/**
 * The mesh issues an assignment's subjects, and a runtime serves what it is issued (novox/hq ADR
 * 0160). A runtime derives one address for itself — `mesh.assignment.<node>.<module>` — reads the
 * membership there, serves exactly what it says, and re-serves when a new one arrives. Against a
 * real bus with JetStream, because the membership is a direct get on a stream.
 *
 *   docker run -d --rm --name t -p 14232:4222 nats:2.10-alpine -js
 *   MESH_TEST_NATS=nats://127.0.0.1:14232 node --test --experimental-strip-types test/membership.test.ts
 */
import assert from "node:assert/strict";
import { test } from "node:test";
import { fileURLToPath } from "node:url";
import { connect, StringCodec } from "nats";

import { resetTools } from "@novox/mesh-sdk/tools";

import { connectNats, membershipSubject } from "../dist/broker-nats.js";
import { callTool, subjectListed } from "../dist/client.js";
import { runTools } from "../dist/runtime.js";

const url = process.env.MESH_TEST_NATS;
const fixture = (name: string) => fileURLToPath(new URL(`./fixtures/${name}`, import.meta.url));
const sc = StringCodec();

/** The ASSIGNMENTS stream as the controller asserts it: last-per-subject, readable by direct get. */
async function anAssignmentsStream() {
  const nc = await connect({ servers: url! });
  const jsm = await nc.jetstreamManager();
  try {
    await jsm.streams.delete("ASSIGNMENTS");
  } catch {
    // none yet
  }
  await jsm.streams.add({
    name: "ASSIGNMENTS",
    subjects: ["mesh.assignment.>"],
    max_msgs_per_subject: 1,
    allow_direct: true,
  } as never);
  return {
    async issue(m: object & { node: string; module: string }) {
      await nc.jetstream().publish(membershipSubject(m.node, m.module), sc.encode(JSON.stringify(m)));
    },
    async close() {
      await nc.close();
    },
  };
}

test("a runtime serves exactly the subjects it is issued, and the listing carries them", async (t) => {
  if (!url) return t.skip("MESH_TEST_NATS unset");
  resetTools();
  const stream = await anAssignmentsStream();
  // The mesh placed shop on two machines that are not interchangeable: each is served by name only.
  await stream.issue({
    node: "anchor",
    module: "shop",
    serves: [{ subject: "mesh.mod.shop.tool.{tool}.anchor" }],
    emits: "mesh.mod.shop.event.{event}",
    tools: "mesh.mod.shop.tool.tools",
  });
  const shop = await connectNats({ url, node: "anchor", module: "shop" });
  const asker = await connectNats({ url, module: "console", node: "workstation" });
  let stop = () => {};
  try {
    stop = await runTools({ broker: shop, moduleEntrypoints: [fixture("shop-tools.mjs")] });
    assert.equal(shop.membership()?.module, "shop", "the runtime read what the mesh issued");
    // By name it answers; the plain subject was not issued, so nothing serves it.
    const named = await callTool(asker, "shop.price@anchor", { of: "a hat" });
    assert.deepEqual(named.result, { of: "a hat", cost: 12 });
    assert.equal(named.node, "anchor");
    await assert.rejects(callTool(asker, "shop.price", {}), /no responders|503/i, "a subject not issued is not served");
    // The tools answer says where each is served, and the client composes nothing.
    const tools = await asker.request<Record<string, never>, { tools: { name: string; subjects?: string[] }[] }>(
      "shop.tools",
      {},
    );
    assert.deepEqual(tools.tools.find((x) => x.name === "price")?.subjects, ["mesh.mod.shop.tool.price.anchor"]);
    const listing = { tools: [{ module: "shop", name: "price", subjects: ["mesh.mod.shop.tool.price.anchor"] }], notAnswering: [] };
    assert.equal(subjectListed("shop.price", "anchor", listing as never), "mesh.mod.shop.tool.price.anchor");
    assert.equal(subjectListed("shop.price", "elsewhere", listing as never), undefined);

    // The mesh re-issues the membership with the plain subject too (the modules became
    // interchangeable); the runtime re-serves on it without a restart.
    await stream.issue({
      node: "anchor",
      module: "shop",
      serves: [{ subject: "mesh.mod.shop.tool.{tool}", queue: "serve.shop" }, { subject: "mesh.mod.shop.tool.{tool}.anchor" }],
      emits: "mesh.mod.shop.event.{event}",
      tools: "mesh.mod.shop.tool.tools",
    });
    await new Promise((r) => setTimeout(r, 300));
    const plain = await callTool(asker, "shop.price", { of: "a coat" });
    assert.deepEqual(plain.result, { of: "a coat", cost: 12 });
    assert.equal(plain.node, "anchor");
  } finally {
    stop();
    await asker.close();
    await shop.close();
    await stream.close();
  }
});

