add delete endpoint

src/main/java/io/autoinvestor/application/HoldingDeleteUseCase/HoldingDeleteCommand.java

@@ -0,0 +1,7 @@
+package io.autoinvestor.application.HoldingDeleteUseCase;
+
+public record HoldingDeleteCommand(
+        String userId,
+        String assetId
+) {
+}

src/main/java/io/autoinvestor/application/HoldingDeleteUseCase/HoldingDeleteCommandHandler.java

@@ -0,0 +1,44 @@
+package io.autoinvestor.application.HoldingDeleteUseCase;
+
+import io.autoinvestor.application.HoldingsReadModel;
+import io.autoinvestor.application.UsersWalletReadModel;
+import io.autoinvestor.domain.events.Event;
+import io.autoinvestor.domain.events.EventPublisher;
+import io.autoinvestor.domain.events.WalletEventStoreRepository;
+import io.autoinvestor.domain.model.Wallet;
+import io.autoinvestor.domain.model.WalletId;
+import io.autoinvestor.exceptions.UserWithoutPortfolio;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Service;
+
+import java.util.List;
+
+@Service
+@RequiredArgsConstructor
+public class HoldingDeleteCommandHandler {
+
+    private final UsersWalletReadModel usersWalletReadModel;
+    private final WalletEventStoreRepository eventStore;
+    private final HoldingsReadModel holdingsReadModel;
+    private final EventPublisher eventPublisher;
+
+    public void handle (HoldingDeleteCommand command) {
+        String walletId = this.usersWalletReadModel.getWalletId(command.userId());
+        if (walletId == null) {
+            throw UserWithoutPortfolio.with(command.userId());
+        }
+        Wallet wallet = this.eventStore.get(WalletId.of(walletId))
+                .orElseThrow(() -> UserWithoutPortfolio.with(command.userId()));
+        wallet.deleteHolding(command.userId(), command.assetId());
+        List<Event<?>> events = wallet.getUncommittedEvents();
+
+        this.eventStore.save(wallet);
+
+        boolean removed = this.holdingsReadModel.delete(command.userId(), command.assetId());
+        if (!removed) {
+            return;
+        }
+        this.eventPublisher.publish(events);
+        wallet.markEventsAsCommitted();
+    }
+}

src/main/java/io/autoinvestor/application/HoldingsReadModel.java

@@ -5,5 +5,7 @@
 public interface HoldingsReadModel {
     void add(HoldingsReadModelDTO dto);
     void update(HoldingsReadModelDTO dto);
+    boolean delete(String userId, String assetId);
     List<HoldingsReadModelDTO> getHoldings(String userId);
+    boolean assetAlreadyExists(String userIs, String assetId);
 }

src/main/java/io/autoinvestor/application/NewHoldingUseCase/NewHoldingCommandHandler.java

@@ -9,6 +9,7 @@
 import io.autoinvestor.domain.model.AssetId;
 import io.autoinvestor.domain.model.Wallet;
 import io.autoinvestor.domain.model.WalletId;
+import io.autoinvestor.exceptions.AssetAlreadyExists;
 import io.autoinvestor.exceptions.UserWithoutPortfolio;
 import lombok.RequiredArgsConstructor;
 import org.springframework.stereotype.Service;
@@ -30,6 +31,9 @@ public void handle(NewHoldingCommand command) {
             throw UserWithoutPortfolio.with(command.userId());
         }
 
+        if (this.holdingsReadModel.assetAlreadyExists(command.userId(), command.assetId())) {
+            throw AssetAlreadyExists.with(command.userId(), command.assetId());
+        }
         Wallet wallet = this.eventStore.get(WalletId.of(walletId))
                 .orElseThrow(() -> UserWithoutPortfolio.with(command.userId()));
 

