Implement in-memory repositories, XML load validation, and menu exit/list commands

- Add generic Repository<T> interface; EventRepository/UserRepository extend it
- Implement InMemoryEventRepository/InMemoryUserRepository backed by ArrayList
- Rename XMLLoader to XMLLoaderV1, add LoadValidator and mapper/v2 package
- Add OrderBookTradingMechanism
- Add User(String, int) convenience constructor
- Add ListEventsMenuCommand and ExitMenuCommand, isExit() on MenuCommand
- Menu now sizes selection range by max command index and exits on isExit()
- LoadFileMenuCommand reports validation issues on failed loads
- Untrack test-data/ and config.properties from .gitignore

21 files changed, 359 insertions, 61 deletions

diff --git a/.gitignore b/.gitignore
index 8e3b8c9..7a9d622 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,12 +2,9 @@
 bin/
 stage/
 dist/
-test-data/
 *.class
 
 # Ignore OS-specific files
 .DS_Store
 Thumbs.db
 
-config.properties
-
diff --git a/service/src/main/java/market/guess/service/LocalGuessMarketContext.java b/service/src/main/java/market/guess/service/LocalGuessMarketContext.java
index 16ee1b8..19c7297 100644
--- a/service/src/main/java/market/guess/service/LocalGuessMarketContext.java
+++ b/service/src/main/java/market/guess/service/LocalGuessMarketContext.java
@@ -41,7 +41,7 @@ public final class LocalGuessMarketContext implements GuessMarketContext {
 
   @Override
   public List<EventSummaryDTO> listEvents() {
-    return eventRepository.getAllEvents().stream().map(Event::toEventSummary).toList();
+    return eventRepository.getAll().stream().map(Event::toEventSummary).toList();
   }
 
   @Override
@@ -58,9 +58,14 @@ public final class LocalGuessMarketContext implements GuessMarketContext {
   public PurchaseReceiptDTO buyShares(
       String userName, String eventKey, String optionKey, int quantity)
       throws GuessMarketException {
-    var event = eventRepository.getEvent(eventKey);
+    var optional = eventRepository.get(eventKey);
+
+    var userOptional = userRepository.get(userName);
+    if (optional.isEmpty() || userOptional.isEmpty()) throw new GuessMarketException();
+
+    var event = optional.get();
+    var user = userOptional.get();
     var option = event.getOption(optionKey);
-    var user = userRepository.getUser(userName);
     var trade = tradingOperation.buy(event, user, option, quantity);
     return new PurchaseReceiptDTO();
   }
diff --git a/service/src/main/java/market/guess/service/domain/Trade.java b/service/src/main/java/market/guess/service/domain/Trade.java
index cb6ed93..0c07749 100644
--- a/service/src/main/java/market/guess/service/domain/Trade.java
+++ b/service/src/main/java/market/guess/service/domain/Trade.java
@@ -4,12 +4,12 @@ import java.math.BigDecimal;
 import java.time.Instant;
 
 public record Trade(
-    long seq,
+    int id,
     Instant at,
     String userName,
     String optionKey,
     String optionName,
-    long quantity,
+    int uantity,
     BigDecimal sharesCost,
     BigDecimal commission) {
 
diff --git a/service/src/main/java/market/guess/service/domain/User.java b/service/src/main/java/market/guess/service/domain/User.java
index af9ac78..b2084b4 100644
--- a/service/src/main/java/market/guess/service/domain/User.java
+++ b/service/src/main/java/market/guess/service/domain/User.java
@@ -6,6 +6,10 @@ public final class User {
   private final String name;
   private final Account account;
 
+  public User(String name, int initialBalance) {
+    this(name, BigDecimalOptions.toMoney(initialBalance));
+  }
+
   public User(String name, BigDecimal initialBalance) {
     this.name = name;
     this.account = new Account(name, initialBalance);
diff --git a/service/src/main/java/market/guess/service/infrastructure/adapter/InstantTypeAdapter.java b/service/src/main/java/market/guess/service/infrastructure/adapter/InstantTypeAdapter.java
index 0e8a0e0..bc5ddb0 100644
--- a/service/src/main/java/market/guess/service/infrastructure/adapter/InstantTypeAdapter.java
+++ b/service/src/main/java/market/guess/service/infrastructure/adapter/InstantTypeAdapter.java
@@ -4,7 +4,8 @@ import com.google.gson.*;
 import java.lang.reflect.Type;
 import java.time.Instant;
 
