✨ feat: Resources Pool | write slices: DepositResources and WithdrawResources (#13)

+ `Cost` value object renamed to `Resources`

Author: MateuszNaKodach

src/main/java/com/dddheroes/heroesofddd/creaturerecruitment/write/Dwelling.java

@@ -10,9 +10,8 @@
 import com.dddheroes.heroesofddd.creaturerecruitment.write.recruitcreature.RecruitCreature;
 import com.dddheroes.heroesofddd.creaturerecruitment.write.recruitcreature.RecruitCreaturesNotExceedAvailableCreatures;
 import com.dddheroes.heroesofddd.shared.Amount;
-import com.dddheroes.heroesofddd.shared.Cost;
+import com.dddheroes.heroesofddd.shared.Resources;
 import com.dddheroes.heroesofddd.shared.CreatureId;
-import com.dddheroes.heroesofddd.shared.DomainRule;
 import org.axonframework.commandhandling.CommandHandler;
 import org.axonframework.eventsourcing.EventSourcingHandler;
 import org.axonframework.modelling.command.AggregateCreationPolicy;
@@ -28,7 +27,7 @@ class Dwelling {
     @AggregateIdentifier
     private DwellingId dwellingId;
     private CreatureId creatureId;
-    private Cost costPerTroop;
+    private Resources costPerTroop;
     private Amount availableCreatures;
 
     @CommandHandler
@@ -49,7 +48,7 @@ void decide(BuildDwelling command) {
     void evolve(DwellingBuilt event) {
         this.dwellingId = new DwellingId(event.dwellingId());
         this.creatureId = new CreatureId(event.creatureId());
-        this.costPerTroop = Cost.fromRaw(event.costPerTroop());
+        this.costPerTroop = Resources.fromRaw(event.costPerTroop());
         this.availableCreatures = Amount.zero();
     }
 

src/main/java/com/dddheroes/heroesofddd/creaturerecruitment/write/builddwelling/BuildDwelling.java

@@ -2,7 +2,7 @@
 
 import com.dddheroes.heroesofddd.creaturerecruitment.write.DwellingCommand;
 import com.dddheroes.heroesofddd.creaturerecruitment.write.DwellingId;
-import com.dddheroes.heroesofddd.shared.Cost;
+import com.dddheroes.heroesofddd.shared.Resources;
 import com.dddheroes.heroesofddd.shared.CreatureId;
 import org.axonframework.modelling.command.TargetAggregateIdentifier;
 
@@ -12,10 +12,10 @@ public record BuildDwelling(
         @TargetAggregateIdentifier
         DwellingId dwellingId,
         CreatureId creatureId,
-        Cost costPerTroop
+        Resources costPerTroop
 ) implements DwellingCommand {
 
     public static BuildDwelling command(String dwellingId, String creatureId, Map<String, Integer> costPerTroop) {
-        return new BuildDwelling(DwellingId.of(dwellingId), CreatureId.of(creatureId), Cost.fromRaw(costPerTroop));
+        return new BuildDwelling(DwellingId.of(dwellingId), CreatureId.of(creatureId), Resources.fromRaw(costPerTroop));
     }
 }

src/main/java/com/dddheroes/heroesofddd/creaturerecruitment/write/builddwelling/DwellingBuilt.java

@@ -2,7 +2,7 @@
 
 import com.dddheroes.heroesofddd.creaturerecruitment.write.DwellingEvent;
 import com.dddheroes.heroesofddd.creaturerecruitment.write.DwellingId;
-import com.dddheroes.heroesofddd.shared.Cost;
+import com.dddheroes.heroesofddd.shared.Resources;
 import com.dddheroes.heroesofddd.shared.CreatureId;
 
 import java.util.Map;
@@ -13,7 +13,7 @@ public record DwellingBuilt(
         Map<String, Integer> costPerTroop
 ) implements DwellingEvent {
 
-    public static DwellingBuilt event(DwellingId dwellingId, CreatureId creatureId, Cost costPerTroop) {
+    public static DwellingBuilt event(DwellingId dwellingId, CreatureId creatureId, Resources costPerTroop) {
         return new DwellingBuilt(dwellingId.raw(), creatureId.raw(), costPerTroop.raw());
     }
 }

src/main/java/com/dddheroes/heroesofddd/creaturerecruitment/write/recruitcreature/CreatureRecruited.java

@@ -4,7 +4,7 @@
 import com.dddheroes.heroesofddd.creaturerecruitment.write.DwellingId;
 import com.dddheroes.heroesofddd.shared.Amount;
 import com.dddheroes.heroesofddd.shared.ArmyId;
-import com.dddheroes.heroesofddd.shared.Cost;
+import com.dddheroes.heroesofddd.shared.Resources;
 import com.dddheroes.heroesofddd.shared.CreatureId;
 
 import java.util.Map;
@@ -22,7 +22,7 @@ public static CreatureRecruited event(
             CreatureId creatureId,
             ArmyId toArmy,
             Amount quantity,
-            Cost totalCost
+            Resources totalCost
     ) {
         return new CreatureRecruited(
                 dwellingId.raw(),

