// Copyright 2017 The NXT 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 "backend/metal/ComputePipelineMTL.h"

#include "backend/metal/MetalBackend.h"
#include "backend/metal/ShaderModuleMTL.h"

namespace backend {
namespace metal {

    ComputePipeline::ComputePipeline(ComputePipelineBuilder* builder)
        : ComputePipelineBase(builder) {

        auto mtlDevice = ToBackend(builder->GetDevice())->GetMTLDevice();

        const auto& module = ToBackend(builder->GetStageInfo(nxt::ShaderStage::Compute).module);
        const auto& entryPoint = builder->GetStageInfo(nxt::ShaderStage::Compute).entryPoint;

        auto compilationData = module->GetFunction(entryPoint.c_str(), ToBackend(GetLayout()));

        NSError *error = nil;
        mMtlComputePipelineState = [mtlDevice
            newComputePipelineStateWithFunction:compilationData.function error:&error];
        if (error != nil) {
            NSLog(@" error => %@", error);
            builder->HandleError("Error creating pipeline state");
            return;
        }

        // Copy over the local workgroup size as it is passed to dispatch explicitly in Metal
        mLocalWorkgroupSize = compilationData.localWorkgroupSize;
    }

    ComputePipeline::~ComputePipeline() {
        [mMtlComputePipelineState release];
    }

    void ComputePipeline::Encode(id<MTLComputeCommandEncoder> encoder) {
        [encoder setComputePipelineState:mMtlComputePipelineState];
    }

    MTLSize ComputePipeline::GetLocalWorkGroupSize() const {
        return mLocalWorkgroupSize;
    }

}
}