/*
-----------------------------------------------------------------------------
This source file is part of OGRE
    (Object-oriented Graphics Rendering Engine)
For the latest info, see http://www.ogre3d.org/

Copyright (c) 2000-2009 Torus Knot Software Ltd

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
-----------------------------------------------------------------------------
*/
#include "OgreStableHeaders.h"
#include "OgreResourceBackgroundQueue.h"
#include "OgreLogManager.h"
#include "OgreException.h"
#include "OgreResourceGroupManager.h"
#include "OgreResourceManager.h"
#include "OgreRoot.h"
#include "OgreRenderSystem.h"

namespace Ogre {

	// Note, no locks are required here anymore because all of the parallelisation
	// is now contained in WorkQueue - this class is entirely single-threaded
	//------------------------------------------------------------------------
    //-----------------------------------------------------------------------
    template<> ResourceBackgroundQueue* Singleton<ResourceBackgroundQueue>::ms_Singleton = 0;
    ResourceBackgroundQueue* ResourceBackgroundQueue::getSingletonPtr(void)
    {
        return ms_Singleton;
    }
    ResourceBackgroundQueue& ResourceBackgroundQueue::getSingleton(void)
    {  
        assert( ms_Singleton );  return ( *ms_Singleton );  
    }
    //-----------------------------------------------------------------------	
	//------------------------------------------------------------------------
	ResourceBackgroundQueue::ResourceBackgroundQueue()
	{
	}
	//------------------------------------------------------------------------
	ResourceBackgroundQueue::~ResourceBackgroundQueue()
	{
		shutdown();
	}
	//---------------------------------------------------------------------
	void ResourceBackgroundQueue::initialise()
	{
		WorkQueue* wq = Root::getSingleton().getWorkQueue();
		mWorkQueueChannel = wq->getChannel("Ogre/ResourceBGQ");
		wq->addResponseHandler(mWorkQueueChannel, this);
		wq->addRequestHandler(mWorkQueueChannel, this);
	}
	//---------------------------------------------------------------------
	void ResourceBackgroundQueue::shutdown()
	{
		WorkQueue* wq = Root::getSingleton().getWorkQueue();
		wq->abortRequestsByChannel(mWorkQueueChannel);
		wq->removeRequestHandler(mWorkQueueChannel, this);
		wq->removeResponseHandler(mWorkQueueChannel, this);
	}
	//------------------------------------------------------------------------
	BackgroundProcessTicket ResourceBackgroundQueue::initialiseResourceGroup(
		const String& name, ResourceBackgroundQueue::Listener* listener)
	{
#if OGRE_THREAD_SUPPORT
		// queue a request
		ResourceRequest req;
		req.type = RT_INITIALISE_GROUP;
		req.groupName = name;
		req.listener = listener;
		return addRequest(req);
#else
		// synchronous
		ResourceGroupManager::getSingleton().initialiseResourceGroup(name);
		return 0; 
#endif
	}
	//------------------------------------------------------------------------
	BackgroundProcessTicket 
	ResourceBackgroundQueue::initialiseAllResourceGroups( 
		ResourceBackgroundQueue::Listener* listener)
	{
#if OGRE_THREAD_SUPPORT
		// queue a request
		ResourceRequest req;
		req.type = RT_INITIALISE_ALL_GROUPS;
		req.listener = listener;
		return addRequest(req);
#else
		// synchronous
		ResourceGroupManager::getSingleton().initialiseAllResourceGroups();
		return 0; 
#endif
	}
	//------------------------------------------------------------------------
	BackgroundProcessTicket ResourceBackgroundQueue::prepareResourceGroup(
		const String& name, ResourceBackgroundQueue::Listener* listener)
	{
#if OGRE_THREAD_SUPPORT
		// queue a request
		ResourceRequest req;
		req.type = RT_PREPARE_GROUP;
		req.groupName = name;
		req.listener = listener;
		return addRequest(req);
