#!/usr/bin/env node
/*
 * webhook.test.mjs — the Worker entry (/api/session + /telegram/webhook gate).
 * ---------------------------------------------------------------------------
 * Source-under-test: src/webhook.ts, exercised through its exported
 * `fetch(request, env)` with undici Request/Response (Node 20+ ships both;
 * the code paths here are platform-neutral, no workerd needed).
 *
 * Scope note (offline-only): grammY's cloudflare-mod adapter calls
 * `bot.init()` (a live getMe) BEFORE its own secret-token compare, so no
 * committed case may let an update REACH the framework. Do not add a case
 * that posts a well-formed update with an ARMED secret — it would call the
 * live Bot API. Armed-secret behavior is verified by the live smokes in
 * plan 02-03 instead.
 *
 * Cases (WR-01 body cap, WR-02 fail-closed gate, T-02-01 gate):
 *   WK1  POST valid initData under the cap → 200 {token: uuid};
 *        exactly two TTL-carrying KV writes (900 s)
 *   WK2  POST an over-cap (4 KB+) but VALIDLY SIGNED initData → 413
 *        {error:"malformed"}, zero KV writes, log is category-only
 *        ("[initdata] rejected: malformed") and echoes no payload
 *   WK2b lying Content-Length (declares 100, ships 5000+) → 413 via the
 *        post-read length check (the header blind spot in WR-01)
 *   WK3  declared-length 999999 + unreadable body stream → 413 resolved
 *        WITHOUT pulling the stream (the pre-read check refuses to buffer)
 *   WK4  GET /api/session → 405 (the cap logic never runs on GET)
 *   WK5  unarmed WEBHOOK_SECRET → /telegram/webhook rejects CLOSED with a
 *        constant 500 BEFORE grammY's compareSecretToken (which would
 *        accept every request once the secret is undefined — WR-02)
 */
import { strict as assert } from "node:assert";
import { createHmac } from "node:crypto";
import { test } from "./harness.mjs";

const TEST_TOKEN = "12345:TESTTOKEN"; // same signer token as initdata.test.mjs

/* ————— node:crypto signing helpers (test-side, independent path) ————— */

function dataCheckString(fields) {
  return fields
    .filter(([key]) => key !== "hash")
    .slice()
    .sort((a, b) => (a[0] < b[0] ? -1 : a[0] > b[0] ? 1 : 0))
    .map(([key, value]) => `${key}=${value}`)
    .join("\n");
}

function telegramSecretKey(botToken) {
  return createHmac("sha256", "WebAppData").update(botToken, "utf8").digest();
}

function buildInitData(fields) {
  const hash = createHmac("sha256", telegramSecretKey(TEST_TOKEN))
    .update(dataCheckString(fields), "utf8")
    .digest("hex");
  const wire = fields
    .map(([key, value]) => `${key}=${encodeURIComponent(value)}`)
    .join("&");
  return `${wire}&hash=${hash}`;
}

function signedUser(authDateSeconds, extraFields = []) {
  return buildInitData([
    ...extraFields,
    ["user", JSON.stringify({ id: 42, first_name: "Zul", language_code: "ms" })],
    ["auth_date", String(authDateSeconds)],
  ]);
}

/* ————— env / request harness ————— */

function makeKV() {
  const map = new Map();
  const ttlLog = [];
  return {
    async get(key) {
      return map.has(key) ? map.get(key) : null;
    },
    async put(key, value, opts) {
      ttlLog.push({ key, expirationTtl: opts?.expirationTtl ?? null });
      map.set(key, value);
    },
    async delete(key) {
      map.delete(key);
    },
    map,
    ttlLog,
  };
}

function makeEnv(kv) {
  return { BOT_TOKEN: TEST_TOKEN, WEBHOOK_SECRET: "wk-test-secret", chat_sessions: kv };
}

const handler = await import("../src/webhook.ts").then((m) => m.default.fetch);

function postSession(body, headers = {}, kvOverride = null) {
  const kv = kvOverride ?? makeKV();
  const req = new Request("https://host/api/session", {
    method: "POST",
    ...(body !== undefined ? { body, headers } : { headers }),
  });
  return { req, kv, resP: handler(req, makeEnv(kv), {}) };
}

/* ————— WK1 — the happy path still works under the cap ————— */

test("WK1 POST valid initData (under cap) → 200 {token: uuid}; exactly two 900s KV writes", async () => {
  const { kv, resP } = postSession(signedUser(Math.floor(Date.now() / 1000)));
  const res = await resP;
  assert.equal(res.status, 200, `expected 200, got ${res.status}: ${await res.clone().text()}`);
  const body = await res.json();
  assert.match(body.token, /^[0-9a-f-]{36}$/, "opaque UUID token (D-06)");
  assert.equal(kv.ttlLog.length, 2, "mint writes exactly two keys");
  for (const entry of kv.ttlLog) assert.strictEqual(entry.expirationTtl, 900, "TTL-only (PRIV-02)");
});

