finish up group service?

src/main/java/mops/gruppen2/controller/GroupCreationController.java

@@ -3,6 +3,7 @@ package mops.gruppen2.controller;
 import mops.gruppen2.domain.Account;
 import mops.gruppen2.domain.Group;
 import mops.gruppen2.domain.GroupType;
+import mops.gruppen2.domain.User;
 import mops.gruppen2.service.ControllerService;
 import mops.gruppen2.service.CsvService;
 import mops.gruppen2.service.GroupService;
@@ -74,8 +75,9 @@ public class GroupCreationController {
         validationService.checkFields(description, title, userLimit, isInfinite);
 
         Account account = new Account(token);
+        User user = new User(account);
         UUID parentUUID = IdService.stringToUUID(parent);
-        Group group = groupService.createGroup(account,
+        Group group = groupService.createGroup(user,
                                                title,
                                                description,
                                                getVisibility(isPrivate),
@@ -83,7 +85,7 @@ public class GroupCreationController {
                                                getUserLimit(isInfinite, userLimit),
                                                parentUUID);
 
-        groupService.addUsersToGroup(CsvService.readCsvFile(file), group, account);
+        groupService.addUsersToGroup(CsvService.readCsvFile(file), group, user);
 
         return "redirect:/gruppen2/details/" + uuidToString(group.getId());
     }
@@ -113,8 +115,9 @@ public class GroupCreationController {
         validationService.checkFields(description, title, userLimit, isInfinite);
 
         Account account = new Account(token);
+        User user = new User(account);
         UUID parentUUID = IdService.stringToUUID(parent);
-        Group group = groupService.createGroup(account,
+        Group group = groupService.createGroup(user,
                                                title,
                                                description,
                                                getVisibility(isPrivate),

src/main/java/mops/gruppen2/controller/GroupDetailsController.java

@@ -80,7 +80,7 @@ public class GroupDetailsController {
         model.addAttribute("private", Visibility.PRIVATE);
 
         if (validationService.checkIfAdmin(group, user)) {
-            model.addAttribute("link", serverURL + "gruppen2/acceptinvite/" + inviteService.getLinkByGroupId(group.getId()));
+            model.addAttribute("link", serverURL + "gruppen2/acceptinvite/" + inviteService.getLinkByGroup(group.getId()));
         }
 
         return "detailsMember";
@@ -124,8 +124,8 @@ public class GroupDetailsController {
         validationService.throwIfNoAdmin(group, user);
         validationService.checkFields(title, description);
 
-        groupService.updateTitle(account, IdService.stringToUUID(groupId), title);
+        groupService.updateTitle(user, group, title);
-        groupService.updateDescription(account, IdService.stringToUUID(groupId), description);
+        groupService.updateDescription(user, group, description);
 
         return "redirect:/gruppen2/details/" + groupId;
     }
@@ -160,13 +160,10 @@ public class GroupDetailsController {
         Account account = new Account(token);
         Group group = projectionService.projectSingleGroup(UUID.fromString(groupId));
         User principle = new User(account);
-        User user = new User(userId, "", "", "");
+        User user = new User(userId);
 
         validationService.throwIfNoAdmin(group, principle);
-
+        groupService.toggleMemberRole(user, group);
-        //TODO: checkIfAdmin checkt nicht, dass die rolle geändert wurde. oder die rolle wird nicht geändert
-
-        groupService.changeRole(account, user, group);
 
         if (!validationService.checkIfAdmin(group, principle)) {
             return "redirect:/gruppen2/details/" + groupId;
@@ -183,11 +180,12 @@ public class GroupDetailsController {
                                 @RequestParam("group_id") String groupId) {
 
         Account account = new Account(token);
+        User user = new User(account);
         Group group = projectionService.projectSingleGroup(UUID.fromString(groupId));
 
         validationService.throwIfNewUserLimitIsValid(userLimit, group);
 
-        groupService.updateUserLimit(account, group, userLimit);
+        groupService.updateUserLimit(user, group, userLimit);
 
         return "redirect:/gruppen2/details/members/" + groupId;
     }
@@ -206,7 +204,7 @@ public class GroupDetailsController {
 
         validationService.throwIfNoAdmin(group, principle);
 
-        groupService.deleteUser(account, user, group);
+        groupService.deleteUser(user, group);
 
         if (!validationService.checkIfUserInGroup(group, principle)) {
             return "redirect:/gruppen2";
@@ -229,7 +227,7 @@ public class GroupDetailsController {
         validationService.throwIfUserAlreadyInGroup(group, user);
         validationService.throwIfGroupFull(group);
 
