import {
  createUser,
  db,
  del,
  type FakeInstance,
  fakeInstance,
  formWithFile,
  get,
  patch,
  PNG,
  post,
  put,
  stubNetwork,
  test,
} from "../helpers.ts";
import { assert, assertEquals, assertMatch } from "@std/assert";
import { clearInstanceCaches } from "../../remote/gerbeur-instance.ts";
import type {
  FederationLoginResponse,
  FederationPeer,
} from "../../../shared/federation.ts";
import type { AuthResponse, SelfUser } from "../../../shared/user.ts";

const HOME = "https://home.test";

/** Puts `fake` behind the network, every other host answering 404. */
function network(...fakes: FakeInstance[]) {
  return stubNetwork((url, init) => {
    for (const fake of fakes) {
      const res = fake.handle(url, init);
      if (res) return res;
    }
    return new Response("", { status: 404 });
  });
}

async function trust(issuer: string, status = "trusted") {
  const admin = await createUser({ role: "admin" });
  return await put<FederationPeer>("/api/federation/peers", {
    auth: admin.auth,
    json: { instance: issuer, status },
  });
}

/** Signs in through `home` as `identity`, as the pages would. */
async function signIn(
  home: FakeInstance,
  identity: {
    sub: string;
    preferred_username: string;
    email: string;
    picture?: string;
  },
  inviteToken?: string,
) {
  const start = await post<FederationLoginResponse>("/api/federation/logins", {
    json: { instance: new URL(home.origin).host, inviteToken },
  });
  if (start.status !== 200) return start;
  const authorizeUrl = start.data.authorizeUrl;
  const code = home.issue(authorizeUrl, identity);
  return await post<AuthResponse>("/api/federation/sessions", {
    json: { code, state: new URL(authorizeUrl).searchParams.get("state") },
  });
}

const ALICE = {
  sub: "alice-id",
  preferred_username: "alice",
  email: "alice@home.example",
  picture: `${HOME}/api/users/alice-id/avatar?v=1`,
};

test("federation: a trusted instance's user signs in as name@host, once made", async () => {
  const home = await fakeInstance(HOME);
  using net = network(home);
  assertEquals((await trust("home.test")).data.name, "Fake home.test");

  const start = await post<FederationLoginResponse>("/api/federation/logins", {
    json: { instance: "home.test" },
  });
  const url = new URL(start.data.authorizeUrl);
  assertEquals(url.origin + url.pathname, `${HOME}/authorize`);
  assertEquals(url.searchParams.get("client_id"), "http://gerbeur.test");
  assertEquals(
    url.searchParams.get("redirect_uri"),
    "http://gerbeur.test/federation/callback",
  );
  assertEquals(url.searchParams.get("code_challenge_method"), "S256");

  const first = await signIn(home, ALICE);
  const { user, token } = first.data as AuthResponse;
  assertEquals(user.username, "alice@home.test");
  assertEquals(user.email, "alice@home.example");
  assertEquals(user.role, "user");
  assertEquals(user.avatarMime, "image/png");
  assert(net.calls.some((u) => u.pathname === "/api/users/alice-id/avatar"));

  const me = await get<SelfUser>("/api/me", {
    auth: { Authorization: `Bearer ${token}` },
  });
  assertEquals(me.data.id, user.id);

  // The same identity signs in to the same account.
  const again = await signIn(home, ALICE);
  assertEquals((again.data as AuthResponse).user.id, user.id);

  // It has no password here.
  const login = await post("/api/sessions", {
    json: { username: "alice@home.test", password: "" },
  });
  assertEquals(login.status, 401);
  assertEquals(
    (await get<SelfUser>("/api/users/@alice@home.test")).data.id,
    user.id,
  );
  // The client encodes the handle's `@`.
  assertEquals(
    (await get<SelfUser>("/api/users/@alice%40home.test")).data.id,
    user.id,
  );
});

test("federation: a login works once, with the code the home made for it", async () => {
  const home = await fakeInstance(HOME);
  using _net = network(home);
  await trust(HOME);
  const start = await post<FederationLoginResponse>("/api/federation/logins", {
    json: { instance: HOME },
  });
  const state = new URL(start.data.authorizeUrl).searchParams.get("state");
  const wrong = await post("/api/federation/sessions", {
    json: { code: "made-up", state },
  });
  assertEquals(wrong.status, 502);
  // The failed try used the login up.
  const code = home.issue(start.data.authorizeUrl, ALICE);
  const replay = await post("/api/federation/sessions", {
    json: { code, state },
  });
  assertEquals(replay.status, 400);
});

