import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
import { createServer, type Server } from "node:http";
import type { AddressInfo } from "node:net";
import { existsSync, readdirSync, rmSync } from "node:fs";
import { Agent } from "undici";
import { loadModules } from "./helpers.js";

const HOUR = 60 * 60 * 1000;

let origin: Server;
let originUrl: string;

beforeEach(async () => {
    vi.useFakeTimers({ toFake: ["setInterval", "Date"] });
    origin = createServer((_req, res) => {
        res.setHeader("content-length", "5");
        res.end("hello");
    });
    await new Promise<void>((done) => origin.listen(0, "127.0.0.1", done));
    originUrl = `http://127.0.0.1:${(origin.address() as AddressInfo).port}/file.txt`;
});

afterEach(async () => {
    vi.useRealTimers();
    await new Promise((done) => origin.close(done));
});

async function waitForStatus(
    read: () => string | undefined,
    wanted: string,
) {
    for (let i = 0; i < 500 && read() !== wanted; i++) {
        await new Promise((done) => setImmediate(done));
    }
    expect(read()).toBe(wanted);
}

describe("tasks e sessões", () => {
    it("descarta as tasks e os arquivos quando a sessão expira", async () => {
        const { sessionManager, DownloadManager, storageRoot } = await loadModules();
        const manager = new DownloadManager(new Agent());

        const session = sessionManager.getSession();
        const task = await manager.queueDownload(session.id, originUrl);
        await waitForStatus(() => manager.getTask(task.id)?.status, "completed");
        expect(readdirSync(`${storageRoot}/${session.id}`)).toHaveLength(1);

        vi.setSystemTime(Date.now() + HOUR + 1000);
        vi.advanceTimersByTime(60_000); // dispara o coletor

        expect(manager.getTask(task.id)).toBeUndefined();
        expect(manager.getTasks(session.id)).toEqual([]);
        expect(existsSync(`${storageRoot}/${session.id}`)).toBe(false);
        rmSync(storageRoot, { recursive: true, force: true });
    });

    it("mantém as tasks de outras sessões ainda ativas", async () => {
        const { sessionManager, DownloadManager, storageRoot } = await loadModules();
        const manager = new DownloadManager(new Agent());

        const expiring = sessionManager.getSession();
        await manager.queueDownload(expiring.id, originUrl);

        vi.setSystemTime(Date.now() + HOUR - 1000);
        const alive = sessionManager.getSession(); // criada perto do fim da outra
        const kept = await manager.queueDownload(alive.id, originUrl);
        vi.setSystemTime(Date.now() + 2000);
        vi.advanceTimersByTime(60_000);

        expect(manager.getTasks(expiring.id)).toEqual([]);
        expect(manager.getTask(kept.id)).toBeDefined();
        rmSync(storageRoot, { recursive: true, force: true });
    });
});