#else
		// synchronous
		ResourceGroupManager::getSingleton().prepareResourceGroup(name);
		return 0; 
#endif
	}
	//------------------------------------------------------------------------
	BackgroundProcessTicket ResourceBackgroundQueue::loadResourceGroup(
		const String& name, ResourceBackgroundQueue::Listener* listener)
	{
#if OGRE_THREAD_SUPPORT
		// queue a request
		ResourceRequest req;
		req.type = RT_LOAD_GROUP;
		req.groupName = name;
		req.listener = listener;
		return addRequest(req);
#else
		// synchronous
		ResourceGroupManager::getSingleton().loadResourceGroup(name);
		return 0; 
#endif
	}
	//------------------------------------------------------------------------
	BackgroundProcessTicket ResourceBackgroundQueue::prepare(
		const String& resType, const String& name, 
		const String& group, bool isManual, 
		ManualResourceLoader* loader, 
		const NameValuePairList* loadParams, 
		ResourceBackgroundQueue::Listener* listener)
	{
#if OGRE_THREAD_SUPPORT
		// queue a request
		ResourceRequest req;
		req.type = RT_PREPARE_RESOURCE;
		req.resourceType = resType;
		req.resourceName = name;
		req.groupName = group;
		req.isManual = isManual;
		req.loader = loader;
		// Make instance copy of loadParams for thread independence
		req.loadParams = ( loadParams ? OGRE_NEW_T(NameValuePairList, MEMCATEGORY_GENERAL)( *loadParams ) : 0 );
		req.listener = listener;
		return addRequest(req);
#else
		// synchronous
		ResourceManager* rm = 
			ResourceGroupManager::getSingleton()._getResourceManager(resType);
		rm->prepare(name, group, isManual, loader, loadParams);
		return 0; 
#endif
	}
	//------------------------------------------------------------------------
	BackgroundProcessTicket ResourceBackgroundQueue::load(
		const String& resType, const String& name, 
		const String& group, bool isManual, 
		ManualResourceLoader* loader, 
		const NameValuePairList* loadParams, 
		ResourceBackgroundQueue::Listener* listener)
	{
#if OGRE_THREAD_SUPPORT
		// queue a request
		ResourceRequest req;
		req.type = RT_LOAD_RESOURCE;
		req.resourceType = resType;
		req.resourceName = name;
		req.groupName = group;
		req.isManual = isManual;
		req.loader = loader;
		// Make instance copy of loadParams for thread independence
		req.loadParams = ( loadParams ? OGRE_NEW_T(NameValuePairList, MEMCATEGORY_GENERAL)( *loadParams ) : 0 );
		req.listener = listener;
		return addRequest(req);
#else
		// synchronous
		ResourceManager* rm = 
			ResourceGroupManager::getSingleton()._getResourceManager(resType);
		rm->load(name, group, isManual, loader, loadParams);
		return 0; 
#endif
	}
	//---------------------------------------------------------------------
	BackgroundProcessTicket ResourceBackgroundQueue::unload(
		const String& resType, const String& name, Listener* listener)
	{
#if OGRE_THREAD_SUPPORT
		// queue a request
		ResourceRequest req;
		req.type = RT_UNLOAD_RESOURCE;
		req.resourceType = resType;
		req.resourceName = name;
		req.listener = listener;
		return addRequest(req);
#else
		// synchronous
		ResourceManager* rm = 
			ResourceGroupManager::getSingleton()._getResourceManager(resType);
		rm->unload(name);
		return 0; 
#endif

	}
	//---------------------------------------------------------------------
	BackgroundProcessTicket ResourceBackgroundQueue::unload(
		const String& resType, ResourceHandle handle, Listener* listener)
	{
#if OGRE_THREAD_SUPPORT
		// queue a request
		ResourceRequest req;
		req.type = RT_UNLOAD_RESOURCE;
		req.resourceType = resType;
		req.resourceHandle = handle;
		req.listener = listener;
		return addRequest(req);
#else
		// synchronous
		ResourceManager* rm = 
			ResourceGroupManager::getSingleton()._getResourceManager(resType);
		rm->unload(handle);
		return 0; 
#endif

