import {
  computeLocalizationMap,
  createLocalizationAnalysisPlan,
  estimateLocalizationWorkload,
} from "/packages/acoustics-core/localization.js";
import {
  DEFAULT_LOCALIZATION_ALGORITHM,
  LOCALIZATION_ALGORITHM_IDS,
  localizationAlgorithmDefinition,
  localizationAlgorithmSupportsBackend,
} from "/packages/acoustics-core/localization-algorithms.js";
import {
  StreamingDasLocalizer,
  StreamingLocalizer,
  createLocalizationPlan,
  detectBandPeaks,
  localizeMultichannel,
} from "/packages/acoustics-core/realtime-localizer.js";
import {
  computeDasWithBackend,
  computeLocalizationWithBackend,
} from "/packages/webgpu-kernels/compute.js";

function createFixture(algorithm = "das") {
  const sampleRate = 4096;
  const arrayDefinition = {
    id: "algorithm-fixture",
    microphones: [
      { id: "nw", position: [-0.1, 0.1, 0] },
      { id: "ne", position: [0.1, 0.1, 0] },
      { id: "sw", position: [-0.1, -0.1, 0] },
      { id: "se", position: [0.1, -0.1, 0] },
    ],
  };
  let state = 0x9e3779b9;
  const emitted = Float32Array.from({ length: 128 }, () => {
    state ^= state << 13;
    state ^= state >>> 17;
    state ^= state << 5;
    return ((state >>> 0) / 0xffff_ffff) * 2 - 1;
  });
  const channels = arrayDefinition.microphones.map((_, microphoneIndex) =>
    Float32Array.from(
      { length: emitted.length },
      (_, sampleIndex) => emitted[Math.max(0, sampleIndex - microphoneIndex)],
    )
  );
  const scan = {
    z: 1,
    xMin: -0.2,
    xMax: 0.2,
    yMin: -0.2,
    yMax: 0.2,
    columns: 3,
    rows: 3,
  };
  const frequencyBands = [
    { id: "wide", minHz: 128, maxHz: 1800, color: "#65f2bf" },
  ];
  const experiment = {
    stft: { fftSize: 64, hopSize: 32, window: "hann" },
    scan,
    frequencyBands,
    beamforming: {
      algorithm,
      backend: "cpu",
      normalization: "peak",
      compensateFrequencyResponse: true,
    },
  };
  return {
    channels,
    sampleRate,
    arrayDefinition,
    scene: { speedOfSound: 343 },
    experiment,
  };
}

test("localization algorithm registry exposes explicit scale and backend semantics", () => {
  assertEqual(DEFAULT_LOCALIZATION_ALGORITHM, "das", "default algorithm");
  assertEqual(LOCALIZATION_ALGORITHM_IDS.join(","), "das,das-phat,gcc-phat", "registered ids");
  assertEqual(localizationAlgorithmDefinition("das").rawScale, "power", "DAS power scale");
  assertEqual(localizationAlgorithmDefinition("das-phat").rawScale, "score", "DAS-PHAT score scale");
  assertEqual(localizationAlgorithmDefinition("gcc-phat").rawScale, "score", "GCC-PHAT score scale");
  assert(localizationAlgorithmSupportsBackend("das-phat", "webgpu"), "DAS-PHAT WebGPU support");
  assert(!localizationAlgorithmSupportsBackend("gcc-phat", "webgpu"), "GCC-PHAT CPU-only support");
});

test("generic CPU dispatcher runs all algorithms with explicit raw-map scales", async () => {
  for (const algorithm of LOCALIZATION_ALGORITHM_IDS) {
    const fixture = createFixture(algorithm);
    const analysisPlan = createLocalizationAnalysisPlan(fixture);
    const workload = estimateLocalizationWorkload({ ...fixture, analysisPlan });
    const result = await computeLocalizationMap({
      ...fixture,
      analysisPlan,
      pointBatchSize: 1024,
      stftTransformBatchSize: 1024,
    });
    const definition = localizationAlgorithmDefinition(algorithm);

