context: #region Copyright & License Information
  /*
   * Copyright 2007-2019 The OpenRA Developers (see AUTHORS)
   * This file is part of OpenRA, which is free software. It is made
   * available to you under the terms of the GNU General Public License
   * as published by the Free Software Foundation, either version 3 of
   * the License, or (at your option) any later version. For more
   * information, see COPYING.
   */
  #endregion
  
  using System.Collections.Generic;
  using System.Linq;
  using OpenRA.Graphics;
  using OpenRA.Mods.Common.Graphics;
  using OpenRA.Mods.Common.Orders;
  using OpenRA.Mods.Common.Traits;
  using OpenRA.Primitives;
  using OpenRA.Traits;
  
  namespace OpenRA.Mods.Cnc.Traits
  {
  	class ChronoshiftPowerInfo : SupportPowerInfo
  	{
  		[Desc("Target actor selection radius in cells.")]
  		public readonly int Range = 1;
  
  		[Desc("Ticks until returning after teleportation.")]
  		public readonly int Duration = 750;
  
  		[PaletteReference] public readonly string TargetOverlayPalette = TileSet.TerrainPaletteInternalName;
  
  		public readonly string OverlaySpriteGroup = "overlay";
  		[SequenceReference("OverlaySpriteGroup", true)] public readonly string ValidTileSequencePrefix = "target-valid-";
  		[SequenceReference("OverlaySpriteGroup")] public readonly string InvalidTileSequence = "target-invalid";
  		[SequenceReference("OverlaySpriteGroup")] public readonly string SourceTileSequence = "target-select";
  
  		public readonly bool KillCargo = true;
  
  		[Desc("Cursor sequence to use when selecting targets for the chronoshift.")]
  		public readonly string SelectionCursor = "chrono-select";
  
  		[Desc("Cursor sequence to use when targeting an area for the chronoshift.")]
  		public readonly string TargetCursor = "chrono-target";
  
  		[Desc("Cursor sequence to use when the targeted area is blocked.")]
  		public readonly string TargetBlockedCursor = "move-blocked";
  
  		public override object Create(ActorInitializer init) { return new ChronoshiftPower(init.Self, this); }
  	}
  
  	class ChronoshiftPower : SupportPower
  	{
  		public ChronoshiftPower(Actor self, ChronoshiftPowerInfo info)
  			: base(self, info) { }
  
  		public override void SelectTarget(Actor self, string order, SupportPowerManager manager)
  		{
  			Game.Sound.PlayToPlayer(SoundType.UI, manager.Self.Owner, Info.SelectTargetSound);
  			self.World.OrderGenerator = new SelectChronoshiftTarget(Self.World, order, manager, this);
  		}
  
  		public override void Activate(Actor self, Order order, SupportPowerManager manager)
  		{
  			base.Activate(self, order, manager);
  
  			var info = (ChronoshiftPowerInfo)Info;
  			var targetDelta = self.World.Map.CellContaining(order.Target.CenterPosition) - order.ExtraLocation;
  			foreach (var target in UnitsInRange(order.ExtraLocation))
  			{
  				var cs = target.TraitsImplementing<Chronoshiftable>()
  					.FirstEnabledTraitOrDefault();
  
  				if (cs == null)
  					continue;
  
  				var targetCell = target.Location + targetDelta;
  
  				if (self.Owner.Shroud.IsExplored(targetCell) && cs.CanChronoshiftTo(target, targetCell))
  					cs.Teleport(target, targetCell, info.Duration, info.KillCargo, self);
  			}
  		}
  
  		public IEnumerable<Actor> UnitsInRange(CPos xy)
  		{
  			var range = ((ChronoshiftPowerInfo)Info).Range;
  			var tiles = Self.World.Map.FindTilesInCircle(xy, range);
  			var units = new HashSet<Actor>();
  			foreach (var t in tiles)
  				units.UnionWith(Self.World.ActorMap.GetActorsAt(t));
  
  			return units.Where(a => a.TraitsImplementing<Chronoshiftable>().Any(cs => !cs.IsTraitDisabled));
  		}
  
  		public bool SimilarTerrain(CPos xy, CPos sourceLocation)
  		{
  			if (!Self.Owner.Shroud.IsExplored(xy))
  				return false;
  
  			var range = ((ChronoshiftPowerInfo)Info).Range;
  			var sourceTiles = Self.World.Map.FindTilesInCircle(xy, range);
  			var destTiles = Self.World.Map.FindTilesInCircle(sourceLocation, range);
  
  			if (!sourceTiles.Any() || !destTiles.Any())
  				return false;
  
  			using (var se = sourceTiles.GetEnumerator())
  			using (var de = destTiles.GetEnumerator())
  				while (se.MoveNext() && de.MoveNext())
  				{
  					var a = se.Current;
  					var b = de.Current;
  
  					if (!Self.Owner.Shroud.IsExplored(a) || !Self.Owner.Shroud.IsExplored(b))
  						return false;
  
  					if (Self.World.Map.GetTerrainIndex(a) != Self.World.Map.GetTerrainIndex(b))
  						return false;
  				}
  
