#region ================== Namespaces

using System;
using System.Collections.Generic;
using System.Drawing;
using CodeImp.DoomBuilder.Map;
using CodeImp.DoomBuilder.Geometry;
using CodeImp.DoomBuilder.Rendering;
using CodeImp.DoomBuilder.Types;
using CodeImp.DoomBuilder.VisualModes;
using CodeImp.DoomBuilder.Data;

#endregion

namespace CodeImp.DoomBuilder.BuilderModes {
	//mxd. Used to render translucent 3D floor's inner sides
	internal sealed class VisualMiddleBack : BaseVisualGeometrySidedef 
	{
		#region ================== Variables

		private Effect3DFloor extrafloor;

		#endregion
		
		#region ================== Constructor / Setup
		
		// Constructor
		public VisualMiddleBack(BaseVisualMode mode, VisualSector vs, Sidedef s)
			: base(mode, vs, s)
		{
			//mxd
			geoType = VisualGeometryType.WALL_MIDDLE;
			
			// We have no destructor
			GC.SuppressFinalize(this);
		}
		
		// This builds the geometry. Returns false when no geometry created.
		public override bool Setup() { return this.Setup(this.extrafloor); }
		public bool Setup(Effect3DFloor extrafloor)
		{
			Vector2D vl, vr;

			Sidedef sourceside = extrafloor.Linedef.Front;
			this.extrafloor = extrafloor;

			//mxd. lightfog flag support
			bool lightabsolute = Sidedef.Fields.GetValue("lightabsolute", false);
			bool ignoreUDMFLight = (!Sidedef.Fields.GetValue("lightfog", false) || !lightabsolute) && Sector.Sector.Fields.ContainsKey("fadecolor");
			int lightvalue = ignoreUDMFLight ? 0 : Sidedef.Fields.GetValue("light", 0); //mxd
			if (ignoreUDMFLight) lightabsolute = false;

			Vector2D tscale = new Vector2D(sourceside.Fields.GetValue("scalex_mid", 1.0f),
										   sourceside.Fields.GetValue("scaley_mid", 1.0f));
			Vector2D toffset1 = new Vector2D(Sidedef.Fields.GetValue("offsetx_mid", 0.0f),
											 Sidedef.Fields.GetValue("offsety_mid", 0.0f));
			Vector2D toffset2 = new Vector2D(sourceside.Fields.GetValue("offsetx_mid", 0.0f),
											 sourceside.Fields.GetValue("offsety_mid", 0.0f));
			
			// Left and right vertices for this sidedef
			if(Sidedef.IsFront)
			{
				vl = new Vector2D(Sidedef.Line.Start.Position.x, Sidedef.Line.Start.Position.y);
				vr = new Vector2D(Sidedef.Line.End.Position.x, Sidedef.Line.End.Position.y);
			}
			else
			{
				vl = new Vector2D(Sidedef.Line.End.Position.x, Sidedef.Line.End.Position.y);
				vr = new Vector2D(Sidedef.Line.Start.Position.x, Sidedef.Line.Start.Position.y);
			}

			// Load sector data
			SectorData sd = mode.GetSectorData(Sidedef.Other.Sector);

			//mxd. which texture we must use?
			long textureLong = 0;
			if ((sourceside.Line.Args[2] & (int)Effect3DFloor.Flags.UseUpperTexture) != 0) 
			{
				if (Sidedef.Other.LongHighTexture != MapSet.EmptyLongName)
					textureLong = Sidedef.Other.LongHighTexture;
			} 
			else if ((sourceside.Line.Args[2] & (int)Effect3DFloor.Flags.UseLowerTexture) != 0) 
			{
				if(Sidedef.Other.LongLowTexture != MapSet.EmptyLongName)
					textureLong = Sidedef.Other.LongLowTexture;
			} 
			else if ((sourceside.LongMiddleTexture != MapSet.EmptyLongName)) 
			{
				textureLong = sourceside.LongMiddleTexture;
			}