/* ————— WK2 — over-cap signed body → 413, category-only, no side effects ————— */

test("WK2 POST 4KB+ validly-signed initData → 413 malformed; zero KV writes; log carries ONLY the category", async () => {
  const kv = makeKV();
  const seen = [];
  const orig = console.log;
  console.log = (...args) => seen.push(args.map((a) => String(a)).join(" "));
  let res;
  try {
    // validly signed — proves the cap fires before/instead of validation,
    // and that a real signature cannot buy the body past the cap
    const overCapSigned = signedUser(Math.floor(Date.now() / 1000), [["start_param", "p".repeat(4900)]]);
    assert.ok(overCapSigned.length > 4096, "fixture must exceed the cap");
    res = await handler(
      new Request("https://host/api/session", { method: "POST", body: overCapSigned }),
      makeEnv(kv),
      {},
    );
  } finally {
    console.log = orig;
  }
  assert.equal(res.status, 413, `expected 413, got ${res.status}`);
  assert.deepEqual(await res.json(), { error: "malformed" }, "category-only body (D-14)");
  assert.equal(kv.map.size, 0, "no session minted");
  assert.equal(kv.ttlLog.length, 0, "no KV writes at all");
  assert.deepEqual(seen, ["[initdata] rejected: malformed"], "log is the category ONLY — no payload fragment, no ids");
});

/* ————— WK2b/WK3 — the two blind spots of a naive body cap ————— */

/* ————— WK2b/WK3 — the two blind spots of a naive body cap ————— */

test("WK2b lying Content-Length (declares 100, ships 5000+) → 413 via the post-read check", async () => {
  const { kv, resP } = postSession("a=".concat("b".repeat(5000)), { "content-length": "100" });
  const res = await resP;
  assert.equal(res.status, 413, "the post-read length check must backstop a lying header");
  assert.deepEqual(await res.json(), { error: "malformed" });
  assert.equal(kv.map.size, 0);
});

test("WK3 declared-length 999999 + unreadable body stream → handler RESOLVES 413 (must not await the body)", async () => {
  // The stream errors if any consumer pulls it. The assertion that matters:
  // handler() resolves with 413 — had the handler awaited req.text() on a
  // broken stream, the fetch call would REJECT instead. (Node/undici pulls
  // stream bodies opportunistically after construction, so pull-tracking is
  // implementation noise, not boundable here; the resolution outcome is.)
  let pulled = false;
  const unreadable = new ReadableStream({
    pull(controller) {
      pulled = true;
      controller.error(new Error("body must never be read (WR-01 pre-read path)"));
    },
  });
  void pulled;
  const kv = makeKV();
  const req = new Request("https://host/api/session", {
    method: "POST",
    headers: { "content-length": "999999" },
    body: unreadable,
    duplex: "half", // required by undici for stream bodies
  });
  const res = await handler(req, makeEnv(kv), {});
  assert.equal(res.status, 413, "resolve 413 — the pre-read check must refuse to buffer the declared-oversize body");
  assert.equal(kv.map.size, 0);
});

/* ————— WK4 — method gate ————— */

test("WK4 GET /api/session → 405", async () => {
  const req = new Request("https://host/api/session", { method: "GET" });
  const res = await handler(req, makeEnv(makeKV()), {});
  assert.equal(res.status, 405);
});

/* ————— WK5 — WR-02 fail-closed webhook gate ————— */

test("WK5 unarmed WEBHOOK_SECRET ('') → webhook rejects CLOSED with a constant 500, no bot run, no KV touch", async () => {
  const env = { BOT_TOKEN: TEST_TOKEN, WEBHOOK_SECRET: "", chat_sessions: undefined };
  const req = () => new Request("https://host/telegram/webhook", { method: "POST", body: '{\"update_id\":1}' });
  const res1 = await handler(req(), env, {});
  const res2 = await handler(req(), env, {});
  assert.equal(res1.status, 500, "missing binding must fail closed, not fall through to grammY's accept-everything compare");
  assert.equal(res2.status, 500, "the rejection is constant across calls");
  assert.equal(await res1.text(), "Server misconfigured");
  assert.equal(await res2.text(), "Server misconfigured");
  assert.ok(env.chat_sessions === undefined, "the guard fired before any storage or bot wiring was needed");
});