-public class InstantTypeAdapter implements JsonSerializer<Instant>, JsonDeserializer<Instant> {
+public final class InstantTypeAdapter
+    implements JsonSerializer<Instant>, JsonDeserializer<Instant> {
   @Override
   public JsonElement serialize(Instant src, Type typeOfSrc, JsonSerializationContext context) {
     return new JsonPrimitive(src.toString());
diff --git a/service/src/main/java/market/guess/service/infrastructure/mapper/v2/EventMapperV2.java b/service/src/main/java/market/guess/service/infrastructure/mapper/v2/EventMapperV2.java
new file mode 100644
index 0000000..687ec33
--- /dev/null
+++ b/service/src/main/java/market/guess/service/infrastructure/mapper/v2/EventMapperV2.java
@@ -0,0 +1,66 @@
+package market.guess.service.infrastructure.mapper.v2;
+
+import java.util.ArrayList;
+import java.util.List;
+import market.guess.api.CommissionTiming;
+import market.guess.api.EventStatus;
+import market.guess.service.domain.Event;
+import market.guess.service.domain.Option;
+import market.guess.service.infrastructure.mapper.Mapper;
+import market.guess.service.mechanism.LmsrTradingMechanism;
+import market.guess.service.mechanism.OrderBookTradingMechanism;
+import market.guess.service.mechanism.TradingMechanism;
+import market.guess.service.model.v2.GMEvent;
+import market.guess.service.model.v2.GMLMSR;
+import market.guess.service.model.v2.GMOrderBook;
+
+public final class EventMapperV2 implements Mapper<GMEvent, Event> {
+
+  @Override
+  public Event toDomain(GMEvent source) {
+    return new Event(
+        getEventKey(source),
+        source.getId(),
+        source.getName(),
+        source.getDescription(),
+        source.getCommission().getValue(),
+        getTiming(source.getCommission().getType()),
+        getMechanism(source),
+        EventStatus.NOT_STARTED,
+        getOptions(source),
+        "");
+  }
+
+  private static String getEventKey(GMEvent event) {
+    return String.valueOf(event.getId());
+  }
+
+  private static CommissionTiming getTiming(String type) throws IllegalArgumentException {
+    return switch (type) {
+      case "on-close" -> CommissionTiming.ON_CLOSE;
+      case "on-purchase" -> CommissionTiming.ON_PURCHASE;
+      default -> throw new IllegalArgumentException("Unknown commission type: " + type);
+    };
+  }
+
+  private static TradingMechanism getMechanism(GMEvent source) {
+    if (source.getGMMethod().getGMLMSR() instanceof GMLMSR lmsr) {
+      return new LmsrTradingMechanism(lmsr.getB());
+    }
+    if (source.getGMMethod().getGMOrderBook() instanceof GMOrderBook orderBook) {
+      return new OrderBookTradingMechanism(
+          orderBook.getAllowMint().equalsIgnoreCase("true"),
+          orderBook.getInitial(),
+          orderBook.getD());
+    }
+    throw new IllegalArgumentException();
+  }
+
+  private static List<Option> getOptions(GMEvent x) {
+    var ret = new ArrayList<Option>(x.getGMOptions().getGMOption().size());
+    for (var i = 0; i < x.getGMOptions().getGMOption().size(); i++) {
+      ret.add(new Option(getEventKey(x) + ":" + i, x.getGMOptions().getGMOption().get(i)));
+    }
+    return ret;
+  }
+}
diff --git a/service/src/main/java/market/guess/service/infrastructure/provider/LoadValidator.java b/service/src/main/java/market/guess/service/infrastructure/provider/LoadValidator.java
new file mode 100644
index 0000000..c1c3895
--- /dev/null
+++ b/service/src/main/java/market/guess/service/infrastructure/provider/LoadValidator.java
@@ -0,0 +1,22 @@
+package market.guess.service.infrastructure.provider;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import market.guess.api.ProblemDTO;
+
+public final class LoadValidator {
+  private final List<ProblemDTO> problems = new ArrayList<>();
+
+  public void append(String code, String humanizedMessage, String location) {
+    problems.add(new ProblemDTO(code, humanizedMessage, location));
+  }
+
+  public boolean isValid() {
+    return problems.isEmpty();
+  }
+
+  public List<ProblemDTO> getIssues() {
+    return Collections.unmodifiableList(problems);
+  }
+}
diff --git a/service/src/main/java/market/guess/service/infrastructure/provider/v1/XMLLoader.java b/service/src/main/java/market/guess/service/infrastructure/provider/v1/XMLLoaderV1.java
index 9333350..7af22ea 100644
--- a/service/src/main/java/market/guess/service/infrastructure/provider/v1/XMLLoader.java
+++ b/service/src/main/java/market/guess/service/infrastructure/provider/v1/XMLLoaderV1.java
@@ -4,28 +4,24 @@ import jakarta.xml.bind.JAXBContext;
 import jakarta.xml.bind.JAXBException;
 import java.nio.file.Files;
 import java.nio.file.Path;
-import java.util.List;
 import market.guess.api.LoadResultDTO;
-import market.guess.service.domain.BigDecimalOptions;
-import market.guess.service.domain.Event;
-import market.guess.service.infrastructure.mapper.Mapper;
+import market.guess.service.domain.User;
+import market.guess.service.infrastructure.mapper.v1.EventMapperV1;
+import market.guess.service.infrastructure.provider.LoadValidator;
 import market.guess.service.infrastructure.provider.Loader;
-import market.guess.service.model.v1.GMEvent;
 import market.guess.service.model.v1.GuessMarket;
 import market.guess.service.repository.EventRepository;
 import market.guess.service.repository.UserRepository;
 
