// Copyright 2021 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/ExternalTexture.h"

#include <algorithm>
#include <utility>

#include "dawn/native/Buffer.h"
#include "dawn/native/Device.h"
#include "dawn/native/ObjectType_autogen.h"
#include "dawn/native/Queue.h"
#include "dawn/native/Texture.h"

#include "dawn/native/dawn_platform.h"

namespace dawn::native {

MaybeError ValidateExternalTexturePlane(const TextureViewBase* textureView) {
    DAWN_INVALID_IF(
        (textureView->GetTexture()->GetUsage() & wgpu::TextureUsage::TextureBinding) == 0,
        "The external texture plane (%s) usage (%s) doesn't include the required usage (%s)",
        textureView, textureView->GetTexture()->GetUsage(), wgpu::TextureUsage::TextureBinding);

    DAWN_INVALID_IF(textureView->GetDimension() != wgpu::TextureViewDimension::e2D,
                    "The external texture plane (%s) dimension (%s) is not 2D.", textureView,
                    textureView->GetDimension());

    DAWN_INVALID_IF(textureView->GetLevelCount() > 1,
                    "The external texture plane (%s) mip level count (%u) is not 1.", textureView,
                    textureView->GetLevelCount());

    DAWN_INVALID_IF(textureView->GetTexture()->GetSampleCount() != 1,
                    "The external texture plane (%s) sample count (%u) is not one.", textureView,
                    textureView->GetTexture()->GetSampleCount());

    return {};
}

MaybeError ValidateExternalTextureDescriptor(const DeviceBase* device,
                                             const ExternalTextureDescriptor* descriptor) {
    ASSERT(descriptor);
    ASSERT(descriptor->plane0);

    DAWN_TRY(device->ValidateObject(descriptor->plane0));

    wgpu::TextureFormat plane0Format = descriptor->plane0->GetFormat().format;

    DAWN_INVALID_IF(!descriptor->gamutConversionMatrix,
                    "The gamut conversion matrix must be non-null.");

    DAWN_INVALID_IF(!descriptor->srcTransferFunctionParameters,
                    "The source transfer function parameters must be non-null.");

    DAWN_INVALID_IF(!descriptor->dstTransferFunctionParameters,
                    "The destination transfer function parameters must be non-null.");

    if (descriptor->plane1) {
        DAWN_INVALID_IF(
            !descriptor->yuvToRgbConversionMatrix,
            "When more than one plane is set, the YUV-to-RGB conversion matrix must be non-null.");

        DAWN_TRY(device->ValidateObject(descriptor->plane1));
        wgpu::TextureFormat plane1Format = descriptor->plane1->GetFormat().format;

        DAWN_INVALID_IF(plane0Format != wgpu::TextureFormat::R8Unorm,
                        "The bi-planar external texture plane (%s) format (%s) is not %s.",
                        descriptor->plane0, plane0Format, wgpu::TextureFormat::R8Unorm);
        DAWN_INVALID_IF(plane1Format != wgpu::TextureFormat::RG8Unorm,
                        "The bi-planar external texture plane (%s) format (%s) is not %s.",
                        descriptor->plane1, plane1Format, wgpu::TextureFormat::RG8Unorm);

        DAWN_TRY(ValidateExternalTexturePlane(descriptor->plane0));
        DAWN_TRY(ValidateExternalTexturePlane(descriptor->plane1));
    } else {
        switch (plane0Format) {
            case wgpu::TextureFormat::RGBA8Unorm:
            case wgpu::TextureFormat::BGRA8Unorm:
            case wgpu::TextureFormat::RGBA16Float:
                DAWN_TRY(ValidateExternalTexturePlane(descriptor->plane0));
                break;
            default:
                return DAWN_FORMAT_VALIDATION_ERROR(
                    "The external texture plane (%s) format (%s) is not a supported format "
                    "(%s, %s, %s).",
                    descriptor->plane0, plane0Format, wgpu::TextureFormat::RGBA8Unorm,
                    wgpu::TextureFormat::BGRA8Unorm, wgpu::TextureFormat::RGBA16Float);
        }
    }

    return {};
}

// static
ResultOrError<Ref<ExternalTextureBase>> ExternalTextureBase::Create(
    DeviceBase* device,
    const ExternalTextureDescriptor* descriptor) {
    Ref<ExternalTextureBase> externalTexture =
        AcquireRef(new ExternalTextureBase(device, descriptor));
    DAWN_TRY(externalTexture->Initialize(device, descriptor));
    return std::move(externalTexture);
}

ExternalTextureBase::ExternalTextureBase(DeviceBase* device,
                                         const ExternalTextureDescriptor* descriptor)
    : ApiObjectBase(device, descriptor->label), mState(ExternalTextureState::Alive) {
    TrackInDevice();
}

