#include <gtest/gtest.h>

#include <XCEngine/Components/AudioSourceComponent.h>
#include <XCEngine/Components/GameObject.h>
#include <XCEngine/Core/Math/Quaternion.h>
#include <XCEngine/Core/Math/Vector3.h>
#include <sstream>

using namespace XCEngine::Components;
using namespace XCEngine::Resources;

namespace {

AudioClip CreateMono16Clip(std::initializer_list<int16_t> samples, XCEngine::Core::uint32 sampleRate = 4) {
    AudioClip clip;
    XCEngine::Containers::Array<XCEngine::Core::uint8> pcmData;
    pcmData.ResizeUninitialized(samples.size() * sizeof(int16_t));

    size_t byteOffset = 0;
    for (const int16_t sample : samples) {
        const uint16_t encoded = static_cast<uint16_t>(sample);
        pcmData[byteOffset++] = static_cast<XCEngine::Core::uint8>(encoded & 0xFFu);
        pcmData[byteOffset++] = static_cast<XCEngine::Core::uint8>((encoded >> 8) & 0xFFu);
    }

    clip.SetSampleRate(sampleRate);
    clip.SetChannels(1);
    clip.SetBitsPerSample(16);
    clip.SetAudioFormat(AudioFormat::WAV);
    clip.SetPCMData(pcmData);
    clip.m_isValid = true;
    return clip;
}

AudioClip CreateStereo16Clip(std::initializer_list<int16_t> samples, XCEngine::Core::uint32 sampleRate = 4) {
    AudioClip clip;
    XCEngine::Containers::Array<XCEngine::Core::uint8> pcmData;
    pcmData.ResizeUninitialized(samples.size() * sizeof(int16_t));

    size_t byteOffset = 0;
    for (const int16_t sample : samples) {
        const uint16_t encoded = static_cast<uint16_t>(sample);
        pcmData[byteOffset++] = static_cast<XCEngine::Core::uint8>(encoded & 0xFFu);
        pcmData[byteOffset++] = static_cast<XCEngine::Core::uint8>((encoded >> 8) & 0xFFu);
    }

    clip.SetSampleRate(sampleRate);
    clip.SetChannels(2);
    clip.SetBitsPerSample(16);
    clip.SetAudioFormat(AudioFormat::WAV);
    clip.SetPCMData(pcmData);
    clip.m_isValid = true;
    return clip;
}

TEST(AudioSourceComponent, MonoClipMapsToStereoOutput) {
    AudioClip clip = CreateMono16Clip({32767, -32768}, 4);

    AudioSourceComponent source;
    source.SetSpatialize(false);
    source.SetClip(&clip);
    source.Play();

    float buffer[4] = {};
    source.ProcessAudio(
        buffer,
        2,
        2,
        XCEngine::Math::Vector3::Zero(),
        XCEngine::Math::Quaternion::Identity());

    EXPECT_NEAR(buffer[0], 32767.0f / 32768.0f, 1e-5f);
    EXPECT_NEAR(buffer[1], 32767.0f / 32768.0f, 1e-5f);
    EXPECT_NEAR(buffer[2], -1.0f, 1e-5f);
    EXPECT_NEAR(buffer[3], -1.0f, 1e-5f);
    EXPECT_FALSE(source.IsPlaying());
    EXPECT_FLOAT_EQ(source.GetTime(), 0.0f);
}

TEST(AudioSourceComponent, PauseSilencesUntilResumed) {
    AudioClip clip = CreateMono16Clip({32767, 16384}, 4);

    AudioSourceComponent source;
    source.SetSpatialize(false);
    source.SetClip(&clip);
    source.Play();
    source.Pause();

    float pausedBuffer[1] = {};
    source.ProcessAudio(
        pausedBuffer,
        1,
        1,
        XCEngine::Math::Vector3::Zero(),
        XCEngine::Math::Quaternion::Identity());
    EXPECT_FLOAT_EQ(pausedBuffer[0], 0.0f);

    source.Play();

    float resumedBuffer[1] = {};
    source.ProcessAudio(
        resumedBuffer,
        1,
        1,
        XCEngine::Math::Vector3::Zero(),
        XCEngine::Math::Quaternion::Identity());
    EXPECT_NEAR(resumedBuffer[0], 32767.0f / 32768.0f, 1e-5f);
}

