import { chmod, mkdtemp, rm, writeFile } from "node:fs/promises";
import { join } from "node:path";

const TEMP_ROOT = "/tmp";
const TEMP_PREFIX = "pi-web-core-";
const directories = new Set<string>();

export interface TempContentFile {
	path: string;
	chars: number;
	bytes: number;
}

export async function writeTempContent(content: string, extension = ".md"): Promise<TempContentFile> {
	const dir = await mkdtemp(join(TEMP_ROOT, TEMP_PREFIX));
	await chmod(dir, 0o700);
	directories.add(dir);
	const safeExtension = extension === ".txt" ? ".txt" : ".md";
	const path = join(dir, `content${safeExtension}`);
	await writeFile(path, content, { encoding: "utf8", mode: 0o600 });
	return { path, chars: content.length, bytes: Buffer.byteLength(content) };
}

export async function cleanupTempContent(): Promise<void> {
	const pending = [...directories];
	directories.clear();
	await Promise.all(pending.map(async (dir) => {
		try {
			await rm(dir, { recursive: true, force: true });
		} catch {
			// Temporary output must never make session shutdown fail.
		}
	}));
}