-public final class XMLLoader implements Loader {
+public final class XMLLoaderV1 implements Loader {
   private final JAXBContext context;
 
   private final EventRepository eventRepository;
   private final UserRepository userRepository;
-  private final Mapper<GMEvent, Event> mapper;
+  private final EventMapperV1 mapper;
 
-  public XMLLoader(
-      EventRepository eventRepository,
-      UserRepository userRepository,
-      Mapper<GMEvent, Event> mapper) {
+  public XMLLoaderV1(
+      EventRepository eventRepository, UserRepository userRepository, EventMapperV1 mapper) {
     super();
     this.eventRepository = eventRepository;
     this.userRepository = userRepository;
@@ -39,22 +35,27 @@ public final class XMLLoader implements Loader {
 
   @Override
   public LoadResultDTO load(Path path) {
+    var validator = new LoadValidator();
+    if (path.getFileName() == null
+        || !path.getFileName().toString().toLowerCase().endsWith(".xml")) {
+      validator.append("NOT_XML", "The file must be an XML.", path.toString());
+    }
 
     try (var stream = Files.newInputStream(path)) {
 
       var doc = (GuessMarket) context.createUnmarshaller().unmarshal(stream);
 
       for (var event : doc.getGMEvents().getGMEvent()) {
-        eventRepository.addEvent(mapper.toDomain(event));
+        eventRepository.add(mapper.toDomain(event));
       }
 
-      userRepository.addUser("Tester", BigDecimalOptions.toMoney(9_999_999));
+      userRepository.add(new User("Tester", 9_999_999));
 
-      return LoadResultDTO.success("udk", 1);
+      return LoadResultDTO.success(path.toString(), eventRepository.getAll().size());
     } catch (Exception e) {
-
+      validator.append("UNREADABLE", "The file could not be read.", path.toString());
     }
 
