/************************************************************************************

PublicHeader:   OVR.h
Filename    :   OVR_Device.h
Content     :   Definition of HMD-related Device interfaces
Created     :   September 21, 2012
Authors     :   Michael Antonov

Copyright   :   Copyright 2012 Oculus VR, Inc. All Rights reserved.

Use of this software is subject to the terms of the Oculus license
agreement provided at the time of installation or download, or which
otherwise accompanies this software in either electronic or hard copy form.

*************************************************************************************/

#ifndef OVR_Device_h
#define OVR_Device_h

#include "OVR_DeviceConstants.h"
#include "OVR_DeviceHandle.h"
#include "OVR_DeviceMessages.h"
#include "OVR_HIDDeviceBase.h"

#include "Kernel/OVR_Atomic.h"
#include "Kernel/OVR_RefCount.h"
#include "Kernel/OVR_String.h"

namespace OVR {

class SensorDevice;
class DeviceCommon;
class DeviceManager;

// MessageHandler is a base class from which users derive to receive messages,
// its OnMessage handler will be called for messages once it is installed on
// a device. Same message handler can be installed on multiple devices.
class MessageHandler
{
    friend class MessageHandlerImpl;
public:
    MessageHandler();
    virtual ~MessageHandler();

    // Returns 'true' if handler is currently installed on any devices.
    bool        IsHandlerInstalled() const;

    // Should be called from derived class destructor to avoid handler
    // being called after it exits.
    void        RemoveHandlerFromDevices();

    // Returns a pointer to the internal lock object that is locked by a
    // background thread while OnMessage() is called.
    // This lock guaranteed to survive until ~MessageHandler.
    Lock*       GetHandlerLock() const;


    virtual void OnMessage(const Message&) { }

    // Determines if handler supports a specific message type. Can
    // be used to filter out entire message groups. The result
    // returned by this function shouldn't change after handler creation.
    virtual bool SupportsMessageType(MessageType) const { return true; }    

private:    
    UPInt Internal[4];
};


//-------------------------------------------------------------------------------------
// ***** DeviceBase

// DeviceBase is the base class for all OVR Devices. It provides the following basic
// functionality:
//   - Reports device type, manager, and associated parent (if any).
//   - Supports installable message handlers, which are notified of device events.
//   - Device objects are created through DeviceHandle::CreateDevice or more commonly
//     through DeviceEnumerator<>::CreateDevice.
//   - Created devices are reference counted, starting with RefCount of 1.
//   - Device is resources are cleaned up when it is Released, although its handles
//     may survive longer if referenced.

class DeviceBase : public NewOverrideBase
{    
    friend class DeviceHandle;  
    friend class DeviceManagerImpl;
public:

    // Enumerating DeviceBase enumerates all devices.
    enum { EnumDeviceType = Device_All };

    virtual ~DeviceBase() { }
    virtual void            AddRef();
    virtual void            Release();
    
    virtual DeviceBase*     GetParent() const;
    virtual DeviceManager*  GetManager() const;  

    virtual void            SetMessageHandler(MessageHandler* handler);
    virtual MessageHandler* GetMessageHandler() const;

    virtual DeviceType      GetType() const;
    virtual bool            GetDeviceInfo(DeviceInfo* info) const;

    // returns the MessageHandler's lock
    Lock*                   GetHandlerLock() const;
protected:
    // Internal
    virtual DeviceCommon*   getDeviceCommon() const = 0;
};


//-------------------------------------------------------------------------------------
// ***** DeviceInfo

// DeviceInfo describes a device and its capabilities, obtained by calling
// GetDeviceInfo. This base class only contains device-independent functionality;
// users will normally use a derived HMDInfo or SensorInfo classes for more
// extensive device info.

class DeviceInfo
{
public:
    DeviceInfo() : InfoClassType(Device_None), Type(Device_None), Version(0)
    {  ProductName[0] = Manufacturer[0] = 0; }

    enum { MaxNameLength = 32 };
    