-        groupService.addUser(account, UUID.fromString(groupId));
+        groupService.addUser(user, group);
 
         model.addAttribute("account", account);
 
@@ -246,7 +244,7 @@ public class GroupDetailsController {
         User user = new User(account);
         Group group = projectionService.projectSingleGroup(UUID.fromString(groupId));
 
-        groupService.deleteUser(account, user, group);
+        groupService.deleteUser(user, group);
 
         return "redirect:/gruppen2";
     }
@@ -263,7 +261,7 @@ public class GroupDetailsController {
 
         validationService.throwIfNoAdmin(group, user);
 
-        groupService.deleteGroup(user.getId(), UUID.fromString(groupId));
+        groupService.deleteGroup(user, group);
 
         return "redirect:/gruppen2";
     }
@@ -276,9 +274,10 @@ public class GroupDetailsController {
                                   @RequestParam(value = "file", required = false) MultipartFile file) {
 
         Account account = new Account(token);
+        User user = new User(account);
         Group group = projectionService.projectSingleGroup(IdService.stringToUUID(groupId));
 
-        groupService.addUsersToGroup(CsvService.readCsvFile(file), group, account);
+        groupService.addUsersToGroup(CsvService.readCsvFile(file), group, user);
 
         return "redirect:/gruppen2/details/members/" + groupId;
     }

src/main/java/mops/gruppen2/controller/SearchAndInviteController.java

@@ -115,7 +115,7 @@ public class SearchAndInviteController {
         validationService.throwIfUserAlreadyInGroup(group, user);
         validationService.throwIfGroupFull(group);
 
-        groupService.addUser(account, UUID.fromString(groupId));
+        groupService.addUser(user, group);
 
         return "redirect:/gruppen2/details/" + groupId;
     }

src/main/java/mops/gruppen2/domain/Role.java

@@ -2,5 +2,9 @@ package mops.gruppen2.domain;
 
 public enum Role {
     ADMIN,
-    MEMBER
+    MEMBER;
+
+    public Role toggle() {
+        return this == ADMIN ? MEMBER : ADMIN;
+    }
 }

src/main/java/mops/gruppen2/domain/event/AddUserEvent.java

@@ -36,6 +36,13 @@ public class AddUserEvent extends Event {
         email = user.getEmail();
     }
 
+    public AddUserEvent(Group group, User user) {
+        super(group.getId(), user.getId());
+        givenname = user.getGivenname();
+        familyname = user.getFamilyname();
+        email = user.getEmail();
+    }
+
     @Override
     protected void applyEvent(Group group) throws EventException {
         User user = new User(userId, givenname, familyname, email);

src/main/java/mops/gruppen2/domain/event/DeleteGroupEvent.java

@@ -3,6 +3,7 @@ package mops.gruppen2.domain.event;
 import lombok.Getter;
 import lombok.NoArgsConstructor;
 import mops.gruppen2.domain.Group;
+import mops.gruppen2.domain.User;
 
 import java.util.UUID;
 
@@ -14,6 +15,10 @@ public class DeleteGroupEvent extends Event {
         super(groupId, userId);
     }
 
+    public DeleteGroupEvent(Group group, User user) {
+        super(group.getId(), user.getId());
+    }
+
     @Override
     protected void applyEvent(Group group) {
         group.getRoles().clear();

src/main/java/mops/gruppen2/domain/event/DeleteUserEvent.java

@@ -20,15 +20,19 @@ public class DeleteUserEvent extends Event {
         super(groupId, userId);
     }
 
+    public DeleteUserEvent(Group group, User user) {
+        super(group.getId(), user.getId());
+    }
+
     @Override
     protected void applyEvent(Group group) throws EventException {
         for (User user : group.getMembers()) {
-            if (user.getId().equals(this.userId)) {
+            if (user.getId().equals(userId)) {
                 group.getMembers().remove(user);
                 group.getRoles().remove(user.getId());
                 return;
             }
         }
-        throw new UserNotFoundException(this.getClass().toString());
+        throw new UserNotFoundException(getClass().toString());
     }
 }

src/main/java/mops/gruppen2/domain/event/UpdateGroupDescriptionEvent.java

@@ -3,6 +3,7 @@ package mops.gruppen2.domain.event;
 import lombok.Getter;
 import lombok.NoArgsConstructor;
 import mops.gruppen2.domain.Group;
+import mops.gruppen2.domain.User;
 import mops.gruppen2.domain.exception.BadParameterException;
 
 import java.util.UUID;
@@ -21,6 +22,11 @@ public class UpdateGroupDescriptionEvent extends Event {
         this.newGroupDescription = newGroupDescription.trim();
     }
 