TEST(AudioSourceComponent, LoopingWrapsAtClipEnd) {
    AudioClip clip = CreateMono16Clip({32767, -32768}, 4);

    AudioSourceComponent source;
    source.SetSpatialize(false);
    source.SetLooping(true);
    source.SetClip(&clip);
    source.Play();

    float buffer[4] = {};
    source.ProcessAudio(
        buffer,
        4,
        1,
        XCEngine::Math::Vector3::Zero(),
        XCEngine::Math::Quaternion::Identity());

    EXPECT_NEAR(buffer[0], 32767.0f / 32768.0f, 1e-5f);
    EXPECT_NEAR(buffer[1], -1.0f, 1e-5f);
    EXPECT_NEAR(buffer[2], 32767.0f / 32768.0f, 1e-5f);
    EXPECT_NEAR(buffer[3], -1.0f, 1e-5f);
    EXPECT_TRUE(source.IsPlaying());
}

TEST(AudioSourceComponent, PitchSupportsFractionalFramePlayback) {
    AudioClip clip = CreateMono16Clip({0, 32767, 0}, 4);

    AudioSourceComponent source;
    source.SetSpatialize(false);
    source.SetPitch(0.5f);
    source.SetClip(&clip);
    source.Play();

    float buffer[3] = {};
    source.ProcessAudio(
        buffer,
        3,
        1,
        XCEngine::Math::Vector3::Zero(),
        XCEngine::Math::Quaternion::Identity());

    const float peak = 32767.0f / 32768.0f;
    EXPECT_NEAR(buffer[0], 0.0f, 1e-5f);
    EXPECT_NEAR(buffer[1], peak * 0.5f, 1e-4f);
    EXPECT_NEAR(buffer[2], peak, 1e-5f);
    EXPECT_TRUE(source.IsPlaying());
    EXPECT_NEAR(source.GetTime(), 0.375f, 1e-5f);
}

TEST(AudioSourceComponent, PanControlsStereoBalanceForMonoClip) {
    AudioClip clip = CreateMono16Clip({32767}, 4);

    AudioSourceComponent leftSource;
    leftSource.SetSpatialize(false);
    leftSource.SetPan(-1.0f);
    leftSource.SetClip(&clip);
    leftSource.Play();

    float leftBuffer[2] = {};
    leftSource.ProcessAudio(
        leftBuffer,
        1,
        2,
        XCEngine::Math::Vector3::Zero(),
        XCEngine::Math::Quaternion::Identity());

    EXPECT_NEAR(leftBuffer[0], 32767.0f / 32768.0f, 1e-5f);
    EXPECT_NEAR(leftBuffer[1], 0.0f, 1e-5f);

    AudioSourceComponent rightSource;
    rightSource.SetSpatialize(false);
    rightSource.SetPan(1.0f);
    rightSource.SetClip(&clip);
    rightSource.Play();

    float rightBuffer[2] = {};
    rightSource.ProcessAudio(
        rightBuffer,
        1,
        2,
        XCEngine::Math::Vector3::Zero(),
        XCEngine::Math::Quaternion::Identity());

    EXPECT_NEAR(rightBuffer[0], 0.0f, 1e-5f);
    EXPECT_NEAR(rightBuffer[1], 32767.0f / 32768.0f, 1e-5f);
}

TEST(AudioSourceComponent, DopplerAdjustsPlaybackRateFromListenerVelocity) {
    AudioClip clip = CreateMono16Clip({0, 32767, 0, 0, 0}, 4);

    GameObject sourceObject("AudioSourceObject");
    sourceObject.GetTransform()->SetPosition(XCEngine::Math::Vector3(10.0f, 0.0f, 0.0f));

    auto* source = sourceObject.AddComponent<AudioSourceComponent>();
    XCEngine::Audio::Audio3DParams params;
    params.minDistance = 100.0f;
    params.maxDistance = 100000.0f;
    source->Set3DParams(params);
    source->SetClip(&clip);
    source->Play();

    float buffer[2] = {};
    source->ProcessAudio(
        buffer,
        2,
        1,
        XCEngine::Math::Vector3::Zero(),
        XCEngine::Math::Quaternion::Identity(),
        XCEngine::Math::Vector3(10.0f, 0.0f, 0.0f),
        1.0f,
        20.0f,
        4);

    const float peak = 32767.0f / 32768.0f;
    EXPECT_NEAR(buffer[0], 0.0f, 1e-5f);
    EXPECT_NEAR(buffer[1], peak * 0.5f, 1e-3f);
    EXPECT_TRUE(source->IsPlaying());
}

