// Copyright 2017 The Dawn Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// 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.

#ifndef DAWNNATIVE_D3D12_PIPELINELAYOUTD3D12_H_
#define DAWNNATIVE_D3D12_PIPELINELAYOUTD3D12_H_

#include "common/Constants.h"
#include "common/ityp_array.h"
#include "dawn_native/BindingInfo.h"
#include "dawn_native/PipelineLayout.h"
#include "dawn_native/d3d12/d3d12_platform.h"

namespace dawn_native { namespace d3d12 {

    class Device;

    class PipelineLayout final : public PipelineLayoutBase {
      public:
        static ResultOrError<Ref<PipelineLayout>> Create(
            Device* device,
            const PipelineLayoutDescriptor* descriptor);

        uint32_t GetCbvUavSrvRootParameterIndex(BindGroupIndex group) const;
        uint32_t GetSamplerRootParameterIndex(BindGroupIndex group) const;

        // Returns the index of the root parameter reserved for a dynamic buffer binding
        uint32_t GetDynamicRootParameterIndex(BindGroupIndex group,
                                              BindingIndex bindingIndex) const;

        uint32_t GetFirstIndexOffsetRegisterSpace() const;
        uint32_t GetFirstIndexOffsetShaderRegister() const;
        uint32_t GetFirstIndexOffsetParameterIndex() const;

        uint32_t GetNumWorkgroupsRegisterSpace() const;
        uint32_t GetNumWorkgroupsShaderRegister() const;
        uint32_t GetNumWorkgroupsParameterIndex() const;

        uint32_t GetDynamicStorageBufferLengthsRegisterSpace() const;
        uint32_t GetDynamicStorageBufferLengthsShaderRegister() const;
        uint32_t GetDynamicStorageBufferLengthsParameterIndex() const;

        ID3D12RootSignature* GetRootSignature() const;

        ID3D12CommandSignature* GetDispatchIndirectCommandSignatureWithNumWorkgroups();

        struct PerBindGroupDynamicStorageBufferLengthInfo {
            // First register offset for a bind group's dynamic storage buffer lengths.
            // This is the index into the array of root constants where this bind group's
            // lengths start.
            uint32_t firstRegisterOffset;

            struct BindingAndRegisterOffset {
                BindingNumber binding;
                uint32_t registerOffset;
            };
            // Associative list of (BindingNumber,registerOffset) pairs, which is passed into
            // the shader to map the BindingPoint(thisGroup, BindingNumber) to the registerOffset
            // into the root constant array which holds the dynamic storage buffer lengths.
            std::vector<BindingAndRegisterOffset> bindingAndRegisterOffsets;
        };

        // Flat map from bind group index to the list of (BindingNumber,Register) pairs.
        // Each pair is used in shader translation to
        using DynamicStorageBufferLengthInfo =
            ityp::array<BindGroupIndex, PerBindGroupDynamicStorageBufferLengthInfo, kMaxBindGroups>;

        const DynamicStorageBufferLengthInfo& GetDynamicStorageBufferLengthInfo() const;

      private:
        ~PipelineLayout() override = default;
        using PipelineLayoutBase::PipelineLayoutBase;
        MaybeError Initialize();
        ityp::array<BindGroupIndex, uint32_t, kMaxBindGroups> mCbvUavSrvRootParameterInfo;
        ityp::array<BindGroupIndex, uint32_t, kMaxBindGroups> mSamplerRootParameterInfo;
        ityp::array<BindGroupIndex,
                    ityp::array<BindingIndex, uint32_t, kMaxDynamicBuffersPerPipelineLayout>,
                    kMaxBindGroups>
            mDynamicRootParameterIndices;
        DynamicStorageBufferLengthInfo mDynamicStorageBufferLengthInfo;
        uint32_t mFirstIndexOffsetParameterIndex;
        uint32_t mNumWorkgroupsParameterIndex;
        uint32_t mDynamicStorageBufferLengthsParameterIndex;
        ComPtr<ID3D12RootSignature> mRootSignature;
        ComPtr<ID3D12CommandSignature> mDispatchIndirectCommandSignatureWithNumWorkgroups;
    };

}}  // namespace dawn_native::d3d12

#endif  // DAWNNATIVE_D3D12_PIPELINELAYOUTD3D12_H_