//
// Copyright © 2017 Arm Ltd. All rights reserved.
// SPDX-License-Identifier: MIT
//

#include <armnn/backends/SubgraphView.hpp>

#include <Graph.hpp>

#include <armnn/utility/IgnoreUnused.hpp>
#include <armnn/utility/NumericCast.hpp>
#include <armnn/utility/PolymorphicDowncast.hpp>

#include <utility>

namespace armnn
{

namespace
{

template <class C>
void AssertIfNullsOrDuplicates(const C& container, const std::string& errorMessage)
{
    using T = typename C::value_type;
    std::unordered_set<T> duplicateSet;
    std::for_each(container.begin(), container.end(), [&duplicateSet, &errorMessage](const T& i)
    {
        // Ignore unused for release builds
        IgnoreUnused(errorMessage);

        // Check if the item is valid
        ARMNN_ASSERT_MSG(i, errorMessage.c_str());

        // Check if a duplicate has been found
        ARMNN_ASSERT_MSG(duplicateSet.find(i) == duplicateSet.end(), errorMessage.c_str());

        duplicateSet.insert(i);
    });
}

} // anonymous namespace

SubgraphView::SubgraphView(Graph& graph)
    : m_InputSlots{}
    , m_OutputSlots{}
    , m_Layers(graph.begin(), graph.end())
    , m_IConnectableLayers(graph.begin(), graph.end())
{
    ArrangeBySortOrder();
    CheckSubgraph();
}

/// IConnectable Duplication to maintain backwards compatibility
SubgraphView::SubgraphView(InputSlots&& inputs, OutputSlots&& outputs, Layers&& layers)
    : m_InputSlots{InputSlots{inputs.begin(), inputs.end()}}
    , m_IInputSlots{IInputSlots{inputs.begin(), inputs.end()}}
    , m_OutputSlots{OutputSlots{outputs.begin(), outputs.end()}}
    , m_IOutputSlots{IOutputSlots{outputs.begin(), outputs.end()}}
    , m_Layers(layers)
    , m_IConnectableLayers(IConnectableLayers{layers.begin(), layers.end()})
{
    ArrangeBySortOrder();
    CheckSubgraph();
}

/// IConnectable Duplication to maintain backwards compatibility
SubgraphView::SubgraphView(SubgraphView::IConnectableLayers &&layers,
                           SubgraphView::IInputSlots &&inputs,
                           SubgraphView::IOutputSlots &&outputs)
        : m_IInputSlots{inputs}
        , m_IOutputSlots{outputs}
        , m_IConnectableLayers(IConnectableLayers{layers.begin(), layers.end()})
{
    // Cast from IConnectableLayer to Layer for backward compatibility
    auto f = [](IConnectableLayer* value)
    {
        return PolymorphicDowncast<Layer*>(value);
    };
    std::transform(layers.begin(), layers.end(), std::back_inserter(m_Layers), f);


    m_InputSlots.resize(inputs.size());
    m_IInputSlots.resize(inputs.size());
    for (unsigned int i = 0; i < inputs.size(); i++)
    {
        m_InputSlots.at(i) = PolymorphicDowncast<InputSlot*>(inputs[i]);
        m_IInputSlots.at(i) = inputs[i];
    }

    m_OutputSlots.resize(outputs.size());
    m_IOutputSlots.resize(outputs.size());
    for (unsigned int i = 0; i < outputs.size(); i++)
    {
        m_OutputSlots.at(i) = PolymorphicDowncast<OutputSlot*>(outputs[i]);
        m_IOutputSlots.at(i) = outputs[i];
    }

    ArrangeBySortOrder();
    CheckSubgraph();
}

SubgraphView::SubgraphView(const SubgraphView& subgraph)
    : m_InputSlots(subgraph.m_InputSlots.begin(), subgraph.m_InputSlots.end())
    , m_IInputSlots(subgraph.m_IInputSlots.begin(), subgraph.m_IInputSlots.end())
    , m_OutputSlots(subgraph.m_OutputSlots.begin(), subgraph.m_OutputSlots.end())
    , m_IOutputSlots(subgraph.m_IOutputSlots.begin(), subgraph.m_IOutputSlots.end())
    , m_Layers(subgraph.m_Layers.begin(), subgraph.m_Layers.end())
    , m_IConnectableLayers(IConnectableLayers{subgraph.m_IConnectableLayers.begin(),
                                              subgraph.m_IConnectableLayers.end()})
{
    ArrangeBySortOrder();
    CheckSubgraph();
}