+    public UpdateGroupDescriptionEvent(Group group, User user, String newGroupDescription) {
+        super(group.getId(), user.getId());
+        this.newGroupDescription = newGroupDescription.trim();
+    }
+
     @Override
     protected void applyEvent(Group group) {
         if (newGroupDescription.isEmpty()) {

src/main/java/mops/gruppen2/domain/event/UpdateGroupTitleEvent.java

@@ -3,6 +3,7 @@ package mops.gruppen2.domain.event;
 import lombok.Getter;
 import lombok.NoArgsConstructor;
 import mops.gruppen2.domain.Group;
+import mops.gruppen2.domain.User;
 import mops.gruppen2.domain.exception.BadParameterException;
 
 import java.util.UUID;
@@ -21,6 +22,11 @@ public class UpdateGroupTitleEvent extends Event {
         this.newGroupTitle = newGroupTitle.trim();
     }
 
+    public UpdateGroupTitleEvent(Group group, User user, String newGroupTitle) {
+        super(group.getId(), user.getId());
+        this.newGroupTitle = newGroupTitle.trim();
+    }
+
     @Override
     protected void applyEvent(Group group) {
         if (newGroupTitle.isEmpty()) {

src/main/java/mops/gruppen2/domain/event/UpdateRoleEvent.java

@@ -4,6 +4,7 @@ import lombok.Getter;
 import lombok.NoArgsConstructor;
 import mops.gruppen2.domain.Group;
 import mops.gruppen2.domain.Role;
+import mops.gruppen2.domain.User;
 import mops.gruppen2.domain.exception.UserNotFoundException;
 
 import java.util.UUID;
@@ -22,6 +23,11 @@ public class UpdateRoleEvent extends Event {
         this.newRole = newRole;
     }
 
+    public UpdateRoleEvent(Group group, User user, Role newRole) {
+        super(group.getId(), user.getId());
+        this.newRole = newRole;
+    }
+
     @Override
     protected void applyEvent(Group group) throws UserNotFoundException {
         if (group.getRoles().containsKey(userId)) {

src/main/java/mops/gruppen2/domain/event/UpdateUserLimitEvent.java

@@ -3,6 +3,7 @@ package mops.gruppen2.domain.event;
 import lombok.Getter;
 import lombok.NoArgsConstructor;
 import mops.gruppen2.domain.Group;
+import mops.gruppen2.domain.User;
 import mops.gruppen2.domain.exception.BadParameterException;
 import mops.gruppen2.domain.exception.EventException;
 
@@ -19,6 +20,11 @@ public class UpdateUserLimitEvent extends Event {
         this.userLimit = userLimit;
     }
 
+    public UpdateUserLimitEvent(Group group, User user, long userLimit) {
+        super(group.getId(), user.getId());
+        this.userLimit = userLimit;
+    }
+
     @Override
     protected void applyEvent(Group group) throws EventException {
         if (userLimit <= 0 || userLimit < group.getMembers().size()) {

src/main/java/mops/gruppen2/service/CsvService.java

@@ -32,8 +32,9 @@ public final class CsvService {
                 return userList.stream()
                                .distinct()
                                .collect(Collectors.toList()); //filter duplicates from list
-            } catch (IOException ex) {
+            } catch (IOException e) {
-                log.error("File konnte nicht gelesen werden:\n{}", ex.getMessage());
+                log.error("File konnte nicht gelesen werden:\n{}", e.getMessage());
+                e.printStackTrace();
                 throw new WrongFileException(file.getOriginalFilename());
             }
         }

src/main/java/mops/gruppen2/service/EventStoreService.java

@@ -38,14 +38,12 @@ public class EventStoreService {
      */
     public void saveEvent(Event event) {
         eventStore.save(getDTOFromEvent(event));
-        log.trace("Ein Event wurde gespeichert!");
     }
 
     public void saveAll(Event... events) {
         for (Event event : events) {
             eventStore.save(getDTOFromEvent(event));
         }
-        log.trace("{} Events wurden gespeichert!", events.length);
     }
 
     /**
@@ -59,7 +57,6 @@ public class EventStoreService {
             for (Event event : eventlist) {
                 eventStore.save(getDTOFromEvent(event));
             }
-            log.trace("{} Events wurden gespeichert!", eventlist.size());
         }
     }
 
