✨ feat: Creature Recruitment | Dwelling read model (#3)

Author: MateuszNaKodach

pom.xml

@@ -122,6 +122,13 @@
 		<dependency>
 			<groupId>org.axonframework</groupId>
 			<artifactId>axon-test</artifactId>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.assertj</groupId>
+			<artifactId>assertj-core</artifactId>
+			<version>3.27.3</version>
+			<scope>test</scope>
 		</dependency>
 	</dependencies>
 

src/main/java/com/dddheroes/heroesofddd/armies/write/Army.java

@@ -21,6 +21,7 @@
 
 import static org.axonframework.modelling.command.AggregateLifecycle.apply;
 
+// todo: probably we should model events ArmyEstablished and ArmyDestroyed, more on that on Event Model
 @Aggregate
 class Army {
 
@@ -29,7 +30,7 @@ class Army {
     private final Map<CreatureId, Amount> creatureStacks = new HashMap<>();
 
     @CommandHandler
-    @CreationPolicy(AggregateCreationPolicy.CREATE_IF_MISSING)
+    @CreationPolicy(AggregateCreationPolicy.CREATE_IF_MISSING) // performance downside in comparison to constructor
     void handle(AddCreatureToArmy command) {
         new CanHaveMax7CreatureStacksInArmy(command.creatureId(), creatureStacks).verify();
 

src/main/java/com/dddheroes/heroesofddd/creaturerecruitment/read/DwellingReadModel.java

@@ -0,0 +1,67 @@
+package com.dddheroes.heroesofddd.creaturerecruitment.read;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.Id;
+import jakarta.persistence.Table;
+import org.hibernate.annotations.JdbcTypeCode;
+import org.hibernate.type.SqlTypes;
+
+import java.util.Map;
+
+@Entity
+@Table(name = "read_model_dwelling")
+public class DwellingReadModel {
+
+    @Id
+    private String dwellingId;
+
+    private String creatureId;
+
+    @JdbcTypeCode(SqlTypes.JSON)
+    @Column(columnDefinition = "jsonb")
+    private Map<String, Integer> costPerTroop;
+
+    private Integer availableCreatures;
+
+    DwellingReadModel(String dwellingId,
+                      String creatureId,
+                      Map<String, Integer> costPerTroop,
+                      Integer availableCreatures
+    ) {
+        this.dwellingId = dwellingId;
+        this.creatureId = creatureId;
+        this.costPerTroop = costPerTroop;
+        this.availableCreatures = availableCreatures;
+    }
+
+    DwellingReadModel withAvailableCreatures(Integer availableCreatures) {
+        this.availableCreatures = availableCreatures;
+        return this;
+    }
+
+    DwellingReadModel withAvailableCreaturesDecreasedBy(Integer decreasedBy) {
+        this.availableCreatures = this.availableCreatures - decreasedBy;
+        return this;
+    }
+
+    public String getDwellingId() {
+        return dwellingId;
+    }
+
+    public String getCreatureId() {
+        return creatureId;
+    }
+
+    public Map<String, Integer> getCostPerTroop() {
+        return costPerTroop;
+    }
+
+    public Integer getAvailableCreatures() {
+        return availableCreatures;
+    }
+
+    protected DwellingReadModel() {
+        // Required by JPA
+    }
+}

src/main/java/com/dddheroes/heroesofddd/creaturerecruitment/read/DwellingReadModelProjector.java

@@ -0,0 +1,42 @@
+package com.dddheroes.heroesofddd.creaturerecruitment.read;
+
+import com.dddheroes.heroesofddd.creaturerecruitment.write.builddwelling.DwellingBuilt;
+import com.dddheroes.heroesofddd.creaturerecruitment.write.changeavailablecreatures.AvailableCreaturesChanged;
+import com.dddheroes.heroesofddd.creaturerecruitment.write.recruitcreature.CreatureRecruited;
+import org.axonframework.eventhandling.EventHandler;
+import org.springframework.stereotype.Component;
+
+@Component
+class DwellingReadModelProjector {
+
+    private final DwellingReadModelRepository repository;
+
+    DwellingReadModelProjector(DwellingReadModelRepository repository) {
+        this.repository = repository;
+    }
+
+    @EventHandler
+    void on(DwellingBuilt event) {
+        var state = new DwellingReadModel(
+                event.dwellingId(),
+                event.creatureId(),
+                event.costPerTroop(),
+                0
+        );
+        repository.save(state);
+    }
+
+    @EventHandler
+    void on(AvailableCreaturesChanged event) {
+        repository.findById(event.dwellingId())
+                  .map(state -> state.withAvailableCreatures(event.changedTo()))
+                  .ifPresent(repository::save);
+    }
+
+    @EventHandler
+    void on(CreatureRecruited event) {
+        repository.findById(event.dwellingId())
+                  .map(state -> state.withAvailableCreaturesDecreasedBy(event.quantity()))
+                  .ifPresent(repository::save);
+    }
+}

src/main/java/com/dddheroes/heroesofddd/creaturerecruitment/read/DwellingReadModelRepository.java

@@ -0,0 +1,9 @@
+package com.dddheroes.heroesofddd.creaturerecruitment.read;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.stereotype.Repository;
+
+@Repository
+public interface DwellingReadModelRepository extends JpaRepository<DwellingReadModel, String> {
+
+}

src/main/java/com/dddheroes/heroesofddd/creaturerecruitment/read/getdwellingbyid/GetDwellingById.java

