#include "UI.hpp"

#include "Model/GlobalStates.hpp"
#include "Model/Project.hpp"
#include "Model/Workflow/Nodes/DocumentNodes.hpp"
#include "Model/Workflow/Nodes/NumericNodes.hpp"
#include "Model/Workflow/Nodes/TextNodes.hpp"
#include "Model/Workflow/Nodes/UserInputNodes.hpp"
#include "Model/Workflow/Workflow.hpp"
#include "Utils/I18n.hpp"
#include "Utils/Macros.hpp"

#include <IconsFontAwesome.h>
#include <imgui.h>
#include <imgui_node_editor.h>
#include <imgui_stdlib.h>
#include <memory>
#include <span>
#include <vector>

namespace ImNodes = ax::NodeEditor;

namespace {
class WorkflowUI
{
private:
	std::unique_ptr<Workflow> mWorkflow;

	ImNodes::EditorContext* mContext;

	ImNodes::NodeId mContextMenuNodeId = 0;
	ImNodes::PinId mContextMenuPinId = 0;
	ImNodes::LinkId mContextMenuLinkId = 0;

public:
	WorkflowUI(std::unique_ptr<Workflow> workflow)
		: mWorkflow{ std::move(workflow) }
	{
		mContext = ImNodes::CreateEditor();
	}

	~WorkflowUI()
	{
		ImNodes::DestroyEditor(mContext);
	}

	void Display()
	{
		ImNodes::SetCurrentEditor(mContext);
		ImNodes::Begin("");

		// Defer creation of tooltip because within the node editor, cursor positioning is going to be off
		const char* tooltipMessage = nullptr;

		for (auto& node : mWorkflow->GetNodes()) {
			if (!node) continue;

			ImNodes::BeginNode(node->GetId());
			node->Draw();
			ImNodes::EndNode();
		}

		for (auto& conn : mWorkflow->GetConnections()) {
			if (!conn.IsValid()) continue;

			auto srcId = mWorkflow->GetNodes()[conn.SourceNode]->GetOutputPinUniqueId(conn.SourcePin);
			auto dstId = mWorkflow->GetNodes()[conn.DestinationNode]->GetInputPinUniqueId(conn.DestinationPin);
			ImNodes::Link(conn.GetLinkId(), srcId, dstId);
		}

		if (ImNodes::BeginCreate()) {
			ImNodes::PinId src = 0, dst = 0;
			if (ImNodes::QueryNewLink(&src, &dst)) {
				if (!src || !dst) {
					goto createError;
				}

				auto [srcNode, srcPinId, srcIsOutput] = mWorkflow->DisassembleGlobalPinId(src);
				auto [dstNode, dstPinId, dstIsOutput] = mWorkflow->DisassembleGlobalPinId(dst);

				if (srcNode == dstNode) {
					ImNodes::RejectNewItem();
					goto createError;
				}

				if (srcIsOutput == dstIsOutput) {
					ImNodes::RejectNewItem();
					goto createError;
				}

				auto srcPin = srcNode->GetOutputPin(srcPinId);
				auto dstPin = dstNode->GetOutputPin(dstPinId);

				if (srcPin.MatchingType != dstPin.MatchingType) {
					ImNodes::RejectNewItem();
					goto createError;
				}

				if (ImNodes::AcceptNewItem()) {
					mWorkflow->Connect(*srcNode, srcPinId, *dstNode, dstPinId);
				}
			}

			ImNodes::PinId newNodePin = 0;
			if (ImNodes::QueryNewNode(&newNodePin)) {
				auto [node, pinId, isOutput] = mWorkflow->DisassembleGlobalPinId(newNodePin);

				if ((isOutput && node->GetOutputPin(pinId).IsConnected()) ||
					(!isOutput && node->GetInputPin(pinId).IsConnected()))
				{
					ImNodes::RejectNewItem();
					goto createError;
				}

				if (ImNodes::AcceptNewItem()) {
					ImNodes::Suspend();
					ImGui::BeginPopup("CreateNodeCtxMenu");
					ImNodes::Resume();
				}
			}
		}
	createError:
		ImNodes::EndCreate();

		if (ImNodes::BeginDelete()) {
			ImNodes::LinkId deletedLinkId;
			if (ImNodes::QueryDeletedLink(&deletedLinkId)) {
				auto& conn = *mWorkflow->GetConnectionByLinkId(deletedLinkId);
				mWorkflow->RemoveConnection(conn.Id);
			}

			ImNodes::NodeId deletedNodeId;
			if (ImNodes::QueryDeletedNode(&deletedNodeId)) {
				auto node = mWorkflow->GetNodeByNodeId(deletedNodeId);
				if (!node) {
					ImNodes::RejectDeletedItem();
					goto deleteError;
				}

				if (node->IsLocked()) {
					ImNodes::RejectDeletedItem();
					goto deleteError;
				}
			}
		}
	deleteError:
		ImNodes::EndDelete();

		// Popups
		ImNodes::Suspend();
		if (ImNodes::ShowNodeContextMenu(&mContextMenuNodeId)) {
			ImGui::OpenPopup("NodeCtxMenu");
		} else if (ImNodes::ShowPinContextMenu(&mContextMenuPinId)) {
			ImGui::OpenPopup("PinCtxMenu");
		} else if (ImNodes::ShowLinkContextMenu(&mContextMenuLinkId)) {
			ImGui::OpenPopup("LinkCtxMenu");
		}

		if (ImGui::BeginPopup("NodeCtxMenu")) {
			auto& node = *mWorkflow->GetNodeByNodeId(mContextMenuNodeId);
			node.DrawDebugInfo();

			if (ImGui::MenuItem(ICON_FA_TRASH " " I18N_TEXT("Delete", L10N_DELETE))) {
				ImNodes::DeleteNode(mContextMenuNodeId);
			}

