/**
 * The runtime as the node-tools module (novox/hq ADR 0175 §6, to-be 38 WP3): started the way the
 * host starts it — `main.js` with the node's credential and MESH_TOOL_MODULES — it serves the bundles
 * AND answers MCP on loopback as the console, through which a tool it serves can be called.
 *
 *   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/node-tools-serve.test.ts
 */
import assert from "node:assert/strict";
import { test } from "node:test";
import { spawn, type ChildProcess } from "node:child_process";
import { mkdtemp, writeFile } from "node:fs/promises";
import { join } from "node:path";
import { fileURLToPath } from "node:url";

import { connectNats } from "../dist/broker-nats.js";

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

async function post(endpoint: string, body: unknown): Promise<any> {
  const res = await fetch(endpoint, { method: "POST", headers: { "content-type": "application/json" }, body: JSON.stringify(body) });
  return res.json();
}

test("as node-tools, serve loads the bundles and is the console on loopback", async (t) => {
  if (!url) return t.skip("MESH_TEST_NATS unset");
  // The catalogue, for discovery; the node credential names the runtime module and no claims.
  const catalogue = await connectNats({ url, module: "mesh-catalog" });
  await catalogue.handle("catalog_modules", async () => ({ modules: [{ module: "alpha" }] }));
  t.after(() => catalogue.close());
  const dir = await mkdtemp("/tmp/node-tools-");
  const credential = join(dir, "broker");
  await writeFile(credential, JSON.stringify({ url, node: "desk", module: "node-tools", user: "desk.node-tools", password: "x" }));
  const child: ChildProcess = spawn(process.execPath, ["dist/main.js"], {
    env: {
      ...process.env,
      MESH_BROKER_FILE: credential,
      MESH_TOOL_MODULES: `alpha=${fixture("many-alpha.serve.mjs")}`,
      MESH_CONSOLE_LISTEN: "127.0.0.1:0",
    },
    stdio: ["ignore", "pipe", "pipe"],
  });
  t.after(() => {
    child.kill("SIGTERM");
  });
  const endpoint = await new Promise<string>((resolve, reject) => {
    let out = "";
    let err = "";
    child.stdout!.on("data", (d) => {
      out += d.toString();
      const m = /listening on (http:\/\/[^/]+\/mcp) as desk\.node-tools/.exec(out);
      if (m) resolve(m[1]!);
    });
    child.stderr!.on("data", (d) => (err += d.toString()));
    child.on("exit", (code) => reject(new Error(`serve exited ${code}: ${err}`)));
  });
  const listed = await post(endpoint, { jsonrpc: "2.0", id: 1, method: "tools/list" });
  assert.deepEqual(listed.result.tools.map((x: any) => x.name).filter((n: string) => n.startsWith("alpha.")), ["alpha.one", "alpha.two"]);
  // A tool the same process serves on the bus, called through the console it also is.
  const called = await post(endpoint, { jsonrpc: "2.0", id: 2, method: "tools/call", params: { name: "alpha.one", arguments: { node: "desk" } } });
  assert.deepEqual(JSON.parse(called.result.content[0].text), { alpha: 1 });
});