@@ -0,0 +1,11 @@
+package com.dddheroes.heroesofddd.creaturerecruitment.read.getdwellingbyid;
+
+import com.dddheroes.heroesofddd.creaturerecruitment.write.DwellingId;
+
+public record GetDwellingById(DwellingId dwellingId) {
+
+    public static GetDwellingById query(String dwellingId) {
+        return new GetDwellingById(DwellingId.of(dwellingId));
+    }
+
+}

src/main/java/com/dddheroes/heroesofddd/creaturerecruitment/read/getdwellingbyid/GetDwellingByIdQueryHandler.java

@@ -0,0 +1,22 @@
+package com.dddheroes.heroesofddd.creaturerecruitment.read.getdwellingbyid;
+
+import com.dddheroes.heroesofddd.creaturerecruitment.read.DwellingReadModel;
+import com.dddheroes.heroesofddd.creaturerecruitment.read.DwellingReadModelRepository;
+import org.axonframework.queryhandling.QueryHandler;
+import org.springframework.stereotype.Component;
+
+import java.util.Optional;
+
+@Component
+class GetDwellingByIdQueryHandler {
+    private final DwellingReadModelRepository dwellingReadModelRepository;
+
+    GetDwellingByIdQueryHandler(DwellingReadModelRepository dwellingReadModelRepository) {
+        this.dwellingReadModelRepository = dwellingReadModelRepository;
+    }
+
+    @QueryHandler
+    DwellingReadModel handle(GetDwellingById query){
+        return dwellingReadModelRepository.findById(query.dwellingId().raw()).orElse(null);
+    }
+}

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

@@ -12,6 +12,7 @@
 import com.dddheroes.heroesofddd.shared.Amount;
 import com.dddheroes.heroesofddd.shared.Cost;
 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;
@@ -31,7 +32,7 @@ class Dwelling {
     private Amount availableCreatures;
 
     @CommandHandler
-    @CreationPolicy(AggregateCreationPolicy.CREATE_IF_MISSING)
+    @CreationPolicy(AggregateCreationPolicy.CREATE_IF_MISSING) // performance downside in comparison to constructor
     void handle(BuildDwelling command) {
         new OnlyNotBuiltBuildingCanBeBuild(dwellingId).verify();
 
@@ -72,7 +73,11 @@ void on(AvailableCreaturesChanged event) {
     }
 
     @CommandHandler
+//    @CreationPolicy(AggregateCreationPolicy.CREATE_IF_MISSING)
     void handle(RecruitCreature command) {
+//        if(dwellingId == null){
+//            throw new DomainRule.ViolatedException("Only not built building can be build");
+//        }
         new RecruitCreaturesNotExceedAvailableCreatures(
                 creatureId,
                 availableCreatures,

src/test/java/com/dddheroes/heroesofddd/TestAxonServerConnection.java

@@ -0,0 +1,50 @@
+package com.dddheroes.heroesofddd;
+
+import io.axoniq.axonserver.connector.AxonServerConnection;
+import org.axonframework.axonserver.connector.AxonServerConfiguration;
+import org.axonframework.axonserver.connector.AxonServerConnectionManager;
+import org.axonframework.springboot.service.connection.AxonServerConnectionDetails;
+import org.axonframework.test.server.AxonServerContainer;
+import org.junit.jupiter.api.*;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.testcontainers.service.connection.ServiceConnection;
+import org.springframework.context.annotation.Import;
+import org.testcontainers.junit.jupiter.Container;
+
+import java.time.Duration;
+
+import static org.awaitility.Awaitility.await;
+import static org.junit.jupiter.api.Assertions.*;
+
+@Import(TestcontainersConfiguration.class)
+@SpringBootTest
+class TestAxonServerConnection {
+
+    @Autowired
+    private AxonServerContainer axonServer;
+
+    @Autowired
+    private AxonServerConfiguration axonServerConfiguration;
+
+    @Autowired
+    private AxonServerConnectionDetails connectionDetails;
+
+    @Autowired
+    private AxonServerConnectionManager axonServerConnectionManager;
+
+    @Test
+    void verifyApplicationStartsNormallyWithAxonServerInstance() {
+        assertTrue(axonServer.isRunning());
+        assertNotNull(connectionDetails);
+        assertTrue(connectionDetails.routingServers().endsWith("" + axonServer.getGrpcPort()));
+        assertNotNull(axonServerConfiguration);
+
+        assertNotEquals("localhost:8024", axonServerConfiguration.getServers());
+
+        AxonServerConnection connection = axonServerConnectionManager.getConnection();
+
+        await().atMost(Duration.ofSeconds(5))
+               .untilAsserted(() -> assertTrue(connection.isConnected()));
+    }
+}

src/test/java/com/dddheroes/heroesofddd/TestcontainersConfiguration.java

@@ -1,17 +1,24 @@
 package com.dddheroes.heroesofddd;
 
+import org.axonframework.test.server.AxonServerContainer;
 import org.springframework.boot.test.context.TestConfiguration;
 import org.springframework.boot.testcontainers.service.connection.ServiceConnection;
 import org.springframework.context.annotation.Bean;
 import org.testcontainers.containers.PostgreSQLContainer;
 import org.testcontainers.utility.DockerImageName;
 
 @TestConfiguration(proxyBeanMethods = false)
-class TestcontainersConfiguration {
+public class TestcontainersConfiguration {
 
     @Bean
     @ServiceConnection
     PostgreSQLContainer<?> postgresContainer() {
         return new PostgreSQLContainer<>(DockerImageName.parse("postgres:latest"));
     }
+
+    @Bean
+    @ServiceConnection
+    AxonServerContainer axonServerContainer() {
+        return new AxonServerContainer().withDevMode(true);
+    }
 }