TEST(AudioSourceComponent, SourceVelocityAdjustsDopplerWhenMovingAway) {
    AudioClip clip = CreateMono16Clip({0, 32767, 0}, 4);

    GameObject sourceObject("MovingAudioSource");
    sourceObject.GetTransform()->SetPosition(XCEngine::Math::Vector3(10.0f, 0.0f, 0.0f));

    auto* source = sourceObject.AddComponent<AudioSourceComponent>();
    XCEngine::Audio::Audio3DParams params;
    params.minDistance = 100.0f;
    params.maxDistance = 100000.0f;
    source->Set3DParams(params);
    source->SetClip(&clip);
    source->Play();

    source->Update(0.0f);
    sourceObject.GetTransform()->SetPosition(XCEngine::Math::Vector3(20.0f, 0.0f, 0.0f));
    source->Update(1.0f);

    float buffer[2] = {};
    source->ProcessAudio(
        buffer,
        2,
        1,
        XCEngine::Math::Vector3::Zero(),
        XCEngine::Math::Quaternion::Identity(),
        XCEngine::Math::Vector3::Zero(),
        1.0f,
        20.0f,
        4);

    const float peak = 32767.0f / 32768.0f;
    EXPECT_NEAR(buffer[0], 0.0f, 1e-5f);
    EXPECT_NEAR(buffer[1], peak * (20.0f / 30.0f), 1e-3f);
}

TEST(AudioSourceComponent, SpatialPanUsesListenerRotationAndPanLevel) {
    AudioClip clip = CreateMono16Clip({32767}, 4);

    GameObject rightSourceObject("RightSource");
    rightSourceObject.GetTransform()->SetPosition(XCEngine::Math::Vector3(10.0f, 0.0f, 0.0f));

    auto* rightSource = rightSourceObject.AddComponent<AudioSourceComponent>();
    XCEngine::Audio::Audio3DParams params;
    params.minDistance = 0.0f;
    params.maxDistance = 100000.0f;
    params.panLevel = 1.0f;
    rightSource->Set3DParams(params);
    rightSource->SetClip(&clip);
    rightSource->Play();

    float identityBuffer[2] = {};
    rightSource->ProcessAudio(
        identityBuffer,
        1,
        2,
        XCEngine::Math::Vector3::Zero(),
        XCEngine::Math::Quaternion::Identity());

    EXPECT_GT(identityBuffer[1], identityBuffer[0]);

    GameObject rotatedSourceObject("RotatedRightSource");
    rotatedSourceObject.GetTransform()->SetPosition(XCEngine::Math::Vector3(10.0f, 0.0f, 0.0f));

    auto* rotatedSource = rotatedSourceObject.AddComponent<AudioSourceComponent>();
    rotatedSource->Set3DParams(params);
    rotatedSource->SetClip(&clip);
    rotatedSource->Play();

    float rotatedBuffer[2] = {};
    rotatedSource->ProcessAudio(
        rotatedBuffer,
        1,
        2,
        XCEngine::Math::Vector3::Zero(),
        XCEngine::Math::Quaternion::FromEulerAngles(0.0f, XCEngine::Math::PI, 0.0f));

    EXPECT_GT(rotatedBuffer[0], rotatedBuffer[1]);

    GameObject neutralSourceObject("NeutralPanSource");
    neutralSourceObject.GetTransform()->SetPosition(XCEngine::Math::Vector3(10.0f, 0.0f, 0.0f));

    auto* neutralSource = neutralSourceObject.AddComponent<AudioSourceComponent>();
    params.panLevel = 0.0f;
    neutralSource->Set3DParams(params);
    neutralSource->SetClip(&clip);
    neutralSource->Play();

    float neutralBuffer[2] = {};
    neutralSource->ProcessAudio(
        neutralBuffer,
        1,
        2,
        XCEngine::Math::Vector3::Zero(),
        XCEngine::Math::Quaternion::Identity());