test("a seat's verbs are implemented under the seat's name, served where issued, never listed as the module's", async (t) => {
  if (!url) return t.skip("MESH_TEST_NATS unset");
  resetTools();
  const stream = await anAssignmentsStream();
  await stream.issue({
    node: "anchor",
    module: "postgres",
    serves: [{ subject: "mesh.mod.postgres.tool.{tool}", queue: "serve.postgres" }, { subject: "mesh.mod.postgres.tool.{tool}.anchor" }],
    seats: [{ seat: "mesh-store", verb: "databases", subject: "mesh.seat.mesh-store.tool.databases" }],
    emits: "mesh.mod.postgres.event.{event}",
    tools: "mesh.mod.postgres.tool.tools",
  });
  const credential = { url, node: "anchor", module: "postgres", claims: [{ seat: "mesh-store", scope: "mesh", serves: ["databases", "query"] }] };
  const pg = await connectNats(credential);
  const asker = await connectNats({ url, module: "console", node: "workstation" });
  let stop = () => {};
  try {
    stop = await runTools({ broker: pg, credential, moduleEntrypoints: [fixture("store-seat.mjs")] });
    // The module's own `databases` and the seat's are two tools: postgres's on its subject, the
    // store's on the seat's, each answering as itself.
    const own = await callTool(asker, "postgres.databases", {});
    assert.deepEqual(own.result, { software: "postgres" });
    const seat = await callTool(asker, "seat:mesh-store.databases", {});
    assert.deepEqual(seat.result, { seat: "mesh-store" });
    assert.equal(seat.node, "anchor");
    // What the seat does not promise — creating a database — is postgres's tool and not the store's.
    await assert.rejects(callTool(asker, "seat:mesh-store.postgres_create_database", {}), /no responders|503/i);
    // And the module's `tools` lists only postgres's own, never the seat's implementation.
    const tools = await asker.request<Record<string, never>, { module: string; tools: { name: string }[] }>("postgres.tools", {});
    assert.deepEqual(tools.tools.map((x) => x.name).sort(), ["databases", "postgres_create_database"]);
    await assert.rejects(asker.request("mesh-store.tools", {}), /no responders|503/i, "a seat is not a module with a tools verb");
  } finally {
    stop();
    await asker.close();
    await pg.close();
    await stream.close();
  }
});

test("a module named like its seat registers once, and answers as the module and as the seat", async (t) => {
  if (!url) return t.skip("MESH_TEST_NATS unset");
  resetTools();
  const stream = await anAssignmentsStream();
  await stream.issue({
    node: "anchor",
    module: "shop",
    serves: [{ subject: "mesh.mod.shop.tool.{tool}", queue: "serve.shop" }, { subject: "mesh.mod.shop.tool.{tool}.anchor" }],
    seats: [{ seat: "shop", verb: "price", subject: "mesh.seat.shop.tool.price" }],
    emits: "mesh.mod.shop.event.{event}",
    tools: "mesh.mod.shop.tool.tools",
  });
  const credential = { url, node: "anchor", module: "shop", claims: [{ seat: "shop", scope: "mesh", serves: ["price"] }] };
  const shop = await connectNats(credential);
  const asker = await connectNats({ url, module: "console", node: "workstation" });
  let stop = () => {};
  try {
    stop = await runTools({ broker: shop, credential, moduleEntrypoints: [fixture("shop-seat.mjs")] });
    assert.deepEqual((await callTool(asker, "shop.price", { of: "a hat" })).result, { of: "a hat", cost: 12 });
    assert.deepEqual((await callTool(asker, "seat:shop.price", { of: "a hat" })).result, { of: "a hat", cost: 12 });
    const tools = await asker.request<Record<string, never>, { tools: { name: string }[] }>("shop.tools", {});
    assert.deepEqual(tools.tools.map((x) => x.name), ["price", "refund"]);
  } finally {
    stop();
    await asker.close();
    await shop.close();
    await stream.close();
  }
});

test("a mesh that has issued nothing yet gets the derived shape, and says so", async (t) => {
  if (!url) return t.skip("MESH_TEST_NATS unset");
  const stream = await anAssignmentsStream();
  const said: string[] = [];
  const log = console.log;
  console.log = (...a: unknown[]) => said.push(a.join(" "));
  let lone;
  try {
    lone = await connectNats({ url, node: "home-server", module: "lone" });
  } finally {
    console.log = log;
  }
  const asker = await connectNats({ url, module: "console", node: "workstation" });
  try {
    assert.equal(lone.membership(), undefined);
    assert.ok(said.some((s) => /no membership issued for lone on home-server/.test(s)), said.join("\n"));
    await lone.handle("ping", async () => ({ pong: true }));
    assert.deepEqual((await callTool(asker, "lone.ping", {})).result, { pong: true });
    assert.deepEqual((await callTool(asker, "lone.ping@home-server", {})).result, { pong: true });
  } finally {
    await asker.close();
    await lone.close();
    await stream.close();
  }
});

// A module that implements a seat its credential does not (yet) claim is not served for it and does
// not fall over either: the runtime says so and serves the module's own tools.
test("a registration under a seat the credential does not claim is said and skipped, not fatal", async (t) => {
  if (!url) return t.skip("MESH_TEST_NATS unset");
  resetTools();
  const stream = await anAssignmentsStream();
  const credential = { url, node: "anchor", module: "postgres" };
  const pg = await connectNats(credential);
  const asker = await connectNats({ url, module: "console", node: "workstation" });
  const said: string[] = [];
  const log = console.log;
  console.log = (...a: unknown[]) => said.push(a.join(" "));
  let stop = () => {};
  try {
    stop = await runTools({ broker: pg, credential, moduleEntrypoints: [fixture("store-seat-unclaimed.mjs")] });
    console.log = log;
    assert.ok(said.some((s) => /registers tools under "mesh-store".*not served/.test(s)), said.join("\n"));
    assert.deepEqual((await callTool(asker, "postgres.databases", {})).result, { software: "postgres" });
    await assert.rejects(callTool(asker, "seat:mesh-store.databases", {}), /no responders|503/i);
  } finally {
    console.log = log;
    stop();
    await asker.close();
    await pg.close();
    await stream.close();
  }
});