#include "D3D10InputLayout.hpp"
#include "D3D10Shader.hpp"
#include "D3D10Exception.hpp"

#include <boost/cast.hpp>

#include <iostream>

namespace drone
{
	namespace d3d10
	{

struct InputLayout::Implementation
{
	Implementation(RenderDevicePtr pDevice) : pDevice_(pDevice), locked(false){}

	void Add(LPCSTR semantic, 
		 int semanticindex, 
		 UINT format, 
		 UINT slot, 
		 UINT offset, 
		 UINT slotclass, 
		 UINT steprate)
	{

		assert(!locked && "Cannot change inputlayout once used.");

		D3D10_INPUT_ELEMENT_DESC layout[] =
		{
			{semantic, semanticindex, static_cast<DXGI_FORMAT>(format), slot, offset, static_cast<D3D10_INPUT_CLASSIFICATION>(slotclass), steprate },  
		};
		inputElementDesc_.push_back(layout[0]);
	}

	void Bind(graphics::IShaderPtr shader)
	{
		locked = true;
		ID3D10InputLayoutPtr layout;
		ShaderPtr d3d10shader = boost::shared_polymorphic_cast<Shader>(shader);

		if (associations_.empty() || activeLayout_->first != shader->Hash())
		{				    
			AssocMap::const_iterator i = associations_.find(shader->Hash());
			if (i != associations_.end())		
			{
			  activeLayout_ = i;	
			}
			else
			{
				D3D10_PASS_DESC PassDesc;
				d3d10shader->GetTech()->GetPassByIndex(d3d10shader->ActivePass())->GetDesc(&PassDesc);

				HRESULT hr = pDevice_->Device()->CreateInputLayout(&inputElementDesc_[0], 
																  inputElementDesc_.size(), 
																  PassDesc.pIAInputSignature, 
																  PassDesc.IAInputSignatureSize, 
																  &layout);

				if(FAILED(hr))
					throw Exception(L"Failed to Create Input layout", hr);

				activeLayout_ = associations_.insert(AssocMap::value_type(d3d10shader->Hash(), layout)).first;
			}			
		}
		pDevice_->Device()->IASetInputLayout(activeLayout_->second.get());
	}

	bool locked;
	
	RenderDevicePtr pDevice_;

	typedef std::map<int, ID3D10InputLayoutPtr> AssocMap;
	AssocMap associations_;

	AssocMap::const_iterator activeLayout_;

	std::vector<D3D10_INPUT_ELEMENT_DESC> inputElementDesc_;
};

InputLayout::InputLayout(const std::string& id, RenderDevicePtr pDevice) : IInputLayout(id), pImpl_(new Implementation(pDevice))
{
	std::wcout <<">> Created InputLayout: \"" << id.c_str() << "\". (D3D10)\n";
}

void InputLayout::Add(LPCSTR semantic, 
		 int semanticindex, 
		 UINT format, 
		 UINT slot, 
		 UINT offset, 
		 UINT slotclass, 
		 UINT steprate)
{
	pImpl_->Add(semantic, semanticindex, format, slot, offset, slotclass, steprate);
}

void InputLayout::Bind(graphics::IShaderPtr shader)
{
	pImpl_->Bind(shader);
}

int InputLayout::NumElements()
{
	return pImpl_->inputElementDesc_.size();
}

	}
}