/*
Copyright (c) 2019, Lars Brubaker, John Lewin
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

1. Redistributions of source code must retain the above copyright notice, this
   list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice,
   this list of conditions and the following disclaimer in the documentation
   and/or other materials provided with the distribution.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

The views and conclusions contained in the software and documentation are those
of the authors and should not be interpreted as representing official policies,
either expressed or implied, of the FreeBSD Project.
*/

using System;
using System.Collections.Generic;
using System.Linq;
using MatterHackers.Agg;
using MatterHackers.Agg.Image;
using MatterHackers.Agg.UI;
using MatterHackers.DataConverters3D;
using MatterHackers.MatterControl.DesignTools;
using MatterHackers.MeshVisualizer;
using MatterHackers.RayTracer;
using MatterHackers.RayTracer.Traceable;
using MatterHackers.RenderOpenGl;
using MatterHackers.VectorMath;

namespace MatterHackers.MatterControl.PartPreviewWindow
{
	public partial class InteractionLayer : GuiWidget, IInteractionVolumeContext
	{
		private InteractionVolume mouseDownIAVolume = null;

		/// <summary>
		/// Contains type to IAVolume mappings
		/// </summary>
		private Dictionary<Type, List<InteractionVolume>> iavMappings = new Dictionary<Type, List<InteractionVolume>>();

		/// <summary>
		/// Interaction Volume Overrides for the selected scene item
		/// </summary>
		private List<InteractionVolume> iavOverrides = null;

		private Type selectedItemType;

		public WorldView World => sceneContext.World;

		public InteractiveScene Scene => sceneContext.Scene;

		public bool DrawOpenGLContent { get; set; } = true;

		private List<InteractionVolume> registeredIAVolumes = new List<InteractionVolume>();

		public IEnumerable<InteractionVolume> InteractionVolumes
		{
			get
			{
				if (selectedItemType == null)
				{
					return Enumerable.Empty<InteractionVolume>();
				}
				else
				{
					return iavOverrides ?? registeredIAVolumes;
				}
			}
		}

		private LightingData lighting = new LightingData();
		private GuiWidget renderSource;

		public InteractionLayer(ISceneContext sceneContext, ThemeConfig theme, EditorType editorType = EditorType.Part)
		{
			this.sceneContext = sceneContext;
			this.EditorMode = editorType;
			this.theme = theme;

			scene = sceneContext.Scene;

			gCodeMeshColor = new Color(theme.PrimaryAccentColor, 35);

			BuildVolumeColor = new ColorF(.2, .8, .3, .2).ToColor();

			floorDrawable = new FloorDrawable(editorType, sceneContext, this.BuildVolumeColor, theme);

			if (ViewOnlyTexture == null)
			{
				// TODO: What is the ViewOnlyTexture???
				UiThread.RunOnIdle(() =>
				{
					ViewOnlyTexture = new ImageBuffer(32, 32, 32);
					var graphics2D = ViewOnlyTexture.NewGraphics2D();
					graphics2D.Clear(Color.White);
					graphics2D.FillRectangle(0, 0, ViewOnlyTexture.Width / 2, ViewOnlyTexture.Height, Color.LightGray);
					// request the texture so we can set it to repeat
					var plugin = ImageGlPlugin.GetImageGlPlugin(ViewOnlyTexture, true, true, false);
				});
			}

			iavMappings.Add(typeof(ImageObject3D), new List<InteractionVolume> { new MoveInZControl(this) });

			// Register listeners
			sceneContext.Scene.SelectionChanged += this.Scene_SelectionChanged;
		}

		public void RegisterDrawable(IDrawable drawable)
		{
			drawables.Add(drawable);
		}

		public void RegisterIAVolume(InteractionVolume interactionVolume)
		{
			registeredIAVolumes.Add(interactionVolume);
		}

		public void RegisterIAVolumes(IEnumerable<InteractionVolume> interactionVolumes)
		{
			registeredIAVolumes.AddRange(interactionVolumes);
		}

		public IEnumerable<IDrawable> Drawables => drawables;

		public IEnumerable<IDrawableItem> ItemDrawables => itemDrawables;

		internal void SetRenderTarget(GuiWidget renderSource)
		{
			// Unregister listener
			if (renderSource != null)
			{
				renderSource.BeforeDraw -= RenderSource_BeforeDraw;
			}

			this.renderSource = renderSource;

			// Hook our drawing operation to the renderSource so we can draw unclipped in the source objects bounds. At the time of writing,
			// this mechanism is needed to draw bed items under the semi-transparent right treeview/editor panel
			renderSource.BeforeDraw += RenderSource_BeforeDraw;
		}

