// 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.

#include "dawn_native/ComputePassEncoder.h"

#include "dawn_native/Buffer.h"
#include "dawn_native/CommandEncoder.h"
#include "dawn_native/CommandValidation.h"
#include "dawn_native/Commands.h"
#include "dawn_native/ComputePipeline.h"
#include "dawn_native/Device.h"
#include "dawn_native/QuerySet.h"

namespace dawn_native {

    ComputePassEncoder::ComputePassEncoder(DeviceBase* device,
                                           CommandEncoder* commandEncoder,
                                           EncodingContext* encodingContext)
        : ProgrammablePassEncoder(device, encodingContext, PassType::Compute),
          mCommandEncoder(commandEncoder) {
    }

    ComputePassEncoder::ComputePassEncoder(DeviceBase* device,
                                           CommandEncoder* commandEncoder,
                                           EncodingContext* encodingContext,
                                           ErrorTag errorTag)
        : ProgrammablePassEncoder(device, encodingContext, errorTag, PassType::Compute),
          mCommandEncoder(commandEncoder) {
    }

    ComputePassEncoder* ComputePassEncoder::MakeError(DeviceBase* device,
                                                      CommandEncoder* commandEncoder,
                                                      EncodingContext* encodingContext) {
        return new ComputePassEncoder(device, commandEncoder, encodingContext, ObjectBase::kError);
    }

    void ComputePassEncoder::EndPass() {
        if (mEncodingContext->TryEncode(this, [&](CommandAllocator* allocator) -> MaybeError {
                if (IsValidationEnabled()) {
                    DAWN_TRY(ValidateProgrammableEncoderEnd());
                }

                allocator->Allocate<EndComputePassCmd>(Command::EndComputePass);

                return {};
            })) {
            mEncodingContext->ExitPass(this, mUsageTracker.AcquireResourceUsage());
        }
    }

    void ComputePassEncoder::Dispatch(uint32_t x, uint32_t y, uint32_t z) {
        mEncodingContext->TryEncode(this, [&](CommandAllocator* allocator) -> MaybeError {
            if (IsValidationEnabled()) {
                DAWN_TRY(mCommandBufferState.ValidateCanDispatch());
            }

            // Skip noop dispatch. It is a workaround for system crashes on 0 dispatches on some
            // platforms.
            if (x != 0 && y != 0 && z != 0) {
                DispatchCmd* dispatch = allocator->Allocate<DispatchCmd>(Command::Dispatch);
                dispatch->x = x;
                dispatch->y = y;
                dispatch->z = z;
            }

            return {};
        });
    }

    void ComputePassEncoder::DispatchIndirect(BufferBase* indirectBuffer, uint64_t indirectOffset) {
        mEncodingContext->TryEncode(this, [&](CommandAllocator* allocator) -> MaybeError {
            if (IsValidationEnabled()) {
                DAWN_TRY(GetDevice()->ValidateObject(indirectBuffer));
                DAWN_TRY(ValidateCanUseAs(indirectBuffer, wgpu::BufferUsage::Indirect));
                DAWN_TRY(mCommandBufferState.ValidateCanDispatch());

                // Indexed dispatches need a compute-shader based validation to check that the
                // dispatch sizes aren't too big. Disallow them as unsafe until the validation is
                // implemented.
                if (GetDevice()->IsToggleEnabled(Toggle::DisallowUnsafeAPIs)) {
                    return DAWN_VALIDATION_ERROR(
                        "DispatchIndirect is disallowed because it doesn't validate that the "
                        "dispatch "
                        "size is valid yet.");
                }

                if (indirectOffset % 4 != 0) {
                    return DAWN_VALIDATION_ERROR("Indirect offset must be a multiple of 4");
                }

                if (indirectOffset >= indirectBuffer->GetSize() ||
                    indirectOffset + kDispatchIndirectSize > indirectBuffer->GetSize()) {
                    return DAWN_VALIDATION_ERROR("Indirect offset out of bounds");
                }
            }

            DispatchIndirectCmd* dispatch =
                allocator->Allocate<DispatchIndirectCmd>(Command::DispatchIndirect);
            dispatch->indirectBuffer = indirectBuffer;
            dispatch->indirectOffset = indirectOffset;

            mUsageTracker.BufferUsedAs(indirectBuffer, wgpu::BufferUsage::Indirect);

            return {};
        });
    }

    void ComputePassEncoder::SetPipeline(ComputePipelineBase* pipeline) {
        mEncodingContext->TryEncode(this, [&](CommandAllocator* allocator) -> MaybeError {
            if (IsValidationEnabled()) {
                DAWN_TRY(GetDevice()->ValidateObject(pipeline));
            }

            mCommandBufferState.SetComputePipeline(pipeline);

            SetComputePipelineCmd* cmd =
                allocator->Allocate<SetComputePipelineCmd>(Command::SetComputePipeline);
            cmd->pipeline = pipeline;

            return {};
        });
    }

    void ComputePassEncoder::WriteTimestamp(QuerySetBase* querySet, uint32_t queryIndex) {
        mEncodingContext->TryEncode(this, [&](CommandAllocator* allocator) -> MaybeError {
            if (IsValidationEnabled()) {
                DAWN_TRY(GetDevice()->ValidateObject(querySet));
                DAWN_TRY(ValidateTimestampQuery(querySet, queryIndex));
            }

            mCommandEncoder->TrackQueryAvailability(querySet, queryIndex);

            WriteTimestampCmd* cmd =
                allocator->Allocate<WriteTimestampCmd>(Command::WriteTimestamp);
            cmd->querySet = querySet;
            cmd->queryIndex = queryIndex;

            return {};
        });
    }

}  // namespace dawn_native