    EXPECT_NEAR(neutralBuffer[0], neutralBuffer[1], 1e-5f);
}

TEST(AudioSourceComponent, SpreadControlsStereoWidthWhenSpatialized) {
    AudioClip clip = CreateStereo16Clip({32767, 0}, 4);

    GameObject narrowSourceObject("NarrowStereoSource");
    narrowSourceObject.GetTransform()->SetPosition(XCEngine::Math::Vector3::Zero());

    auto* narrowSource = narrowSourceObject.AddComponent<AudioSourceComponent>();
    XCEngine::Audio::Audio3DParams narrowParams;
    narrowParams.minDistance = 0.0f;
    narrowParams.maxDistance = 100000.0f;
    narrowParams.spread = 0.0f;
    narrowSource->Set3DParams(narrowParams);
    narrowSource->SetClip(&clip);
    narrowSource->Play();

    float narrowBuffer[2] = {};
    narrowSource->ProcessAudio(
        narrowBuffer,
        1,
        2,
        XCEngine::Math::Vector3::Zero(),
        XCEngine::Math::Quaternion::Identity());

    const float peak = 32767.0f / 32768.0f;
    EXPECT_NEAR(narrowBuffer[0], peak * 0.5f, 1e-5f);
    EXPECT_NEAR(narrowBuffer[1], peak * 0.5f, 1e-5f);

    GameObject wideSourceObject("WideStereoSource");
    wideSourceObject.GetTransform()->SetPosition(XCEngine::Math::Vector3::Zero());

    auto* wideSource = wideSourceObject.AddComponent<AudioSourceComponent>();
    XCEngine::Audio::Audio3DParams wideParams = narrowParams;
    wideParams.spread = 1.0f;
    wideSource->Set3DParams(wideParams);
    wideSource->SetClip(&clip);
    wideSource->Play();

    float wideBuffer[2] = {};
    wideSource->ProcessAudio(
        wideBuffer,
        1,
        2,
        XCEngine::Math::Vector3::Zero(),
        XCEngine::Math::Quaternion::Identity());

    EXPECT_NEAR(wideBuffer[0], peak, 1e-5f);
    EXPECT_NEAR(wideBuffer[1], 0.0f, 1e-5f);
}

TEST(AudioSourceComponent, HRTFSpatializesMonoSourceOnStereoOutput) {
    AudioClip clip = CreateMono16Clip({32767}, 4);

    XCEngine::Audio::Audio3DParams params;
    params.minDistance = 100.0f;
    params.maxDistance = 100000.0f;
    params.panLevel = 1.0f;

    GameObject baselineObject("BaselineSpatialSource");
    baselineObject.GetTransform()->SetPosition(XCEngine::Math::Vector3(10.0f, 0.0f, 0.0f));
    auto* baselineSource = baselineObject.AddComponent<AudioSourceComponent>();
    baselineSource->Set3DParams(params);
    baselineSource->SetClip(&clip);
    baselineSource->Play();

    float baselineBuffer[2] = {};
    baselineSource->ProcessAudio(
        baselineBuffer,
        1,
        2,
        XCEngine::Math::Vector3::Zero(),
        XCEngine::Math::Quaternion::Identity());

    EXPECT_NEAR(baselineBuffer[0], 0.0f, 1e-5f);
    EXPECT_GT(baselineBuffer[1], 0.0f);

    GameObject hrtfObject("HRTFSpatialSource");
    hrtfObject.GetTransform()->SetPosition(XCEngine::Math::Vector3(10.0f, 0.0f, 0.0f));
    auto* hrtfSource = hrtfObject.AddComponent<AudioSourceComponent>();
    hrtfSource->Set3DParams(params);
    hrtfSource->SetHRTFEnabled(true);
    hrtfSource->SetHRTFCrossFeed(0.25f);
    hrtfSource->SetClip(&clip);
    hrtfSource->Play();

    float hrtfBuffer[2] = {};
    hrtfSource->ProcessAudio(
        hrtfBuffer,
        1,
        2,
        XCEngine::Math::Vector3::Zero(),
        XCEngine::Math::Quaternion::Identity());