SubgraphView::SubgraphView(SubgraphView&& subgraph)
    : m_InputSlots(std::move(subgraph.m_InputSlots))
    , m_IInputSlots(std::move(subgraph.m_IInputSlots))
    , m_OutputSlots(std::move(subgraph.m_OutputSlots))
    , m_IOutputSlots(std::move(subgraph.m_IOutputSlots))
    , m_Layers(std::move(subgraph.m_Layers))
    , m_IConnectableLayers(std::move(subgraph.m_IConnectableLayers))
{
    ArrangeBySortOrder();
    CheckSubgraph();
}

SubgraphView::SubgraphView(IConnectableLayer* layer)
    : m_Layers{PolymorphicDowncast<Layer*>(layer)}
    , m_IConnectableLayers{layer}
{
    unsigned int numInputSlots = layer->GetNumInputSlots();
    m_InputSlots.resize(numInputSlots);
    m_IInputSlots.resize(numInputSlots);
    for (unsigned int i = 0; i < numInputSlots; i++)
    {
        m_InputSlots.at(i) = PolymorphicDowncast<InputSlot*>(&(layer->GetInputSlot(i)));
        m_IInputSlots.at(i) = &(layer->GetInputSlot(i));
    }

    unsigned int numOutputSlots = layer->GetNumOutputSlots();
    m_OutputSlots.resize(numOutputSlots);
    m_IOutputSlots.resize(numOutputSlots);
    for (unsigned int i = 0; i < numOutputSlots; i++)
    {
        m_OutputSlots.at(i) = PolymorphicDowncast<OutputSlot*>(&(layer->GetOutputSlot(i)));
        m_IOutputSlots.at(i) = &(layer->GetOutputSlot(i));
    }

    CheckSubgraph();
}

SubgraphView& SubgraphView::operator=(SubgraphView&& other)
{
    m_InputSlots = std::move(other.m_InputSlots);
    m_IInputSlots = std::move(other.m_IInputSlots);
    m_OutputSlots = std::move(other.m_OutputSlots);
    m_IOutputSlots = std::move(other.m_IOutputSlots);
    m_Layers = std::move(other.m_Layers);
    m_IConnectableLayers = std::move(other.m_IConnectableLayers);

    CheckSubgraph();

    return *this;
}

void SubgraphView::CheckSubgraph()
{
    // Check for invalid or duplicate input slots
    AssertIfNullsOrDuplicates(m_InputSlots, "Sub-graphs cannot contain null or duplicate input slots");

    // Check for invalid or duplicate output slots
    AssertIfNullsOrDuplicates(m_OutputSlots, "Sub-graphs cannot contain null or duplicate output slots");

    // Check for invalid or duplicate layers
    AssertIfNullsOrDuplicates(m_Layers, "Sub-graphs cannot contain null or duplicate layers");

    // Check for invalid or duplicate input slots
    AssertIfNullsOrDuplicates(m_IInputSlots, "Sub-graphs cannot contain null or duplicate IInputSlots");

    // Check for invalid or duplicate output slots
    AssertIfNullsOrDuplicates(m_IOutputSlots, "Sub-graphs cannot contain null or duplicate IOutputSlots");

    // Check for invalid or duplicate layers
    AssertIfNullsOrDuplicates(m_IConnectableLayers,
                              "Sub-graphs cannot contain null or duplicate IConnectableLayers");
}

const SubgraphView::InputSlots& SubgraphView::GetInputSlots() const
{
    return m_InputSlots;
}

const SubgraphView::IInputSlots& SubgraphView::GetIInputSlots() const
{
    return m_IInputSlots;
}

const SubgraphView::OutputSlots& SubgraphView::GetOutputSlots() const
{
    return m_OutputSlots;
}

const SubgraphView::IOutputSlots& SubgraphView::GetIOutputSlots() const
{
    return m_IOutputSlots;
}

const InputSlot* SubgraphView::GetInputSlot(unsigned int index) const
{
    return m_InputSlots.at(index);
}

const IInputSlot* SubgraphView::GetIInputSlot(unsigned int index) const
{
    return m_IInputSlots.at(index);
}