ExternalTextureBase::ExternalTextureBase(DeviceBase* device)
    : ApiObjectBase(device, kLabelNotImplemented), mState(ExternalTextureState::Alive) {
    TrackInDevice();
}

// Error external texture cannot be used in bind group.
ExternalTextureBase::ExternalTextureBase(DeviceBase* device, ObjectBase::ErrorTag tag)
    : ApiObjectBase(device, tag), mState(ExternalTextureState::Destroyed) {}

ExternalTextureBase::~ExternalTextureBase() = default;

MaybeError ExternalTextureBase::Initialize(DeviceBase* device,
                                           const ExternalTextureDescriptor* descriptor) {
    // Store any passed in TextureViews associated with individual planes.
    mTextureViews[0] = descriptor->plane0;

    if (descriptor->plane1) {
        mTextureViews[1] = descriptor->plane1;
    } else {
        DAWN_TRY_ASSIGN(mTextureViews[1],
                        device->GetOrCreatePlaceholderTextureViewForExternalTexture());
    }

    // We must create a buffer to store parameters needed by a shader that operates on this
    // external texture.
    BufferDescriptor bufferDesc;
    bufferDesc.size = sizeof(ExternalTextureParams);
    bufferDesc.usage = wgpu::BufferUsage::Uniform | wgpu::BufferUsage::CopyDst;
    bufferDesc.label = "Dawn_External_Texture_Params_Buffer";

    DAWN_TRY_ASSIGN(mParamsBuffer, device->CreateBuffer(&bufferDesc));

    ExternalTextureParams params;
    params.numPlanes = descriptor->plane1 == nullptr ? 1 : 2;

    params.doYuvToRgbConversionOnly = descriptor->doYuvToRgbConversionOnly ? 1 : 0;

    // YUV-to-RGB conversion is performed by multiplying the source YUV values with a 4x3 matrix
    // passed from Chromium. The matrix was originally sourced from /skia/src/core/SkYUVMath.cpp.
    // This matrix is only used in multiplanar scenarios.
    if (params.numPlanes == 2) {
        ASSERT(descriptor->yuvToRgbConversionMatrix);
        const float* yMat = descriptor->yuvToRgbConversionMatrix;
        std::copy(yMat, yMat + 12, params.yuvToRgbConversionMatrix.begin());
    }

    // Gamut correction is performed by multiplying a 3x3 matrix passed from Chromium. The
    // matrix was computed by multiplying the appropriate source and destination gamut
    // matrices sourced from ui/gfx/color_space.cc.
    const float* gMat = descriptor->gamutConversionMatrix;
    params.gamutConversionMatrix = {gMat[0], gMat[1], gMat[2], 0.0f,  //
                                    gMat[3], gMat[4], gMat[5], 0.0f,  //
                                    gMat[6], gMat[7], gMat[8], 0.0f};

    // Gamma decode/encode is performed by the logic:
    //    if (abs(v) < params.D) {
    //        return sign(v) * (params.C * abs(v) + params.F);
    //    }
    //    return pow(A * x + B, G) + E
    //
    // Constants are passed from Chromium and originally sourced from ui/gfx/color_space.cc
    const float* srcFn = descriptor->srcTransferFunctionParameters;
    std::copy(srcFn, srcFn + 7, params.gammaDecodingParams.begin());

    const float* dstFn = descriptor->dstTransferFunctionParameters;
    std::copy(dstFn, dstFn + 7, params.gammaEncodingParams.begin());

    DAWN_TRY(device->GetQueue()->WriteBuffer(mParamsBuffer.Get(), 0, &params,
                                             sizeof(ExternalTextureParams)));

    return {};
}

const std::array<Ref<TextureViewBase>, kMaxPlanesPerFormat>& ExternalTextureBase::GetTextureViews()
    const {
    return mTextureViews;
}

MaybeError ExternalTextureBase::ValidateCanUseInSubmitNow() const {
    ASSERT(!IsError());
    DAWN_INVALID_IF(mState == ExternalTextureState::Destroyed,
                    "Destroyed external texture %s is used in a submit.", this);
    return {};
}

void ExternalTextureBase::APIDestroy() {
    if (GetDevice()->ConsumedError(GetDevice()->ValidateObject(this))) {
        return;
    }
    Destroy();
}

void ExternalTextureBase::DestroyImpl() {
    mState = ExternalTextureState::Destroyed;
}

// static
ExternalTextureBase* ExternalTextureBase::MakeError(DeviceBase* device) {
    return new ExternalTextureBase(device, ObjectBase::kError);
}

BufferBase* ExternalTextureBase::GetParamsBuffer() const {
    return mParamsBuffer.Get();
}

ObjectType ExternalTextureBase::GetType() const {
    return ObjectType::ExternalTexture;
}

}  // namespace dawn::native