-    return LoadResultDTO.failure(path.toFile().getName(), List.of());
+    return LoadResultDTO.failure(path.toString(), validator.getIssues());
   }
 }
diff --git a/service/src/main/java/market/guess/service/mechanism/OrderBookTradingMechanism.java b/service/src/main/java/market/guess/service/mechanism/OrderBookTradingMechanism.java
new file mode 100644
index 0000000..62feb02
--- /dev/null
+++ b/service/src/main/java/market/guess/service/mechanism/OrderBookTradingMechanism.java
@@ -0,0 +1,40 @@
+package market.guess.service.mechanism;
+
+import java.math.BigDecimal;
+import market.guess.api.MechanismType;
+
+public final class OrderBookTradingMechanism implements TradingMechanism {
+  private final boolean allowMint;
+  private final int initial;
+  private final int d;
+
+  public OrderBookTradingMechanism(boolean allowMint, int initial, int d) {
+    super();
+    this.allowMint = allowMint;
+    this.initial = initial;
+    this.d = d;
+  }
+
+  @Override
+  public MechanismType type() {
+    return MechanismType.ORDER_BOOK;
+  }
+
+  @Override
+  public BigDecimal openingCost(int optionCount) {
+    // TODO Auto-generated method stub
+    throw new UnsupportedOperationException("Unimplemented method 'openingCost'");
+  }
+
+  @Override
+  public BigDecimal costOfBuying(long[] q, int optionIndex, long quantity) {
+    // TODO Auto-generated method stub
+    throw new UnsupportedOperationException("Unimplemented method 'costOfBuying'");
+  }
+
+  @Override
+  public double[] prices(long[] q) {
+    // TODO Auto-generated method stub
+    throw new UnsupportedOperationException("Unimplemented method 'prices'");
+  }
+}
diff --git a/service/src/main/java/market/guess/service/repository/EventRepository.java b/service/src/main/java/market/guess/service/repository/EventRepository.java
index 94999cb..afc5371 100644
--- a/service/src/main/java/market/guess/service/repository/EventRepository.java
+++ b/service/src/main/java/market/guess/service/repository/EventRepository.java
@@ -1,12 +1,5 @@
 package market.guess.service.repository;
 
-import java.util.List;
 import market.guess.service.domain.Event;
 
-public interface EventRepository {
-  Event getEvent(String id);
-
-  List<Event> getAllEvents();
-
-  void addEvent(Event event);
-}
+public interface EventRepository extends Repository<Event> {}
diff --git a/service/src/main/java/market/guess/service/repository/InMemoryEventRepository.java b/service/src/main/java/market/guess/service/repository/InMemoryEventRepository.java
index 81eba74..eb7763e 100644
--- a/service/src/main/java/market/guess/service/repository/InMemoryEventRepository.java
+++ b/service/src/main/java/market/guess/service/repository/InMemoryEventRepository.java
@@ -1,25 +1,27 @@
 package market.guess.service.repository;
 
+import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
+import java.util.Optional;
 import market.guess.service.domain.Event;
 
 public final class InMemoryEventRepository implements EventRepository {
+  private final List<Event> events = new ArrayList<>();
 
   @Override
-  public Event getEvent(String id) {
-    // TODO Auto-generated method stub
-    throw new UnsupportedOperationException("Unimplemented method 'getEvent'");
+  public Event add(Event element) {
+    events.add(element);
+    return element;
   }
 
   @Override
-  public List<Event> getAllEvents() {
-    // TODO Auto-generated method stub
-    throw new UnsupportedOperationException("Unimplemented method 'getAllEvents'");
+  public Optional<Event> get(String id) {
+    return events.stream().filter(event -> event.getEventKey().equalsIgnoreCase(id)).findFirst();
   }
 
   @Override
-  public void addEvent(Event event) {
-    // TODO Auto-generated method stub
-    throw new UnsupportedOperationException("Unimplemented method 'addEvent'");
+  public List<Event> getAll() {
+    return Collections.unmodifiableList(events);
   }
 }
diff --git a/service/src/main/java/market/guess/service/repository/InMemoryUserRepository.java b/service/src/main/java/market/guess/service/repository/InMemoryUserRepository.java
index 951dea8..0b5cfe7 100644
--- a/service/src/main/java/market/guess/service/repository/InMemoryUserRepository.java
+++ b/service/src/main/java/market/guess/service/repository/InMemoryUserRepository.java
@@ -1,19 +1,27 @@
 package market.guess.service.repository;
 
