Objectives ecs rework (#19967)

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

Content.Server/Objectives/Systems/KeepAliveCondition.cs

@@ -0,0 +1,66 @@
+using Content.Server.Objectives.Components;
+using Content.Server.GameTicking.Rules;
+using Content.Shared.Mind;
+using Content.Shared.Objectives.Components;
+using Content.Shared.Roles.Jobs;
+using Robust.Shared.Random;
+using System.Linq;
+
+namespace Content.Server.Objectives.Systems;
+
+/// <summary>
+/// Handles keep alive condition logic and picking random traitors to keep alive.
+/// </summary>
+public sealed class KeepAliveConditionSystem : EntitySystem
+{
+    [Dependency] private readonly IRobustRandom _random = default!;
+    [Dependency] private readonly SharedMindSystem _mind = default!;
+    [Dependency] private readonly TargetObjectiveSystem _target = default!;
+    [Dependency] private readonly TraitorRuleSystem _traitorRule = default!;
+
+    public override void Initialize()
+    {
+        base.Initialize();
+
+        SubscribeLocalEvent<KeepAliveConditionComponent, ObjectiveGetProgressEvent>(OnGetProgress);
+
+        SubscribeLocalEvent<RandomTraitorAliveComponent, ObjectiveAssignedEvent>(OnAssigned);
+    }
+
+    private void OnGetProgress(EntityUid uid, KeepAliveConditionComponent comp, ref ObjectiveGetProgressEvent args)
+    {
+        if (!_target.GetTarget(uid, out var target))
+            return;
+
+        args.Progress = GetProgress(target.Value);
+    }
+
+    private void OnAssigned(EntityUid uid, RandomTraitorAliveComponent comp, ref ObjectiveAssignedEvent args)
+    {
+        // invalid prototype
+        if (!TryComp<TargetObjectiveComponent>(uid, out var target))
+        {
+            args.Cancelled = true;
+            return;
+        }
+
+        var traitors = Enumerable.ToList<(EntityUid Id, MindComponent Mind)>(_traitorRule.GetOtherTraitorMindsAliveAndConnected(args.Mind));
+
+        // You are the first/only traitor.
+        if (traitors.Count == 0)
+        {
+            args.Cancelled = true;
+            return;
+        }
+
+        _target.SetTarget(uid, _random.Pick(traitors).Id, target);
+    }
+
+    private float GetProgress(EntityUid target)
+    {
+        if (!TryComp<MindComponent>(target, out var mind))
+            return 0f;
+
+        return _mind.IsCharacterDeadIc(mind) ? 0f : 1f;
+    }
+}