@@ -90,6 +87,7 @@ public class EventStoreService {
                                 payload);
         } catch (JsonProcessingException e) {
             log.error("Event ({}) konnte nicht serialisiert werden!", e.getMessage());
+            e.printStackTrace();
             throw new BadPayloadException(EventStoreService.class.toString());
         }
     }
@@ -112,6 +110,7 @@ public class EventStoreService {
             return JsonService.deserializeEvent(dto.getEvent_payload());
         } catch (JsonProcessingException e) {
             log.error("Payload\n {}\n konnte nicht deserialisiert werden!", e.getMessage());
+            e.printStackTrace();
             throw new BadPayloadException(EventStoreService.class.toString());
         }
     }
@@ -213,6 +212,7 @@ public class EventStoreService {
             return eventStore.findMaxEventId();
         } catch (NullPointerException e) {
             log.trace("Eine maxId von 0 wurde zurückgegeben, da keine Events vorhanden sind.");
+            e.printStackTrace();
             return 0;
         }
     }

src/main/java/mops/gruppen2/service/GroupService.java

@@ -1,7 +1,6 @@
 package mops.gruppen2.service;
 
 import lombok.extern.log4j.Log4j2;
-import mops.gruppen2.domain.Account;
 import mops.gruppen2.domain.Group;
 import mops.gruppen2.domain.GroupType;
 import mops.gruppen2.domain.Role;
@@ -24,8 +23,6 @@ import java.util.List;
 import java.util.UUID;
 import java.util.stream.Collectors;
 
-import static mops.gruppen2.domain.Role.ADMIN;
-
 /**
  * Behandelt Aufgaben, welche sich auf eine Gruppe beziehen.
  * Es werden übergebene Gruppen bearbeitet und dementsprechend Events erzeugt und gespeichert.
@@ -38,13 +35,11 @@ public class GroupService {
     private final EventStoreService eventStoreService;
     private final ValidationService validationService;
     private final InviteService inviteService;
-    private final ProjectionService projectionService;
 
-    public GroupService(EventStoreService eventStoreService, ValidationService validationService, InviteService inviteService, ProjectionService projectionService) {
+    public GroupService(EventStoreService eventStoreService, ValidationService validationService, InviteService inviteService) {
         this.eventStoreService = eventStoreService;
         this.validationService = validationService;
         this.inviteService = inviteService;
-        this.projectionService = projectionService;
     }
 
 
@@ -56,11 +51,11 @@ public class GroupService {
      * Zudem wird der Gruppentitel und die Gruppenbeschreibung erzeugt, welche vorher der Methode übergeben wurden.
      * Aus diesen Event-Objekten wird eine Liste erzeugt, welche daraufhin mithilfe des EventServices gesichert wird.
      *
-     * @param account     Keycloak-Account
+     * @param user        Keycloak-Account
      * @param title       Gruppentitel
      * @param description Gruppenbeschreibung
      */
-    public Group createGroup(Account account,
+    public Group createGroup(User user,
                              String title,
                              String description,
                              Visibility visibility,
@@ -73,19 +68,21 @@ public class GroupService {
 
         //TODO: etwas auslagern?
         events.add(new CreateGroupEvent(groupId,
-                                        account.getName(),
+                                        user.getId(),
                                         parent,
                                         groupType,
                                         visibility,
                                         userLimit));
-        events.add(new AddUserEvent(groupId, new User(account)));
+        events.add(new AddUserEvent(groupId, user));
-        events.add(new UpdateGroupTitleEvent(groupId, account.getName(), title));
+        events.add(new UpdateGroupTitleEvent(groupId, user.getId(), title));
-        events.add(new UpdateGroupDescriptionEvent(groupId, account.getName(), description));
+        events.add(new UpdateGroupDescriptionEvent(groupId, user.getId(), description));
-        events.add(new UpdateRoleEvent(groupId, account.getName(), ADMIN));
+        events.add(new UpdateRoleEvent(groupId, user.getId(), Role.ADMIN));
 
         inviteService.createLink(groupId);
         eventStoreService.saveAll(events);
 
+        log.trace("Es wurde eine Gruppe erstellt. ({})", visibility);
+
         return ProjectionService.projectSingleGroup(events);
     }
 
@@ -100,84 +97,19 @@ public class GroupService {
      *
      * @param newUsers Userliste
      * @param group    Gruppe
-     * @param account  Ausführender User
+     * @param user     Ausführender User
      */
-    public void addUsersToGroup(List<User> newUsers, Group group, Account account) {
+    public void addUsersToGroup(List<User> newUsers, Group group, User user) {
-        updateUserLimit(account, group, getAdjustedUserLimit(newUsers, group));
+        updateUserLimit(user, group, getAdjustedUserLimit(newUsers, group));
 