    // Type of device for which DeviceInfo is intended.
    // This will be set to Device_HMD for HMDInfo structure, note that this may be
    // different form the actual device type since (Device_None) is valid.
    const DeviceType InfoClassType;
    // Type of device this describes. This must be the same as InfoClassType when
    // InfoClassType != Device_None.
    DeviceType       Type;
    // Name string describing the product: "Oculus Rift DK1", etc.
    char             ProductName[MaxNameLength];    
    char             Manufacturer[MaxNameLength];
    unsigned         Version;
    
protected:
    DeviceInfo(DeviceType type) : InfoClassType(type), Type(type), Version(0)
    { ProductName[0] = Manufacturer[0] = 0; }
    void operator = (const DeviceInfo&) { OVR_ASSERT(0); } // Assignment not allowed.
};


//-------------------------------------------------------------------------------------
// DeviceEnumerationArgs provides device enumeration argumenrs for DeviceManager::EnumerateDevicesEx.
class DeviceEnumerationArgs
{
public:
    DeviceEnumerationArgs(DeviceType enumType, bool availableOnly)
        : EnumType(enumType), AvailableOnly(availableOnly)
    { }

    // Helper; returns true if args match our enumeration criteria.
    bool         MatchRule(DeviceType type, bool available) const
    {
        return ((EnumType == type) || (EnumType == Device_All)) &&
                (available || !AvailableOnly);
    }

protected:    
    DeviceType   EnumType;
    bool         AvailableOnly;
};


// DeviceEnumerator<> is used to enumerate and create devices of specified class,
// it is returned by calling MeviceManager::EnumerateDevices. Initially, the enumerator will
// refer to the first device of specified type. Additional devices can be accessed by
// calling Next().

template<class T = DeviceBase>
class DeviceEnumerator : public DeviceHandle
{
    friend class DeviceManager;
    friend class DeviceManagerImpl;
public:
    DeviceEnumerator()
        : DeviceHandle(), EnumArgs(Device_None, true) { }

    // Next advances enumeration to the next device that first criteria.
    // Returns false if no more devices exist that match enumeration criteria.
    bool    Next()          { return enumerateNext(EnumArgs); }

    // Creates an instance of the device referenced by enumerator; returns null
    // if enumerator does not refer to a valid device or device is unavailable.
    // If device was already created, the same object with incremented ref-count is returned.
    T*      CreateDevice()  { return static_cast<T*>(DeviceHandle::CreateDevice()); }

protected:
    DeviceEnumerator(const DeviceHandle &dev, const DeviceEnumerationArgs& args)
        : DeviceHandle(dev), EnumArgs(args)
    { }

    DeviceEnumerationArgs EnumArgs;
};

//-------------------------------------------------------------------------------------
// ***** DeviceManager

// DeviceManager maintains and provides access to devices supported by OVR, such as
// HMDs and sensors. A single instance of DeviceManager is normally created at
// program startup, allowing devices to be enumerated and created. DeviceManager is
// reference counted and is AddRefed by its created child devices, causing it to
// always be the last object that is released.
//
// Install MessageHandler on DeviceManager to detect when devices are inserted or removed.
//
// The following code will create the manager and its first available HMDDevice,
// and then release it when not needed:
//
//  DeviceManager* manager = DeviceManager::Create();
//  HMDDevice*     hmd = manager->EnumerateDevices<HMDDevice>().CreateDevice();
//
//  if (hmd) hmd->Release();
//  if (manager) manager->Release();


class DeviceManager : public DeviceBase
{
public:
  
    DeviceManager()
    { }

    // DeviceBase implementation.
    virtual DeviceType      GetType() const     { return Device_Manager; }
    virtual DeviceManager*  GetManager() const  { return const_cast<DeviceManager*>(this); }


