import assert from "node:assert/strict";
import { readFileSync } from "node:fs";
import { test } from "node:test";
import { type LlamaSwapConfig } from "../src/lib/util";
import { MetricsPoller } from "../src/lib/metrics-poller";
import { parseGpuMetrics } from "../src/lib/metrics-parser";

const FIXTURE = readFileSync(new URL("./fixtures/metrics.txt", import.meta.url), "utf8");
const FIXTURE2 = FIXTURE
  .replace(/llamaswap_gpu_util_percent\{id="0"[^}]*\} 100/, 'llamaswap_gpu_util_percent{id="0",name="RTX PRO 6000"} 30')
  .replace(/llamaswap_gpu_util_percent\{id="1"[^}]*\} 100/, 'llamaswap_gpu_util_percent{id="1",name="RTX PRO 6000"} 50')
  .replace(/llamaswap_gpu_util_percent\{id="2"[^}]*\} 100/, 'llamaswap_gpu_util_percent{id="2",name="RTX 5090"} 80');

function stubFetch(bodies: string[]) {
  let i = 0;
  return async () => bodies[Math.min(i++, bodies.length - 1)];
}

const CFG: LlamaSwapConfig = { baseUrl: "http://test" };

test("poller stores per-GPU history and computes aggregates", async () => {
  const poller = new MetricsPoller(CFG, 5000, stubFetch([FIXTURE, FIXTURE2]));
  await poller.tick();
  await poller.tick();

  assert.equal(poller.getValue("0", "util_percent"), 30);
  assert.deepEqual(poller.getHistory("0", "util_percent"), [100, 30]);

  const allUtil = poller.getValue("all", "util_percent");
  assert.ok(allUtil !== undefined);
  assert.ok(Math.abs(allUtil - (30 + 50 + 80) / 3) < 1e-9);

  const allTemp = poller.getValue("all", "temperature");
  assert.equal(allTemp, 64);

  const allPower = poller.getValue("all", "power");
  assert.ok(allPower !== undefined);
  assert.ok(Math.abs(allPower - (316.56 + 336.17 + 377.28)) < 1e-9);

  assert.deepEqual(poller.gpus().map((g) => g.id), ["0", "1", "2"]);
  assert.equal(poller.gpus()[2].name, "NVIDIA GeForce RTX 5090");
});

test("poller ring buffer caps at 60 samples", async () => {
  const poller = new MetricsPoller(CFG, 5000, stubFetch([FIXTURE]));
  for (let i = 0; i < 70; i++) await poller.tick();
  assert.equal(poller.getHistory("0", "fan").length, 60);
});

test("poller reports offline after a fetch failure and recovers", async () => {
  let fail = true;
  const fetchFn = async () => {
    if (fail) throw new Error("boom");
    return FIXTURE;
  };
  const poller = new MetricsPoller(CFG, 5000, fetchFn);
  await poller.tick();
  assert.equal(poller.isOffline(), true);
  fail = false;
  await poller.tick();
  assert.equal(poller.isOffline(), false);
  assert.ok(poller.getValue("0", "util_percent") !== undefined);
});