Refactor minds to be entities with components, make roles components (#19591)

Co-authored-by: ShadowCommander <10494922+ShadowCommander@users.noreply.github.com>
Co-authored-by: DrSmugleaf <DrSmugleaf@users.noreply.github.com>

Content.Server/Objectives/ObjectivesSystem.cs

@@ -0,0 +1,44 @@
+using Content.Server.Mind;
+using Content.Shared.Random;
+using Content.Shared.Random.Helpers;
+using Robust.Shared.Prototypes;
+using Robust.Shared.Random;
+
+namespace Content.Server.Objectives;
+
+public sealed class ObjectivesSystem : EntitySystem
+{
+    [Dependency] private readonly IPrototypeManager _prototypeManager = default!;
+    [Dependency] private readonly IRobustRandom _random = default!;
+
+    public ObjectivePrototype? GetRandomObjective(EntityUid mindId, MindComponent mind, string objectiveGroupProto)
+    {
+        if (!_prototypeManager.TryIndex<WeightedRandomPrototype>(objectiveGroupProto, out var groups))
+        {
+            Log.Error("Tried to get a random objective, but can't index WeightedRandomPrototype " + objectiveGroupProto);
+            return null;
+        }
+
+        // TODO replace whatever the fuck this is with a proper objective selection system
+        // yeah the old 'preventing infinite loops' thing wasn't super elegant either and it mislead people on what exactly it did
+        var tries = 0;
+        while (tries < 20)
+        {
+            var groupName = groups.Pick(_random);
+
+            if (!_prototypeManager.TryIndex<WeightedRandomPrototype>(groupName, out var group))
+            {
+                Log.Error("Couldn't index objective group prototype" + groupName);
+                return null;
+            }
+
+            if (_prototypeManager.TryIndex<ObjectivePrototype>(group.Pick(_random), out var objective)
+                && objective.CanBeAssigned(mindId, mind))
+                return objective;
+            else
+                tries++;
+        }
+
+        return null;
+    }
+}