    // EnumerateDevices enumerates all of the available devices of the specified class,
    // returning an enumerator that references the first device. An empty enumerator is
    // returned if no devices are available. The following APIs are exposed through
    // DeviceEnumerator:
    //   DeviceEnumerator::GetType()        - Check device type. Returns Device_None 
    //                                        if no device was found/pointed to.
    //   DeviceEnumerator::GetDeviceInfo()  - Get more information on device.
    //   DeviceEnumerator::CreateDevice()   - Create an instance of device.
    //   DeviceEnumerator::Next()           - Move onto next device.
    template<class D>
    DeviceEnumerator<D>     EnumerateDevices(bool availableOnly = true)
    {
        // TBD: A cleaner (but less efficient) alternative is though enumeratorFromHandle.
        DeviceEnumerator<> e = EnumerateDevicesEx(DeviceEnumerationArgs((DeviceType)D::EnumDeviceType, availableOnly));
        return *reinterpret_cast<DeviceEnumerator<D>*>(&e);
    }
  
    // EnumerateDevicesEx provides internal implementation for device enumeration, enumerating
    // devices based on dynamically specified DeviceType in DeviceEnumerationArgs.
    // End users should call DeumerateDevices<>() instead.
    virtual DeviceEnumerator<> EnumerateDevicesEx(const DeviceEnumerationArgs& args) = 0;

    // Adds a device (DeviceCreateDesc*) into Devices. Returns NULL, 
    // if unsuccessful or device is already in the list.
    virtual Ptr<DeviceCreateDesc> AddDevice_NeedsLock(const DeviceCreateDesc& createDesc) = 0;

    // Creates a new DeviceManager. Only one instance of DeviceManager should be created at a time.
    static   DeviceManager* Create();

    // Static constant for this device type, used in template cast type checks.
    enum { EnumDeviceType = Device_Manager };

protected:
    DeviceEnumerator<> enumeratorFromHandle(const DeviceHandle& h, const DeviceEnumerationArgs& args)
    { return DeviceEnumerator<>(h, args); }

    DeviceManager* getThis() { return this; }
};



//-------------------------------------------------------------------------------------
// ***** HMDInfo 

// This structure describes various aspects of the HMD allowing us to configure rendering.
//
//  Currently included data:
//   - Physical screen dimensions, resolution, and eye distances.
//     (some of these will be configurable with a tool in the future).
//     These arguments allow us to properly setup projection across HMDs.
//   - DisplayDeviceName for identifying HMD screen; system-specific interpretation.
//
// TBD:
//  - Power on/ off?
//  - Sensor rates and capabilities
//  - Distortion radius/variables    
//  - Screen update frequency
//  - Distortion needed flag
//  - Update modes:
//      Set update mode: Stereo (both sides together), mono (same in both eyes),
//                       Alternating, Alternating scan-lines.

class HMDInfo : public DeviceInfo
{
public:
    // Size of the entire screen, in pixels.
    unsigned  HResolution, VResolution; 
    // Physical dimensions of the active screen in meters. Can be used to calculate
    // projection center while considering IPD.
    float     HScreenSize, VScreenSize;
    // Physical offset from the top of the screen to the eye center, in meters.
    // This will usually, but not necessarily be half of VScreenSize.
    float     VScreenCenter;
    // Distance from the eye to screen surface, in meters.
    // Useful for calculating FOV and projection.
    float     EyeToScreenDistance;
    // Distance between physical lens centers useful for calculating distortion center.
    float     LensSeparationDistance;
    // Configured distance between the user's eye centers, in meters. Defaults to 0.064.
    float     InterpupillaryDistance;
    
    // Radial distortion correction coefficients.
    // The distortion assumes that the input texture coordinates will be scaled
    // by the following equation:    
    //   uvResult = uvInput * (K0 + K1 * uvLength^2 + K2 * uvLength^4)
    // Where uvInput is the UV vector from the center of distortion in direction
    // of the mapped pixel, uvLength is the magnitude of that vector, and uvResult
    // the corresponding location after distortion.
    float     DistortionK[4];

    float     ChromaAbCorrection[4];

