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

Filename    :   OVR_DeviceHandle.cpp
Content     :   Implementation of device handle class
Created     :   February 5, 2013
Authors     :   Lee Cooper

Copyright   :   Copyright 2013 Oculus VR, Inc. All Rights reserved.

Licensed under the Oculus VR SDK License Version 2.0 (the "License"); 
you may not use the Oculus VR SDK except in compliance with the License, 
which is provided at the time of installation or download, or which 
otherwise accompanies this software in either electronic or hard copy form.

You may obtain a copy of the License at

http://www.oculusvr.com/licenses/LICENSE-2.0 

Unless required by applicable law or agreed to in writing, the Oculus VR SDK 
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

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

#include "OVR_DeviceHandle.h"

#include "OVR_DeviceImpl.h"

namespace OVR {

//-------------------------------------------------------------------------------------
// ***** DeviceHandle

DeviceHandle::DeviceHandle(DeviceCreateDesc* impl) : pImpl(impl)
{
    if (pImpl)
        pImpl->AddRef();
}

DeviceHandle::DeviceHandle(const DeviceHandle& src) : pImpl(src.pImpl)
{
    if (pImpl)
        pImpl->AddRef();
}    

DeviceHandle::~DeviceHandle()
{
    if (pImpl)
        pImpl->Release();
}

void DeviceHandle::operator = (const DeviceHandle& src)
{
    if (src.pImpl)
        src.pImpl->AddRef();
    if (pImpl)
        pImpl->Release();
    pImpl = src.pImpl;
}

DeviceBase* DeviceHandle::GetDevice_AddRef() const
{ 
    if (pImpl && pImpl->pDevice)
    {
        pImpl->pDevice->AddRef();
        return pImpl->pDevice;
    }
    return NULL;
}

// Returns true, if the handle contains the same device ptr
// as specified in the parameter.
bool DeviceHandle::IsDevice(DeviceBase* pdev) const
{
    return (pdev && pImpl && pImpl->pDevice) ? 
        pImpl->pDevice == pdev : false;
}

DeviceType  DeviceHandle::GetType() const
{
    return pImpl ? pImpl->Type : Device_None;
}

bool DeviceHandle::GetDeviceInfo(DeviceInfo* info) const
{
    return pImpl ? pImpl->GetDeviceInfo(info) : false;
}
bool DeviceHandle::IsAvailable() const
{
    // This isn't "atomically safe", but the function only returns the
    // recent state that may change.
    return pImpl ? (pImpl->Enumerated && pImpl->pLock->pManager) : false;
}

bool DeviceHandle::IsCreated() const
{
    return pImpl ? (pImpl->pDevice != 0) : false;
}

DeviceBase* DeviceHandle::CreateDevice()
{       
    if (!pImpl)
        return 0;
    
    DeviceBase*            device = 0;
    Ptr<DeviceManagerImpl> manager= 0;

    // Since both manager and device pointers can only be destroyed during a lock,
    // hold it while checking for availability.
    // AddRef to manager so that it doesn't get released on us.
    {
        Lock::Locker deviceLockScope(pImpl->GetLock());

        if (pImpl->pDevice)
        {
            pImpl->pDevice->AddRef();
            return pImpl->pDevice;
        }
        manager = pImpl->GetManagerImpl();
    }

    if (manager)
    {
        if (manager->GetThreadId() != OVR::GetCurrentThreadId())
        {
            // Queue up a CreateDevice request. This fills in '&device' with AddRefed value,
            // or keep it at null.
            manager->GetThreadQueue()->PushCallAndWaitResult(
                manager.GetPtr(), &DeviceManagerImpl::CreateDevice_MgrThread,
                &device, pImpl, (DeviceBase*)0);
        }
        else
            device = manager->CreateDevice_MgrThread(pImpl, (DeviceBase*)0);
    }
    return device;
}

void DeviceHandle::Clear()
{
    if (pImpl)
    {
        pImpl->Release();
        pImpl = 0;
    }
}

bool DeviceHandle::enumerateNext(const DeviceEnumerationArgs& args)
{
    if (GetType() == Device_None)
        return false;
    
    Ptr<DeviceManagerImpl> managerKeepAlive;
    Lock::Locker           lockScope(pImpl->GetLock());
    
    DeviceCreateDesc* next = pImpl;
    // If manager was destroyed, we get removed from the list.
    if (!pImpl->pNext)
        return false;

    managerKeepAlive = next->GetManagerImpl();
    OVR_ASSERT(managerKeepAlive);
    
    do {
        next = next->pNext;

        if (managerKeepAlive->Devices.IsNull(next))
        {
            pImpl->Release();
            pImpl = 0;
            return false;
        }

    } while(!args.MatchRule(next->Type, next->Enumerated));

    next->AddRef();
    pImpl->Release();
    pImpl = next;

    return true;
}

} // namespace OVR