import { test } from "node:test";
import assert from "node:assert/strict";
import { EventEmitter } from "node:events";
import { delegateToQwen } from "../src/qwen-delegate.ts";

// Fake child_process.spawn: returns an EventEmitter with stdout/stderr sub-emitters and a
// kill() spy, driven manually by each test via the returned `child` handle.
function fakeSpawn() {
  const child: any = new EventEmitter();
  child.stdout = new EventEmitter();
  child.stderr = new EventEmitter();
  child.killed = false;
  child.kill = () => {
    child.killed = true;
  };
  const spawnFn = () => child;
  return { spawnFn, child };
}

test("resolves ok with trimmed stdout on exit code 0", async () => {
  const { spawnFn, child } = fakeSpawn();
  const promise = delegateToQwen("hi", { spawnFn });

  child.stdout.emit("data", "  OK\n");
  child.emit("close", 0);

  assert.deepEqual(await promise, { ok: true, output: "OK" });
});

test("resolves not-ok with stderr detail on non-zero exit", async () => {
  const { spawnFn, child } = fakeSpawn();
  const promise = delegateToQwen("hi", { spawnFn });

  child.stderr.emit("data", "API Key fehlt.\n");
  child.emit("close", 1);

  const result = await promise;
  assert.equal(result.ok, false);
  assert.match(result.output, /exited with code 1/);
  assert.match(result.output, /API Key fehlt/);
});

test("resolves not-ok when spawn itself fails (e.g. qwen not on PATH)", async () => {
  const { spawnFn, child } = fakeSpawn();
  const promise = delegateToQwen("hi", { spawnFn });

  child.emit("error", new Error("ENOENT"));

  const result = await promise;
  assert.equal(result.ok, false);
  assert.match(result.output, /failed to start qwen/);
});

test("times out and kills the child if it never exits", async () => {
  const { spawnFn, child } = fakeSpawn();
  const promise = delegateToQwen("hi", { spawnFn, timeoutMs: 10 });

  const result = await promise;
  assert.equal(result.ok, false);
  assert.match(result.output, /timed out/);
  assert.equal(child.killed, true);
});

test("ignores stderr warnings when the run still succeeds", async () => {
  const { spawnFn, child } = fakeSpawn();
  const promise = delegateToQwen("hi", { spawnFn });

  child.stderr.emit("data", "Warning: MCP server(s) failed to start: omniroute-search\n");
  child.stdout.emit("data", "OK\n");
  child.emit("close", 0);

  assert.deepEqual(await promise, { ok: true, output: "OK" });
});