// What holds keycloak to the `oidc-client` provision (oidc.ts): one confidential client per consumer,
// under the id and secret the mesh gave, redirecting only to the consumer's own callback under the
// names the mesh composed; made once and brought back on every apply; and a client the mesh did not
// make — same id or not — never adopted, changed or deleted.
//
// Keycloak is a fake: the admin routes the module touches, answering with the status codes and the
// shapes Keycloak gives. Run against the compiled module (npm test builds first), the way the runtime
// loads it.

import { test, after } from "node:test";
import assert from "node:assert/strict";
import { createServer, type IncomingMessage, type ServerResponse } from "node:http";
import { randomUUID } from "node:crypto";

import { KeycloakClient } from "../dist/client.js";
import { MARK, OidcClients, ROLES_MAPPER, realmOf, redirectsOf } from "../dist/oidc.js";

type Client = Record<string, any>;

/** The realm's clients, by internal id, and what the fake was asked. */
const realm = "Novox";
const clients = new Map<string, Client>();
const calls: string[] = [];

function body(req: IncomingMessage): Promise<any> {
  return new Promise((resolve) => {
    let raw = "";
    req.on("data", (c) => (raw += c));
    req.on("end", () => resolve(raw ? JSON.parse(raw) : undefined));
  });
}

function send(res: ServerResponse, status: number, value?: unknown): void {
  res.writeHead(status, { "Content-Type": "application/json" });
  res.end(value === undefined ? "" : JSON.stringify(value));
}

const server = createServer(async (req, res) => {
  const url = new URL(req.url!, "http://fake");
  calls.push(`${req.method} ${url.pathname}`);
  if (url.pathname === "/realms/master/protocol/openid-connect/token") {
    return send(res, 200, { access_token: "t", expires_in: 300 });
  }
  const base = `/admin/realms/${realm}/clients`;
  if (!url.pathname.startsWith(base)) return send(res, 404, { error: "Realm not found." });
  const rest = url.pathname.slice(base.length).split("/").filter(Boolean);
  if (rest.length === 0 && req.method === "GET") {
    const want = url.searchParams.get("clientId");
    return send(res, 200, [...clients.values()].filter((c) => !want || c.clientId === want));
  }
  if (rest.length === 0 && req.method === "POST") {
    const rep = await body(req);
    if ([...clients.values()].some((c) => c.clientId === rep.clientId)) {
      return send(res, 409, { errorMessage: `Client ${rep.clientId} already exists` });
    }
    const id = randomUUID();
    const mappers = (rep.protocolMappers ?? []).map((m: Client) => ({ ...m, id: randomUUID() }));
    clients.set(id, { ...rep, id, protocolMappers: mappers });
    return send(res, 201);
  }
  const c = clients.get(rest[0]);
  if (!c) return send(res, 404, { error: "Could not find client" });
  if (rest.length === 1 && req.method === "PUT") {
    // Keycloak ignores protocolMappers on a client update: they have their own endpoints.
    const rep = await body(req);
    clients.set(c.id, { ...rep, id: c.id, protocolMappers: c.protocolMappers });
    return send(res, 204);
  }
  if (rest.length === 1 && req.method === "DELETE") {
    clients.delete(c.id);
    return send(res, 204);
  }
  if (rest[1] === "client-secret" && req.method === "GET") {
    return send(res, 200, { type: "secret", value: c.secret });
  }
  if (rest[1] === "protocol-mappers") {
    if (req.method === "GET") return send(res, 200, c.protocolMappers ?? []);
    if (req.method === "POST") {
      c.protocolMappers = [...(c.protocolMappers ?? []), { ...(await body(req)), id: randomUUID() }];
      return send(res, 201);
    }
    if (req.method === "PUT") {
      const m = await body(req);
      c.protocolMappers = c.protocolMappers.map((x: Client) => (x.id === rest[4] ? m : x));
      return send(res, 204);
    }
  }
  send(res, 405);
});
await new Promise<void>((r) => server.listen(0, "127.0.0.1", r));
after(() => server.close());
const port = (server.address() as { port: number }).port;

const oidc = new OidcClients(new KeycloakClient(`http://127.0.0.1:${port}`, "admin", "pw"), realm);