	}
	//---------------------------------------------------------------------
	BackgroundProcessTicket ResourceBackgroundQueue::unloadResourceGroup(
		const String& name, Listener* listener)
	{
#if OGRE_THREAD_SUPPORT
		// queue a request
		ResourceRequest req;
		req.type = RT_UNLOAD_GROUP;
		req.groupName = name;
		req.listener = listener;
		return addRequest(req);
#else
		// synchronous
		ResourceGroupManager::getSingleton().unloadResourceGroup(name);
		return 0; 
#endif

	}
	//------------------------------------------------------------------------
	bool ResourceBackgroundQueue::isProcessComplete(
			BackgroundProcessTicket ticket)
	{
		return mOutstandingRequestSet.find(ticket) == mOutstandingRequestSet.end();
	}
	//------------------------------------------------------------------------
    void ResourceBackgroundQueue::abortRequest( BackgroundProcessTicket ticket )
    {
		WorkQueue* queue = Root::getSingleton().getWorkQueue();

		queue->abortRequest( ticket );
	}
	//------------------------------------------------------------------------
	BackgroundProcessTicket ResourceBackgroundQueue::addRequest(ResourceRequest& req)
	{
		WorkQueue* queue = Root::getSingleton().getWorkQueue();

		Any data(req);

		WorkQueue::RequestID requestID = 
			queue->addRequest(mWorkQueueChannel, (uint16)req.type, data);


		mOutstandingRequestSet.insert(requestID);

		return requestID;
	}
	//-----------------------------------------------------------------------
	bool ResourceBackgroundQueue::canHandleRequest(const WorkQueue::Request* req, const WorkQueue* srcQ)
	{
		return true;
	}
	//-----------------------------------------------------------------------
	WorkQueue::Response* ResourceBackgroundQueue::handleRequest(const WorkQueue::Request* req, const WorkQueue* srcQ)
	{

		ResourceRequest resreq = any_cast<ResourceRequest>(req->getData());

		if( req->getAborted() )
		{
			if( resreq.type == RT_PREPARE_RESOURCE || resreq.type == RT_LOAD_RESOURCE )
			{
				OGRE_DELETE_T(resreq.loadParams, NameValuePairList, MEMCATEGORY_GENERAL);
				resreq.loadParams = 0;
			}
			resreq.result.error = false;
			ResourceResponse resresp(ResourcePtr(), resreq);
			return OGRE_NEW WorkQueue::Response(req, true, Any(resresp));
		}