    // Desktop coordinate position of the screen (can be negative; may not be present on all platforms)
    int       DesktopX, DesktopY;
    
    // Windows:
    // "\\\\.\\DISPLAY3", etc. Can be used in EnumDisplaySettings/CreateDC.
    char      DisplayDeviceName[32];
    
    // MacOS:
    long      DisplayId;


    HMDInfo()
        : DeviceInfo(Device_HMD),          
          HResolution(0), VResolution(0), HScreenSize(0), VScreenSize(0),
          VScreenCenter(0), EyeToScreenDistance(0),
          LensSeparationDistance(0), InterpupillaryDistance(0),
          DesktopX(0), DesktopY(0), DisplayId(0)
    {
        DisplayDeviceName[0] = 0;
        memset(DistortionK, 0, sizeof(DistortionK));
        DistortionK[0] = 1;
        ChromaAbCorrection[0] = ChromaAbCorrection[2] = 1;
        ChromaAbCorrection[1] = ChromaAbCorrection[3] = 0;
    }

    // Operator = copies local fields only (base class must be correct already)
    void operator = (const HMDInfo& src)
    {        
        HResolution             = src.HResolution;
        VResolution             = src.VResolution;
        HScreenSize             = src.HScreenSize;
        VScreenSize             = src.VScreenSize;
        VScreenCenter           = src.VScreenCenter;
        EyeToScreenDistance     = src.EyeToScreenDistance;
        LensSeparationDistance  = src.LensSeparationDistance;
        InterpupillaryDistance  = src.InterpupillaryDistance;
        DistortionK[0]          = src.DistortionK[0];
        DistortionK[1]          = src.DistortionK[1];
        DistortionK[2]          = src.DistortionK[2];
        DistortionK[3]          = src.DistortionK[3];
        ChromaAbCorrection[0]   = src.ChromaAbCorrection[0];
        ChromaAbCorrection[1]   = src.ChromaAbCorrection[1];
        ChromaAbCorrection[2]   = src.ChromaAbCorrection[2];
        ChromaAbCorrection[3]   = src.ChromaAbCorrection[3];
        DesktopX                = src.DesktopX;
        DesktopY                = src.DesktopY;
        memcpy(DisplayDeviceName, src.DisplayDeviceName, sizeof(DisplayDeviceName));
        DisplayId               = src.DisplayId;
    }

    bool IsSameDisplay(const HMDInfo& o) const
    {
        return DisplayId == o.DisplayId &&
               String::CompareNoCase(DisplayDeviceName, 
                                     o.DisplayDeviceName) == 0;
    }

};


// HMDDevice represents an Oculus HMD device unit. An instance of this class
// is typically created from the DeviceManager.
//  After HMD device is created, we its sensor data can be obtained by 
//  first creating a Sensor object and then.

//  TBD:
//  - Configure Sensor
//  - APIs to set On-Screen message, other states?

class HMDDevice : public DeviceBase
{
public:
    HMDDevice()
    { }

    // Static constant for this device type, used in template cast type checks.
    enum { EnumDeviceType = Device_HMD };

    virtual DeviceType      GetType() const   { return Device_HMD; }    

    // Creates a sensor associated with this HMD.
    virtual SensorDevice*   GetSensor() = 0;

    // Disconnects from real HMD device. This HMDDevice remains as 'fake' HMD.
    // SensorDevice ptr is used to restore the 'fake' HMD (can be NULL).
    HMDDevice* Disconnect(SensorDevice*);
    
    // Returns 'true' if HMD device is a 'fake' HMD (was created this way or 
    // 'Disconnect' method was called).
    bool IsDisconnected() const;
};


//-------------------------------------------------------------------------------------
// ***** SensorRange & SensorInfo