test("federation: an instance on neither list needs an invite, claimed on joining", async () => {
  const home = await fakeInstance(HOME);
  using _net = network(home);
  const refused = await signIn(home, ALICE);
  assertEquals(refused.status, 403);

  const inviter = await createUser();
  const { token } = (await post<{ token: string }>("/api/invites", {
    auth: inviter.auth,
  })).data;
  const joined = await signIn(home, ALICE, token);
  const { user } = joined.data as AuthResponse;
  assertEquals(user.username, "alice@home.test");
  const row = db.prepare(`SELECT invited_by FROM users WHERE id = ?;`).get(
    user.id,
  ) as { invited_by: string };
  assertEquals(row.invited_by, inviter.id);
  assertEquals((await get(`/api/invites/${token}`)).status, 404);

  // Once here, no invite is needed; another user of that instance still
  // needs one.
  assertEquals((await signIn(home, ALICE)).status, 200);
  const bob = { ...ALICE, sub: "bob-id", preferred_username: "bob" };
  assertEquals((await signIn(home, bob)).status, 403);
});

test("federation: blocking an instance refuses its users and ends their sessions", async () => {
  const home = await fakeInstance(HOME);
  using _net = network(home);
  await trust(HOME);
  const { token } = (await signIn(home, ALICE)).data as AuthResponse;
  const auth = { Authorization: `Bearer ${token}` };
  assertEquals((await get("/api/me", { auth })).status, 200);

  await trust(HOME, "blocked");
  assertEquals((await get("/api/me", { auth })).status, 401);
  assertEquals((await signIn(home, ALICE)).status, 403);

  const admin = await createUser({ role: "admin" });
  const peers = await get<FederationPeer[]>("/api/federation/peers", {
    auth: admin.auth,
  });
  assertEquals(peers.data.map((p) => p.status), ["blocked"]);
  assertEquals((await get<FederationPeer[]>("/api/federation/peers")).data, []);
  assertEquals(
    (await del("/api/federation/peers/home.test", { auth: admin.auth }))
      .status,
    200,
  );
  assertEquals((await get("/api/me", { auth })).status, 200);
});

test("federation: only admins edit the peers, which must answer as gerbeurs", async () => {
  const home = await fakeInstance(HOME);
  using _net = network(home);
  const user = await createUser();
  const admin = await createUser({ role: "admin" });
  assertEquals(
    (await put("/api/federation/peers", {
      auth: user.auth,
      json: { instance: HOME, status: "trusted" },
    })).status,
    403,
  );
  for (const instance of ["elsewhere.test", "https://home.test/path"]) {
    const res = await put("/api/federation/peers", {
      auth: admin.auth,
      json: { instance, status: "trusted" },
    });
    assert(res.status >= 400, instance);
  }
  assertEquals(
    (await put("/api/federation/peers", {
      auth: admin.auth,
      json: { instance: "http://gerbeur.test", status: "trusted" },
    })).status,
    400,
  );
});

test("federation: the home's events rename, update and sign out its users", async () => {
  const home = await fakeInstance(HOME);
  const other = await fakeInstance("https://other.test");
  using _net = network(home, other);
  await trust(HOME);
  const { user, token } = (await signIn(home, ALICE)).data as AuthResponse;
  const auth = { Authorization: `Bearer ${token}` };

  const update = await home.event(ALICE.sub, {
    type: "update",
    claims: { ...ALICE, preferred_username: "alicia", email: "a@new.example" },
  });
  assertEquals(
    (await post("/api/federation/events", { json: { event: update } }))
      .status,
    204,
  );
  const renamed = await get<SelfUser>("/api/me", { auth });
  assertEquals(renamed.data.username, "alicia@home.test");
  assertEquals(renamed.data.email, "a@new.example");
  // The old handle still leads to them.
  assertEquals(
    (await get<SelfUser>("/api/users/@alice@home.test")).data.id,
    user.id,
  );

  // Another instance can't speak for this one's users.
  const forged = await other.event(ALICE.sub, { type: "revoke" });
  assertEquals(
    (await post("/api/federation/events", { json: { event: forged } }))
      .status,
    400,
  );

