ninja 2 electric boogaloo (#15534)

Co-authored-by: deltanedas <@deltanedas:kde.org>

Content.Server/StationEvents/Components/NinjaSpawnRuleComponent.cs

@@ -0,0 +1,16 @@
+using Content.Server.StationEvents.Events;
+
+namespace Content.Server.StationEvents.Components;
+
+/// <summary>
+/// Configuration component for the Space Ninja antag.
+/// </summary>
+[RegisterComponent, Access(typeof(NinjaSpawnRule))]
+public sealed partial class NinjaSpawnRuleComponent : Component
+{
+    /// <summary>
+    /// Distance that the ninja spawns from the station's half AABB radius
+    /// </summary>
+    [DataField("spawnDistance")]
+    public float SpawnDistance = 20f;
+}

Content.Server/StationEvents/Events/NinjaSpawnRule.cs

@@ -0,0 +1,51 @@
+using Content.Server.GameTicking.Rules.Components;
+using Content.Server.Ninja.Systems;
+using Content.Server.Station.Components;
+using Content.Server.StationEvents.Components;
+using Robust.Server.GameObjects;
+using Robust.Shared.Map;
+using Robust.Shared.Map.Components;
+using Robust.Shared.Random;
+
+namespace Content.Server.StationEvents.Events;
+
+/// <summary>
+/// Event for spawning a Space Ninja mid-game.
+/// </summary>
+public sealed class NinjaSpawnRule : StationEventSystem<NinjaSpawnRuleComponent>
+{
+    [Dependency] private readonly SpaceNinjaSystem _ninja = default!;
+    [Dependency] private readonly SharedTransformSystem _transform = default!;
+
+    protected override void Started(EntityUid uid, NinjaSpawnRuleComponent comp, GameRuleComponent gameRule, GameRuleStartedEvent args)
+    {
+        base.Started(uid, comp, gameRule, args);
+
+        if (!TryGetRandomStation(out var station))
+            return;
+
+        var stationData = Comp<StationDataComponent>(station.Value);
+
+        // find a station grid
+        var gridUid = StationSystem.GetLargestGrid(stationData);
+        if (gridUid == null || !TryComp<MapGridComponent>(gridUid, out var grid))
+        {
+            Sawmill.Warning("Chosen station has no grids, cannot spawn space ninja!");
+            return;
+        }
+
+        // figure out its AABB size and use that as a guide to how far ninja should be
+        var size = grid.LocalAABB.Size.Length() / 2;
+        var distance = size + comp.SpawnDistance;
+        var angle = RobustRandom.NextAngle();
+        // position relative to station center
+        var location = angle.ToVec() * distance;
+
+        // create the spawner, the ninja will appear when a ghost has picked the role
+        var xform = Transform(gridUid.Value);
+        var position = _transform.GetWorldPosition(xform) + location;
+        var coords = new MapCoordinates(position, xform.MapID);
+        Sawmill.Info($"Creating ninja spawnpoint at {coords}");
+        Spawn("SpawnPointGhostSpaceNinja", coords);
+    }
+}