using ImGuiNET;
using T3.Editor.Gui.OutputUi;
using T3.Editor.Gui.UiHelpers;
using T3.Editor.UiModel;
using T3.Editor.UiModel.InputsAndTypes;

namespace T3.Editor.Gui.Legacy.Interaction.Connections;

/// <summary>
/// A helper that collects potential collection targets during connection drag operations.
/// </summary>
internal static class ConnectionSnapEndHelper
{
    public static void PrepareNewFrame()
    {
        _mousePosition = ImGui.GetMousePos();
        BestMatchLastFrame = _bestMatchYetForCurrentFrame;
        if (BestMatchLastFrame != null)
        {
            // drawList.AddRect(_bestMatchLastFrame.Area.Min, _bestMatchLastFrame.Area.Max, Color.Orange);
            var textSize = ImGui.CalcTextSize(BestMatchLastFrame.Name);
            ImGui.SetNextWindowPos(_mousePosition + new Vector2(-textSize.X - 20, -textSize.Y / 2));
            ImGui.BeginTooltip();
            ImGui.TextUnformatted(BestMatchLastFrame.Name);
            ImGui.EndTooltip();
        }

        _bestMatchYetForCurrentFrame = null;
        _bestMatchDistance = float.PositiveInfinity;
    }

    public static void ResetSnapping()
    {
        BestMatchLastFrame = null;
    }

    internal static void RegisterAsPotentialTarget(IGraphView graph, SymbolUi.Child childUi, IInputUi inputUi, int slotIndex, ImRect areaOnScreen)
    {
        if (ConnectionMaker.IsTargetInvalid(graph, inputUi.Type))
            return;

        var distance = Vector2.Distance(areaOnScreen.Min, _mousePosition);
        if (distance > SnapDistance || distance > _bestMatchDistance)
        {
            return;
        }

        _bestMatchYetForCurrentFrame = new PotentialConnectionTarget()
                                           {
                                               TargetParentOrChildId = childUi.SymbolChild.Id,
                                               TargetInputId = inputUi.InputDefinition.Id,
                                               Area = areaOnScreen,
                                               Name = inputUi.InputDefinition.Name,
                                               SlotIndex = slotIndex
                                           };
        _bestMatchDistance = distance;
    }

    public static void RegisterAsPotentialTarget(IGraphView graph, IOutputUi outputUi, ImRect areaOnScreen)
    {
        if (ConnectionMaker.IsTargetInvalid(graph, outputUi.Type))
            return;

        var distance = Vector2.Distance(areaOnScreen.Min, _mousePosition);
        if (distance > SnapDistance || distance > _bestMatchDistance)
        {
            return;
        }

        _bestMatchYetForCurrentFrame = new PotentialConnectionTarget()
                                           {
                                               TargetParentOrChildId = ConnectionMaker.UseSymbolContainerId,
                                               TargetInputId = outputUi.OutputDefinition.Id,
                                               Area = areaOnScreen,
                                               Name = outputUi.OutputDefinition.Name,
                                               SlotIndex = 0
                                           };
        _bestMatchDistance = distance;
    }

    public static bool IsNextBestTarget(SymbolUi.Child childUi, Guid inputDefinitionId, int socketIndex)
    {
        return BestMatchLastFrame != null && BestMatchLastFrame.TargetParentOrChildId == childUi.SymbolChild.Id
                                          && BestMatchLastFrame.TargetInputId == inputDefinitionId
                                          && BestMatchLastFrame.SlotIndex == socketIndex;
    }

    public static bool IsNextBestTarget(IOutputUi outputUi)
    {
        return BestMatchLastFrame != null && BestMatchLastFrame.TargetParentOrChildId == ConnectionMaker.UseSymbolContainerId
                                          && BestMatchLastFrame.TargetInputId == outputUi.Id
                                          && BestMatchLastFrame.SlotIndex == 0;
    }

    public static ConnectionSnapEndHelper.PotentialConnectionTarget BestMatchLastFrame;
    private static PotentialConnectionTarget _bestMatchYetForCurrentFrame;
    private static float _bestMatchDistance = float.PositiveInfinity;
    private const int SnapDistance = 50;
    private static Vector2 _mousePosition;

    public sealed class PotentialConnectionTarget
    {
        public Guid TargetParentOrChildId;
        public Guid TargetInputId;
        public ImRect Area;
        public string Name;
        public int SlotIndex;
    }
}