Makes Airtight ECS. (#4351)

* Makes Airtight ECS.

* Remove atmos holdovers while at it!

Content.Server/Atmos/Commands/DeleteGasCommand.cs

@@ -0,0 +1,176 @@
+using System;
+using Content.Server.Administration;
+using Content.Server.Atmos.EntitySystems;
+using Content.Shared.Administration;
+using Content.Shared.Atmos;
+using Robust.Server.Player;
+using Robust.Shared.Console;
+using Robust.Shared.GameObjects;
+using Robust.Shared.IoC;
+using Robust.Shared.Map;
+
+namespace Content.Server.Atmos.Commands
+{
+    [AdminCommand(AdminFlags.Debug)]
+    public class DeleteGasCommand : IConsoleCommand
+    {
+        public string Command => "deletegas";
+        public string Description => "Removes all gases from a grid, or just of one type if specified.";
+        public string Help => $"Usage: {Command} <GridId> <Gas> / {Command} <GridId> / {Command} <Gas> / {Command}";
+
+        public void Execute(IConsoleShell shell, string argStr, string[] args)
+        {
+            var player = shell.Player as IPlayerSession;
+            GridId gridId;
+            Gas? gas = null;
+
+            switch (args.Length)
+            {
+                case 0:
+                    if (player == null)
+                    {
+                        shell.WriteLine("A grid must be specified when the command isn't used by a player.");
+                        return;
+                    }
+
+                    if (player.AttachedEntity == null)
+                    {
+                        shell.WriteLine("You have no entity to get a grid from.");
+                        return;
+                    }
+
+                    gridId = player.AttachedEntity.Transform.GridID;
+
+                    if (gridId == GridId.Invalid)
+                    {
+                        shell.WriteLine("You aren't on a grid to delete gas from.");
+                        return;
+                    }
+
+                    break;
+                case 1:
+                {
+                    if (!int.TryParse(args[0], out var number))
+                    {
+                        // Argument is a gas
+                        if (player == null)
+                        {
+                            shell.WriteLine("A grid id must be specified if not using this command as a player.");
+                            return;
+                        }
+
+                        if (player.AttachedEntity == null)
+                        {
+                            shell.WriteLine("You have no entity from which to get a grid id.");
+                            return;
+                        }
+
+                        gridId = player.AttachedEntity.Transform.GridID;
+
+                        if (gridId == GridId.Invalid)
+                        {
+                            shell.WriteLine("You aren't on a grid to delete gas from.");
+                            return;
+                        }
+
+                        if (!Enum.TryParse<Gas>(args[0], true, out var parsedGas))
+                        {
+                            shell.WriteLine($"{args[0]} is not a valid gas name.");
+                            return;
+                        }
+
+                        gas = parsedGas;
+                        break;
+                    }
+
+                    // Argument is a grid
+                    gridId = new GridId(number);
+
+                    if (gridId == GridId.Invalid)
+                    {
+                        shell.WriteLine($"{gridId} is not a valid grid id.");
+                        return;
+                    }
+
+                    break;
+                }
+                case 2:
+                {
+                    if (!int.TryParse(args[0], out var first))
+                    {
+                        shell.WriteLine($"{args[0]} is not a valid integer for a grid id.");
+                        return;
+                    }
+
+                    gridId = new GridId(first);
+
+                    if (gridId == GridId.Invalid)
+                    {
+                        shell.WriteLine($"{gridId} is not a valid grid id.");
+                        return;
+                    }
+
+                    if (!Enum.TryParse<Gas>(args[1], true, out var parsedGas))
+                    {
+                        shell.WriteLine($"{args[1]} is not a valid gas.");
+                        return;
+                    }
+
+                    gas = parsedGas;
+
+                    break;
+                }
+                default:
+                    shell.WriteLine(Help);
+                    return;
+            }
+
+            var mapManager = IoCManager.Resolve<IMapManager>();
+
+            if (!mapManager.TryGetGrid(gridId, out _))
+            {
+                shell.WriteLine($"No grid exists with id {gridId}");
+                return;
+            }
+
+            var atmosphereSystem = EntitySystem.Get<AtmosphereSystem>();
+
+            var tiles = 0;
+            var moles = 0f;
+
+            if (gas == null)
+            {
+                foreach (var tile in atmosphereSystem.GetAllTileMixtures(gridId, true))
+                {
+                    if (tile.Immutable) continue;
+
+                    tiles++;
+                    moles += tile.TotalMoles;
+
+                    tile.Clear();
+                }
+            }
+            else
+            {
+                foreach (var tile in atmosphereSystem.GetAllTileMixtures(gridId, true))
+                {
+                    if (tile.Immutable) continue;
+
+                    tiles++;
+                    moles += tile.TotalMoles;
+
+                    tile.SetMoles(gas.Value, 0);
+                }
+            }
+
+            if (gas == null)
+            {
+                shell.WriteLine($"Removed {moles} moles from {tiles} tiles.");
+                return;
+            }
+
+            shell.WriteLine($"Removed {moles} moles of gas {gas} from {tiles} tiles.");
+        }
+    }
+
+}