// Copyright (c) Wojciech Figat. All rights reserved.

#if COMPILE_WITH_MATERIAL_GRAPH

#include "MaterialLayer.h"
#include "MaterialGenerator.h"

MaterialLayer::MaterialLayer(const Guid& id)
    : ID(id)
    , Root(nullptr)
    , FeaturesFlags(MaterialFeaturesFlags::None)
    , UsageFlags(MaterialUsageFlags::None)
    , Domain(MaterialDomain::Surface)
    , BlendMode(MaterialBlendMode::Opaque)
    , ShadingModel(MaterialShadingModel::Lit)
    , MaskThreshold(0.3f)
    , OpacityThreshold(0.12f)
{
    ASSERT(ID.IsValid());
}

void MaterialLayer::ClearCache()
{
    for (int32 i = 0; i < Graph.Nodes.Count(); i++)
    {
        auto& node = Graph.Nodes[i];
        for (int32 j = 0; j < node.Boxes.Count(); j++)
        {
            node.Boxes[j].Cache.Clear();
        }
    }
    for (int32 i = 0; i < ARRAY_COUNT(Usage); i++)
    {
        Usage[i].VarName.Clear();
        Usage[i].Hint = nullptr;
    }
}

void MaterialLayer::Prepare()
{
    // Clear cached data
    ClearCache();

    // Ensure to have root node set
    if (Root == nullptr)
    {
        for (int32 i = 0; i < Graph.Nodes.Count(); i++)
        {
            const auto node = &Graph.Nodes[i];
            if (node->Type == ROOT_NODE_TYPE)
            {
                Root = node;
                break;
            }
        }
        if (Root == nullptr)
        {
            // Ensure to have root node
            createRootNode();
        }
    }
}

Guid MaterialLayer::GetMappedParamId(const Guid& id)
{
    // TODO: test ParamIdsMappings using Dictionary. will performance change? maybe we don't wont to allocate too much memory

    for (int32 i = 0; i < ParamIdsMappings.Count(); i++)
    {
        if (ParamIdsMappings[i].SrcId == id)
            return ParamIdsMappings[i].DstId;
    }

    return Guid::Empty;
}

String& MaterialLayer::GetVariableName(void* hint)
{
    if (hint == nullptr)
    {
        return Usage[0].VarName;
    }

    for (int32 i = 1; i < ARRAY_COUNT(Usage); i++)
    {
        if (Usage[i].Hint == nullptr)
        {
            Usage[i].Hint = hint;
        }

        if (Usage[i].Hint == hint)
        {
            return Usage[i].VarName;
        }
    }

    LOG(Error, "Too many layer samples per material! Layer {0}", ID);
    return Usage[0].VarName;
}

bool MaterialLayer::HasAnyVariableName()
{
    for (int32 i = 1; i < ARRAY_COUNT(Usage); i++)
    {
        if (Usage[i].Hint || Usage[i].VarName.HasChars())
        {
            return true;
        }
    }

    return false;
}

void MaterialLayer::UpdateFeaturesFlags()
{
    ASSERT(Root);

    // Gather the material features usage
    UsageFlags = MaterialUsageFlags::None;
#define CHECK_BOX_AS_FEATURE(box, feature) \
        if (Root->GetBox(static_cast<int32>(MaterialGraphBoxes::box))->HasConnection()) \
            UsageFlags |= MaterialUsageFlags::feature; \
        else \
            UsageFlags &= ~MaterialUsageFlags::feature;
    CHECK_BOX_AS_FEATURE(Emissive, UseEmissive);
    CHECK_BOX_AS_FEATURE(Normal, UseNormal);
    CHECK_BOX_AS_FEATURE(Mask, UseMask);
    CHECK_BOX_AS_FEATURE(PositionOffset, UsePositionOffset);
    CHECK_BOX_AS_FEATURE(WorldDisplacement, UseDisplacement);
    CHECK_BOX_AS_FEATURE(Refraction, UseRefraction);
#undef CHECK_BOX_AS_FEATURE
}

MaterialLayer* MaterialLayer::CreateDefault(const Guid& id)
{
    // Create new layer object
    auto layer = New<MaterialLayer>(id);