-import java.math.BigDecimal;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.Optional;
 import market.guess.service.domain.User;
 
 public final class InMemoryUserRepository implements UserRepository {
+  private final List<User> users = new ArrayList<>();
 
   @Override
-  public User getUser(String name) {
-    // TODO Auto-generated method stub
-    throw new UnsupportedOperationException("Unimplemented method 'getUser'");
+  public User add(User element) {
+    users.add(element);
+    return element;
   }
 
   @Override
-  public void addUser(String name, BigDecimal initialBalance) {
-    // TODO Auto-generated method stub
-    throw new UnsupportedOperationException("Unimplemented method 'addUser'");
+  public Optional<User> get(String id) {
+    return users.stream().filter(u -> u.getName().equalsIgnoreCase(id)).findFirst();
+  }
+
+  @Override
+  public List<User> getAll() {
+    return Collections.unmodifiableList(users);
   }
 }
diff --git a/service/src/main/java/market/guess/service/repository/Repository.java b/service/src/main/java/market/guess/service/repository/Repository.java
new file mode 100644
index 0000000..8ea1817
--- /dev/null
+++ b/service/src/main/java/market/guess/service/repository/Repository.java
@@ -0,0 +1,12 @@
+package market.guess.service.repository;
+
+import java.util.List;
+import java.util.Optional;
+
+public interface Repository<T> {
+  T add(T element);
+
+  Optional<T> get(String id);
+
+  List<T> getAll();
+}
diff --git a/service/src/main/java/market/guess/service/repository/UserRepository.java b/service/src/main/java/market/guess/service/repository/UserRepository.java
index 78d620d..86cc9a6 100644
--- a/service/src/main/java/market/guess/service/repository/UserRepository.java
+++ b/service/src/main/java/market/guess/service/repository/UserRepository.java
@@ -1,11 +1,5 @@
 package market.guess.service.repository;
 
-import java.math.BigDecimal;
 import market.guess.service.domain.User;
 
-public interface UserRepository {
-
-  User getUser(String name);
-
-  void addUser(String name, BigDecimal initialBalance);
-}
+public interface UserRepository extends Repository<User> {}
diff --git a/test-data/ex-1/multiple.xml b/test-data/ex-1/multiple.xml
new file mode 100644
index 0000000..3f2432d
--- /dev/null
+++ b/test-data/ex-1/multiple.xml
@@ -0,0 +1,47 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Guess-Market xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="GM-EX1-schema.xsd">
+        <GM-events>
+                <GM-event name="Mujtaba is Dead">
+                        <id>1</id>
+                        <description>This event gambles if Mujtaba is a live or not. it will be determined if he will be shown in public until 31.8.26</description>
+                        <comision type="on-purchase">5</comision>
+                        <GM-options>
+                                <GM-option>Hell Yea !</GM-option>
+                                <GM-option>No way !</GM-option>
+                        </GM-options>
+                        <GM-method>
+                                <GM-LMSR>
+                                        <b>100</b>
+                                </GM-LMSR>
+                        </GM-method>
+                </GM-event>
+                <GM-event name="World Cap Winner">
+                        <id>2</id>
+                        <description>Who do you think will win the world cap ?</description>
+                        <comision type="on-close">15</comision>
+                        <GM-options>
+                                <GM-option>Argentina</GM-option>
+                                <GM-option>Spain</GM-option>
+                        </GM-options>
+                        <GM-method>
+                                <GM-LMSR>
+                                        <b>50</b>
+                                </GM-LMSR>
+                        </GM-method>
+                </GM-event>
+                <GM-event name="Earth Quake on Dead Sea">
+                        <id>3</id>
+                        <description>Will there be an earth quake on the dead sea until the December 31th 2026</description>
+                        <comision type="on-purchase">50</comision>
+                        <GM-options>
+                                <GM-option>Yes</GM-option>
+                                <GM-option>No</GM-option>
+                        </GM-options>
+                        <GM-method>
+                                <GM-LMSR>
+                                        <b>400</b>
+                                </GM-LMSR>
+                        </GM-method>
+                </GM-event>
+        </GM-events>
+</Guess-Market>
diff --git a/ui-console/src/main/java/market/guess/ui/console/App.java b/ui-console/src/main/java/market/guess/ui/console/App.java
index 2bff741..34638ac 100644
--- a/ui-console/src/main/java/market/guess/ui/console/App.java
+++ b/ui-console/src/main/java/market/guess/ui/console/App.java
@@ -4,12 +4,15 @@ import market.guess.api.GuessMarketContext;
 import market.guess.service.LocalGuessMarketContext;
 import market.guess.service.TradingOperation;
 import market.guess.service.TradingOperationImpl;
+import market.guess.service.infrastructure.mapper.v1.EventMapperV1;
 import market.guess.service.infrastructure.provider.Loader;
-import market.guess.service.infrastructure.provider.v1.XMLLoader;
+import market.guess.service.infrastructure.provider.v1.XMLLoaderV1;
 import market.guess.service.repository.EventRepository;
 import market.guess.service.repository.InMemoryEventRepository;
 import market.guess.service.repository.InMemoryUserRepository;
 import market.guess.service.repository.UserRepository;
+import market.guess.ui.console.command.ExitMenuCommand;
+import market.guess.ui.console.command.ListEventsMenuCommand;
 import market.guess.ui.console.command.LoadFileMenuCommand;
 import market.guess.ui.console.io.ConsoleInputProvider;
 import market.guess.ui.console.io.ConsoleOutputProvider;
@@ -27,10 +30,13 @@ public class App {
     pico.addComponent(UserRepository.class, InMemoryUserRepository.class);
 
