dragon refactor, objectives and use GenericAntag (#20201)

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

Content.Server/Objectives/Systems/CarpRiftsConditionSystem.cs

@@ -0,0 +1,56 @@
+using Content.Server.Objectives.Components;
+using Content.Server.Roles;
+using Content.Shared.Objectives.Components;
+
+namespace Content.Server.Objectives.Systems;
+
+public sealed class CarpRiftsConditionSystem : EntitySystem
+{
+    [Dependency] private readonly NumberObjectiveSystem _number = default!;
+
+    public override void Initialize()
+    {
+        base.Initialize();
+
+        SubscribeLocalEvent<CarpRiftsConditionComponent, ObjectiveGetProgressEvent>(OnGetProgress);
+    }
+
+    private void OnGetProgress(EntityUid uid, CarpRiftsConditionComponent comp, ref ObjectiveGetProgressEvent args)
+    {
+        args.Progress = GetProgress(comp, _number.GetTarget(uid));
+    }
+
+    private float GetProgress(CarpRiftsConditionComponent comp, int target)
+    {
+        // prevent divide-by-zero
+        if (target == 0)
+            return 1f;
+
+        if (comp.RiftsCharged >= target)
+            return 1f;
+
+        return (float) comp.RiftsCharged / (float) target;
+    }
+
+    /// <summary>
+    /// Increments RiftsCharged, called after a rift fully charges.
+    /// </summary>
+    public void RiftCharged(EntityUid uid, CarpRiftsConditionComponent? comp = null)
+    {
+        if (!Resolve(uid, ref comp))
+            return;
+
+        comp.RiftsCharged++;
+    }
+
+    /// <summary>
+    /// Resets RiftsCharged to 0, called after rifts get destroyed.
+    /// </summary>
+    public void ResetRifts(EntityUid uid, CarpRiftsConditionComponent? comp = null)
+    {
+        if (!Resolve(uid, ref comp))
+            return;
+
+        comp.RiftsCharged = 0;
+    }
+}