    // Create default root node
    layer->createRootNode();

    return layer;
}

MaterialLayer* MaterialLayer::Load(const Guid& id, ReadStream* graphData, const MaterialInfo& info, const String& caller)
{
    // Create new layer object
    auto layer = New<MaterialLayer>(id);

    // Load graph
    if (layer->Graph.Load(graphData, false))
    {
        LOG(Warning, "Cannot load graph '{0}'.", caller);
    }

    // Find root node
    for (int32 i = 0; i < layer->Graph.Nodes.Count(); i++)
    {
        if (layer->Graph.Nodes[i].Type == ROOT_NODE_TYPE)
        {
            layer->Root = &layer->Graph.Nodes[i];
            break;
        }
    }

    // Ensure to have root node
    if (layer->Root == nullptr)
    {
        LOG(Warning, "Missing root node in '{0}'.", caller);
        layer->createRootNode();
    }
    // Ensure to have valid root node
    else if (layer->Root->Boxes.Count() < static_cast<int32>(MaterialGraphBoxes::MAX))
    {
#define ADD_BOX(type, valueType) \
		if (layer->Root->Boxes.Count() <= static_cast<int32>(MaterialGraphBoxes::type)) \
			layer->Root->Boxes.Add(MaterialGraphBox(layer->Root, static_cast<int32>(MaterialGraphBoxes::type), VariantType::valueType))
        ADD_BOX(TessellationMultiplier, Float);
        ADD_BOX(WorldDisplacement, Float3);
        ADD_BOX(SubsurfaceColor, Float3);
        static_assert(static_cast<int32>(MaterialGraphBoxes::MAX) == 15, "Invalid amount of boxes added for root node. Please update the code above");
        ASSERT(layer->Root->Boxes.Count() == static_cast<int32>(MaterialGraphBoxes::MAX));
#if BUILD_DEBUG
        // Test for valid pointers after node upgrade
        for (int32 i = 0; i < layer->Root->Boxes.Count(); i++)
        {
            if (layer->Root->Boxes[i].Parent != layer->Root)
            {
                CRASH;
            }
        }
#endif
#undef ADD_BOX
    }

    // Setup
    layer->FeaturesFlags = info.FeaturesFlags;
    layer->UsageFlags = info.UsageFlags;
    layer->Domain = info.Domain;
    layer->BlendMode = info.BlendMode;
    layer->ShadingModel = info.ShadingModel;
    layer->MaskThreshold = info.MaskThreshold;
    layer->OpacityThreshold = info.OpacityThreshold;

    return layer;
}

void MaterialLayer::createRootNode()
{
    // Create node
    auto& rootNode = Graph.Nodes.AddOne();
    rootNode.ID = 1;
    rootNode.Type = ROOT_NODE_TYPE;
    rootNode.Boxes.Resize(static_cast<int32>(MaterialGraphBoxes::MAX));
#define INIT_BOX(type, valueType) rootNode.Boxes[static_cast<int32>(MaterialGraphBoxes::type)] = MaterialGraphBox(&rootNode, static_cast<int32>(MaterialGraphBoxes::type), VariantType::valueType)
    INIT_BOX(Layer, Void);
    INIT_BOX(Color, Float3);
    INIT_BOX(Mask, Float);
    INIT_BOX(Emissive, Float3);
    INIT_BOX(Metalness, Float);
    INIT_BOX(Specular, Float);
    INIT_BOX(Roughness, Float);
    INIT_BOX(AmbientOcclusion, Float);
    INIT_BOX(Normal, Float3);
    INIT_BOX(Opacity, Float);
    INIT_BOX(Refraction, Float);
    INIT_BOX(PositionOffset, Float3);
    INIT_BOX(TessellationMultiplier, Float);
    INIT_BOX(WorldDisplacement, Float3);
    INIT_BOX(SubsurfaceColor, Float3);
    static_assert(static_cast<int32>(MaterialGraphBoxes::MAX) == 15, "Invalid amount of boxes created for root node. Please update the code above");
#undef INIT_BOX

    // Mark as root
    Root = &rootNode;
}

#endif