import assert from "node:assert/strict";
import { spawn } from "node:child_process";
import { createServer } from "node:http";
import test from "node:test";

const bunCommand = process.env.HWLAB_TEST_BUN_COMMAND || process.env.HWLAB_BUN_COMMAND || (process.versions.bun ? process.execPath : "bun");

test("edge proxy reports local health and proxies live health to upstream", async () => {
  const upstream = await startUpstream();
  const proxy = await startEdgeProxy(upstream.port);
  try {
    const health = await fetchJson(`http://127.0.0.1:${proxy.port}/health`);
    assert.equal(health.serviceId, "hwlab-edge-proxy");
    assert.equal(health.status, "ok");
    assert.equal(health.service.role, "public-dev-ingress");
    assert.equal(health.details.upstream, `http://127.0.0.1:${upstream.port}`);
    assert.equal(health.details.mode, "dev-edge-proxy");

    const routes = await fetchJson(`http://127.0.0.1:${proxy.port}/routes`);
    assert.equal(routes.serviceId, "hwlab-edge-proxy");
    assert.deepEqual(routes.routes, [{
      pathPrefix: "/",
      upstream: `http://127.0.0.1:${upstream.port}`,
      mode: "http-proxy"
    }]);

    const live = await fetchJson(`http://127.0.0.1:${proxy.port}/health/live`);
    assert.equal(live.serviceId, "hwlab-cloud-api");
    assert.equal(live.environment, "v02");
    assert.equal(upstream.captured.method, "GET");
    assert.equal(upstream.captured.url, "/health/live");
  } finally {
    await proxy.stop();
    await upstream.stop();
  }
});

async function startUpstream() {
  let captured = null;
  const server = createServer(async (request, response) => {
    const chunks = [];
    for await (const chunk of request) chunks.push(chunk);
    captured = {
      method: request.method,
      url: request.url,
      body: Buffer.concat(chunks).toString("utf8")
    };
    response.writeHead(200, { "content-type": "application/json" });
    response.end(JSON.stringify({
      serviceId: "hwlab-cloud-api",
      environment: "v02",
      status: "live"
    }));
  });
  await new Promise((resolve) => server.listen(0, "127.0.0.1", resolve));
  return {
    port: server.address().port,
    get captured() {
      return captured;
    },
    stop: () => new Promise((resolve) => server.close(resolve))
  };
}

async function startEdgeProxy(upstreamPort) {
  const port = await freePort();
  const child = spawn(bunCommand, ["run", "cmd/hwlab-edge-proxy/main.ts"], {
    cwd: process.cwd(),
    env: {
      ...process.env,
      HWLAB_EDGE_HOST: "127.0.0.1",
      HWLAB_EDGE_PORT: String(port),
      HWLAB_EDGE_UPSTREAM: `http://127.0.0.1:${upstreamPort}`
    },
    stdio: ["ignore", "pipe", "pipe"]
  });
  await waitForListening(child, "edge proxy");
  return {
    port,
    stop: () => stopChild(child)
  };
}

async function fetchJson(url, options = {}) {
  const response = await fetch(url, options);
  assert.equal(response.ok, true, `${url} returned ${response.status}`);
  return response.json();
}

async function freePort() {
  const server = createServer();
  await new Promise((resolve) => server.listen(0, "127.0.0.1", resolve));
  const port = server.address().port;
  await new Promise((resolve) => server.close(resolve));
  return port;
}

async function waitForListening(child, label) {
  let stderr = "";
  child.stderr.on("data", (chunk) => {
    stderr += chunk;
  });
  await new Promise((resolve, reject) => {
    const timer = setTimeout(() => reject(new Error(`${label} did not start: ${stderr}`)), 5000);
    child.stdout.on("data", (chunk) => {
      if (chunk.toString().includes("listening")) {
        clearTimeout(timer);
        resolve();
      }
    });
    child.on("exit", (code) => {
      clearTimeout(timer);
      reject(new Error(`${label} exited early code=${code}: ${stderr}`));
    });
  });
}

async function stopChild(child) {
  if (child.exitCode !== null) return;
  child.kill("SIGTERM");
  await new Promise((resolve) => child.once("exit", resolve));
}