// Include only the application API header
#include <openvr.h> //OpenVR library is located at "C:\Users\decid\Documents\Visual Studio 2022\Libraries\openvr-2.5.1"
#include <string>
#include <cstring>
#include <iostream>

// Forward declare the driver interfaces we need
namespace vr
{
    class IVRDriverManager;
    class IVRDriverInput;
    
    // These interfaces would be defined in a modified OpenVR
    class IVRDriverContext;
    class IVRServerDriverHost;
    class IVRDevice;
    class IVRIMUDevice;
}

// Define the export macro based on the platform
#if defined(_WIN32)
    #define EXPORT_API __declspec(dllexport)
#else
    #define EXPORT_API
#endif

// Global variables
vr::IVRSystem* g_pVRSystem = nullptr;
vr::IVRDriverManager* g_pDriverManager = nullptr;
vr::IVRDriverInput* g_pDriverInput = nullptr;
std::string g_driverName = "Unknown";
bool g_isInitialized = false;

// Helper function to get a generic interface
template<class T>
T* GetGenericInterface(const char* interfaceName) {
    vr::EVRInitError error = vr::VRInitError_None;
    T* interface_ptr = (T*)vr::VR_GetGenericInterface(interfaceName, &error);
    
    if (error != vr::VRInitError_None) {
        std::cerr << "Failed to get interface " << interfaceName << ": " << error << std::endl;
        return nullptr;
    }
    
    return interface_ptr;
}

// Initialize the plugin and connect to OpenVR
extern "C" EXPORT_API bool InitializePlugin() {
    if (g_isInitialized) {
        return true;
    }
    
    // Initialize OpenVR
    vr::EVRInitError error = vr::VRInitError_None;
    g_pVRSystem = vr::VR_Init(&error, vr::VRApplication_Background);
    
    if (error != vr::VRInitError_None) {
        std::cerr << "Failed to initialize OpenVR: " << error << std::endl;
        return false;
    }
    
    // Try to get driver manager interface
    g_pDriverManager = GetGenericInterface<vr::IVRDriverManager>("IVRDriverManager_001");
    
    // Try to get driver input interface
    g_pDriverInput = GetGenericInterface<vr::IVRDriverInput>("IVRDriverInput_005");
    
    // Get the driver name
    if (g_pVRSystem) {
        char buffer[256];
        vr::ETrackedPropertyError propError = vr::TrackedProp_Success;
        g_pVRSystem->GetStringTrackedDeviceProperty(vr::k_unTrackedDeviceIndex_Hmd, 
            vr::Prop_TrackingSystemName_String, buffer, sizeof(buffer), &propError);
            
        if (propError == vr::TrackedProp_Success) {
            g_driverName = buffer;
        }
    }
    
    g_isInitialized = true;
    return true;
}

// Shutdown the plugin and disconnect from OpenVR
extern "C" EXPORT_API void ShutdownPlugin() {
    if (g_isInitialized) {
        vr::VR_Shutdown();
        g_pVRSystem = nullptr;
        g_pDriverManager = nullptr;
        g_pDriverInput = nullptr;
        g_isInitialized = false;
    }
}

// Forward declaration of our direct driver access function
bool GetRawIMUDataFromDriver(float* gyroX, float* gyroY, float* gyroZ);

// Get raw gyroscope data from the headset
extern "C" EXPORT_API bool GetRawGyroscopeData(float* x, float* y, float* z) {
    if (!g_isInitialized || !g_pVRSystem) {
        return false;
    }
    
    // Method 1: Try to get it from the tracked device pose first
    // This works when optical tracking is available
    vr::TrackedDevicePose_t poses[vr::k_unMaxTrackedDeviceCount];
    g_pVRSystem->GetDeviceToAbsoluteTrackingPose(
        vr::TrackingUniverseRawAndUncalibrated,
        0,
        poses,
        vr::k_unMaxTrackedDeviceCount);
    
    if (poses[vr::k_unTrackedDeviceIndex_Hmd].bDeviceIsConnected) {
        *x = poses[vr::k_unTrackedDeviceIndex_Hmd].vAngularVelocity.v[0];
        *y = poses[vr::k_unTrackedDeviceIndex_Hmd].vAngularVelocity.v[1];
        *z = poses[vr::k_unTrackedDeviceIndex_Hmd].vAngularVelocity.v[2];
        return true;
    }
    
    // Method 2: Try to access through direct driver access
    // This is the recommended approach for continuous IMU data
    if (GetRawIMUDataFromDriver(x, y, z)) {
        return true;
    }
    
    // Method 3: Fallback to zero values
    *x = 0.0f;
    *y = 0.0f;
    *z = 0.0f;
    
    // We always return true since we're providing fallback values
    return true;
}

// Forward declaration of our direct driver access function for accelerometer
bool GetRawAccelDataFromDriver(float* accelX, float* accelY, float* accelZ);

// Get raw accelerometer data from the headset
extern "C" EXPORT_API bool GetRawAccelerometerData(float* x, float* y, float* z) {
    if (!g_isInitialized || !g_pVRSystem) {
        return false;
    }
    