			// Texture given?
			if (textureLong != 0) 
			{
				// Load texture
				base.Texture = General.Map.Data.GetTextureImage(textureLong);
				if(base.Texture == null || base.Texture is UnknownImage) 
				{
					base.Texture = General.Map.Data.UnknownTexture3D;
					setuponloadedtexture = textureLong;
				} 
				else if (!base.Texture.IsImageLoaded) 
				{
					setuponloadedtexture = textureLong;
				}
			} 
			else 
			{
				// Use missing texture
				base.Texture = General.Map.Data.MissingTexture3D;
				setuponloadedtexture = 0;
			}
			
			// Get texture scaled size
			Vector2D tsz = new Vector2D(base.Texture.ScaledWidth, base.Texture.ScaledHeight);
			tsz = tsz / tscale;
			
			// Get texture offsets
			Vector2D tof = new Vector2D(Sidedef.OffsetX, Sidedef.OffsetY) + new Vector2D(sourceside.OffsetX, sourceside.OffsetY);
			tof = tof + toffset1 + toffset2;
			tof = tof / tscale;
			if(General.Map.Config.ScaledTextureOffsets && !base.Texture.WorldPanning)
				tof = tof * base.Texture.Scale;

			// For Vavoom type 3D floors the ceiling is lower than floor and they are reversed.
			// We choose here.
			float sourcetopheight = extrafloor.VavoomType ? sourceside.Sector.FloorHeight : sourceside.Sector.CeilHeight;
			float sourcebottomheight = extrafloor.VavoomType ? sourceside.Sector.CeilHeight : sourceside.Sector.FloorHeight;
			
			// Determine texture coordinates plane as they would be in normal circumstances.
			// We can then use this plane to find any texture coordinate we need.
			// The logic here is the same as in the original VisualMiddleSingle (except that
			// the values are stored in a TexturePlane)
			// NOTE: I use a small bias for the floor height, because if the difference in
			// height is 0 then the TexturePlane doesn't work!
			TexturePlane tp = new TexturePlane();
			float floorbias = (sourcetopheight == sourcebottomheight) ? 1.0f : 0.0f;

			tp.trb.x = tp.tlt.x + Sidedef.Line.Length;
			tp.trb.y = tp.tlt.y + (sourcetopheight - sourcebottomheight) + floorbias;
			
			// Apply texture offset
			tp.tlt += tof;
			tp.trb += tof;
			
			// Transform pixel coordinates to texture coordinates
			tp.tlt /= tsz;
			tp.trb /= tsz;
			
			// Left top and right bottom of the geometry that
			tp.vlt = new Vector3D(vl.x, vl.y, sourcetopheight);
			tp.vrb = new Vector3D(vr.x, vr.y, sourcebottomheight + floorbias);
			
			// Make the right-top coordinates
			tp.trt = new Vector2D(tp.trb.x, tp.tlt.y);
			tp.vrt = new Vector3D(tp.vrb.x, tp.vrb.y, tp.vlt.z);
			
			// Get ceiling and floor heights
			float flo = Sector.Floor.Level.plane.GetZ(vl);
			float fro = Sector.Floor.Level.plane.GetZ(vr);
			float clo = Sector.Ceiling.Level.plane.GetZ(vl);
			float cro = Sector.Ceiling.Level.plane.GetZ(vr);

			float fle = sd.Floor.plane.GetZ(vl);
			float fre = sd.Floor.plane.GetZ(vr);
			float cle = sd.Ceiling.plane.GetZ(vl);
			float cre = sd.Ceiling.plane.GetZ(vr);

			float fl = flo > fle ? flo : fle;
			float fr = fro > fre ? fro : fre;
			float cl = clo < cle ? clo : cle;
			float cr = cro < cre ? cro : cre;
			
			// Anything to see?
			if(((cl - fl) > 0.01f) || ((cr - fr) > 0.01f))
			{
				// Keep top and bottom planes for intersection testing
				bottom = extrafloor.Ceiling.plane;
				top = extrafloor.Floor.plane;
				