// SensorRange specifies maximum value ranges that SensorDevice hardware is configured
// to detect. Although this range doesn't affect the scale of MessageBodyFrame values,
// physical motions whose positive or negative magnitude is outside the specified range
// may get clamped or misreported. Setting lower values may result in higher precision
// tracking.
struct SensorRange
{
    SensorRange(float maxAcceleration = 0.0f, float maxRotationRate = 0.0f,
                float maxMagneticField = 0.0f)
        : MaxAcceleration(maxAcceleration), MaxRotationRate(maxRotationRate),
          MaxMagneticField(maxMagneticField)
    { }

    // Maximum detected acceleration in m/s^2. Up to 8*G equivalent support guaranteed,
    // where G is ~9.81 m/s^2.
    // Oculus DK1 HW has thresholds near: 2, 4 (default), 8, 16 G.
    float   MaxAcceleration;  
    // Maximum detected angular velocity in rad/s. Up to 8*Pi support guaranteed.
    // Oculus DK1 HW thresholds near: 1, 2, 4, 8 Pi (default).
    float   MaxRotationRate;
    // Maximum detectable Magnetic field strength in Gauss. Up to 2.5 Gauss support guaranteed.
    // Oculus DK1 HW thresholds near: 0.88, 1.3, 1.9, 2.5 gauss.
    float   MaxMagneticField;
};

// SensorInfo describes capabilities of the sensor device.
class SensorInfo : public DeviceInfo
{
public:
    SensorInfo() : DeviceInfo(Device_Sensor), VendorId(0), ProductId(0)
    {
        SerialNumber[0] = 0;
    }

    // HID Vendor and ProductId of the device.
    UInt16      VendorId;
    UInt16      ProductId;
    // MaxRanges report maximum sensor range values supported by HW.
    SensorRange MaxRanges;
    // Sensor (and display) serial number.
    char        SerialNumber[20];

private:
    void operator = (const SensorInfo&) { OVR_ASSERT(0); } // Assignment not allowed.
};


//-------------------------------------------------------------------------------------
// ***** SensorDevice

// SensorDevice is an interface to sensor data.
// Install a MessageHandler of SensorDevice instance to receive MessageBodyFrame
// notifications.
//
// TBD: Add Polling API? More HID interfaces?

class SensorDevice : public HIDDeviceBase, public DeviceBase
{
public:
    SensorDevice() 
    { }

    // Static constant for this device type, used in template cast type checks.
    enum { EnumDeviceType = Device_Sensor };

    virtual DeviceType GetType() const   { return Device_Sensor; }

    
    // CoordinateFrame defines whether messages come in the coordinate frame
    // of the sensor device or HMD, which has a different internal sensor.
    // Sensors obtained form the HMD will automatically use HMD coordinates.
    enum CoordinateFrame
    {
        Coord_Sensor = 0,
        Coord_HMD    = 1
    };

    virtual void            SetCoordinateFrame(CoordinateFrame coordframe) = 0;
    virtual CoordinateFrame GetCoordinateFrame() const = 0;

    // Sets report rate (in Hz) of MessageBodyFrame messages (delivered through MessageHandler::OnMessage call). 
    // Currently supported maximum rate is 1000Hz. If the rate is set to 500 or 333 Hz then OnMessage will be 
    // called twice or thrice at the same 'tick'. 
    // If the rate is  < 333 then the OnMessage / MessageBodyFrame will be called three
    // times for each 'tick': the first call will contain averaged values, the second
    // and third calls will provide with most recent two recorded samples.
    virtual void        SetReportRate(unsigned rateHz) = 0;
    // Returns currently set report rate, in Hz. If 0 - error occurred.
    // Note, this value may be different from the one provided for SetReportRate. The return
    // value will contain the actual rate.
    virtual unsigned    GetReportRate() const = 0;

