[FEAT] Blood feeding and blood examining

Content.Shared/Body/Systems/SharedBloodstreamSystem.cs

@@ -8,6 +8,7 @@
 using Content.Shared.Damage;
 using Content.Shared.Damage.Systems;
 using Content.Shared.EntityEffects.Effects.Solution;
+using Content.Shared.Examine;
 using Content.Shared.FixedPoint;
 using Content.Shared.Fluids;
 using Content.Shared.Forensics.Components;
@@ -26,7 +27,7 @@
 
 namespace Content.Shared.Body.Systems;
 
-public abstract class SharedBloodstreamSystem : EntitySystem
+public abstract partial class SharedBloodstreamSystem : EntitySystem // DEN: Make partial
 {
     public static readonly EntProtoId Bloodloss = "StatusEffectBloodloss";
 
@@ -55,6 +56,8 @@ public override void Initialize()
         SubscribeLocalEvent<BloodstreamComponent, ApplyMetabolicMultiplierEvent>(OnApplyMetabolicMultiplier);
         SubscribeLocalEvent<BloodstreamComponent, RejuvenateEvent>(OnRejuvenate);
         SubscribeLocalEvent<BloodstreamComponent, MetabolismExclusionEvent>(OnMetabolismExclusion);
+
+        SubscribeLocalEvent<BloodstreamComponent, ExaminedEvent>(OnExamined); // DEN
     }
 
     public override void Update(float frameTime)

Content.Shared/_DEN/Body/Components/BloodExaminerComponent.cs

@@ -0,0 +1,18 @@
+using Content.Shared.Body.Systems;
+
+namespace Content.Shared._DEN.Body.Systems;
+
+/// <summary>
+///     This entity can see the bloodstream reagents of other species.
+///     Note that this does not detect all chemicals in the bloodstream - just whatever their
+///     actual BloodstreamComponent blood is.
+/// </summary>
+[RegisterComponent, Access(typeof(SharedBloodstreamSystem))]
+public sealed partial class BloodExaminerComponent : Component
+{
+    [DataField]
+    public LocId ExamineText = "blood-examiner-component-examine";
+
+    [DataField]
+    public LocId BloodSuffix = "blood-examiner-component-blood-suffix";
+}

Content.Shared/_DEN/Body/EntitySystems/BloodstreamSystem.cs

@@ -0,0 +1,66 @@
+using System.Linq;
+using Content.Shared._DEN.Body.Systems;
+using Content.Shared.Body.Components;
+using Content.Shared.Examine;
+using Content.Shared.Interaction;
+using Content.Shared.Localizations;
+
+namespace Content.Shared.Body.Systems;
+
+public abstract partial class SharedBloodstreamSystem
+{
+    [Dependency] private readonly SharedInteractionSystem _interactionSystem = default!;
+
+    private void OnExamined(Entity<BloodstreamComponent> target, ref ExaminedEvent args)
+    {
+        if (TryComp<BloodExaminerComponent>(args.Examiner, out var bloodExaminer))
+            BloodExaminerExamined((args.Examiner, bloodExaminer), target, ref args);
+    }
+
+    private void BloodExaminerExamined(Entity<BloodExaminerComponent> examiner,
+        Entity<BloodstreamComponent> target,
+        ref ExaminedEvent args)
+    {
+        if (examiner.Owner == target.Owner)
+            return;
+
+        // Blood drinker range.
+        if (!_interactionSystem.InRangeUnobstructed(examiner.Owner, target.Owner))
+            return;
+
+        var bloodSuffix = Loc.GetString(examiner.Comp.BloodSuffix);
+        var bloodNames = LocalizeBloodReagentNames(target, bloodSuffix);
+        var bloodText = ContentLocalizationManager.FormatList(bloodNames);
+
+        var examineText = Loc.GetString(examiner.Comp.ExamineText, ("target", target), ("blood", bloodText));
+        args.PushMarkup(examineText);
+    }
+
+    private List<string> LocalizeBloodReagentNames(Entity<BloodstreamComponent> ent, string suffix)
+    {
+        var reference = ent.Comp.BloodReferenceSolution;
+        var names = new List<string>();
+        var protos = reference.GetReagentPrototypes(PrototypeManager).Select(p => p.Key);
+
+        foreach (var blood in protos)
+        {
+            var bloodName = blood.LocalizedName;
+
+            // Blood reagent text is colored.
+            var bloodText = Loc.GetString("blood-examiner-component-chemical",
+                ("color", blood.SubstanceColor.ToHexNoAlpha()),
+                ("blood", bloodName));
+
+            // Add "blood" to the end if it doesn't already have it, to make the sentence make sense.
+            // E.g. "You can smell her apple juice." -> "You can smell her apple juice blood."
+            if (protos.Last() == blood && !bloodName.EndsWith(suffix))
+                bloodText = Loc.GetString("blood-examiner-component-examine-not-blood",
+                    ("chemical", bloodText),
+                    ("suffix", suffix));
+
+            names.Add(bloodText);
+        }
+
+        return names;
+    }
+}

Resources/Locale/en-US/_DEN/bloodstream/blood-examiner-component.ftl

@@ -0,0 +1,4 @@
+blood-examiner-component-examine = [color=lightgray]You can smell {POSS-ADJ($target)} {$blood}.[/color]
+blood-examiner-component-examine-not-blood = {$chemical} {$suffix}
+blood-examiner-component-blood-suffix = blood
+blood-examiner-component-chemical = [color={$color}]{$blood}[/color]

Resources/Locale/en-US/_DEN/traits/categories.ftl

@@ -1,2 +1,3 @@
+trait-category-perks = Perks
 trait-category-species-morphs = Morphotypes
 trait-category-species-specific = Species-specific

Resources/Locale/en-US/_DEN/traits/perks.ftl

@@ -0,0 +1,5 @@
+trait-blood-examiner-name = Blood Smell
+trait-blood-examiner-desc =
+    You can [color=yellow]identify the blood chemical of mobs[/color] when you stand close enough to them.
+    Note that this trait [color=orange]does not detect other chemicals in their blood stream[/color], only what
+    the mob's blood stream is actually made of - such as [color=lightblue]synth blood[/color] or [color=lightblue]insect blood[/color].

Resources/Prototypes/_DEN/EntityTraits/categories.yml

@@ -8,3 +8,7 @@
   id: SpeciesSpecific
   priority: -10
   name: trait-category-species-specific
+
+- type: traitCategory
+  id: Perks
+  name: trait-category-perks

Resources/Prototypes/_DEN/EntityTraits/perks.yml

@@ -0,0 +1,9 @@
+- type: entityTrait
+  id: BloodExaminer
+  name: trait-blood-examiner-name
+  description: trait-blood-examiner-desc
+  category: Perks
+  functions:
+  - !type:AddComponentTrait
+      components:
+      - type: BloodExaminer