		// The primary draw hook. Kick off our draw operation when the renderSource fires AfterDraw
		private void RenderSource_BeforeDraw(object sender, DrawEventArgs e)
		{
			if (this.DrawOpenGLContent)
			{
				this.DrawGlContent(e);
			}
		}

		private void Scene_SelectionChanged(object sender, EventArgs e)
		{
			// On selection change, update state for mappings
			selectedItemType = scene.SelectedItem?.GetType();
			iavOverrides = null;

			if (selectedItemType != null)
			{
				iavMappings.TryGetValue(selectedItemType, out iavOverrides);
			}
		}


		public static void RenderBounds(DrawEventArgs e, WorldView world, IEnumerable<BvhIterator> allResults)
		{
			foreach (var bvhIterator in allResults)
			{
				InteractionLayer.RenderBounds(e, world, bvhIterator.TransformToWorld, bvhIterator.Bvh, bvhIterator.Depth);
			}
		}

		public static void RenderBounds(DrawEventArgs e, WorldView world, Matrix4X4 transformToWorld, IBvhItem bvh, int depth = int.MinValue)
		{
			for (int i = 0; i < 4; i++)
			{
				Vector3 bottomStartPosition = Vector3Ex.Transform(bvh.GetAxisAlignedBoundingBox().GetBottomCorner(i), transformToWorld);
				var bottomStartScreenPos = world.GetScreenPosition(bottomStartPosition);

				Vector3 bottomEndPosition = Vector3Ex.Transform(bvh.GetAxisAlignedBoundingBox().GetBottomCorner((i + 1) % 4), transformToWorld);
				var bottomEndScreenPos = world.GetScreenPosition(bottomEndPosition);

				Vector3 topStartPosition = Vector3Ex.Transform(bvh.GetAxisAlignedBoundingBox().GetTopCorner(i), transformToWorld);
				var topStartScreenPos = world.GetScreenPosition(topStartPosition);

				Vector3 topEndPosition = Vector3Ex.Transform(bvh.GetAxisAlignedBoundingBox().GetTopCorner((i + 1) % 4), transformToWorld);
				var topEndScreenPos = world.GetScreenPosition(topEndPosition);

				e.Graphics2D.Line(bottomStartScreenPos, bottomEndScreenPos, Color.Black);
				e.Graphics2D.Line(topStartScreenPos, topEndScreenPos, Color.Black);
				e.Graphics2D.Line(topStartScreenPos, bottomStartScreenPos, Color.Black);
			}

			if (bvh is ITriangle tri)
			{
				for (int i = 0; i < 3; i++)
				{
					var vertexPos = tri.GetVertex(i);
					var screenCenter = Vector3Ex.Transform(vertexPos, transformToWorld);
					var screenPos = world.GetScreenPosition(screenCenter);

					e.Graphics2D.Circle(screenPos, 3, Color.Red);
				}
			}
			else
			{
				var center = bvh.GetCenter();
				var worldCenter = Vector3Ex.Transform(center, transformToWorld);
				var screenPos2 = world.GetScreenPosition(worldCenter);

				if (depth != int.MinValue)
				{
					e.Graphics2D.Circle(screenPos2, 3, Color.Yellow);
					e.Graphics2D.DrawString($"{depth},", screenPos2.X + 12 * depth, screenPos2.Y);
				}
			}
		}

		public override void OnMouseDown(MouseEventArgs mouseEvent)
		{
			base.OnMouseDown(mouseEvent);

			Ray ray = this.World.GetRayForLocalBounds(mouseEvent.Position);
			IntersectInfo info;
			if (this.Scene.SelectedItem != null
				&& !SuppressUiVolumes
				&& FindInteractionVolumeHit(ray, out mouseDownIAVolume, out info))
			{
				mouseDownIAVolume.OnMouseDown(new MouseEvent3DArgs(mouseEvent, ray, info));
				SelectedInteractionVolume = mouseDownIAVolume;
			}
			else
			{
				SelectedInteractionVolume = null;
			}
		}

		public override void OnMouseMove(MouseEventArgs mouseEvent)
		{
			base.OnMouseMove(mouseEvent);

			if (SuppressUiVolumes
				|| !this.PositionWithinLocalBounds(mouseEvent.X, mouseEvent.Y))
			{
				return;
			}

			Ray ray = this.World.GetRayForLocalBounds(mouseEvent.Position);
			IntersectInfo info = null;
			var mouseEvent3D = new MouseEvent3DArgs(mouseEvent, ray, info);

			if (MouseDownOnInteractionVolume && mouseDownIAVolume != null)
			{
				mouseDownIAVolume.OnMouseMove(mouseEvent3D);
			}
			else
			{
				this.FindInteractionVolumeHit(ray, out InteractionVolume hitIAVolume, out info);

				var iaVolumes = this.InteractionVolumes;

				foreach (var iaVolume in iaVolumes)
				{
					if (hitIAVolume == iaVolume)
					{
						iaVolume.MouseOver = true;
						iaVolume.MouseMoveInfo = info;
						HoveredInteractionVolume = iaVolume;
					}
					else
					{
						iaVolume.MouseOver = false;
						iaVolume.MouseMoveInfo = null;
					}