src/main/java/io/autoinvestor/domain/events/HoldingWasDeletedEvent.java

@@ -0,0 +1,44 @@
+package io.autoinvestor.domain.events;
+
+import io.autoinvestor.domain.Id;
+import io.autoinvestor.domain.model.Amount;
+import io.autoinvestor.domain.model.AssetId;
+import io.autoinvestor.domain.model.UserId;
+import io.autoinvestor.domain.model.WalletId;
+
+import java.util.Date;
+
+public class HoldingWasDeletedEvent extends Event<HoldingWasDeletedEventPayload> {
+    public static final String TYPE = "PORTFOLIO_ASSET_REMOVED";
+
+    private HoldingWasDeletedEvent(Id aggregateId, HoldingWasDeletedEventPayload payload) {
+        super (aggregateId, TYPE, payload);
+    }
+
+    protected HoldingWasDeletedEvent(
+            EventId id,
+            Id aggregateId,
+            HoldingWasDeletedEventPayload payload,
+            Date occurredAt,
+            int version) {
+        super(id, aggregateId, TYPE, payload, occurredAt, version);
+    }
+
+    public static HoldingWasDeletedEvent with(WalletId walletId,
+                                              UserId userId,
+                                              AssetId assetId) {
+        HoldingWasDeletedEventPayload payload = new HoldingWasDeletedEventPayload(
+                userId.value(), assetId.value()
+        );
+        return new HoldingWasDeletedEvent(walletId, payload);
+    }
+
+    public static HoldingWasDeletedEvent hydrate (EventId id,
+                                                  Id aggregateId,
+                                                  HoldingWasDeletedEventPayload payload,
+                                                  Date occurredAt,
+                                                  int version) {
+        return new HoldingWasDeletedEvent(id, aggregateId, payload, occurredAt, version);
+    }
+
+}

src/main/java/io/autoinvestor/domain/events/HoldingWasDeletedEventPayload.java

@@ -0,0 +1,16 @@
+package io.autoinvestor.domain.events;
+
+import java.util.Map;
+
+public record HoldingWasDeletedEventPayload(
+        String userId,
+        String assetId
+) implements EventPayload {
+    @Override
+    public Map<String, Object> asMap() {
+        return Map.of(
+                "userId" , userId,
+                "assetId", assetId
+        );
+    }
+}

src/main/java/io/autoinvestor/domain/model/Wallet.java

@@ -57,6 +57,14 @@ public void updateHolding(String userId, String assetId, Integer amount, Integer
         ));
     }
 
+    public void deleteHolding(String userId, String assetId) {
+        this.apply(HoldingWasDeletedEvent.with(
+                this.state.getWalletId(),
+                UserId.of(userId),
+                AssetId.of(assetId)
+        ));
+    }
+
     @Override
     protected void when(Event<?> e) {
         switch (e.getType()) {
@@ -69,6 +77,8 @@ protected void when(Event<?> e) {
             case HoldingWasUpdatedEvent.TYPE:
                 whenHoldingUpdated((HoldingWasUpdatedEvent) e);
                 break;
+            case HoldingWasDeletedEvent.TYPE:
+
             default:
                 throw new IllegalArgumentException("Unknown event type");
         }
@@ -88,4 +98,8 @@ private void whenHoldingCreated(HoldingWasCreatedEvent event) {
     private void whenHoldingUpdated(HoldingWasUpdatedEvent event) {
         this.state = this.state.withHoldingUpdated(event);
     }
+
+    private void whenHoldingDeleted(HoldingWasDeletedEvent event) {
+        this.state = this.state.withHoldingDeleted(event);
+    }
 }

src/main/java/io/autoinvestor/domain/model/WalletState.java

@@ -56,4 +56,14 @@ public WalletState withHoldingUpdated(HoldingWasUpdatedEvent event) {
                 this.holdings
         );
     }
+
+    public WalletState withHoldingDeleted(HoldingWasDeletedEvent event) {
+        HoldingWasDeletedEventPayload payload = event.getPayload();
+        holdings.remove(AssetId.of(payload.assetId()));
+        return new WalletState(
+                this.walletId,
+                this.userId,
+                this.holdings
+        );
+    }
 }

src/main/java/io/autoinvestor/exceptions/AssetAlreadyExists.java

@@ -0,0 +1,12 @@
+package io.autoinvestor.exceptions;
+
+public class AssetAlreadyExists extends RuntimeException {
+    private AssetAlreadyExists(String message) {
+        super(message);
+    }
+
+    public static AssetAlreadyExists with (String userId, String assetId) {
+        String message = "Duplicate asset " + assetId + " for user " + userId;
+        return new AssetAlreadyExists(message);
+    }
+}

src/main/java/io/autoinvestor/infrastructure/read_models/InMemoryHoldingsReadModel.java