     pico.addComponent(TradingOperation.class, TradingOperationImpl.class);
-    pico.addComponent(Loader.class, XMLLoader.class);
+    pico.addComponent(EventMapperV1.class);
+    pico.addComponent(Loader.class, XMLLoaderV1.class);
     pico.addComponent(GuessMarketContext.class, LocalGuessMarketContext.class);
 
     pico.addComponent(LoadFileMenuCommand.class);
+    pico.addComponent(ListEventsMenuCommand.class);
+    pico.addComponent(ExitMenuCommand.class);
 
     pico.addComponent(InputProvider.class, ConsoleInputProvider.class);
     pico.addComponent(OutputProvider.class, ConsoleOutputProvider.class);
diff --git a/ui-console/src/main/java/market/guess/ui/console/Menu.java b/ui-console/src/main/java/market/guess/ui/console/Menu.java
index 0521e5f..c1762dc 100644
--- a/ui-console/src/main/java/market/guess/ui/console/Menu.java
+++ b/ui-console/src/main/java/market/guess/ui/console/Menu.java
@@ -19,12 +19,12 @@ public final class Menu implements Startable {
 
   @Override
   public void start() {
+    var max = commands.stream().mapToInt(MenuCommand::getIndex).max().orElse(0);
     out.splashScreen();
-
     while (true) {
       printMenu();
 
-      var selection = in.readInt("Choose a command: ", 1, commands.size());
+      var selection = in.readInt("Choose a command: ", 1, max);
       var commandOptional = commands.stream().filter(c -> c.getIndex() == selection).findFirst();
 
       if (commandOptional.isEmpty()) {
@@ -34,6 +34,8 @@ public final class Menu implements Startable {
       var command = commandOptional.get();
 