  			return true;
  		}
  
  		class SelectChronoshiftTarget : OrderGenerator
  		{
  			readonly ChronoshiftPower power;
  			readonly int range;
  			readonly Sprite tile;
  			readonly SupportPowerManager manager;
  			readonly string order;
  
  			public SelectChronoshiftTarget(World world, string order, SupportPowerManager manager, ChronoshiftPower power)
  			{
  				// Clear selection if using Left-Click Orders
  				if (Game.Settings.Game.UseClassicMouseStyle)
  					manager.Self.World.Selection.Clear();
  
  				this.manager = manager;
  				this.order = order;
  				this.power = power;
  
  				var info = (ChronoshiftPowerInfo)power.Info;
  				range = info.Range;
  				tile = world.Map.Rules.Sequences.GetSequence(info.OverlaySpriteGroup, info.SourceTileSequence).GetSprite(0);
  			}
  
  			protected override IEnumerable<Order> OrderInner(World world, CPos cell, int2 worldPixel, MouseInput mi)
  			{
  				world.CancelInputMode();
  				if (mi.Button == MouseButton.Left)
  					world.OrderGenerator = new SelectDestination(world, order, manager, power, cell);
  
  				yield break;
  			}
  
  			protected override void Tick(World world)
  			{
  				// Cancel the OG if we can't use the power
  				if (!manager.Powers.ContainsKey(order))
  					world.CancelInputMode();
  			}
  
  			protected override IEnumerable<IRenderable> RenderAboveShroud(WorldRenderer wr, World world)
  			{
  				var xy = wr.Viewport.ViewToWorld(Viewport.LastMousePos);
  				var targetUnits = power.UnitsInRange(xy).Where(a => !world.FogObscures(a));
  
  				foreach (var unit in targetUnits)
  				{
  					if (unit.CanBeViewedByPlayer(manager.Self.Owner))
  					{
  						var bounds = unit.TraitsImplementing<IDecorationBounds>().FirstNonEmptyBounds(unit, wr);
  						yield return new SelectionBoxRenderable(unit, bounds, Color.Red);
  					}
  				}
  			}
  
  			protected override IEnumerable<IRenderable> Render(WorldRenderer wr, World world)
  			{
  				var xy = wr.Viewport.ViewToWorld(Viewport.LastMousePos);
  				var tiles = world.Map.FindTilesInCircle(xy, range);
  				var palette = wr.Palette(((ChronoshiftPowerInfo)power.Info).TargetOverlayPalette);
  				foreach (var t in tiles)
  					yield return new SpriteRenderable(tile, wr.World.Map.CenterOfCell(t), WVec.Zero, -511, palette, 1f, true);
  			}
  
  			protected override string GetCursor(World world, CPos cell, int2 worldPixel, MouseInput mi)
  			{
  				return ((ChronoshiftPowerInfo)power.Info).SelectionCursor;
  			}
  		}
  
  		class SelectDestination : OrderGenerator
  		{
  			readonly ChronoshiftPower power;
  			readonly CPos sourceLocation;
  			readonly int range;
  			readonly Sprite validTile, invalidTile, sourceTile;
  			readonly SupportPowerManager manager;
  			readonly string order;
  
  			public SelectDestination(World world, string order, SupportPowerManager manager, ChronoshiftPower power, CPos sourceLocation)
  			{
  				this.manager = manager;
  				this.order = order;
  				this.power = power;
  				this.sourceLocation = sourceLocation;
  
  				var info = (ChronoshiftPowerInfo)power.Info;
  				range = info.Range;
  
  				var tileset = world.Map.Tileset.ToLowerInvariant();
  				validTile = world.Map.Rules.Sequences.GetSequence(info.OverlaySpriteGroup, info.ValidTileSequencePrefix + tileset).GetSprite(0);
  				invalidTile = world.Map.Rules.Sequences.GetSequence(info.OverlaySpriteGroup, info.InvalidTileSequence).GetSprite(0);
  				sourceTile = world.Map.Rules.Sequences.GetSequence(info.OverlaySpriteGroup, info.SourceTileSequence).GetSprite(0);
  			}
  
  			protected override IEnumerable<Order> OrderInner(World world, CPos cell, int2 worldPixel, MouseInput mi)
  			{
  				if (mi.Button == MouseButton.Right)
  				{
  					world.CancelInputMode();
  					yield break;
  				}
  
  				var ret = OrderInner(cell).FirstOrDefault();
  				if (ret == null)
  					yield break;
  
  				world.CancelInputMode();
  				yield return ret;
  			}
  
  			IEnumerable<Order> OrderInner(CPos xy)
  			{
  				// Cannot chronoshift into unexplored location
  				if (IsValidTarget(xy))
  					yield return new Order(order, manager.Self, Target.FromCell(manager.Self.World, xy), false)
  					{
  						ExtraLocation = sourceLocation,
  						SuppressVisualFeedback = true
  					};
  			}
  
  			protected override void Tick(World world)
  			{
  				// Cancel the OG if we can't use the power
  				if (!manager.Powers.ContainsKey(order))
  					world.CancelInputMode();
  			}
  
  			protected override IEnumerable<IRenderable> RenderAboveShroud(WorldRenderer wr, World world)
  			{
  
gt: 				var xy = wr.Viewport.ViewToWorld(Viewport.LastMousePos);