// 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.

#include "dawn/native/opengl/PipelineLayoutGL.h"

#include "dawn/common/BitSetIterator.h"
#include "dawn/native/BindGroupLayout.h"
#include "dawn/native/opengl/DeviceGL.h"

namespace dawn::native::opengl {

PipelineLayout::PipelineLayout(Device* device, const PipelineLayoutDescriptor* descriptor)
    : PipelineLayoutBase(device, descriptor) {
    GLuint uboIndex = 0;
    GLuint samplerIndex = 0;
    GLuint sampledTextureIndex = 0;
    GLuint ssboIndex = 0;
    GLuint storageTextureIndex = 0;

    for (BindGroupIndex group : IterateBitSet(GetBindGroupLayoutsMask())) {
        const BindGroupLayoutBase* bgl = GetBindGroupLayout(group);
        mIndexInfo[group].resize(bgl->GetBindingCount());

        for (BindingIndex bindingIndex{0}; bindingIndex < bgl->GetBindingCount(); ++bindingIndex) {
            const BindingInfo& bindingInfo = bgl->GetBindingInfo(bindingIndex);
            switch (bindingInfo.bindingType) {
                case BindingInfoType::Buffer:
                    switch (bindingInfo.buffer.type) {
                        case wgpu::BufferBindingType::Uniform:
                            mIndexInfo[group][bindingIndex] = uboIndex;
                            uboIndex++;
                            break;
                        case wgpu::BufferBindingType::Storage:
                        case kInternalStorageBufferBinding:
                        case wgpu::BufferBindingType::ReadOnlyStorage:
                            mIndexInfo[group][bindingIndex] = ssboIndex;
                            ssboIndex++;
                            break;
                        case wgpu::BufferBindingType::Undefined:
                            UNREACHABLE();
                    }
                    break;

                case BindingInfoType::Sampler:
                    mIndexInfo[group][bindingIndex] = samplerIndex;
                    samplerIndex++;
                    break;

                case BindingInfoType::Texture:
                case BindingInfoType::ExternalTexture:
                    mIndexInfo[group][bindingIndex] = sampledTextureIndex;
                    sampledTextureIndex++;
                    break;

                case BindingInfoType::StorageTexture:
                    mIndexInfo[group][bindingIndex] = storageTextureIndex;
                    storageTextureIndex++;
                    break;
            }
        }
    }

    mNumSamplers = samplerIndex;
    mNumSampledTextures = sampledTextureIndex;
}

const PipelineLayout::BindingIndexInfo& PipelineLayout::GetBindingIndexInfo() const {
    return mIndexInfo;
}

GLuint PipelineLayout::GetTextureUnitsUsed() const {
    return 0;
}

size_t PipelineLayout::GetNumSamplers() const {
    return mNumSamplers;
}

size_t PipelineLayout::GetNumSampledTextures() const {
    return mNumSampledTextures;
}

}  // namespace dawn::native::opengl