Objectives ecs rework (#19967)

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

Content.Shared/Objectives/Systems/SharedObjectivesSystem.cs

@@ -0,0 +1,130 @@
+using Content.Shared.Mind;
+using Content.Shared.Objectives;
+using Content.Shared.Objectives.Components;
+using Robust.Shared.Utility;
+
+namespace Content.Shared.Objectives.Systems;
+
+/// <summary>
+/// Provides API for creating and interacting with objectives.
+/// </summary>
+public abstract class SharedObjectivesSystem : EntitySystem
+{
+    [Dependency] private readonly SharedMindSystem _mind = default!;
+
+    private EntityQuery<MetaDataComponent> _metaQuery;
+
+    public override void Initialize()
+    {
+        base.Initialize();
+
+        _metaQuery = GetEntityQuery<MetaDataComponent>();
+    }
+
+    /// <summary>
+    /// Checks requirements and duplicate objectives to see if an objective can be assigned.
+    /// </summary>
+    public bool CanBeAssigned(EntityUid uid, EntityUid mindId, MindComponent mind, ObjectiveComponent? comp = null)
+    {
+        if (!Resolve(uid, ref comp))
+            return false;
+
+        var ev = new RequirementCheckEvent(mindId, mind);
+        RaiseLocalEvent(uid, ref ev);
+        if (ev.Cancelled)
+            return false;
+
+        // only check for duplicate prototypes if it's unique
+        if (comp.Unique)
+        {
+            var proto = _metaQuery.GetComponent(uid).EntityPrototype?.ID;
+            foreach (var objective in mind.AllObjectives)
+            {
+                if (_metaQuery.GetComponent(objective).EntityPrototype?.ID == proto)
+                    return false;
+            }
+        }
+
+        return true;
+    }
+
+    /// <summary>
+    /// Spawns and assigns an objective for a mind.
+    /// The objective is not added to the mind's objectives, mind system does that in TryAddObjective.
+    /// If the objective could not be assigned the objective is deleted and null is returned.
+    /// </summary>
+    public EntityUid? TryCreateObjective(EntityUid mindId, MindComponent mind, string proto)
+    {
+        var uid = Spawn(proto);
+        if (!TryComp<ObjectiveComponent>(uid, out var comp))
+        {
+            Del(uid);
+            Log.Error($"Invalid objective prototype {proto}, missing ObjectiveComponent");
+            return null;
+        }
+
+        Log.Debug($"Created objective {proto} ({uid})");
+
+        if (!CanBeAssigned(uid, mindId, mind, comp))
+        {
+            Del(uid);
+            Log.Warning($"Objective {uid} did not match the requirements for {_mind.MindOwnerLoggingString(mind)}, deleted it");
+            return null;
+        }
+
+        var ev = new ObjectiveAssignedEvent(mindId, mind);
+        RaiseLocalEvent(uid, ref ev);
+        if (ev.Cancelled)
+        {
+            Del(uid);
+            Log.Warning($"Could not assign objective {uid}, deleted it");
+            return null;
+        }
+
+        // let the title description and icon be set by systems
+        var afterEv = new ObjectiveAfterAssignEvent(mindId, mind, comp, MetaData(uid));
+        RaiseLocalEvent(uid, ref afterEv);
+
+        return uid;
+    }
+
+    /// <summary>
+    /// Get the title, description, icon and progress of an objective using <see cref="ObjectiveGetInfoEvent"/>.
+    /// If any of them are null it is logged and null is returned.
+    /// </summary>
+    /// <param name="uid"/>ID of the condition entity</param>
+    /// <param name="mindId"/>ID of the player's mind entity</param>
+    /// <param name="mind"/>Mind component of the player's mind</param>
+    public ObjectiveInfo? GetInfo(EntityUid uid, EntityUid mindId, MindComponent? mind = null)
+    {
+        if (!Resolve(mindId, ref mind))
+            return null;
+
+        var ev = new ObjectiveGetProgressEvent(mindId, mind);
+        RaiseLocalEvent(uid, ref ev);
+
+        var comp = Comp<ObjectiveComponent>(uid);
+        var meta = MetaData(uid);
+        var title = meta.EntityName;
+        var description = meta.EntityDescription;
+        if (comp.Icon == null || ev.Progress == null)
+        {
+            Log.Error($"An objective {ToPrettyString(uid):objective} of {_mind.MindOwnerLoggingString(mind)} is missing icon or progress ({ev.Progress})");
+            return null;
+        }
+
+        return new ObjectiveInfo(title, description, comp.Icon, ev.Progress.Value);
+    }
+
+    /// <summary>
+    /// Sets the objective's icon to the one specified.
+    /// Intended for <see cref="ObjectiveAfterAssignEvent"/> handlers to set an icon.
+    /// </summary>
+    public void SetIcon(EntityUid uid, SpriteSpecifier icon, ObjectiveComponent? comp = null)
+    {
+        if (!Resolve(uid, ref comp))
+            return;
+
+        comp.Icon = icon;
+    }
+}