    // Method 1: Try to get it from the tracked device pose
    // Note: Standard OpenVR API doesn't expose raw accelerometer data through poses
    // but we can try to derive it from position data if available
    vr::TrackedDevicePose_t poses[vr::k_unMaxTrackedDeviceCount];
    g_pVRSystem->GetDeviceToAbsoluteTrackingPose(
        vr::TrackingUniverseRawAndUncalibrated,
        0,
        poses,
        vr::k_unMaxTrackedDeviceCount);
    
    if (poses[vr::k_unTrackedDeviceIndex_Hmd].bDeviceIsConnected &&
        poses[vr::k_unTrackedDeviceIndex_Hmd].bPoseIsValid) {
        // This is a simplistic approach - in a real implementation,
        // you would need to derive acceleration from position changes over time
        // or access the raw accelerometer data directly
        
        // For now, we'll just use gravity as a placeholder
        *x = 0.0f;
        *y = -9.81f; // Assuming Y is up
        *z = 0.0f;
        return true;
    }
    
    // Method 2: Try to access through direct driver access
    if (GetRawAccelDataFromDriver(x, y, z)) {
        return true;
    }
    
    // Method 3: Fallback to zero values
    *x = 0.0f;
    *y = 0.0f;
    *z = 0.0f;
    
    // We always return true since we're providing fallback values
    return true;
}

// Check if the headset is connected
extern "C" EXPORT_API bool IsHeadsetConnected() {
    if (!g_isInitialized || !g_pVRSystem) {
        return false;
    }
    
    return g_pVRSystem->IsTrackedDeviceConnected(vr::k_unTrackedDeviceIndex_Hmd);
}

// Get the current tracking state
extern "C" EXPORT_API bool IsTrackingValid() {
    if (!g_isInitialized || !g_pVRSystem) {
        return false;
    }
    
    vr::TrackedDevicePose_t pose;
    g_pVRSystem->GetDeviceToAbsoluteTrackingPose(
        vr::TrackingUniverseStanding, 
        0, 
        &pose, 
        1);
    
    return pose.bPoseIsValid;
}

// Get the driver name
extern "C" EXPORT_API const char* GetDriverName() {
    return g_driverName.c_str();
}

// Implementation of direct driver access for gyroscope data
bool GetRawIMUDataFromDriver(float* gyroX, float* gyroY, float* gyroZ) {
    // This function implements direct access to the driver's IMU data
    // There are several approaches we can take:
    
    // Approach 1: Use the OpenVR driver API directly
    // This requires modifying the OpenVR library to expose the driver's IMU data
    
    // Approach 2: Use a custom driver that exposes the IMU data
    // This requires creating a custom driver or modifying an existing one
    
    // Approach 3: Use reverse engineering to access the driver's memory directly
    // This is more complex but doesn't require modifying OpenVR
    
    // For this implementation, we'll focus on Approach 1:
    // Modifying OpenVR to expose the driver's IMU data
    
    // 1. Get the driver context
    vr::IVRDriverContext* pDriverContext = nullptr;
    
    // This would require a modified OpenVR that exposes this function
    // vr::EVRInitError error = vr::VRInitError_None;
    // pDriverContext = (vr::IVRDriverContext*)vr::VR_GetGenericInterface("IVRDriverContext", &error);
    
    if (!pDriverContext) {
        // If we can't get the driver context, we can't access the IMU data directly
        return false;
    }
    
    // 2. Get the driver host
    vr::IVRServerDriverHost* pDriverHost = nullptr;
    
    // This would be available through the driver context
    // pDriverHost = pDriverContext->GetDriverHost();
    
    if (!pDriverHost) {
        return false;
    }
    
    // 3. Get the device driver
    // This is where we would access the specific driver implementation
    // The exact code would depend on the driver being used
    
    // Example for a hypothetical driver:
    // vr::IVRDevice* pDevice = pDriverHost->GetDevice(vr::k_unTrackedDeviceIndex_Hmd);
    // if (pDevice) {
    //     // 4. Get the IMU interface from the device
    //     vr::IVRIMUDevice* pIMUDevice = pDevice->GetIMUInterface();
    //     if (pIMUDevice) {
    //         // 5. Get the raw gyroscope data
    //         return pIMUDevice->GetRawGyroscopeData(gyroX, gyroY, gyroZ);
    //     }
    // }
    
    // Since this requires modifying OpenVR, we'll return false for now
    return false;
}

// Implementation of direct driver access for accelerometer data
bool GetRawAccelDataFromDriver(float* accelX, float* accelY, float* accelZ) {
    // Similar to the gyroscope implementation, but for accelerometer data
    // The implementation would follow the same pattern as GetRawIMUDataFromDriver
    
    // For now, we'll return false since this requires modifying OpenVR
    return false;
}

// Additional functions for direct driver access could be added here
// These would depend on the specific driver implementation and might
// require reverse engineering or access to driver source code