    EXPECT_GT(hrtfBuffer[0], baselineBuffer[0]);
    EXPECT_GT(hrtfBuffer[0], 0.0f);
    EXPECT_GT(hrtfBuffer[1], hrtfBuffer[0]);
}

TEST(AudioSourceComponent, MultipleSourcesCanReuseSameClipDecodedCache) {
    AudioClip clip = CreateMono16Clip({32767, -32768}, 4);
    const float* decodedBuffer = clip.GetDecodedPCMData().data();

    AudioSourceComponent sourceA;
    sourceA.SetSpatialize(false);
    sourceA.SetClip(&clip);
    sourceA.Play();

    AudioSourceComponent sourceB;
    sourceB.SetSpatialize(false);
    sourceB.SetClip(&clip);
    sourceB.Play();

    float bufferA[2] = {};
    float bufferB[2] = {};
    sourceA.ProcessAudio(
        bufferA,
        2,
        1,
        XCEngine::Math::Vector3::Zero(),
        XCEngine::Math::Quaternion::Identity());
    sourceB.ProcessAudio(
        bufferB,
        2,
        1,
        XCEngine::Math::Vector3::Zero(),
        XCEngine::Math::Quaternion::Identity());

    EXPECT_EQ(decodedBuffer, clip.GetDecodedPCMData().data());
    EXPECT_NEAR(bufferA[0], 32767.0f / 32768.0f, 1e-5f);
    EXPECT_NEAR(bufferA[1], -1.0f, 1e-5f);
    EXPECT_NEAR(bufferB[0], 32767.0f / 32768.0f, 1e-5f);
    EXPECT_NEAR(bufferB[1], -1.0f, 1e-5f);
}

TEST(AudioSourceComponent, SerializeRoundTripPreservesClipPathAndSpatialSettings) {
    AudioClip clip = CreateMono16Clip({32767}, 4);
    clip.m_path = "test://audio/runtime.wav";
    clip.m_name = "runtime.wav";

    AudioSourceComponent source;
    source.SetClip(&clip);
    source.SetVolume(0.75f);
    source.SetPitch(1.5f);
    source.SetPan(-0.25f);
    source.SetLooping(true);
    source.SetSpatialize(true);
    source.SetHRTFEnabled(true);
    source.SetHRTFCrossFeed(0.4f);
    source.SetHRTFQuality(3);

    XCEngine::Audio::Audio3DParams params;
    params.dopplerLevel = 2.0f;
    params.speedOfSound = 280.0f;
    params.minDistance = 2.0f;
    params.maxDistance = 64.0f;
    params.panLevel = 0.6f;
    params.spread = 0.3f;
    params.reverbZoneMix = 0.2f;
    source.Set3DParams(params);

    std::stringstream stream;
    source.Serialize(stream);

    AudioSourceComponent target;
    target.Deserialize(stream);

    EXPECT_EQ(target.GetClip(), nullptr);
    EXPECT_EQ(target.GetClipPath(), "test://audio/runtime.wav");
    EXPECT_FLOAT_EQ(target.GetVolume(), 0.75f);
    EXPECT_FLOAT_EQ(target.GetPitch(), 1.5f);
    EXPECT_FLOAT_EQ(target.GetPan(), -0.25f);
    EXPECT_TRUE(target.IsLooping());
    EXPECT_TRUE(target.IsSpatialize());
    EXPECT_TRUE(target.IsHRTFEnabled());
    EXPECT_FLOAT_EQ(target.GetHRTFCrossFeed(), 0.4f);
    EXPECT_EQ(target.GetHRTFQuality(), 3u);
    EXPECT_FLOAT_EQ(target.GetDopplerLevel(), 2.0f);
    EXPECT_FLOAT_EQ(target.Get3DParams().speedOfSound, 280.0f);
    EXPECT_FLOAT_EQ(target.Get3DParams().minDistance, 2.0f);
    EXPECT_FLOAT_EQ(target.Get3DParams().maxDistance, 64.0f);
    EXPECT_FLOAT_EQ(target.Get3DParams().panLevel, 0.6f);
    EXPECT_FLOAT_EQ(target.GetSpread(), 0.3f);
    EXPECT_FLOAT_EQ(target.GetReverbZoneMix(), 0.2f);
}

} // namespace