@@ -20,8 +20,18 @@ public void update(HoldingsReadModelDTO dto) {
 
     }
 
+    @Override
+    public boolean delete(String userId, String assetId) {
+        return false;
+    }
+
     @Override
     public List<HoldingsReadModelDTO> getHoldings(String userId) {
         return List.of();
     }
+
+    @Override
+    public boolean assetAlreadyExists(String userIs, String assetId) {
+        return false;
+    }
 }

src/main/java/io/autoinvestor/infrastructure/read_models/MongoHoldingsReadModel.java

@@ -1,5 +1,6 @@
 package io.autoinvestor.infrastructure.read_models;
 
+import com.mongodb.client.result.DeleteResult;
 import io.autoinvestor.application.HoldingsReadModel;
 import io.autoinvestor.application.HoldingsReadModelDTO;
 import org.springframework.context.annotation.Profile;
@@ -39,10 +40,26 @@ public void update(HoldingsReadModelDTO dto) {
         this.template.updateFirst(query, update, MongoHoldingsReadModelDocument.class);
     }
 
+    @Override
+    public boolean delete(String userId, String assetId) {
+        Query query = new Query(Criteria.where("userId").is(userId)
+                .and("assetId").is(assetId));
+        DeleteResult result = this.template.remove(query, MongoHoldingsReadModelDocument.class);
+        return result.getDeletedCount() > 0;
+    }
+
     @Override
     public List<HoldingsReadModelDTO> getHoldings(String userId) {
         Query query = new Query(Criteria.where("userId").is(userId));
         return this.template.find(query, MongoHoldingsReadModelDocument.class)
                 .stream().map(mapper::toDTO).toList();
     }
+
+    @Override
+    public boolean assetAlreadyExists(String userId, String assetId) {
+        Query query = new Query(Criteria.where("userId").is(userId)
+                .and("assetId").is(assetId));
+        return this.template.exists(query, MongoHoldingsReadModelDocument.class);
+    }
+
 }

src/main/java/io/autoinvestor/ui/PortfolioController.java

@@ -1,5 +1,7 @@
 package io.autoinvestor.ui;
 
+import io.autoinvestor.application.HoldingDeleteUseCase.HoldingDeleteCommand;
+import io.autoinvestor.application.HoldingDeleteUseCase.HoldingDeleteCommandHandler;
 import io.autoinvestor.application.HoldingsReadModelDTO;
 import io.autoinvestor.application.NewHoldingUseCase.NewHoldingCommand;
 import io.autoinvestor.application.NewHoldingUseCase.NewHoldingCommandHandler;
@@ -27,6 +29,7 @@ public class PortfolioController {
     private final WalletCreatedHandler walletCreatedHandler;
     private final GetHoldingResponseDocumentMapper mapperGetHoldingResponse;
     private final UpdateHoldingCommandHandler updateHoldingCommandHandler;
+    private final HoldingDeleteCommandHandler holdingDeleteCommandHandler;
     @PostMapping
     public ResponseEntity<Void> addHolding(
             @RequestHeader(value = "X-User-Id", required = true) String userId,
@@ -67,6 +70,13 @@ public ResponseEntity<Void> putHolding (
         return ResponseEntity.status(HttpStatus.CREATED).build();
     }
 
+    public ResponseEntity<Void> deleteHolding (
+            @RequestHeader (value = "X-User-Id", required = true) String userId,
+            @RequestParam(value = "assetId", required = true) String assetId
+    ) {
+        holdingDeleteCommandHandler.handle(new HoldingDeleteCommand(userId, assetId));
+        return ResponseEntity.status(HttpStatus.OK).build();
+    }
 
     @PostMapping("/user")
     public ResponseEntity<Void> simulateIncomingUserCreatedMessage (