#include <XCEngine/Resources/AudioClip/AudioLoader.h>
#include <XCEngine/Core/Asset/ResourceManager.h>
#include <XCEngine/Core/Asset/ResourceTypes.h>
#include <cstring>

namespace XCEngine {
namespace Resources {

namespace {

struct WAVHeader {
    uint32_t sampleRate = 44100;
    uint32_t channels = 2;
    uint32_t bitsPerSample = 16;
    uint32_t dataSize = 0;
    uint32_t dataOffset = 44;
};

bool ParseWAVHeader(const uint8_t* data, size_t size, WAVHeader& header) {
    if (size < 44) {
        return false;
    }

    if (data[0] != 'R' || data[1] != 'I' || data[2] != 'F' || data[3] != 'F') {
        return false;
    }

    if (data[8] != 'W' || data[9] != 'A' || data[10] != 'V' || data[11] != 'E') {
        return false;
    }

    if (data[12] != 'f' || data[13] != 'm' || data[14] != 't' || data[15] != ' ') {
        return false;
    }

    uint32_t subchunk1Size = *reinterpret_cast<const uint32_t*>(&data[16]);
    if (subchunk1Size < 16) {
        return false;
    }

    uint16_t audioFormat = *reinterpret_cast<const uint16_t*>(&data[20]);
    if (audioFormat != 1) {
        return false;
    }

    header.channels = *reinterpret_cast<const uint16_t*>(&data[22]);
    header.sampleRate = *reinterpret_cast<const uint32_t*>(&data[24]);
    header.bitsPerSample = *reinterpret_cast<const uint16_t*>(&data[34]);

    if (data[36] != 'd' || data[37] != 'a' || data[38] != 't' || data[39] != 'a') {
        return false;
    }

    header.dataSize = *reinterpret_cast<const uint32_t*>(&data[40]);
    header.dataOffset = 44;

    if (header.dataOffset + header.dataSize > size) {
        return false;
    }

    return true;
}

} // namespace

AudioLoader::AudioLoader() = default;

AudioLoader::~AudioLoader() = default;

Containers::Array<Containers::String> AudioLoader::GetSupportedExtensions() const {
    Containers::Array<Containers::String> extensions;
    extensions.PushBack("wav");
    extensions.PushBack("ogg");
    extensions.PushBack("mp3");
    extensions.PushBack("flac");
    extensions.PushBack("aiff");
    extensions.PushBack("aif");
    return extensions;
}

bool AudioLoader::CanLoad(const Containers::String& path) const {
    Containers::String ext = GetExtension(path);
    return ext == "wav" || ext == "ogg" || ext == "mp3" || 
           ext == "flac" || ext == "aiff" || ext == "aif";
}

LoadResult AudioLoader::Load(const Containers::String& path, const ImportSettings* settings) {
    Containers::Array<Core::uint8> data = ReadFileData(path);
    if (data.Empty()) {
        return LoadResult("Failed to read audio file: " + path);
    }
    
    AudioClip* audioClip = new AudioClip();
    audioClip->m_path = path;
    audioClip->m_name = path;
    audioClip->m_guid = ResourceGUID::Generate(path);
    
    AudioFormat format = DetectAudioFormat(path, data);
    if (format == AudioFormat::WAV) {
        if (!ParseWAVData(data, audioClip)) {
            delete audioClip;
            return LoadResult("Failed to parse WAV data");
        }
    }
    audioClip->SetAudioFormat(format);
    audioClip->SetAudioData(data);
    
    audioClip->m_isValid = true;
    audioClip->m_memorySize = sizeof(AudioClip) + audioClip->m_name.Length() + 
                              audioClip->m_path.Length() + audioClip->GetAudioData().Size();
    
    return LoadResult(audioClip);
}

ImportSettings* AudioLoader::GetDefaultSettings() const {
    return nullptr;
}

bool AudioLoader::ParseWAVData(const Containers::Array<Core::uint8>& data, AudioClip* audioClip) {
    WAVHeader header;
    if (!ParseWAVHeader(data.Data(), data.Size(), header)) {
        return false;
    }

    audioClip->SetSampleRate(header.sampleRate);
    audioClip->SetChannels(header.channels);
    audioClip->SetBitsPerSample(header.bitsPerSample);

    uint32_t bytesPerSample = header.bitsPerSample / 8;
    uint32_t totalSamples = header.dataSize / (bytesPerSample * header.channels);
    float duration = static_cast<float>(totalSamples) / (header.sampleRate * header.channels);
    audioClip->SetDuration(duration);

    return true;
}

AudioFormat AudioLoader::DetectAudioFormat(const Containers::String& path, const Containers::Array<Core::uint8>& data) {
    Containers::String ext = GetExtension(path);
    
    if (ext == "wav") return AudioFormat::WAV;
    if (ext == "ogg") return AudioFormat::OGG;
    if (ext == "mp3") return AudioFormat::MP3;
    if (ext == "flac") return AudioFormat::FLAC;
    
    if (data.Size() >= 4) {
        if (data[0] == 'R' && data[1] == 'I' && data[2] == 'F' && data[3] == 'F') {
            return AudioFormat::WAV;
        }
    }
    
    return AudioFormat::Unknown;
}

} // namespace Resources
} // namespace XCEngine