import { distance3 } from "/packages/acoustics-core/math.js";
import { synthesizeMicrophoneSignals } from "/packages/acoustics-core/propagation.js";
import { computeDasWebGpu } from "/packages/webgpu-kernels/das.js";

const status = document.querySelector("#benchmark-status");
const output = document.querySelector("#benchmark-output");
const runButton = document.querySelector("#run-benchmark");
const downloadButton = document.querySelector("#download-result");
const query = new URLSearchParams(location.search);
const requestedRuns = Number.parseInt(query.get("runs") ?? "3", 10);
const runCount = Number.isInteger(requestedRuns) ? Math.min(5, Math.max(1, requestedRuns)) : 3;
let latestResult = null;

async function loadJson(path) {
  const response = await fetch(path);
  if (!response.ok) throw new Error(`${path}를 불러오지 못했습니다 (${response.status}).`);
  return response.json();
}

function median(values) {
  const sorted = [...values].sort((a, b) => a - b);
  const middle = Math.floor(sorted.length / 2);
  return sorted.length % 2 === 1 ? sorted[middle] : (sorted[middle - 1] + sorted[middle]) / 2;
}

function round(value, digits = 3) {
  const scale = 10 ** digits;
  return Math.round(value * scale) / scale;
}

function cloneExperiment(experiment, size) {
  return {
    ...experiment,
    id: `single-tone-${size}x${size}`,
    scan: { ...experiment.scan, columns: size, rows: size },
    beamforming: { ...experiment.beamforming, backend: "webgpu" },
  };
}

function downloadJson(value, filename) {
  const blob = new Blob([`${JSON.stringify(value, null, 2)}\n`], { type: "application/json" });
  const url = URL.createObjectURL(blob);
  const anchor = document.createElement("a");
  anchor.href = url;
  anchor.download = filename;
  anchor.click();
  setTimeout(() => URL.revokeObjectURL(url), 0);
}

async function runBenchmark() {
  runButton.disabled = true;
  downloadButton.disabled = true;
  document.documentElement.dataset.benchmarkStatus = "running";
  delete document.documentElement.dataset.benchmarkError;
  latestResult = null;
  globalThis.__micarrsimBenchmarkResult = null;
  output.textContent = "";
  try {
    const [arrayDefinition, scene, baseExperiment] = await Promise.all([
      loadJson("/assets/array-geometries/rectangular-16x12.array.json"),
      loadJson("/assets/sample-scenes/single-tone.scene.json"),
      loadJson("/assets/sample-scenes/single-tone.experiment.json"),
    ]);
    status.textContent = "192채널 마이크 신호를 한 번 합성하고 있습니다…";
    const signalStartedAt = performance.now();
    const synthesis = synthesizeMicrophoneSignals({ scene, arrayDefinition });
    const signalGenerationMs = performance.now() - signalStartedAt;
    let adapterInfo = null;

    status.textContent = "WebGPU pipeline을 예열하고 있습니다…";
    await computeDasWebGpu({
      channels: synthesis.channels,
      sampleRate: synthesis.sampleRate,
      arrayDefinition,
      scene,
      experiment: cloneExperiment(baseExperiment, 16),
    });

