#include <XCEngine/Audio/AudioSystem.h>
#include <XCEngine/Audio/WindowsAudioBackend.h>
#include <XCEngine/Components/AudioSourceComponent.h>
#include <iostream>

namespace XCEngine {
namespace Audio {

AudioSystem& AudioSystem::Get() {
    static AudioSystem instance;
    return instance;
}

void AudioSystem::Initialize(const AudioConfig& config) {
    if (m_backend) {
        Shutdown();
    }

    m_backend = std::make_unique<Audio::WASAPI::WASAPIBackend>();
    if (m_backend->Initialize(config)) {
        m_backend->Start();
        std::cout << "AudioSystem initialized successfully" << std::endl;
    } else {
        std::cout << "Failed to initialize AudioSystem" << std::endl;
        m_backend.reset();
    }
}

void AudioSystem::Shutdown() {
    if (m_backend) {
        m_backend->Stop();
        m_backend->Shutdown();
        m_backend.reset();
    }
    m_activeSources.clear();
}

void AudioSystem::Update(float deltaTime) {
    m_deltaTime = deltaTime;

    if (!m_backend || !m_backend->IsRunning()) {
        return;
    }

    const auto& config = m_backend->GetConfig();
    uint32 sampleCount = config.bufferSize * config.channels;

    std::vector<float> mixBuffer(sampleCount, 0.0f);

    for (auto* source : m_activeSources) {
        if (source && source->IsEnabled() && source->IsPlaying()) {
            ProcessSource(source, mixBuffer.data(), sampleCount, config.channels);
        }
    }

    m_backend->ProcessAudio(mixBuffer.data(), sampleCount, config.channels, config.sampleRate);

    uint32 activeCount = 0;
    for (auto* source : m_activeSources) {
        if (source && source->IsPlaying()) {
            activeCount++;
        }
    }
    m_stats.activeSources = activeCount;
    m_stats.totalSources = static_cast<uint32>(m_activeSources.size());
}

void AudioSystem::SetBackend(std::unique_ptr<IAudioBackend> backend) {
    m_backend = std::move(backend);
}

std::string AudioSystem::GetCurrentDevice() const {
    if (m_backend) {
        return m_backend->GetDeviceName();
    }
    return "";
}

void AudioSystem::SetDevice(const std::string& deviceName) {
    if (m_backend) {
        m_backend->SetDevice(deviceName);
    }
}

void AudioSystem::GetAvailableDevices(std::vector<std::string>& devices) {
    if (m_backend) {
        m_backend->GetAvailableDevices(devices);
    }
}

float AudioSystem::GetMasterVolume() const {
    if (m_backend) {
        return m_backend->GetMasterVolume();
    }
    return 1.0f;
}

void AudioSystem::SetMasterVolume(float volume) {
    if (m_backend) {
        m_backend->SetMasterVolume(volume);
    }
}

bool AudioSystem::IsMuted() const {
    if (m_backend) {
        return m_backend->IsMuted();
    }
    return false;
}

void AudioSystem::SetMuted(bool muted) {
    if (m_backend) {
        m_backend->SetMuted(muted);
    }
}

void AudioSystem::ProcessAudio(float* buffer, uint32 sampleCount, uint32 channels) {
    if (m_backend) {
        m_backend->ProcessAudio(buffer, sampleCount, channels, 48000);
    }
}

void AudioSystem::SetListenerTransform(const Math::Vector3& position, const Math::Quaternion& rotation) {
    m_listenerPosition = position;
    m_listenerRotation = rotation;
}

void AudioSystem::SetListenerVelocity(const Math::Vector3& velocity) {
    m_listenerVelocity = velocity;
}

void AudioSystem::RegisterSource(Components::AudioSourceComponent* source) {
    if (source) {
        m_activeSources.push_back(source);
    }
}

void AudioSystem::UnregisterSource(Components::AudioSourceComponent* source) {
    if (!source) {
        return;
    }

    auto it = std::find(m_activeSources.begin(), m_activeSources.end(), source);
    if (it != m_activeSources.end()) {
        m_activeSources.erase(it);
    }
}

void AudioSystem::ProcessSource(Components::AudioSourceComponent* source, float* buffer, uint32 sampleCount, uint32 channels) {
    if (!source || !buffer) {
        return;
    }

    source->ProcessAudio(buffer, sampleCount, channels, m_listenerPosition, m_listenerRotation);
}

} // namespace Audio
} // namespace XCEngine