				// Create initial polygon, which is just a quad between floor and ceiling
				WallPolygon poly = new WallPolygon();
				poly.Add(new Vector3D(vl.x, vl.y, fl));
				poly.Add(new Vector3D(vl.x, vl.y, cl));
				poly.Add(new Vector3D(vr.x, vr.y, cr));
				poly.Add(new Vector3D(vr.x, vr.y, fr));
				
				// Determine initial color
				int lightlevel;
				if(((sourceside.Line.Args[2] & (int)Effect3DFloor.Flags.DisableLighting) != 0))
					lightlevel = lightabsolute ? lightvalue : sd.Ceiling.brightnessbelow + lightvalue;
				else
					lightlevel = lightabsolute ? lightvalue : sourceside.Sector.Brightness + lightvalue;

				//mxd
				PixelColor wallbrightness = PixelColor.FromInt(mode.CalculateBrightness(lightlevel, Sidedef));
				PixelColor wallcolor = PixelColor.Modulate(sd.Ceiling.colorbelow, wallbrightness);
				poly.color = wallcolor.WithAlpha(255).ToInt();

				// Cut off the part above the 3D floor and below the 3D ceiling
				CropPoly(ref poly, bottom, false);
				CropPoly(ref poly, top, false);

				// Cut out pieces that overlap 3D floors in this sector
				List<WallPolygon> polygons = new List<WallPolygon>(1);
				polygons.Add(poly);

				foreach(Effect3DFloor ef in sd.ExtraFloors) 
				{
					int num = polygons.Count;
					for(int pi = 0; pi < num; pi++) 
					{
						// Split by floor plane of 3D floor
						WallPolygon p = polygons[pi];
						WallPolygon np = SplitPoly(ref p, ef.Ceiling.plane, true);

						if(np.Count > 0) 
						{
							// Split part below floor by the ceiling plane of 3D floor
							// and keep only the part below the ceiling (front)
							SplitPoly(ref np, ef.Floor.plane, true);

							if(p.Count == 0) 
							{
								polygons[pi] = np;
							} 
							else 
							{
								polygons[pi] = p;
								polygons.Add(np);
							}
						} 
						else 
						{
							polygons[pi] = p;
						}
					}
				}

				// Process the polygon and create vertices
				if (polygons.Count > 0)
				{
					List<WorldVertex> verts = CreatePolygonVertices(polygons, tp, sd, lightvalue, lightabsolute);
					if (verts.Count > 2)
					{
						if ((extrafloor.Linedef.Args[2] & (int) Effect3DFloor.Flags.RenderAdditive) != 0) //mxd
							this.RenderPass = RenderPass.Additive;
						else if (extrafloor.Alpha < 255) 
							this.RenderPass = RenderPass.Alpha;
						else 
							this.RenderPass = RenderPass.Mask;

						if (extrafloor.Alpha < 255)
						{
							// Apply alpha to vertices
							byte alpha = (byte) General.Clamp(extrafloor.Alpha, 0, 255);
							if (alpha < 255)
							{
								for (int i = 0; i < verts.Count; i++)
								{
									WorldVertex v = verts[i];
									PixelColor c = PixelColor.FromInt(v.c);
									v.c = c.WithAlpha(alpha).ToInt();
									verts[i] = v;
								}
							}
						}

						base.SetVertices(verts);
						return true;
					}
				}
			}
			
			base.SetVertices(null); //mxd
			return false;
		}
		
		#endregion
		
		#region ================== Methods

		// Return texture name
		public override string GetTextureName() 
		{
			//mxd
			if ((extrafloor.Linedef.Args[2] & (int)Effect3DFloor.Flags.UseUpperTexture) != 0)
				return Sidedef.HighTexture;
			if ((extrafloor.Linedef.Args[2] & (int)Effect3DFloor.Flags.UseLowerTexture) != 0)
				return Sidedef.LowTexture;
			return extrafloor.Linedef.Front.MiddleTexture;
		}

