import assert from "node:assert";
import { test } from "node:test";
import fs from "node:fs";
import path from "node:path";
import { fileURLToPath } from "node:url";
import { spawnSync } from "node:child_process";

const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);

test("ui bench driver emits overlay + seed metadata", () => {
  const tmp = fs.mkdtempSync(path.join(process.cwd(), "tmp-ui-bench-"));
  const fixtureDir = path.join(tmp, "fixture");
  fs.mkdirSync(fixtureDir, { recursive: true });

  // minimal fixture files
  fs.writeFileSync(path.join(fixtureDir, "manifest.json"), JSON.stringify({ hashes: { nodes: "abc" } }));
  fs.writeFileSync(path.join(fixtureDir, "overlay.ndjson"), "{\"source\":\"a\",\"target\":\"b\"}\n");

  const scenariosPath = path.join(tmp, "scenarios.json");
  fs.writeFileSync(
    scenariosPath,
    JSON.stringify({ version: "1.0.0", scenarios: [{ id: "load", name: "Load", steps: ["navigate"] }] })
  );

  const outputPath = path.join(tmp, "plan.json");
  const env = { ...process.env, UI_BENCH_SEED: "1337", UI_BENCH_TRACE_ID: "trace-test" };
  const driverPath = path.join(__dirname, "ui_bench_driver.mjs");
  const result = spawnSync(process.execPath, [driverPath, fixtureDir, scenariosPath, outputPath], { env });
  assert.strictEqual(result.status, 0, result.stderr?.toString());

  const plan = JSON.parse(fs.readFileSync(outputPath, "utf-8"));
  assert.strictEqual(plan.fixture, "fixture");
  assert.strictEqual(plan.seed, "1337");
  assert.strictEqual(plan.traceId, "trace-test");
  assert.ok(plan.overlay);
  assert.ok(plan.overlay.path.endsWith("overlay.ndjson"));
  assert.ok(plan.overlay.sha256);
  assert.deepStrictEqual(plan.viewport, { width: 1280, height: 720, deviceScaleFactor: 1 });

  fs.rmSync(tmp, { recursive: true, force: true });
});