using System.Collections.Generic;
using System.Numerics;
using Dalamud.Bindings.ImGui;
using FFXIVClientStructs.FFXIV.Client.Game;
using FFXIVClientStructs.FFXIV.Client.Game.Control;
using FFXIVClientStructs.FFXIV.Client.Graphics.Render;

namespace Auspex.Rendering.ImGuiFallback;

internal sealed class ImGuiFallbackRenderer
{
	private readonly ImDrawListPtr drawList;

	private readonly Matrix4x4 viewProj;

	private readonly Vector4 nearPlane;

	public unsafe ImGuiFallbackRenderer(ImDrawListPtr drawList)
	{
		this.drawList = drawList;
		viewProj = Control.Instance()->ViewProjectionMatrix;
		FFXIVClientStructs.FFXIV.Client.Game.Camera* activeCamera = Control.Instance()->CameraManager.GetActiveCamera();
		FFXIVClientStructs.FFXIV.Client.Graphics.Render.Camera* ptr = ((activeCamera != null) ? activeCamera->SceneCamera.RenderCamera : null);
		if (ptr == null)
		{
			nearPlane = new Vector4(viewProj.M13, viewProj.M23, viewProj.M33, viewProj.M43);
			return;
		}
		if (!Matrix4x4.Invert(ptr->ProjectionMatrix, out var result))
		{
			nearPlane = new Vector4(viewProj.M13, viewProj.M23, viewProj.M33, viewProj.M43);
			return;
		}
		Matrix4x4 matrix4x = viewProj * result;
		nearPlane = new Vector4(matrix4x.M13, matrix4x.M23, matrix4x.M33, matrix4x.M43 + ptr->NearPlane);
	}

	public void DrawStroke(List<Vector3> world, float thickness, uint color, bool closed = false, float dashLength = 0f, float gapLength = 0f, float dashOffset = 0f, uint? colorEnd = null, AxLineCap cap = AxLineCap.Butt, AxLineJoin join = AxLineJoin.None)
	{
		if (world.Count != 0)
		{
			for (int i = 1; i < world.Count; i++)
			{
				DrawStroke(world[i - 1], world[i], thickness, color);
			}
			if (closed)
			{
				DrawStroke(world[world.Count - 1], world[0], thickness, color);
			}
		}
	}

	public void DrawStroke(Vector3 start, Vector3 stop, float thickness, uint color)
	{
		if (FallbackClipMath.ClipLineToPlane(nearPlane, ref start, ref stop, out var _) != FallbackClipMath.LineClipStatus.NotVisible)
		{
			drawList.PathClear();
			drawList.PathLineTo(FallbackClipMath.WorldToScreenOld(in viewProj, in start));
			drawList.PathLineTo(FallbackClipMath.WorldToScreenOld(in viewProj, in stop));
			drawList.PathStroke(color, ImDrawFlags.None, thickness);
		}
	}
}