InputSlot* SubgraphView::GetInputSlot(unsigned int index)
{
    return m_InputSlots.at(index);
}

IInputSlot* SubgraphView::GetIInputSlot(unsigned int index)
{
    return m_IInputSlots.at(index);
}

const OutputSlot* SubgraphView::GetOutputSlot(unsigned int index) const
{
    return m_OutputSlots.at(index);
}

const IOutputSlot* SubgraphView::GetIOutputSlot(unsigned int index) const
{
    return m_IOutputSlots.at(index);
}

OutputSlot* SubgraphView::GetOutputSlot(unsigned int index)
{
    return m_OutputSlots.at(index);
}

IOutputSlot* SubgraphView::GetIOutputSlot(unsigned int index)
{
    return m_IOutputSlots.at(index);
}

unsigned int SubgraphView::GetNumInputSlots() const
{
    return armnn::numeric_cast<unsigned int>(m_IInputSlots.size());
}

unsigned int SubgraphView::GetNumOutputSlots() const
{
    return armnn::numeric_cast<unsigned int>(m_IOutputSlots.size());
}

const SubgraphView::Layers& SubgraphView::GetLayers() const
{
    return m_Layers;
}

const SubgraphView::IConnectableLayers& SubgraphView::GetIConnectableLayers() const
{
    return m_IConnectableLayers;
}

SubgraphView::Iterator SubgraphView::begin()
{
    return m_Layers.begin();
}

SubgraphView::Iterator SubgraphView::end()
{
    return m_Layers.end();
}

// IConnectable Duplication to maintain backwards compatibility
SubgraphView::IConnectableLayerIterator SubgraphView::beginIConnectable()
{
    return m_IConnectableLayers.begin();
}

SubgraphView::IConnectableLayerIterator SubgraphView::endIConnectable()
{
    return m_IConnectableLayers.end();
}

SubgraphView::ConstIterator SubgraphView::begin() const
{
    return m_Layers.begin();
}

SubgraphView::ConstIterator SubgraphView::end() const
{
    return m_Layers.end();
}

// IConnectable Duplication to maintain backwards compatibility
SubgraphView::ConstIConnectableIterator SubgraphView::beginIConnectable() const
{
    return m_IConnectableLayers.begin();
}

SubgraphView::ConstIConnectableIterator SubgraphView::endIConnectable() const
{
    return m_IConnectableLayers.end();
}

SubgraphView::ConstIterator SubgraphView::cbegin() const
{
    // Ignore deprecated call as this is internal to SubgraphView
    ARMNN_NO_DEPRECATE_WARN_BEGIN
    return begin();
    ARMNN_NO_DEPRECATE_WARN_END
}

SubgraphView::ConstIterator SubgraphView::cend() const
{
    // Ignore deprecated call as this is internal to SubgraphView
    ARMNN_NO_DEPRECATE_WARN_BEGIN
    return end();
    ARMNN_NO_DEPRECATE_WARN_END
}

// IConnectable Duplication to maintain backwards compatibility
SubgraphView::ConstIConnectableIterator SubgraphView::cbeginIConnectable() const
{
    return beginIConnectable();
}

SubgraphView::ConstIConnectableIterator SubgraphView::cendIConnectable() const
{
    return endIConnectable();
}

void SubgraphView::Clear()
{
    m_InputSlots.clear();
    m_OutputSlots.clear();
    m_Layers.clear();

    m_IInputSlots.clear();
    m_IOutputSlots.clear();
    m_IConnectableLayers.clear();
}

void SubgraphView::ArrangeBySortOrder()
{
    using LayerList = std::list<Layer*>;
    auto compareLayerPriority = [](const LayerList::value_type& layerA, const LayerList::value_type& layerB)
        {
            return layerA->GetPriority() < layerB->GetPriority();
        };

    m_Layers.sort(compareLayerPriority);

    using IConnectableLayersList = std::list<IConnectableLayer*>;
    auto compareIConnectableLayerPriority = [](const IConnectableLayersList::value_type& layerA,
                                               const IConnectableLayersList::value_type& layerB)
        {
            return PolymorphicDowncast<Layer*>(layerA)->GetPriority() <
                   PolymorphicDowncast<Layer*>(layerB)->GetPriority();
        };

    m_IConnectableLayers.sort(compareIConnectableLayerPriority);
}

} // namespace armnn