					// TODO: Why do non-hit volumes get mouse move?
					iaVolume.OnMouseMove(mouseEvent3D);
				}
			}
		}

		public override void OnMouseUp(MouseEventArgs mouseEvent)
		{
			Invalidate();

			if (SuppressUiVolumes)
			{
				return;
			}

			Ray ray = this.World.GetRayForLocalBounds(mouseEvent.Position);
			IntersectInfo info;
			bool anyInteractionVolumeHit = FindInteractionVolumeHit(ray, out InteractionVolume iaVolume, out info);
			MouseEvent3DArgs mouseEvent3D = new MouseEvent3DArgs(mouseEvent, ray, info);

			if (MouseDownOnInteractionVolume && mouseDownIAVolume != null)
			{
				mouseDownIAVolume.OnMouseUp(mouseEvent3D);
				SelectedInteractionVolume = null;

				mouseDownIAVolume = null;
			}
			else
			{
				mouseDownIAVolume = null;
				
				if (anyInteractionVolumeHit)
				{
					iaVolume.OnMouseUp(mouseEvent3D);
				}
				SelectedInteractionVolume = null;
			}

			base.OnMouseUp(mouseEvent);
		}

		public override void OnClosed(EventArgs e)
		{
			// Unregister listeners
			sceneContext.Scene.SelectionChanged -= this.Scene_SelectionChanged;
			if (renderSource != null)
			{
				renderSource.BeforeDraw -= RenderSource_BeforeDraw;
			}

			// If implemented, invoke Dispose on Drawables
			foreach (var item in drawables)
			{
				if (item is IDisposable disposable)
				{
					disposable.Dispose();
				}
			}

			foreach (var item in itemDrawables)
			{
				if (item is IDisposable disposable)
				{
					disposable.Dispose();
				}
			}

			base.OnClosed(e);
		}

		private bool FindInteractionVolumeHit(Ray ray, out InteractionVolume hitIAVolume, out IntersectInfo info)
		{
			var iaVolumes = this.InteractionVolumes;

			hitIAVolume = null;

			if (!iaVolumes.Any())
			{
				info = null;
				return false;
			}

			// TODO: Rewrite as projection without extra list
			// - Looks like the extra list is always required as CreateNewHierachy requires a List and we can only produce an IEnumerable without the list overhead
			// - var uiTraceables = iaVolumes.Where(ia => ia.CollisionVolume != null).Select(ia => new Transform(ia.CollisionVolume, ia.TotalTransform)).ToList<IPrimitive>();
			var uiTraceables = new List<IPrimitive>();
			foreach (InteractionVolume interactionVolume in iaVolumes)
			{
				if (interactionVolume.CollisionVolume != null)
				{
					IPrimitive traceData = interactionVolume.CollisionVolume;
					uiTraceables.Add(new Transform(traceData, interactionVolume.TotalTransform));
				}
			}

			IPrimitive allUiObjects = BoundingVolumeHierarchy.CreateNewHierachy(uiTraceables);

			info = allUiObjects.GetClosestIntersection(ray);
			if (info != null)
			{
				foreach (var iaVolume in iaVolumes)
				{
					var insideBounds = new List<IBvhItem>();
					if (iaVolume.CollisionVolume != null)
					{
						iaVolume.CollisionVolume.GetContained(insideBounds, info.closestHitObject.GetAxisAlignedBoundingBox());
						if (insideBounds.Contains(info.closestHitObject))
						{
							hitIAVolume = iaVolume;
							return true;
						}
					}
				}
			}

			return false;
		}

		public bool SuppressUiVolumes { get; set; } = false;

		public bool MouseDownOnInteractionVolume => SelectedInteractionVolume != null;

		public InteractionVolume SelectedInteractionVolume { get; set; } = null;
		public InteractionVolume HoveredInteractionVolume { get; set; } = null;

		public double SnapGridDistance
		{
			get
			{
				if(string.IsNullOrEmpty(UserSettings.Instance.get(UserSettingsKey.SnapGridDistance)))
				{
					return 1;
				}
				return UserSettings.Instance.GetValue<double>(UserSettingsKey.SnapGridDistance);
			}

			set
			{
				UserSettings.Instance.set(UserSettingsKey.SnapGridDistance, value.ToString());
			}
		} 

		public GuiWidget GuiSurface => this;
	}
}