/** Grafana on ace, as the mesh hands it to the provisioner. */
function grafana(secret = "s3cret", values: Record<string, unknown> = {}) {
  return {
    as: "mesh_ace_grafana",
    password: secret,
    consumer: "ace",
    values: {
      label: "grafana", endpoint: "web", port: 20010, callback: "/login/generic_oauth",
      name: "grafana.zurag.be", "internal-name": "grafana.ace.internal", ...values,
    },
  };
}

function only(clientId: string): Client {
  const found = [...clients.values()].filter((c) => c.clientId === clientId);
  assert.equal(found.length, 1, `exactly one client ${clientId}, found ${found.length}`);
  return found[0];
}

test("the realm is read out of the issuer, and an issuer that names none is refused", () => {
  assert.equal(realmOf("https://keycloak.novox.be/realms/Novox"), "Novox");
  assert.equal(realmOf("https://keycloak.novox.be/realms/Novox/"), "Novox");
  assert.equal(realmOf("http://127.0.0.1:18500/realms/master"), "master");
  assert.throws(() => realmOf("https://keycloak.novox.be"), /realms/);
  assert.throws(() => realmOf("keycloak"), /not a URL/);
});

test("the redirect is the consumer's callback under every name the mesh composed for it", () => {
  assert.deepEqual(redirectsOf(grafana().values), {
    root: "https://grafana.zurag.be",
    redirects: ["https://grafana.zurag.be/login/generic_oauth", "https://grafana.ace.internal/login/generic_oauth"],
  });
  // A route reaching only the private network has only the internal name, and that is enough.
  assert.deepEqual(redirectsOf({ callback: "/cb", "internal-name": "x.ace.internal" }).redirects,
    ["https://x.ace.internal/cb"]);
  assert.throws(() => redirectsOf({ name: "grafana.zurag.be" }), /callback/);
  assert.throws(() => redirectsOf({ name: "grafana.zurag.be", callback: "login" }), /callback/);
  assert.throws(() => redirectsOf({ callback: "/cb" }), /label/);
});

test("a consumer is given one confidential client, under its id and the mesh's secret", async () => {
  clients.clear();
  assert.equal(await oidc.ensure(grafana()), "created");
  const c = only("mesh_ace_grafana");
  assert.equal(c.publicClient, false);
  assert.equal(c.clientAuthenticatorType, "client-secret");
  assert.equal(c.secret, "s3cret");
  assert.equal(c.enabled, true);
  assert.equal(c.standardFlowEnabled, true);
  assert.equal(c.directAccessGrantsEnabled, false);
  assert.equal(c.implicitFlowEnabled, false);
  assert.deepEqual(c.redirectUris, [
    "https://grafana.zurag.be/login/generic_oauth", "https://grafana.ace.internal/login/generic_oauth"]);
  assert.equal(c.attributes[MARK], "true");
  assert.deepEqual(c.protocolMappers.map((m: Client) => m.name), [ROLES_MAPPER.name]);
  assert.equal(await oidc.holds(grafana()), true);
});

test("applying the same grant again makes no second client", async () => {
  clients.clear();
  await oidc.ensure(grafana());
  assert.equal(await oidc.ensure(grafana()), "updated");
  assert.equal(await oidc.ensure(grafana()), "updated");
  only("mesh_ace_grafana");
  assert.equal(only("mesh_ace_grafana").protocolMappers.length, 1, "the roles mapper is not added twice");
});