		ResourceManager* rm = 0;
		ResourcePtr resource;
		try
		{

			switch (resreq.type)
			{
			case RT_INITIALISE_GROUP:
				ResourceGroupManager::getSingleton().initialiseResourceGroup(
					resreq.groupName);
				break;
			case RT_INITIALISE_ALL_GROUPS:
				ResourceGroupManager::getSingleton().initialiseAllResourceGroups();
				break;
			case RT_PREPARE_GROUP:
				ResourceGroupManager::getSingleton().prepareResourceGroup(
					resreq.groupName);
				break;
			case RT_LOAD_GROUP:
	#if OGRE_THREAD_SUPPORT == 2
				ResourceGroupManager::getSingleton().prepareResourceGroup(
					resreq.groupName);
	#else
				ResourceGroupManager::getSingleton().loadResourceGroup(
					resreq.groupName);
	#endif
				break;
			case RT_UNLOAD_GROUP:
				ResourceGroupManager::getSingleton().unloadResourceGroup(
					resreq.groupName);
				break;
			case RT_PREPARE_RESOURCE:
				rm = ResourceGroupManager::getSingleton()._getResourceManager(
					resreq.resourceType);
				resource = rm->prepare(resreq.resourceName, resreq.groupName, resreq.isManual, 
					resreq.loader, resreq.loadParams, true);
				break;
			case RT_LOAD_RESOURCE:
				rm = ResourceGroupManager::getSingleton()._getResourceManager(
					resreq.resourceType);
	#if OGRE_THREAD_SUPPORT == 2
				resource = rm->prepare(resreq.resourceName, resreq.groupName, resreq.isManual, 
					resreq.loader, resreq.loadParams, true);
	#else
				resource = rm->load(resreq.resourceName, resreq.groupName, resreq.isManual, 
					resreq.loader, resreq.loadParams, true);
	#endif
				break;
			case RT_UNLOAD_RESOURCE:
				rm = ResourceGroupManager::getSingleton()._getResourceManager(
					resreq.resourceType);
				if (resreq.resourceName.empty())
					rm->unload(resreq.resourceHandle);
				else
					rm->unload(resreq.resourceName);
				break;
			};
		}
		catch (Exception& e)
		{
			if( resreq.type == RT_PREPARE_RESOURCE || resreq.type == RT_LOAD_RESOURCE )
			{
				OGRE_DELETE_T(resreq.loadParams, NameValuePairList, MEMCATEGORY_GENERAL);
				resreq.loadParams = 0;
			}
			resreq.result.error = true;
			resreq.result.message = e.getFullDescription();

			// return error response
			ResourceResponse resresp(resource, resreq);
			return OGRE_NEW WorkQueue::Response(req, false, Any(resresp), e.getFullDescription());
		}


		// success
		if( resreq.type == RT_PREPARE_RESOURCE || resreq.type == RT_LOAD_RESOURCE )
		{
			OGRE_DELETE_T(resreq.loadParams, NameValuePairList, MEMCATEGORY_GENERAL);
			resreq.loadParams = 0;
		}
		resreq.result.error = false;
		ResourceResponse resresp(resource, resreq);
		return OGRE_NEW WorkQueue::Response(req, true, Any(resresp));

	}
	//------------------------------------------------------------------------
	bool ResourceBackgroundQueue::canHandleResponse(const WorkQueue::Response* res, const WorkQueue* srcQ)
	{
		return true;
	}
	//------------------------------------------------------------------------
	void ResourceBackgroundQueue::handleResponse(const WorkQueue::Response* res, const WorkQueue* srcQ)
	{
		if( res->getRequest()->getAborted() )
		{
			mOutstandingRequestSet.erase(res->getRequest()->getID());
			return ;
		}

		if (res->succeeded())
		{
			ResourceResponse resresp = any_cast<ResourceResponse>(res->getData());

			// Complete full loading in main thread if semithreading
			const ResourceRequest& req = resresp.request;
#if OGRE_THREAD_SUPPORT == 2
			// These load commands would have been downgraded to prepare() for the background
			if (req.type == RT_LOAD_RESOURCE)
			{
				ResourceManager *rm = ResourceGroupManager::getSingleton()
					._getResourceManager(req.resourceType);
				rm->load(req.resourceName, req.groupName, req.isManual, req.loader, req.loadParams, true);
			} 
			else if (req.type == RT_LOAD_GROUP) 
			{
				ResourceGroupManager::getSingleton().loadResourceGroup(req.groupName);
			}
#endif
			mOutstandingRequestSet.erase(res->getRequest()->getID());

			// Call resource listener
			if (!resresp.resource.isNull()) 
			{

				if (req.type == RT_LOAD_RESOURCE) 
				{
					resresp.resource->_fireLoadingComplete( true );
				} 
				else 
				{
					resresp.resource->_firePreparingComplete( true );
				}
			} 

			// Call queue listener
			if (req.listener)
				req.listener->operationCompleted(res->getRequest()->getID(), req.result);

		}
	}
	//------------------------------------------------------------------------

}