelcomeInfo } from "../index.js";

function main(): void {
	const { config, source, warnings } = loadConfig();
	for (const warning of warnings) {
		process.stderr.write(`config warning: ${warning}\n`);
	}
	process.stderr.write(`config: ${source ?? "built-in defaults"}\n`);

	const info: WelcomeInfo = {
		version: "17.2.12",
		modelName: "claude-opus-5",
		providerName: "anthropic",
		sessions: [
			{ name: "oh-my-pi", timeAgo: "12m ago" },
			{ name: "portfolio-site", timeAgo: "3h ago" },
			{ name: "scratch", timeAgo: "2d ago" },
		],
		cwd: "~/code/oh-my-pi",
	};

	// Dynamic insert/delete plus iteration on teardown, so Set over Record.
	const handles = new Set<NodeJS.Timeout>();
	const timers = {
		setInterval: (cb: () => void, ms: number) => {
			const handle = setInterval(cb, ms);
			handles.add(handle);
			return handle;
		},
		clearTimer: (handle: unknown) => {
			// Identity lookup keeps the already-typed handle, so no cast is needed.
			for (const known of handles) {
				if (known !== handle) continue;
				clearInterval(known);
				handles.delete(known);
				return;
			}
		},
	};

	const restore = () => {
		for (const handle of handles) clearInterval(handle);
		handles.clear();
		process.stdout.write("\x1b[?25h\x1b[2J\x1b[H");
	};

	const screen = new MatrixWelcome(
		info,
		() => {
			restore();
			process.exit(0);
		},
		timers,
		config,
	);

	process.stdout.write("\x1b[?25l\x1b[2J");
	screen.start({
		requestRender() {
			const width = process.stdout.columns ?? 100;
			process.stdout.write("\x1b[H" + screen.render(width).join("\n"));
		},
	});

	process.on("SIGINT", () => {
		restore();
		process.exit(0);
	});

	// Keep alive when the countdown is disabled.
	setTimeout(() => {}, (config.countdown + 5) * 1000);
}

// Bun (and Node >= 24) set `import.meta.main` on the entry module only.
let isDirectRun = "main" in import.meta && import.meta.main === true;
const entry = process.argv[1];
if (!isDirectRun && entry) {
	try {
		// omp imports with a `?mtime=` cache-buster, so compare without the query.
		isDirectRun = pathToFileURL(entry).href === import.meta.url.split("?")[0];
	} catch {
		isDirectRun = false;
	}
}

if (isDirectRun) main();