		// This changes the texture
		protected override void SetTexture(string texturename) 
		{
			//mxd
			if ((extrafloor.Linedef.Args[2] & (int)Effect3DFloor.Flags.UseUpperTexture) != 0)
				Sidedef.Other.SetTextureHigh(texturename);
			if ((extrafloor.Linedef.Args[2] & (int)Effect3DFloor.Flags.UseLowerTexture) != 0)
				Sidedef.Other.SetTextureLow(texturename);
			else
				extrafloor.Linedef.Front.SetTextureMid(texturename);

			General.Map.Data.UpdateUsedTextures();
			this.Sector.Rebuild();

			//mxd. Other sector also may require updating
			((BaseVisualSector)mode.GetVisualSector(Sidedef.Other.Sector)).Rebuild();

			//mxd. As well as model sector
			mode.GetVisualSector(extrafloor.Linedef.Front.Sector).UpdateSectorGeometry(false);
		}

		protected override void SetTextureOffsetX(int x)
		{
			Sidedef.Fields.BeforeFieldsChange();
			Sidedef.Fields["offsetx_mid"] = new UniValue(UniversalType.Float, (float)x);
		}

		protected override void SetTextureOffsetY(int y)
		{
			Sidedef.Fields.BeforeFieldsChange();
			Sidedef.Fields["offsety_mid"] = new UniValue(UniversalType.Float, (float)y);
		}

		protected override void MoveTextureOffset(Point xy)
		{
			Sidedef.Fields.BeforeFieldsChange();
			float oldx = Sidedef.Fields.GetValue("offsetx_mid", 0.0f);
			float oldy = Sidedef.Fields.GetValue("offsety_mid", 0.0f);
			float scalex = Sidedef.Fields.GetValue("scalex_mid", 1.0f);
			float scaley = Sidedef.Fields.GetValue("scaley_mid", 1.0f);
			Sidedef.Fields["offsetx_mid"] = new UniValue(UniversalType.Float, GetRoundedTextureOffset(oldx, xy.X, scalex, Texture != null ? Texture.Width : -1)); //mxd

			//mxd. Don't clamp offsetY of clipped mid textures
			bool dontClamp = (Texture == null || Sidedef.IsFlagSet("clipmidtex") || Sidedef.Line.IsFlagSet("clipmidtex"));
			Sidedef.Fields["offsety_mid"] = new UniValue(UniversalType.Float, GetRoundedTextureOffset(oldy, xy.Y, scaley, dontClamp ? -1 : Texture.Height));
		}

		protected override Point GetTextureOffset()
		{
			float oldx = Sidedef.Fields.GetValue("offsetx_mid", 0.0f);
			float oldy = Sidedef.Fields.GetValue("offsety_mid", 0.0f);
			return new Point((int)oldx, (int)oldy);
		}

		//mxd
		public override void OnChangeTargetBrightness(bool up) 
		{
			if(!General.Map.UDMF) 
			{
				base.OnChangeTargetBrightness(up);
				return;
			}

			int light = Sidedef.Fields.GetValue("light", 0);
			bool absolute = Sidedef.Fields.GetValue("lightabsolute", false);
			int newLight;

			if(up)
				newLight = General.Map.Config.BrightnessLevels.GetNextHigher(light, absolute);
			else
				newLight = General.Map.Config.BrightnessLevels.GetNextLower(light, absolute);

			if(newLight == light) return;

			//create undo
			mode.CreateUndo("Change middle wall brightness", UndoGroup.SurfaceBrightnessChange, Sector.Sector.FixedIndex);
			Sidedef.Fields.BeforeFieldsChange();

			//apply changes
			Sidedef.Fields["light"] = new UniValue(UniversalType.Integer, newLight);
			mode.SetActionResult("Changed middle wall brightness to " + newLight + ".");
			Sector.Sector.UpdateCache();

			//rebuild sector
			Sector.UpdateSectorGeometry(false);
		}

		//mxd
		public override Linedef GetControlLinedef() 
		{
			return extrafloor.Linedef;
		}

		#endregion
	}
}