// d3d12-resource.h
#pragma once

#pragma push_macro("WIN32_LEAN_AND_MEAN")
#pragma push_macro("NOMINMAX")
#undef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN
#undef NOMINMAX
#define NOMINMAX
#include <windows.h>
#pragma pop_macro("NOMINMAX")
#pragma pop_macro("WIN32_LEAN_AND_MEAN")

#include "../d3d/d3d-util.h"
#include "slang-com-ptr.h"

#include <d3d12.h>
#include <dxgi1_4.h>

namespace gfx
{

// Enables more conservative barriers - restoring the state of resources after they are used.
// Should not need to be enabled in normal builds, as the barriers should correctly sync resources
// If enabling fixes an issue it implies regular barriers are not correctly used.
#define SLANG_ENABLE_CONSERVATIVE_RESOURCE_BARRIERS 0

struct D3D12BarrierSubmitter
{
    enum
    {
        MAX_BARRIERS = 8
    };

    /// Expand one space to hold a barrier
    SLANG_FORCE_INLINE D3D12_RESOURCE_BARRIER& expandOne()
    {
        return (m_numBarriers < MAX_BARRIERS) ? m_barriers[m_numBarriers++] : _expandOne();
    }
    /// Flush barriers to command list
    SLANG_FORCE_INLINE void flush()
    {
        if (m_numBarriers > 0)
            _flush();
    }

    /// Transition resource from prevState to nextState
    void transition(
        ID3D12Resource* resource,
        D3D12_RESOURCE_STATES prevState,
        D3D12_RESOURCE_STATES nextState);

    /// Ctor
    SLANG_FORCE_INLINE D3D12BarrierSubmitter(ID3D12GraphicsCommandList* commandList)
        : m_numBarriers(0), m_commandList(commandList)
    {
    }
    /// Dtor
    SLANG_FORCE_INLINE ~D3D12BarrierSubmitter() { flush(); }

protected:
    D3D12_RESOURCE_BARRIER& _expandOne();
    void _flush();

    ID3D12GraphicsCommandList* m_commandList;
    int m_numBarriers;
    D3D12_RESOURCE_BARRIER m_barriers[MAX_BARRIERS];
};

/** The base class for resource types allows for tracking of state. It does not allow for setting of
the resource though, such that an interface can return a D3D12ResourceBase, and a client cant
manipulate it's state, but it cannot replace/change the actual resource */
struct D3D12ResourceBase
{
    /// Add a transition if necessary to the list
    void transition(
        D3D12_RESOURCE_STATES currentState,
        D3D12_RESOURCE_STATES nextState,
        D3D12BarrierSubmitter& submitter);
    /// Get the associated resource
    SLANG_FORCE_INLINE ID3D12Resource* getResource() const { return m_resource; }

    /// True if a resource is set
    SLANG_FORCE_INLINE bool isSet() const { return m_resource != nullptr; }

    /// Coercible into ID3D12Resource
    SLANG_FORCE_INLINE operator ID3D12Resource*() const { return m_resource; }

    /// Given the usage, flags, and format will return the most suitable format. Will return
    /// DXGI_UNKNOWN if combination is not possible
    static DXGI_FORMAT calcFormat(D3DUtil::UsageType usage, ID3D12Resource* resource);

    /// Ctor
    SLANG_FORCE_INLINE D3D12ResourceBase()
        : m_resource(nullptr)
    {
    }

protected:
    /// This is protected so as clients cannot slice the class, and so state tracking is lost
    ~D3D12ResourceBase() {}

    ID3D12Resource* m_resource; ///< The resource (ref counted)
};

struct D3D12Resource : public D3D12ResourceBase
{

    /// Dtor
    ~D3D12Resource()
    {
        if (m_resource)
        {
            m_resource->Release();
        }
    }

    /// Initialize as committed resource
    Slang::Result initCommitted(
        ID3D12Device* device,
        const D3D12_HEAP_PROPERTIES& heapProps,
        D3D12_HEAP_FLAGS heapFlags,
        const D3D12_RESOURCE_DESC& resourceDesc,
        D3D12_RESOURCE_STATES initState,
        const D3D12_CLEAR_VALUE* clearValue);

    /// Set a resource.
    void setResource(ID3D12Resource* resource);
    /// Make the resource null
    void setResourceNull();
    /// Returns the attached resource (with any ref counts) and sets to nullptr on this.
    ID3D12Resource* detach();

    /// Swaps the resource contents with the contents of the smart pointer
    void swap(Slang::ComPtr<ID3D12Resource>& resourceInOut);

    /// Set the debug name on a resource
    static void setDebugName(ID3D12Resource* resource, const char* name);

    /// Set the the debug name on the resource
    void setDebugName(const wchar_t* name);
    /// Set the debug name
    void setDebugName(const char* name);
};

} // namespace gfx