    // Sets maximum range settings for the sensor described by SensorRange.    
    // The function will fail if you try to pass values outside Maximum supported
    // by the HW, as described by SensorInfo.
    // Pass waitFlag == true to wait for command completion. For waitFlag == true,
    // returns true if the range was applied successfully (no HW error).
    // For waitFlag = false, return 'true' means that command was enqueued successfully.
    virtual bool       SetRange(const SensorRange& range, bool waitFlag = false) = 0;

    // Return the current sensor range settings for the device. These may not exactly
    // match the values applied through SetRange.
    virtual void       GetRange(SensorRange* range) const = 0;
};

//-------------------------------------------------------------------------------------
// ***** LatencyTestConfiguration
// LatencyTestConfiguration specifies configuration information for the Oculus Latency Tester device.
struct LatencyTestConfiguration
{
    LatencyTestConfiguration(const Color& threshold, bool sendSamples = false)
        : Threshold(threshold), SendSamples(sendSamples) 
    {
    }

    // The color threshold for triggering a detected display change.
    Color    Threshold;
    // Flag specifying whether we wish to receive a stream of color values from the sensor.
    bool        SendSamples;
};

//-------------------------------------------------------------------------------------
// ***** LatencyTestCalibrate
// LatencyTestCalibrate specifies colors used for Latency Tester calibration.
struct LatencyTestCalibrate
{
    LatencyTestCalibrate(const Color& value)
        : Value(value)
    {
    }

    // The color being calibrated to.
    Color   Value;
};

//-------------------------------------------------------------------------------------
// ***** LatencyTestStartTest
// LatencyTestStartTest specifies values used when starting the Latency Tester test.
struct LatencyTestStartTest
{
    LatencyTestStartTest(const Color& targetValue)
        : TargetValue(targetValue)
    {
    }

    // The color value that the display is being set to.
    Color    TargetValue;
};

//-------------------------------------------------------------------------------------
// ***** LatencyTestDisplay
// LatencyTestDisplay sets the mode and contents of the Latency Tester LED display.
// See the 'Latency Tester Specification' document for more details.
struct LatencyTestDisplay
{
    LatencyTestDisplay(UByte mode, UInt32 value)
        : Mode(mode), Value(value)
    {
    }

    UByte       Mode;       // The display mode that we wish to select.
    UInt32      Value;      // The value to display.
};

//-------------------------------------------------------------------------------------
// ***** LatencyTestDevice

// LatencyTestDevice provides an interface to the Oculus Latency Tester which is used to test 'motion to photon' latency.
class LatencyTestDevice : public HIDDeviceBase, public DeviceBase
{
public:
    LatencyTestDevice()
    { }

    // Static constant for this device type, used in template cast type checks.
    enum { EnumDeviceType = Device_LatencyTester };

    virtual DeviceType GetType() const { return Device_LatencyTester; }

    // Specifies configuration information including the threshold for triggering a detected color change,
    // and a flag to enable a stream of sensor values (typically used for debugging).
    virtual bool SetConfiguration(const LatencyTestConfiguration& configuration, bool waitFlag = false) = 0;

    // Get configuration information from device.
    virtual bool GetConfiguration(LatencyTestConfiguration* configuration) = 0;

    // Used to calibrate the latency tester at the start of a test. Calibration information is lost
    // when power is removed from the device.
    virtual bool SetCalibrate(const LatencyTestCalibrate& calibrate, bool waitFlag = false) = 0;

    // Get calibration information from device.
    virtual bool GetCalibrate(LatencyTestCalibrate* calibrate) = 0;

    // Triggers the start of a measurement. This starts the millisecond timer on the device and 
    // causes it to respond with the 'MessageLatencyTestStarted' message.
    virtual bool SetStartTest(const LatencyTestStartTest& start, bool waitFlag = false) = 0;

    // Used to set the value displayed on the LED display panel.
    virtual bool SetDisplay(const LatencyTestDisplay& display, bool waitFlag = false) = 0;

    virtual DeviceBase* GetDevice() { return this; }
};

} // namespace OVR

#endif