// 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 BACKEND_PIPELINE_H_
#define BACKEND_PIPELINE_H_

#include "backend/Builder.h"
#include "backend/Forward.h"
#include "backend/PerStage.h"
#include "backend/PipelineLayout.h"
#include "backend/RefCounted.h"
#include "backend/ShaderModule.h"

#include "dawn/dawncpp.h"

#include <array>
#include <bitset>

namespace backend {

    enum PushConstantType : uint8_t {
        Int,
        UInt,
        Float,
    };

    class PipelineBuilder;

    class PipelineBase {
      public:
        PipelineBase(PipelineBuilder* builder);

        struct PushConstantInfo {
            std::bitset<kMaxPushConstants> mask;
            std::array<PushConstantType, kMaxPushConstants> types;
        };
        const PushConstantInfo& GetPushConstants(dawn::ShaderStage stage) const;
        dawn::ShaderStageBit GetStageMask() const;

        PipelineLayoutBase* GetLayout();

      private:
        dawn::ShaderStageBit mStageMask;
        Ref<PipelineLayoutBase> mLayout;
        PerStage<PushConstantInfo> mPushConstants;
    };

    class PipelineBuilder {
      public:
        PipelineBuilder(BuilderBase* parentBuilder);

        struct StageInfo {
            std::string entryPoint;
            Ref<ShaderModuleBase> module;
        };
        const StageInfo& GetStageInfo(dawn::ShaderStage stage) const;
        BuilderBase* GetParentBuilder() const;

        // Dawn API
        void SetLayout(PipelineLayoutBase* layout);
        void SetStage(dawn::ShaderStage stage, ShaderModuleBase* module, const char* entryPoint);

      private:
        friend class PipelineBase;

        BuilderBase* mParentBuilder;
        Ref<PipelineLayoutBase> mLayout;
        dawn::ShaderStageBit mStageMask;
        PerStage<StageInfo> mStages;
    };

}  // namespace backend

#endif  // BACKEND_PIPELINE_H_