    const resolutions = [];
    for (const size of [50, 100, 200]) {
      const samples = [];
      for (let runIndex = 0; runIndex < runCount; runIndex += 1) {
        status.textContent = `${size}×${size} · ${runIndex + 1}/${runCount} 실행 중…`;
        const result = await computeDasWebGpu({
          channels: synthesis.channels,
          sampleRate: synthesis.sampleRate,
          arrayDefinition,
          scene,
          experiment: cloneExperiment(baseExperiment, size),
          onProgress: ({ stage, completedUnits, totalUnits }) => {
            if (stage === "beamforming" && totalUnits) {
              status.textContent =
                `${size}×${size} · ${runIndex + 1}/${runCount} · GPU ${completedUnits}/${totalUnits}`;
            }
          },
        });
        adapterInfo = result.gpu.adapterInfo;
        const localizationErrorM = distance3(result.bands[0].peak.position, scene.sources[0].position);
        samples.push({
          totalMs: result.timingMs.total,
          stftMs: result.timingMs.stft,
          gpuWallMs: result.timingMs.gpuWall,
          beamformingMs: result.timingMs.beamforming,
          localizationErrorM,
          complexMacCount: result.workload.complexMacCount,
          estimatedGpuWorkingBytes: result.gpu.batchPlan.estimatedGpuWorkingBytes,
          binBatchSize: result.gpu.batchPlan.binBatchSize,
          pointBatchSize: result.gpu.batchPlan.pointBatchSize,
        });
      }
      resolutions.push({
        grid: `${size}x${size}`,
        pointCount: size * size,
        runs: runCount,
        medianTotalMs: round(median(samples.map((sample) => sample.totalMs))),
        medianStftMs: round(median(samples.map((sample) => sample.stftMs))),
        medianGpuWallMs: round(median(samples.map((sample) => sample.gpuWallMs))),
        medianBeamformingMs: round(median(samples.map((sample) => sample.beamformingMs))),
        localizationErrorM: round(median(samples.map((sample) => sample.localizationErrorM)), 6),
        complexMacCount: samples[0].complexMacCount,
        estimatedGpuWorkingMiB: round(samples[0].estimatedGpuWorkingBytes / 1024 ** 2),
        binBatchSize: samples[0].binBatchSize,
        pointBatchSize: samples[0].pointBatchSize,
        samples: samples.map((sample) => ({
          totalMs: round(sample.totalMs),
          stftMs: round(sample.stftMs),
          gpuWallMs: round(sample.gpuWallMs),
          beamformingMs: round(sample.beamformingMs),
        })),
      });
      output.textContent = JSON.stringify(resolutions, null, 2);
    }

    const baselineGpuMs = resolutions[0].medianGpuWallMs;
    for (const resolution of resolutions) {
      resolution.gpuWallScalingVs50 = round(resolution.medianGpuWallMs / baselineGpuMs, 2);
    }
    latestResult = {
      schemaVersion: "1.0.0",
      kind: "micarrsim.webgpu-benchmark",
      createdAt: new Date().toISOString(),
      fixture: {
        arrayId: arrayDefinition.id,
        microphoneCount: arrayDefinition.microphones.length,
        sceneId: scene.id,
        durationSeconds: scene.duration,
        sampleRate: scene.sampleRate,
        fftSize: baseExperiment.stft.fftSize,
        hopSize: baseExperiment.stft.hopSize,
        selectedBandHz: baseExperiment.frequencyBands.map(({ minHz, maxHz }) => [minHz, maxHz]),
      },
      environment: {
        userAgent: navigator.userAgent,
        adapterInfo,
        timingKind: "wall-clock",
        note: "GPU wall time starts after host packing/writeBuffer calls and waits for queued transfers, two compute passes, and readback; total also includes device/pipeline setup and CPU STFT.",
      },
      signalGenerationMs: round(signalGenerationMs),
      warmupGrid: "16x16",
      resolutions,
    };
    output.textContent = JSON.stringify(latestResult, null, 2);
    globalThis.__micarrsimBenchmarkResult = latestResult;
    document.documentElement.dataset.benchmarkStatus = "pass";
    status.textContent = "benchmark 완료";
    downloadButton.disabled = false;
  } catch (error) {
    document.documentElement.dataset.benchmarkStatus = "fail";
    document.documentElement.dataset.benchmarkError = error.message;
    status.textContent = `benchmark 실패: ${error.message}`;
    output.textContent = error instanceof Error ? error.stack : String(error);
    throw error;
  } finally {
    runButton.disabled = false;
  }
}

runButton.addEventListener("click", () => runBenchmark().catch(() => {}));
downloadButton.addEventListener("click", () => {
  if (latestResult) downloadJson(latestResult, "micarrsim-webgpu-benchmark.json");
});

if (query.get("autorun") !== "0") runBenchmark().catch(() => {});