/**
 * Security limits: the model gate (per-IP concurrency + the account-wide
 * budget), the data-URL contract, the proxy-hop identity, the disk guards and
 * the response headers.
 *
 * Runs against its own instance with a slow stub Ollama and deliberately tiny
 * limits, so every guard is observable in a second or two.
 */
import http from "node:http";
import { mkdirSync, readFileSync, rmSync } from "node:fs";

import { launchBrowser, makeChecker, makePage, portInUse, seed, spawnApp, waitForHttp } from "./lib.mjs";

const { check, finish } = makeChecker();

const STUB_PORT = 11997;
const APP_PORT = 3210;
const STUB_BASE = `http://127.0.0.1:${STUB_PORT}`;
const APP = `http://127.0.0.1:${APP_PORT}`;

const REPORTS_DIR = new URL("./.tmp/security-reports", import.meta.url).pathname;
const PUSH_DIR = new URL("./.tmp/security-push", import.meta.url).pathname;

/* A deliberately slow stub: model calls stay in flight long enough to test
   the concurrency gate, and the payload itself never matters here. */
const stub = http.createServer((request, response) => {
  if (request.url?.startsWith("/api/tags")) {
    response.writeHead(200, { "Content-Type": "application/json" });
    response.end(JSON.stringify({ models: [{ name: "stub", model: "stub" }] }));
    return;
  }
  request.on("data", () => {});
  request.on("end", () => {
    setTimeout(() => {
      response.writeHead(200, { "Content-Type": "application/json" });
      response.end(JSON.stringify({ message: { content: "{}" } }));
    }, 700);
  });
});
await new Promise((resolve) => stub.listen(STUB_PORT, "127.0.0.1", resolve));

rmSync(REPORTS_DIR, { recursive: true, force: true });
rmSync(PUSH_DIR, { recursive: true, force: true });
mkdirSync(REPORTS_DIR, { recursive: true });
mkdirSync(PUSH_DIR, { recursive: true });

check("security app port is free", !(await portInUse(APP_PORT)));
const app = spawnApp(APP_PORT, {
  OLLAMA_BASE_URL: STUB_BASE,
  OLLAMA_AUTH: "local",
  OLLAMA_VERIFY_KEY: "false",
  OLLAMA_TIMEOUT_MS: "10000",
  RATE_LIMIT_CONCURRENT: "2",
  RATE_LIMIT_CONCURRENT_TOTAL: "3",
  RATE_LIMIT_MODEL_TOTAL: "6",
  RATE_LIMIT_REPORTS: "1",
  REPORTS_DIR,
  REPORTS_MAX_BYTES: "900",
  PUSH_DIR,
  PUSH_MAX_SUBSCRIPTIONS: "2",
  VAPID_PUBLIC_KEY: "BEl62iUYgUivxIkv69yViEuiBIa-Ib9-SkvMeAtA3LFgDzkrxZJjSgSnfckjBJuBkr3qBUYIHBQFLXYp5Nksh8U",
  VAPID_PRIVATE_KEY: "UUxI4O8-FbRouAevSmBQ6o18hgE4nSG3qwvJTfKc-ls",
  VAPID_SUBJECT: "mailto:test@example.com",
});

const browser = await launchBrowser();

try {
  const up = await waitForHttp(`${APP}/api/health`);
  check("security app instance is up", up);

  if (up) {
    /* 1. per-IP concurrency: only N model calls in flight ---------------- */
    const generate = (body) =>
      fetch(`${APP}/api/generate`, {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({ text: "Photosynthesis needs light and water.", ...body }),
      });
    const parallel = await Promise.all([generate({}), generate({}), generate({})]);
    const statuses = parallel.map((response) => response.status).sort();
    check(
      "concurrency: the third parallel model call is refused as busy",
      statuses.filter((status) => status === 200).length === 2 && statuses.includes(429),
      JSON.stringify(statuses),
    );
    const busy = await parallel.find((response) => response.status === 429)?.json();
    check("concurrency: the refusal is a friendly busy 429", busy?.kind === "busy" && typeof busy?.error === "string", JSON.stringify(busy));
    // Drain the two streams so their slots are released.
    await Promise.all(parallel.map((response) => response.text().catch(() => "")));

