Avoid consecutive attempts to build naval structures

If not enough water space can be found inside the base perimeter, stop the AI from trying to build naval production buildings permanently until it deploys another construction yard.

If enough water is available within the base perimeter, check whether any
building that provides buildable area (for adjacency) is close enough to
water, otherwise don't even start producing this naval structure.

OpenRA.Mods.Common/AI/HackyAI.cs

@@ -92,6 +92,11 @@ namespace OpenRA.Mods.Common.AI
 		[Desc("Radius in cells around the center of the base to expand.")]
 		public readonly int MaxBaseRadius = 20;
 
+		[Desc("Radius in cells around each building with ProvideBuildableArea",
+		"to check for a 3x3 area of water where naval structures can be built.",
+		"Should match maximum adjacency of naval structures.")]
+		public readonly int CheckForWaterRadius = 8;
+
 		[Desc("Production queues AI uses for producing units.")]
 		public readonly string[] UnitQueues = { "Vehicle", "Infantry", "Plane", "Ship", "Aircraft" };
 
@@ -257,6 +262,58 @@ namespace OpenRA.Mods.Common.AI
 				resourceTypeIndices.Set(World.TileSet.GetTerrainIndex(t.TerrainType), true);
 		}
 
+		// TODO: Possibly give this a more generic name when terrain type is unhardcoded
+		public bool EnoughWaterToBuildNaval()
+		{
+			var baseBuildings = World.Actors.Where(
+				a => a.Owner == Player
+					&& a.HasTrait<BaseBuilding>()
+					&& !a.HasTrait<Mobile>());
+
+			foreach (var b in baseBuildings)
+			{
+				// TODO: Unhardcode terrain type
+				var playerWorld = Player.World;
+				var countWaterCells = Map.FindTilesInCircle(b.Location, Info.MaxBaseRadius)
+					.Where(c => playerWorld.Map.Contains(c)
+						&& playerWorld.Map.GetTerrainInfo(c).Type == "Water"
+						&& Util.AdjacentCells(playerWorld, Target.FromCell(playerWorld, c))
+							.All(a => playerWorld.Map.GetTerrainInfo(a).Type == "Water"))
+					.Count();
+
+				if (countWaterCells > 0)
+					return true;
+			}
+
+			return false;
+		}
+
+		// Check whether we have at least one building providing buildable area close enough to water to build naval structures
+		public bool CloseEnoughToWater()
+		{
+			var areaProviders = World.Actors.Where(
+				a => a.Owner == Player
+					&& a.HasTrait<GivesBuildableArea>()
+					&& !a.HasTrait<Mobile>());
+
+			foreach (var a in areaProviders)
+			{
+				// TODO: Unhardcode terrain type
+				var playerWorld = Player.World;
+				var adjacentWater = Map.FindTilesInCircle(a.Location, Info.CheckForWaterRadius)
+					.Where(c => playerWorld.Map.Contains(c)
+						&& playerWorld.Map.GetTerrainInfo(c).Type == "Water"
+						&& Util.AdjacentCells(playerWorld, Target.FromCell(playerWorld, c))
+							.All(b => playerWorld.Map.GetTerrainInfo(b).Type == "Water"))
+					.Count();
+
+				if (adjacentWater > 0)
+					return true;
+			}
+
+			return false;
+		}
+
 		public void QueueOrder(Order order)
 		{
 			orders.Enqueue(order);