  // Revoking a little later than the token was issued, as it would be.
  await new Promise((r) => setTimeout(r, 1100));
  const revoke = await home.event(ALICE.sub, { type: "revoke" });
  assertEquals(
    (await post("/api/federation/events", { json: { event: revoke } }))
      .status,
    204,
  );
  assertEquals((await get("/api/me", { auth })).status, 401);
});

test("federation: a home's events are refused from a blocked home, with an avatar elsewhere, and put off when its keys fail", async () => {
  const home = await fakeInstance(HOME);
  let keysDown = false;
  using net = stubNetwork((url, init) =>
    keysDown && url.pathname === "/.well-known/jwks.json"
      ? new Response("", { status: 503 })
      : home.handle(url, init) ?? new Response("", { status: 404 })
  );
  await trust(HOME);
  await signIn(home, ALICE);
  const send = async (payload: Record<string, unknown>) =>
    (await post("/api/federation/events", {
      json: { event: await home.event(ALICE.sub, payload) },
    })).status;

  // Answered 5xx, so that the home tries again rather than give up.
  keysDown = true;
  clearInstanceCaches();
  assertEquals(await send({ type: "revoke" }), 502);
  keysDown = false;

  const avatars = net.calls.filter((u) => u.pathname.endsWith("/avatar"))
    .length;
  assertEquals(
    await send({
      type: "update",
      claims: { ...ALICE, picture: "https://elsewhere.test/a.png" },
    }),
    400,
  );
  assertEquals(
    net.calls.filter((u) => u.pathname.endsWith("/avatar")).length,
    avatars,
  );

  await trust(HOME, "blocked");
  assertEquals(
    await send({
      type: "update",
      claims: { ...ALICE, preferred_username: "mallory" },
    }),
    403,
  );
  assertEquals(
    (await get<SelfUser>("/api/users/@alice@home.test")).data.username,
    "alice@home.test",
  );
});

test("federation: an instance that doesn't answer can be blocked, not trusted", async () => {
  using _net = network();
  assertEquals((await trust("https://down.test")).status, 502);
  const blocked = await trust("https://down.test", "blocked");
  assertEquals(blocked.status, 200);
  assertEquals(blocked.data.status, "blocked");
  assertEquals(blocked.data.name, null);
});

test("federation: an account from another instance changes its password, email, avatar and name there", async () => {
  const home = await fakeInstance(HOME);
  using _net = network(home);
  await trust(HOME);
  const { user, token } = (await signIn(home, ALICE)).data as AuthResponse;
  const auth = { Authorization: `Bearer ${token}` };
  const admin = await createUser({ role: "admin" });

  assertEquals(
    (await put("/api/me/password", {
      auth,
      json: { currentPassword: "", newPassword: "long-enough" },
    })).status,
    400,
  );
  assertEquals(
    (await patch("/api/me", { auth, json: { email: "x@example.test" } }))
      .status,
    400,
  );
  assertEquals(
    (await patch<SelfUser>("/api/me", { auth, json: { description: "hi" } }))
      .data.description,
    "hi",
  );
  assertEquals(
    (await put("/api/me/avatar", { auth, form: formWithFile(PNG) })).status,
    400,
  );
  assertEquals(
    (await patch(`/api/users/${user.id}/username`, {
      auth: admin.auth,
      json: { username: "bob" },
    })).status,
    400,
  );
});

test("federation: an email may be both a local account's and a remote one's", async () => {
  const home = await fakeInstance(HOME);
  using _net = network(home);
  await trust(HOME);
  const local = await createUser({ email: ALICE.email });
  const res = await signIn(home, ALICE);
  assertMatch((res.data as AuthResponse).user.username, /@home\.test$/);
  // A reset by that address reaches the local account only.
  const row = db.prepare(
    `SELECT COUNT(*) AS n FROM users WHERE lower(email) = lower(?);`,
  ).get(ALICE.email) as { n: number };
  assertEquals(row.n, 2);
  assertEquals(
    (await post("/api/password-resets", { json: { email: ALICE.email } }))
      .status,
    200,
  );
  const tokens = db.prepare(`SELECT user_id FROM password_reset_tokens;`)
    .all() as { user_id: string }[];
  assert(tokens.every((t) => t.user_id === local.id));
});