    /* 2. the account-wide budget: even sequential calls stop ------------
       Two calls were admitted above (the refused one never counted), and the
       data-URL call below adds one — so with a budget of six, three more get
       through and the next is refused. */
    const plainUrl = await fetch(`${APP}/api/generate`, {
      method: "POST",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify({ images: [`http://169.254.169.254/latest/meta-data/`, "x".repeat(40)] }),
    });
    check("data URLs: a plain URL is rejected", plainUrl.status === 400, String(plainUrl.status));
    const dataUrl = await fetch(`${APP}/api/generate`, {
      method: "POST",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify({ images: [`data:image/jpeg;base64,${"A".repeat(200)}`] }),
    });
    check("data URLs: a real data URL is accepted", dataUrl.status === 200, String(dataUrl.status));
    await dataUrl.text().catch(() => "");

    const admitted = [];
    for (let index = 0; index < 3; index += 1) {
      const response = await generate({});
      admitted.push(response.status);
      await response.text().catch(() => "");
    }
    const overBudget = await generate({});
    const overBudgetBody = overBudget.status === 429 ? await overBudget.json() : null;
    check(
      "budget: the model-call budget stops a flood",
      admitted.every((status) => status === 200) && overBudget.status === 429 && overBudgetBody?.kind === "rate_limited",
      `${JSON.stringify(admitted)} then ${overBudget.status} ${JSON.stringify(overBudgetBody)}`,
    );

    /* 4. the rate-limit identity is the last proxy hop ------------------ */
    const report = (forwarded) =>
      fetch(`${APP}/api/reports`, {
        method: "POST",
        headers: { "Content-Type": "application/json", "x-forwarded-for": forwarded },
        body: JSON.stringify({
          deckId: "seed_deck",
          activityId: "a1",
          type: "multiple_choice",
          question: "What colour is a clear daytime sky?",
          at: Date.now(),
        }),
      });
    const spoofOne = await report("9.9.9.9, 10.0.0.1");
    const spoofTwo = await report("8.8.8.8, 10.0.0.1");
    const other = await report("7.7.7.7, 10.0.0.2");
    check(
      "identity: a spoofed x-forwarded-for cannot dodge the per-IP limit",
      spoofOne.status === 200 && spoofTwo.status === 429 && other.status === 200,
      `${spoofOne.status}/${spoofTwo.status}/${other.status}`,
    );

    /* 5. the reports file stops growing at its cap ---------------------- */
    for (let index = 0; index < 6; index += 1) {
      await report(`7.7.7.7, 10.0.0.${10 + index}`);
    }
    const reportsSize = readFileSync(`${REPORTS_DIR}/reports.jsonl`, "utf8").length;
    check("reports: the JSONL stops at its size cap", reportsSize > 0 && reportsSize < 2000, `${reportsSize} bytes`);

    /* 6. push endpoints must be real push services ---------------------- */
    const subscribe = (endpoint) =>
      fetch(`${APP}/api/push`, {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({ endpoint, keys: { p256dh: "B".repeat(40), auth: "C".repeat(20) } }),
      });
    const evil = await subscribe("https://evil.example/collect");
    check("push: an arbitrary endpoint is rejected (no SSRF)", evil.status === 400, String(evil.status));
    const good = await subscribe("https://fcm.googleapis.com/fcm/send/abc");
    const goodSecond = await subscribe("https://updates.push.services.mozilla.com/wpush/v2/abc");
    const overCap = await subscribe("https://web.push.apple.com/abc");
    check(
      "push: subscriptions are capped",
      good.status === 200 && goodSecond.status === 200 && overCap.status === 429,
      `${good.status}/${goodSecond.status}/${overCap.status}`,
    );

    /* 7. response headers ------------------------------------------------ */
    const { context, page } = await makePage(browser);
    await seed(page, { decks: [] });
    await page.goto(`${APP}/`, { waitUntil: "domcontentloaded" });
    const headers = await page.evaluate(async () => {
      const response = await fetch("/", { cache: "no-store" });
      return {
        frame: response.headers.get("x-frame-options"),
        csp: response.headers.get("content-security-policy"),
        nosniff: response.headers.get("x-content-type-options"),
        referrer: response.headers.get("referrer-policy"),
      };
    });
    check(
      "headers: the app refuses to be framed and sniffed",
      headers.frame === "DENY" &&
        (headers.csp ?? "").includes("frame-ancestors 'none'") &&
        headers.nosniff === "nosniff" &&
        headers.referrer === "strict-origin-when-cross-origin",
      JSON.stringify(headers),
    );

    /* 8. cross-origin writes stay rejected ------------------------------- */
    const crossOrigin = await fetch(`${APP}/api/reports`, {
      method: "POST",
      headers: { "Content-Type": "application/json", Origin: "https://evil.example" },
      body: JSON.stringify({ deckId: "d", activityId: "a", type: "multiple_choice", question: "q", at: Date.now() }),
    });
    check("cross-origin POST is refused", crossOrigin.status === 403, String(crossOrigin.status));
    await context.close();
  }
} finally {
  app.stop();
  stub.close();
  await browser.close();
}

finish();