Add contract-earned permanent training-rate bonus

Source/RP0/Crew/BoostTrainingRate.cs

@@ -0,0 +1,40 @@
+using Contracts;
+using ContractConfigurator;
+
+namespace ContractConfigurator.RP0
+{
+    /// <summary>
+    /// On contract completion, permanently multiplies the astronaut training rate (both proficiency and
+    /// mission training) by <c>multiplier</c>. The bonus is stored on CrewHandler and persists with the save;
+    /// it stacks multiplicatively if more than one such contract is completed.
+    /// </summary>
+    public class BoostTrainingRate : ContractBehaviour
+    {
+        protected double multiplier = 1d;
+
+        public BoostTrainingRate() { }
+
+        public BoostTrainingRate(double multiplier)
+        {
+            this.multiplier = multiplier;
+        }
+
+        protected override void OnLoad(ConfigNode node)
+        {
+            base.OnLoad(node);
+            node.TryGetValue("multiplier", ref multiplier);
+        }
+
+        protected override void OnSave(ConfigNode node)
+        {
+            base.OnSave(node);
+            node.AddValue("multiplier", multiplier);
+        }
+
+        protected override void OnCompleted()
+        {
+            base.OnCompleted();
+            global::RP0.Crew.CrewHandler.Instance?.ApplyPermanentTrainingRateBonus(multiplier);
+        }
+    }
+}

Source/RP0/Crew/BoostTrainingRateFactory.cs

@@ -0,0 +1,24 @@
+using Contracts;
+using ContractConfigurator;
+
+namespace ContractConfigurator.RP0
+{
+    public class BoostTrainingRateFactory : BehaviourFactory
+    {
+        protected double multiplier;
+
+        public override bool Load(ConfigNode node)
+        {
+            bool valid = base.Load(node);
+
+            valid &= ConfigNodeUtil.ParseValue<double>(node, "multiplier", x => multiplier = x, this, 1.5, x => Validation.GT(x, 0.0));
+
+            return valid;
+        }
+
+        public override ContractBehaviour Generate(ConfiguredContract contract)
+        {
+            return new BoostTrainingRate(multiplier);
+        }
+    }
+}

Source/RP0/Crew/CrewHandler.cs

@@ -59,6 +59,11 @@
         public bool IsMissionTrainingEnabled;
         public double ProfTrainRate;
         public double MissionTrainRate;
+        // Permanent multiplier on training build rate, earned via contracts (see the BoostTrainingRate
+        // behaviour). 1.0 = no bonus. Persisted with the save, and contributed to the RateTraining currency
+        // query (OnCurrencyQuery) so it flows through CalculateBuildRate's existing rate line and composes
+        // with leader/strategy training modifiers.
+        public double TrainingRateBonus = 1d;
 
         private EventData<RDTech> onKctTechQueuedEvent;
         private HashSet<string> _toRemove = new HashSet<string>();
@@ -143,6 +148,7 @@
             GameEvents.OnPartPurchased.Add(OnPartPurchased);
             GameEvents.OnGameSettingsApplied.Add(LoadSettings);
             GameEvents.onGameStateLoad.Add(LoadSettings);
+            GameEvents.Modifiers.OnCurrencyModifierQuery.Add(OnCurrencyQuery);
 
             TrainingDatabase.EnsureInitialized();
         }
@@ -164,12 +170,44 @@
 
             LoadedSaveVersion = VERSION;
 
+            TrainingRateBonus = 1d;
+            node.TryGetValue(nameof(TrainingRateBonus), ref TrainingRateBonus);
+
             KACWrapper.InitKACWrapper();
         }
 
         public override void OnSave(ConfigNode node)
         {
             base.OnSave(node);
+
+            node.AddValue(nameof(TrainingRateBonus), TrainingRateBonus);
+        }
+
+        /// <summary>
+        /// Permanently multiplies the astronaut training rate by <paramref name="multiplier"/> (stacks
+        /// multiplicatively). Applied to both proficiency and mission training via CalculateBuildRate.
+        /// </summary>
+        public void ApplyPermanentTrainingRateBonus(double multiplier)
+        {
+            if (multiplier <= 0d) return;
+            TrainingRateBonus *= multiplier;
+            RP0Debug.Log($"Applied permanent training rate bonus x{multiplier}; total is now x{TrainingRateBonus}");
+
+            foreach (var course in TrainingCourses)
+                course.RecalculateBuildRate();
+        }
+
+        // Contribute the earned training-rate bonus to any RateTraining currency query, the same way leader
+        // and strategy effects do (see Leaders/Effects/CurrencyModifier). CalculateBuildRate already folds in
+        // CurrencyUtils.Rate(RateTraining), so no direct multiply is needed there.
+        private void OnCurrencyQuery(CurrencyModifierQuery qry)
+        {
+            if (TrainingRateBonus == 1d) return;
+            if (qry is CurrencyModifierQueryRP0 qryRP0 &&
+                (qryRP0.reasonRP0 & TransactionReasonsRP0.RateTraining) != 0)
+            {
+                qryRP0.Multiply(CurrencyRP0.Rate, TrainingRateBonus);
+            }
         }
 
         public void Process(double UTDiff)
@@ -210,6 +248,7 @@
             GameEvents.OnPartPurchased.Remove(OnPartPurchased);
             GameEvents.OnGameSettingsApplied.Remove(LoadSettings);
             GameEvents.onGameStateLoad.Remove(LoadSettings);
+            GameEvents.Modifiers.OnCurrencyModifierQuery.Remove(OnCurrencyQuery);
 
             if (onKctTechQueuedEvent != null) onKctTechQueuedEvent.Remove(AddCoursesForQueuedTechNode);
         }

Source/RP0/RP0.csproj

@@ -177,6 +177,8 @@
     <Compile Include="Settings\SpaceCenterSettings.cs" />
     <Compile Include="Maintenance\MaintenanceHandler.cs" />
     <Compile Include="Crew\CrewHandler.cs" />
+    <Compile Include="Crew\BoostTrainingRate.cs" />
+    <Compile Include="Crew\BoostTrainingRateFactory.cs" />
     <Compile Include="Settings\GameParameters.cs" />
     <Compile Include="PartModules\ModuleNonRecharge.cs" />
     <Compile Include="PartModules\ModuleNonReentryRated.cs" />