test("a new secret or a moved name is applied in place, and what the mesh does not own survives", async () => {
  clients.clear();
  await oidc.ensure(grafana());
  const id = only("mesh_ace_grafana").id;
  // Something the mesh does not own, set on the client after it was made.
  clients.get(id)!.consentRequired = true;
  clients.get(id)!.attributes["post.logout.redirect.uris"] = "+";

  assert.equal(await oidc.holds(grafana("rotated")), false, "a rotated secret is not held until applied");
  await oidc.ensure(grafana("rotated", { name: "dash.zurag.be" }));
  const c = only("mesh_ace_grafana");
  assert.equal(c.id, id, "updated, not replaced");
  assert.equal(c.secret, "rotated");
  assert.deepEqual(c.redirectUris, [
    "https://dash.zurag.be/login/generic_oauth", "https://grafana.ace.internal/login/generic_oauth"]);
  assert.equal(c.rootUrl, "https://dash.zurag.be");
  assert.equal(c.consentRequired, true);
  assert.equal(c.attributes["post.logout.redirect.uris"], "+");
  assert.equal(c.attributes[MARK], "true");
  assert.equal(await oidc.holds(grafana("rotated", { name: "dash.zurag.be" })), true);
});

test("a client lost or edited behind the mesh's back is not held, and is made whole again", async () => {
  clients.clear();
  await oidc.ensure(grafana());
  const c = only("mesh_ace_grafana");
  c.redirectUris = ["*"];
  assert.equal(await oidc.holds(grafana()), false, "a widened redirect is not what the mesh gave");
  await oidc.ensure(grafana());
  assert.equal(await oidc.holds(grafana()), true);

  only("mesh_ace_grafana").protocolMappers = [];
  assert.equal(await oidc.holds(grafana()), false, "a client without its roles mapper is not held");
  await oidc.ensure(grafana());
  assert.equal(await oidc.holds(grafana()), true);

  clients.clear();
  assert.equal(await oidc.holds(grafana()), false);
});

test("a client of the same id the mesh did not make is refused, and left exactly as it was", async () => {
  clients.clear();
  clients.set("theirs", { id: "theirs", clientId: "mesh_ace_grafana", secret: "their-secret", redirectUris: ["*"] });
  const before = JSON.stringify(clients.get("theirs"));
  const writes = calls.length;
  await assert.rejects(oidc.ensure(grafana()), /did not make/);
  assert.equal(JSON.stringify(clients.get("theirs")), before);
  assert.ok(calls.slice(writes).every((c) => c.startsWith("GET") || c.startsWith("POST /realms/master")),
    `only reads were made: ${calls.slice(writes).join(", ")}`);
  assert.equal(await oidc.holds(grafana()), false);
  assert.equal(await oidc.remove("mesh_ace_grafana"), "not ours");
  assert.ok(clients.has("theirs"), "a client the mesh did not make is never deleted");
});

test("the predecessor's hand-made client is never touched: the mesh's has its own id", async () => {
  clients.clear();
  clients.set("hal", { id: "hal", clientId: "grafana", secret: "old", redirectUris: ["https://grafana.zurag.be/*"] });
  await oidc.ensure(grafana());
  assert.equal(clients.get("hal")!.secret, "old");
  only("mesh_ace_grafana");
  assert.equal(await oidc.remove("grafana"), "not ours");
  assert.ok(clients.has("hal"));
});

test("a withdrawn consumer's client is removed, and an absent one is not an error", async () => {
  clients.clear();
  await oidc.ensure(grafana());
  assert.equal(await oidc.remove("mesh_ace_grafana"), "removed");
  assert.equal([...clients.values()].length, 0);
  assert.equal(await oidc.remove("mesh_ace_grafana"), "absent");
});

test("a contribution with no callback makes no client at all", async () => {
  clients.clear();
  await assert.rejects(oidc.ensure({ ...grafana(), values: { name: "grafana.zurag.be" } }), /callback/);
  assert.equal(clients.size, 0);
});