       command.execute();
+
+      if (command.isExit()) return;
     }
   }
 
@@ -45,7 +47,7 @@ public final class Menu implements Startable {
   private void printMenu() {
     out.newLine();
     for (var command : commands) {
-      out.println("    %d -- %s".formatted(command.getIndex(), command.getName()));
+      out.println("    [%d]->> %s".formatted(command.getIndex(), command.getName()));
     }
   }
 }
diff --git a/ui-console/src/main/java/market/guess/ui/console/command/ExitMenuCommand.java b/ui-console/src/main/java/market/guess/ui/console/command/ExitMenuCommand.java
new file mode 100644
index 0000000..372c686
--- /dev/null
+++ b/ui-console/src/main/java/market/guess/ui/console/command/ExitMenuCommand.java
@@ -0,0 +1,37 @@
+package market.guess.ui.console.command;
+
+import market.guess.ui.console.io.OutputProvider;
+
+public final class ExitMenuCommand implements MenuCommand {
+  private final OutputProvider out;
+
+  public ExitMenuCommand(OutputProvider out) {
+    super();
+    this.out = out;
+  }
+
+  @Override
+  public int getIndex() {
+    return 6;
+  }
+
+  @Override
+  public String getName() {
+    return "Exit";
+  }
+
+  @Override
+  public boolean allowed() {
+    return true;
+  }
+
+  @Override
+  public boolean isExit() {
+    return true;
+  }
+
+  @Override
+  public void execute() {
+    out.println("Goodbye.");
+  }
+}
diff --git a/ui-console/src/main/java/market/guess/ui/console/command/ListEventsMenuCommand.java b/ui-console/src/main/java/market/guess/ui/console/command/ListEventsMenuCommand.java
new file mode 100644
index 0000000..6e6ace9
--- /dev/null
+++ b/ui-console/src/main/java/market/guess/ui/console/command/ListEventsMenuCommand.java
@@ -0,0 +1,51 @@
+package market.guess.ui.console.command;
+
+import market.guess.api.CommissionTiming;
+import market.guess.api.GuessMarketContext;
+import market.guess.ui.console.io.OutputProvider;
+
+public final class ListEventsMenuCommand implements MenuCommand {
+  private final GuessMarketContext context;
+  private final OutputProvider out;
+
+  public ListEventsMenuCommand(GuessMarketContext context, OutputProvider out) {
+    super();
+    this.context = context;
+    this.out = out;
+  }
+
+  @Override
+  public int getIndex() {
+    return 2;
+  }
+
+  @Override
+  public String getName() {
+    return "List events";
+  }
+
+  @Override
+  public boolean allowed() {
+    return !context.listEvents().isEmpty();
+  }
+
+  @Override
+  public void execute() {
+    var events = context.listEvents();
+
+    for (var event : events) {
+      out.newLine();
+      out.println("    %s".formatted(event.name()));
+      out.println("        %s".formatted(event.description()));
+      out.println(
+          "        Commission: %d%% (%s)"
+              .formatted(event.commissionPercent(), timing(event.commissionTiming())));
+      out.println("        Options:    " + String.join(" | ", event.optionNames()));
+      out.println("        Status:     " + event.status());
+    }
+  }
+
+  private static String timing(CommissionTiming timing) {
+    return timing == CommissionTiming.ON_CLOSE ? "charged on close" : "charged on purchase";
+  }
+}
diff --git a/ui-console/src/main/java/market/guess/ui/console/command/LoadFileMenuCommand.java b/ui-console/src/main/java/market/guess/ui/console/command/LoadFileMenuCommand.java
index 5a91fe0..4a56483 100644
--- a/ui-console/src/main/java/market/guess/ui/console/command/LoadFileMenuCommand.java
+++ b/ui-console/src/main/java/market/guess/ui/console/command/LoadFileMenuCommand.java
@@ -40,5 +40,11 @@ public final class LoadFileMenuCommand implements MenuCommand {
       out.println("Loaded %d event(s) from %s.".formatted(result.eventsLoaded(), result.source()));
       return;
     }
+
+    out.println(
+        "The file was not loaded. %d problem(s) were found: ".formatted(result.issues().size()));
+    for (var issue : result.issues()) {
+      out.println("    - %s: %s".formatted(issue.location(), issue.humanizedMessage()));
+    }
   }
 }
diff --git a/ui-console/src/main/java/market/guess/ui/console/command/MenuCommand.java b/ui-console/src/main/java/market/guess/ui/console/command/MenuCommand.java
index 8a28dfe..50acdac 100644
--- a/ui-console/src/main/java/market/guess/ui/console/command/MenuCommand.java
+++ b/ui-console/src/main/java/market/guess/ui/console/command/MenuCommand.java
@@ -8,4 +8,8 @@ public interface MenuCommand {
   boolean allowed();
 
   void execute();
+
+  default boolean isExit() {
+    return false;
+  }
 }