// Copyright 2018 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 SRC_DAWN_NATIVE_PASSRESOURCEUSAGE_H_
#define SRC_DAWN_NATIVE_PASSRESOURCEUSAGE_H_

#include <set>
#include <vector>

#include "dawn/native/SubresourceStorage.h"
#include "dawn/native/dawn_platform.h"

namespace dawn::native {

// This file declares various "ResourceUsage" structures. They are produced by the frontend
// while recording commands to be used for later validation and also some operations in the
// backends. The are produced by the "Encoder" objects that finalize them on "EndPass" or
// "Finish". Internally the "Encoder" may use the "StateTracker" to create them.

class BufferBase;
class QuerySetBase;
class TextureBase;

// The texture usage inside passes must be tracked per-subresource.
using TextureSubresourceUsage = SubresourceStorage<wgpu::TextureUsage>;

// Which resources are used by a synchronization scope and how they are used. The command
// buffer validation pre-computes this information so that backends with explicit barriers
// don't have to re-compute it.
struct SyncScopeResourceUsage {
    std::vector<BufferBase*> buffers;
    std::vector<wgpu::BufferUsage> bufferUsages;

    std::vector<TextureBase*> textures;
    std::vector<TextureSubresourceUsage> textureUsages;

    std::vector<ExternalTextureBase*> externalTextures;
};

// Contains all the resource usage data for a compute pass.
//
// Essentially a list of SyncScopeResourceUsage, one per Dispatch as required by the WebGPU
// specification. ComputePassResourceUsage also stores nline the set of all buffers and
// textures used, because some unused BindGroups may not be used at all in synchronization
// scope but their resources still need to be validated on Queue::Submit.
struct ComputePassResourceUsage {
    // Somehow without this defaulted constructor, MSVC or its STDlib have an issue where they
    // use the copy constructor (that's deleted) when doing operations on a
    // vector<ComputePassResourceUsage>
    ComputePassResourceUsage(ComputePassResourceUsage&&) = default;
    ComputePassResourceUsage() = default;

    std::vector<SyncScopeResourceUsage> dispatchUsages;

    // All the resources referenced by this compute pass for validation in Queue::Submit.
    std::set<BufferBase*> referencedBuffers;
    std::set<TextureBase*> referencedTextures;
    std::set<ExternalTextureBase*> referencedExternalTextures;
};

// Contains all the resource usage data for a render pass.
//
// In the WebGPU specification render passes are synchronization scopes but we also need to
// track additional data. It is stored for render passes used by a CommandBuffer, but also in
// RenderBundle so they can be merged into the render passes' usage on ExecuteBundles().
struct RenderPassResourceUsage : public SyncScopeResourceUsage {
    // Storage to track the occlusion queries used during the pass.
    std::vector<QuerySetBase*> querySets;
    std::vector<std::vector<bool>> queryAvailabilities;
};

using RenderPassUsages = std::vector<RenderPassResourceUsage>;
using ComputePassUsages = std::vector<ComputePassResourceUsage>;

// Contains a hierarchy of "ResourceUsage" that mirrors the hierarchy of the CommandBuffer and
// is used for validation and to produce barriers and lazy clears in the backends.
struct CommandBufferResourceUsage {
    RenderPassUsages renderPasses;
    ComputePassUsages computePasses;

    // Resources used in commands that aren't in a pass.
    std::set<BufferBase*> topLevelBuffers;
    std::set<TextureBase*> topLevelTextures;
    std::set<QuerySetBase*> usedQuerySets;
};

}  // namespace dawn::native

#endif  // SRC_DAWN_NATIVE_PASSRESOURCEUSAGE_H_