#include "gui.hpp"
#include <algorithm>
#include "GraphEditor.hpp"

namespace GraphC::gui {

void GraphEditor::drawNode(const GraphModel::Node& node){
    ImNodes::BeginNode(node.id);
        ImNodes::BeginNodeTitleBar();
            ImGui::TextUnformatted(node.title.c_str());
        ImNodes::EndNodeTitleBar();

        for(auto& a_p : node.getAttributes()){
            auto&& a = *a_p.value;
            switch (a.type){
                case GraphModel::Attribute::Type::Input:
                    ImNodes::BeginInputAttribute(a.id);
                        ImGui::Text("%s", a.title.c_str());
                    ImNodes::EndInputAttribute();
                    break;
                case GraphModel::Attribute::Type::Output:
                    ImNodes::BeginOutputAttribute(a.id);
                        ImGui::Text("%s", a.title.c_str());
                        ImGui::Indent(40);
                    ImNodes::EndOutputAttribute();
                    break;
                case GraphModel::Attribute::Type::Static:
                    ImNodes::BeginStaticAttribute(a.id);
                        ImGui::Text("%s", a.title.c_str());
                    ImNodes::EndStaticAttribute();
                    break;
                default:
                    throw "Node::draw() invalid type";
                    break;
            }
        }

        static const char* items[]={
            "static","input", "output"
        };
        static int selected_item_i = 0;
        if(ImGui::Button("add attribute"))
            ImGui::OpenPopup("new_attribute_popup");
        
        if(ImGui::BeginPopup("new_attribute_popup")){
            ImGui::SeparatorText("New attribute properties");

            static char buf[256];
            ImGui::InputText("label", buf, sizeof(buf));
            
            if(ImGui::Button("select type"))
                ImGui::OpenPopup("select_type_popup");
            ImGui::SameLine();
            ImGui::TextUnformatted(items[selected_item_i]);

            if(ImGui::BeginPopup("select_type_popup")){
                for (int i = 0; i < IM_ARRAYSIZE(items); i++)
                    if (ImGui::Selectable(items[i]))
                        selected_item_i = i;
                ImGui::EndPopup();
            }
            
            if(ImGui::Button("Create attribute")){
                graph.createAttribute(GraphModel::Attribute(
                    graph.id_gen.getNext(), 
                    const_cast<GraphModel::Node*>(&node), 
                    (GraphModel::Attribute::Type)selected_item_i,
                    std::string(buf)));

                std::cout<<"ATTRIBUTES:\n";
                std::cout<<graph.getAttributes().generateGraphVizCode()<<std::endl;

                ImGui::CloseCurrentPopup();
                buf[0] = 0;
                selected_item_i = 0;
            }

            ImGui::EndPopup();
        }
    ImNodes::EndNode();
}


GraphModel::Node* GraphEditor::CreateExampleNode(const std::string& node_title){
    GraphModel::Node* n = graph.createNode(GraphModel::Node(graph.id_gen.getNext(), node_title));
    graph.createAttribute(GraphModel::Attribute(graph.id_gen.getNext(), n, GraphModel::Attribute::Type::Input, "In"));
    graph.createAttribute(GraphModel::Attribute(graph.id_gen.getNext(), n, GraphModel::Attribute::Type::Output, "Out"));
    graph.createAttribute(GraphModel::Attribute(graph.id_gen.getNext(), n, GraphModel::Attribute::Type::Static, "Static"));
    return n;
}

GraphEditor::GraphEditor(const std::string& _title) 
    : title(_title) 
{
    // CreateExampleNode("Node A");
    // CreateExampleNode("Node B");
    // CreateExampleNode("Node C");
    // CreateExampleNode("Node D");
    std::cout<<"NODES:\n";
    std::cout<<graph.getNodes().generateGraphVizCode()<<std::endl;
    std::cout<<"ATTRIBUTES:\n";
    std::cout<<graph.getAttributes().generateGraphVizCode()<<std::endl;
}

void GraphEditor::show(){
    editor_open = true;
}

void GraphEditor::hide(){
    editor_open = false;
}

void GraphEditor::draw(){
    if(!editor_open)
        return;

    ImGui::Begin(title.c_str(), &editor_open);

        ImGui::SetWindowSizeMin(300,300);
        
        if(ImGui::Button("create node")){
            ImGui::OpenPopup("create_node_popup");
        }
        static char buf[256];
        if(ImGui::BeginPopup("create_node_popup")){
            ImGui::SeparatorText("New node properties");
            ImGui::InputText("label", buf, sizeof(buf));
            if(ImGui::Button("create node")){
                graph.createNode(GraphModel::Node(graph.id_gen.getNext(), buf));

                std::cout<<"NODES:\n";
                std::cout<<graph.getNodes().generateGraphVizCode()<<std::endl;

                buf[0] = 0;
                ImGui::CloseCurrentPopup();
            }
            ImGui::EndPopup();
        }
        
        ImNodes::BeginNodeEditor();
            // draw nodes
            for(auto& n_p : graph.getNodes()){
                drawNode(n_p.value);
            }
            // draw edges
            for(auto& p : graph.getEdges()){
                ImNodes::Link(p.value.id, p.value.to_attr_id, p.value.from_attr_id);
            }

        ImNodes::EndNodeEditor();

        // handle edge creation
        GraphModel::id_t from_attr_id, to_attr_id;
        if (ImNodes::IsLinkCreated(&from_attr_id, &to_attr_id))
        {
            if(!graph.tryCreateEdge(from_attr_id, to_attr_id, nullptr)){
                ImGui::End();
                throw UsefulException(format("can't create edge from attribute %i to attribute %i", from_attr_id, to_attr_id));
            }
            std::cout<<"EDGES:\n";
            std::cout<<graph.getEdges().generateGraphVizCode()<<std::endl;
        }
    
        // handle edge destruction
        GraphModel::id_t edge_id;
        if (ImNodes::IsLinkDestroyed(&edge_id))
        {
            if(!graph.tryDeleteEdge(edge_id)){
                ImGui::End();
                throw UsefulException(format("can't delete edge with id %i", edge_id));
            }
            std::cout<<"EDGES:\n";
            std::cout<<graph.getEdges().generateGraphVizCode()<<std::endl;
        }

    ImGui::End();
}

}