			ImGui::EndPopup();
		}

		if (ImGui::BeginPopup("PinCtxMenu")) {
			auto [node, pinId, isOutput] = mWorkflow->DisassembleGlobalPinId(mContextMenuPinId);
			if (isOutput) {
				node->DrawOutputPinDebugInfo(pinId);
			} else {
				node->DrawInputPinDebugInfo(pinId);
			}

			if (ImGui::MenuItem(ICON_FA_UNLINK " " I18N_TEXT("Disconnect", L10N_DISCONNECT))) {
				if (isOutput) {
					auto& pin = node->GetOutputPin(pinId);
					if (pin.IsConnected()) {
						auto linkId = mWorkflow->GetConnectionById(pin.Connection)->GetLinkId();
						ImNodes::DeleteLink(linkId);
					}
				} else {
					auto& pin = node->GetInputPin(pinId);
					if (pin.IsConstantConnection()) {
						// TODO
					} else if (pin.IsConnected()) {
						auto linkId = mWorkflow->GetConnectionById(pin.Connection)->GetLinkId();
						ImNodes::DeleteLink(linkId);
					}
				}
			}

			ImGui::EndPopup();
		}

		if (ImGui::BeginPopup("LinkCtxMenu")) {
			auto& conn = *mWorkflow->GetConnectionByLinkId(mContextMenuLinkId);
			conn.DrawDebugInfo();

			if (ImGui::MenuItem(ICON_FA_TRASH " " I18N_TEXT("Delete", L10N_DELETE))) {
				ImNodes::DeleteLink(mContextMenuLinkId);
			}

			ImGui::EndPopup();
		}

		if (ImGui::BeginPopup("CreateNodeCtxMenu")) {
			for (int i = WorkflowNode::CG_Numeric; i < WorkflowNode::InvalidCategory; ++i) {
				auto category = (WorkflowNode::Category)i;
				auto members = WorkflowNode::QueryCategoryMembers(category);

				if (ImGui::BeginMenu(WorkflowNode::FormatCategory(category))) {
					for (auto member : members) {
						if (ImGui::MenuItem(WorkflowNode::FormatKind(member))) {
							// Create node
							auto uptr = WorkflowNode::CreateByKind(member);
							mWorkflow->AddNode(std::move(uptr));
						}
					}
					ImGui::EndMenu();
				}
			}
			ImGui::EndPopup();
		}

		if (tooltipMessage) {
			ImGui::BeginTooltip();
			ImGui::TextUnformatted(tooltipMessage);
			ImGui::EndTooltip();
		}
		ImNodes::Resume();

		ImNodes::End();
	}

	void Close()
	{
		// TODO
	}
};
} // namespace

void UI::WorkflowsTab()
{
	auto& project = *GlobalStates::GetInstance().GetCurrentProject();

	static std::unique_ptr<WorkflowUI> openWorkflow;
	static AssetList::ListState state;
	bool openedDummy = true;

	// Toolbar item: close
	if (ImGui::Button(ICON_FA_TIMES " " I18N_TEXT("Close", L10N_CLOSE), openWorkflow == nullptr)) {
		openWorkflow->Close();
		openWorkflow = nullptr;
	}

	// Toolbar item: open...
	ImGui::SameLine();
	if (ImGui::Button((I18N_TEXT("Open asset...", L10N_ASSET_OPEN)))) {
		ImGui::OpenPopup(I18N_TEXT("Open asset", L10N_ASSET_OPEN_DIALOG_TITLE));
	}
	if (ImGui::BeginPopupModal(I18N_TEXT("Open asset", L10N_ASSET_OPEN_DIALOG_TITLE), &openedDummy, ImGuiWindowFlags_AlwaysAutoResize)) {
		if (ImGui::Button(ICON_FA_FOLDER_OPEN " " I18N_TEXT("Open", L10N_OPEN), state.SelectedAsset == nullptr)) {
			ImGui::CloseCurrentPopup();

			auto workflow = project.Workflows.Load(*state.SelectedAsset);
			openWorkflow = std::make_unique<WorkflowUI>(std::move(workflow));
		}
		ImGui::SameLine();
		project.Workflows.DisplayControls(state);
		project.Workflows.DisplayDetailsList(state);

		ImGui::EndPopup();
	}

	// Toolbar item: manage...
	ImGui::SameLine();
	if (ImGui::Button(I18N_TEXT("Manage assets...", L10N_ASSET_MANAGE))) {
		ImGui::OpenPopup(I18N_TEXT("Manage assets", L10N_ASSET_MANAGE_DIALOG_TITLE));
	}
	if (ImGui::BeginPopupModal(I18N_TEXT("Manage assets", L10N_ASSET_MANAGE_DIALOG_TITLE), &openedDummy, ImGuiWindowFlags_AlwaysAutoResize)) {
		project.Workflows.DisplayControls(state);
		project.Workflows.DisplayDetailsList(state);
		ImGui::EndPopup();
	}

	if (openWorkflow) {
		openWorkflow->Display();
	}
}