src/main/java/com/dddheroes/heroesofddd/resourcespool/write/ResourcesPool.java

@@ -0,0 +1,57 @@
+package com.dddheroes.heroesofddd.resourcespool.write;
+
+import com.dddheroes.heroesofddd.resourcespool.write.deposit.DepositResources;
+import com.dddheroes.heroesofddd.resourcespool.write.deposit.ResourcesDeposited;
+import com.dddheroes.heroesofddd.resourcespool.write.withdraw.CannotWithdrawMoreThanDepositedResources;
+import com.dddheroes.heroesofddd.resourcespool.write.withdraw.ResourcesWithdrawn;
+import com.dddheroes.heroesofddd.resourcespool.write.withdraw.WithdrawResources;
+import com.dddheroes.heroesofddd.shared.Amount;
+import com.dddheroes.heroesofddd.shared.ResourceType;
+import com.dddheroes.heroesofddd.shared.Resources;
+import org.axonframework.commandhandling.CommandHandler;
+import org.axonframework.eventsourcing.EventSourcingHandler;
+import org.axonframework.modelling.command.AggregateCreationPolicy;
+import org.axonframework.modelling.command.AggregateIdentifier;
+import org.axonframework.modelling.command.CreationPolicy;
+import org.axonframework.spring.stereotype.Aggregate;
+
+import static org.axonframework.modelling.command.AggregateLifecycle.apply;
+
+@Aggregate
+class ResourcesPool {
+
+    @AggregateIdentifier
+    private ResourcesPoolId resourcesPoolId;
+    private Resources balance = Resources.empty();
+
+    @CommandHandler
+    @CreationPolicy(AggregateCreationPolicy.CREATE_IF_MISSING)
+    void decide(DepositResources command) {
+        apply(ResourcesDeposited.event(command.resourcesPoolId(), command.type(), command.amount()));
+    }
+
+    @EventSourcingHandler
+    void evolve(ResourcesDeposited event) {
+        resourcesPoolId = new ResourcesPoolId(event.resourcesPoolId());
+        this.balance = balance.plus(ResourceType.from(event.type()), new Amount(event.amount()));
+    }
+
+    @CommandHandler
+    void decide(WithdrawResources command) {
+        new CannotWithdrawMoreThanDepositedResources(
+                balance,
+                Resources.from(command.type(), command.amount())
+        ).verify();
+        apply(ResourcesWithdrawn.event(command.resourcesPoolId(), command.type(), command.amount()));
+    }
+
+    @EventSourcingHandler
+    void evolve(ResourcesWithdrawn event) {
+        resourcesPoolId = new ResourcesPoolId(event.resourcesPoolId());
+        this.balance = balance.minus(ResourceType.from(event.type()), new Amount(event.amount()));
+    }
+
+    ResourcesPool() {
+        // required by Axon
+    }
+}

src/main/java/com/dddheroes/heroesofddd/resourcespool/write/ResourcesPoolCommand.java

@@ -0,0 +1,6 @@
+package com.dddheroes.heroesofddd.resourcespool.write;
+
+public interface ResourcesPoolCommand {
+
+    ResourcesPoolId resourcesPoolId();
+}

src/main/java/com/dddheroes/heroesofddd/resourcespool/write/ResourcesPoolEvent.java

@@ -0,0 +1,6 @@
+package com.dddheroes.heroesofddd.resourcespool.write;
+
+public interface ResourcesPoolEvent {
+
+    String resourcesPoolId();
+}

src/main/java/com/dddheroes/heroesofddd/resourcespool/write/ResourcesPoolId.java

@@ -0,0 +1,25 @@
+package com.dddheroes.heroesofddd.resourcespool.write;
+
+import java.util.UUID;
+
+public record ResourcesPoolId(String raw) {
+
+    public ResourcesPoolId {
+        if (raw == null || raw.isBlank()) {
+            throw new IllegalArgumentException("Resources Pool ID cannot be null or empty");
+        }
+    }
+
+    public static ResourcesPoolId of(String raw) {
+        return new ResourcesPoolId(raw);
+    }
+
+    public static ResourcesPoolId random() {
+        return new ResourcesPoolId(UUID.randomUUID().toString());
+    }
+
+    @Override
+    public String toString() {
+        return raw;
+    }
+}

src/main/java/com/dddheroes/heroesofddd/resourcespool/write/deposit/DepositResources.java

@@ -0,0 +1,19 @@
+package com.dddheroes.heroesofddd.resourcespool.write.deposit;
+
+import com.dddheroes.heroesofddd.resourcespool.write.ResourcesPoolCommand;
+import com.dddheroes.heroesofddd.resourcespool.write.ResourcesPoolId;
+import com.dddheroes.heroesofddd.shared.Amount;
+import com.dddheroes.heroesofddd.shared.ResourceType;
+import org.axonframework.modelling.command.TargetAggregateIdentifier;
+
+public record DepositResources(
+        @TargetAggregateIdentifier
+        ResourcesPoolId resourcesPoolId,
+        ResourceType type,
+        Amount amount
+) implements ResourcesPoolCommand {
+
+    public static DepositResources command(String resourcesPoolId, String type, Integer amount) {
+        return new DepositResources(ResourcesPoolId.of(resourcesPoolId), ResourceType.from(type), Amount.of(amount));
+    }
+}

src/main/java/com/dddheroes/heroesofddd/resourcespool/write/deposit/ResourcesDeposited.java

@@ -0,0 +1,17 @@
+package com.dddheroes.heroesofddd.resourcespool.write.deposit;
+
+import com.dddheroes.heroesofddd.resourcespool.write.ResourcesPoolEvent;
+import com.dddheroes.heroesofddd.resourcespool.write.ResourcesPoolId;
+import com.dddheroes.heroesofddd.shared.Amount;
+import com.dddheroes.heroesofddd.shared.ResourceType;
+
+public record ResourcesDeposited(
+        String resourcesPoolId,
+        String type,
+        Integer amount
+) implements ResourcesPoolEvent {
+
+    public static ResourcesDeposited event(ResourcesPoolId resourcesPoolId, ResourceType type, Amount amount) {
+        return new ResourcesDeposited(resourcesPoolId.raw(), type.name(), amount.raw());
+    }
+}