    assertEqual(result.algorithm, algorithm, `${algorithm} result id`);
    assertEqual(result.backend, "cpu", `${algorithm} backend`);
    assertEqual(result.bands[0].rawScale, definition.rawScale, `${algorithm} raw scale`);
    assertEqual(result.bands[0].rawMap.length, 9, `${algorithm} map shape`);
    assertEqual(result.bands[0].peak.rawScale, definition.rawScale, `${algorithm} peak scale`);
    assertEqual(
      "rawPower" in result.bands[0].peak,
      definition.rawScale === "power",
      `${algorithm} peak power field`,
    );
    assert(
      result.bands[0].rawMap.every((value) => Number.isFinite(value) && value >= 0),
      `${algorithm} finite nonnegative map`,
    );
    assert(workload.pointCount === 9 && workload.microphoneCount === 4, `${algorithm} workload`);
  }
});

test("backend dispatcher keeps GCC-PHAT on CPU and rejects an explicit GPU request", async () => {
  const fixture = createFixture("gcc-phat");
  const calls = [];
  const result = await computeLocalizationWithBackend(fixture, {
    computeGpu: async () => {
      calls.push("gpu");
      throw new Error("GCC-PHAT must not call WebGPU");
    },
    computeGccCpu: async () => {
      calls.push("gcc-cpu");
      return { backend: "cpu", algorithm: "gcc-phat", bands: [] };
    },
  });
  assertEqual(calls.join(","), "gcc-cpu", "GCC auto routing");
  assertEqual(result.algorithm, "gcc-phat", "GCC result");

  fixture.experiment.beamforming.backend = "webgpu";
  let backendError;
  try {
    await computeLocalizationWithBackend(fixture);
  } catch (error) {
    backendError = error;
  }
  assert(backendError instanceof TypeError, "explicit GCC WebGPU is rejected");

  let legacyError;
  try {
    await computeDasWithBackend(fixture);
  } catch (error) {
    legacyError = error;
  }
  assert(legacyError instanceof RangeError, "legacy DAS entry rejects GCC");
});

test("portable and streaming API accept an algorithm choice without Scene synthesis", async () => {
  const fixture = createFixture("gcc-phat");
  const config = {
    sampleRate: fixture.sampleRate,
    array: fixture.arrayDefinition,
    scan: fixture.experiment.scan,
    bands: fixture.experiment.frequencyBands,
    speedOfSound: fixture.scene.speedOfSound,
    stft: fixture.experiment.stft,
    algorithm: "gcc-phat",
    phatFloorRatio: 1e-5,
    normalization: "peak",
    computeOptions: { pointBatchSize: 1024, stftTransformBatchSize: 1024 },
  };
  const plan = createLocalizationPlan(config);
  const localized = await localizeMultichannel({ plan, channels: fixture.channels });
  assertEqual(plan.algorithm, "gcc-phat", "portable plan algorithm");
  assertEqual(plan.computeOptions.phatFloorRatio, 1e-5, "portable PHAT floor forwarding");
  assertEqual(plan.analysisPlan, plan.gccPhatPlan, "portable GCC plan alias");
  assertEqual(localized.algorithm, "gcc-phat", "portable result algorithm");
  assertEqual(localized.phatFloorRatio, 1e-5, "portable PHAT floor reaches GCC core");
  assertEqual(localized.bands[0].rawScale, "score", "portable score map");
  assertEqual(StreamingLocalizer, StreamingDasLocalizer, "streaming compatibility alias");

  const stream = new StreamingLocalizer({
    ...config,
    analysisWindowSamples: 128,
    analysisHopSamples: 128,
    maximumBufferedSamples: 256,
  });
  const streamed = await stream.push(fixture.channels);
  assertEqual(streamed.length, 1, "one GCC streaming result");
  assertEqual(streamed[0].algorithm, "gcc-phat", "streaming result algorithm");
  assertEqual(stream.getState().algorithm, "gcc-phat", "streaming state algorithm");
  assertEqual(stream.plan.gccPhatPlan.busy, false, "streaming GCC plan lock released");

  const scorePeaks = detectBandPeaks(
    Float32Array.of(0, 2, 0, 1),
    { z: 1, xMin: 0, xMax: 1, yMin: 0, yMax: 1, columns: 2, rows: 2 },
    { rawScale: "score", minimumPeakDistanceM: 0 },
  );
  assertEqual(scorePeaks[0].rawScale, "score", "portable peak scale");
  assertEqual(scorePeaks[0].rawScore, scorePeaks[0].rawValue, "portable score alias");
  assert(!("rawPower" in scorePeaks[0]), "score is not mislabeled as acoustic power");
});