// Copyright 2020 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_BINDINGINFO_H_
#define SRC_DAWN_NATIVE_BINDINGINFO_H_

#include <cstdint>
#include <vector>

#include "dawn/common/Constants.h"
#include "dawn/common/ityp_array.h"
#include "dawn/native/Error.h"
#include "dawn/native/Format.h"
#include "dawn/native/IntegerTypes.h"
#include "dawn/native/PerStage.h"

#include "dawn/native/dawn_platform.h"

namespace dawn::native {

// Not a real WebGPU limit, but the sum of the two limits is useful for internal optimizations.
static constexpr uint32_t kMaxDynamicBuffersPerPipelineLayout =
    kMaxDynamicUniformBuffersPerPipelineLayout + kMaxDynamicStorageBuffersPerPipelineLayout;

static constexpr BindingIndex kMaxDynamicBuffersPerPipelineLayoutTyped =
    BindingIndex(kMaxDynamicBuffersPerPipelineLayout);

// Not a real WebGPU limit, but used to optimize parts of Dawn which expect valid usage of the
// API. There should never be more bindings than the max per stage, for each stage.
static constexpr uint32_t kMaxBindingsPerPipelineLayout =
    3 * (kMaxSampledTexturesPerShaderStage + kMaxSamplersPerShaderStage +
         kMaxStorageBuffersPerShaderStage + kMaxStorageTexturesPerShaderStage +
         kMaxUniformBuffersPerShaderStage);

static constexpr BindingIndex kMaxBindingsPerPipelineLayoutTyped =
    BindingIndex(kMaxBindingsPerPipelineLayout);

// TODO(enga): Figure out a good number for this.
static constexpr uint32_t kMaxOptimalBindingsPerGroup = 32;

enum class BindingInfoType { Buffer, Sampler, Texture, StorageTexture, ExternalTexture };

struct BindingInfo {
    BindingNumber binding;
    wgpu::ShaderStage visibility;

    BindingInfoType bindingType;

    // TODO(dawn:527): These four values could be made into a union.
    BufferBindingLayout buffer;
    SamplerBindingLayout sampler;
    TextureBindingLayout texture;
    StorageTextureBindingLayout storageTexture;
};

struct BindingSlot {
    BindGroupIndex group;
    BindingNumber binding;
};

struct PerStageBindingCounts {
    uint32_t sampledTextureCount;
    uint32_t samplerCount;
    uint32_t storageBufferCount;
    uint32_t storageTextureCount;
    uint32_t uniformBufferCount;
    uint32_t externalTextureCount;
};

struct BindingCounts {
    uint32_t totalCount;
    uint32_t bufferCount;
    uint32_t unverifiedBufferCount;  // Buffers with minimum buffer size unspecified
    uint32_t dynamicUniformBufferCount;
    uint32_t dynamicStorageBufferCount;
    PerStage<PerStageBindingCounts> perStage;
};

void IncrementBindingCounts(BindingCounts* bindingCounts, const BindGroupLayoutEntry& entry);
void AccumulateBindingCounts(BindingCounts* bindingCounts, const BindingCounts& rhs);
MaybeError ValidateBindingCounts(const BindingCounts& bindingCounts);

// For buffer size validation
using RequiredBufferSizes = ityp::array<BindGroupIndex, std::vector<uint64_t>, kMaxBindGroups>;

}  // namespace dawn::native

#endif  // SRC_DAWN_NATIVE_BINDINGINFO_H_