Chem guidebook (#17123)

* im good at atomizing. welcome to half-finished chem guides.

* wagh

* e

* save work

* aa

* woweee UI

* finishing the last of it

* don't actually update the engine :(

---------

Co-authored-by: moonheart08 <moonheart08@users.noreply.github.com>

Content.Server/Chemistry/ReagentEffects/HealthChange.cs

@@ -1,8 +1,11 @@
+using System.Linq;
 using System.Text.Json.Serialization;
 using Content.Shared.Chemistry.Reagent;
 using Content.Shared.Damage;
 using Content.Shared.FixedPoint;
+using Content.Shared.Localizations;
 using JetBrains.Annotations;
+using Robust.Shared.Prototypes;
 
 namespace Content.Server.Chemistry.ReagentEffects
 {
@@ -31,6 +34,38 @@ namespace Content.Server.Chemistry.ReagentEffects
         [JsonPropertyName("ignoreResistances")]
         public bool IgnoreResistances = true;
 
+        protected override string? ReagentEffectGuidebookText(IPrototypeManager prototype, IEntitySystemManager entSys)
+        {
+            var damages = new List<string>();
+            var heals = false;
+            var deals = false;
+
+            // TODO: This should be smarter. Namely, not showing a damage type as being in a group unless every damage type in the group is present and equal in value.
+            foreach (var (kind, amount) in Damage.GetDamagePerGroup())
+            {
+                var sign = MathF.Sign(amount.Float());
+
+                if (sign < 0)
+                    heals = true;
+                if (sign > 0)
+                    deals = true;
+
+                damages.Add(
+                    Loc.GetString("health-change-display",
+                        ("kind", kind),
+                        ("amount", MathF.Abs(amount.Float())),
+                        ("deltasign", sign)
+                    ));
+            }
+
+            var healsordeals = heals ? (deals ? "both" : "heals") : (deals ? "deals" : "none");
+
+            return Loc.GetString("reagent-effect-guidebook-health-change",
+                ("chance", Probability),
+                ("changes", ContentLocalizationManager.FormatList(damages)),
+                ("healsordeals", healsordeals));
+        }
+
         public override void Effect(ReagentEffectArgs args)
         {
             var scale = ScaleByQuantity ? args.Quantity : FixedPoint2.New(1);