         List<Event> events = newUsers.stream()
-                                     .filter(user -> !group.getMembers().contains(user))
+                                     .filter(newUser -> !group.getMembers().contains(newUser))
-                                     .map(user -> new AddUserEvent(group.getId(), user))
+                                     .map(newUser -> new AddUserEvent(group.getId(), newUser))
                                      .collect(Collectors.toList());
 
         eventStoreService.saveAll(events);
     }
 
-    void toggleMemberRole(User user, UUID groupId) throws EventException {
-        UpdateRoleEvent updateRoleEvent;
-        Group group = projectionService.projectSingleGroup(groupId);
-        validationService.throwIfNotInGroup(group, user);
-
-        if (group.getRoles().get(user.getId()) == ADMIN) {
-            updateRoleEvent = new UpdateRoleEvent(group.getId(), user.getId(), Role.MEMBER);
-        } else {
-            updateRoleEvent = new UpdateRoleEvent(group.getId(), user.getId(), ADMIN);
-        }
-
-        eventStoreService.saveEvent(updateRoleEvent);
-    }
-
-    public void deleteUser(Account account, User user, Group group) throws EventException {
-        changeRoleIfLastAdmin(account, group);
-
-        validationService.throwIfNotInGroup(group, user);
-
-        deleteUser(user, group.getId());
-
-        if (validationService.checkIfGroupEmpty(group.getId())) {
-            deleteGroup(user.getId(), group.getId());
-        }
-    }
-
-    private void promoteVeteranMember(Account account, Group group) {
-        if (validationService.checkIfLastAdmin(account, group)) {
-            User newAdmin = getVeteranMember(account, group);
-            toggleMemberRole(newAdmin, group.getId());
-        }
-    }
-
-    public void changeRoleIfLastAdmin(Account account, Group group) {
-        if (group.getMembers().size() <= 1) {
-            return;
-        }
-        promoteVeteranMember(account, group);
-    }
-
-    public void changeRole(Account account, User user, Group group) {
-        if (user.getId().equals(account.getName())) {
-            if (group.getMembers().size() <= 1) {
-                validationService.throwIfLastAdmin(account, group);
-            }
-            promoteVeteranMember(account, group);
-        }
-        toggleMemberRole(user, group.getId());
-    }
-
-
-    // ############################### GRUPEN ANFRAGEN ###########################################
-
-
-    static User getVeteranMember(Account account, Group group) {
-        List<User> members = group.getMembers();
-        String newAdminId;
-        if (members.get(0).getId().equals(account.getName())) {
-            newAdminId = members.get(1).getId();
-        } else {
-            newAdminId = members.get(0).getId();
-        }
-        return new User(newAdminId);
-    }
-
     /**
      * Ermittelt ein passendes Teilnehmermaximum.
      * Reicht das alte Maximum, wird dieses zurückgegeben.
@@ -188,50 +120,74 @@ public class GroupService {
      *
      * @return Das neue Teilnehmermaximum
      */
-    static long getAdjustedUserLimit(List<User> newUsers, Group group) {
+    private static long getAdjustedUserLimit(List<User> newUsers, Group group) {
-        return Math.max(group.getMembers().size() + newUsers.size(),
+        return Math.max(group.getMembers().size() + newUsers.size(), group.getMembers().size());
-                        group.getMembers().size());
+    }
+
+    /**
+     * Wechselt die Rolle eines Teilnehmers von Admin zu Member oder andersherum.
+     *
+     * @param user  Teilnehmer, welcher geändert wird
+     * @param group Gruppe, in welcher sih der Teilnehmer befindet
+     *
+     * @throws EventException Falls der User nicht gefunden wird
+     */
+    public void toggleMemberRole(User user, Group group) throws EventException {
+        validationService.throwIfNotInGroup(group, user);
+
+        Role role = group.getRoles().get(user.getId());
+        Event updateRoleEvent = new UpdateRoleEvent(group, user, role.toggle());
+
+        eventStoreService.saveEvent(updateRoleEvent);
     }
 
 
     // ################################# SINGLE EVENTS ###########################################
 
 
-    public void deleteUser(User user, UUID groupId) {
+    public void addUser(User user, Group group) {
-        DeleteUserEvent event = new DeleteUserEvent(groupId, user.getId());
+        validationService.throwIfUserAlreadyInGroup(group, user);
+
+        AddUserEvent event = new AddUserEvent(group, user);
         eventStoreService.saveEvent(event);
     }
 
-    public void deleteGroup(String userId, UUID groupId) {
+    public void deleteUser(User user, Group group) throws EventException {
-        DeleteGroupEvent event = new DeleteGroupEvent(groupId, userId);
+        validationService.throwIfNotInGroup(group, user);
-        inviteService.destroyLink(groupId);
+        validationService.throwIfLastAdmin(user, group);
+
+        DeleteUserEvent event = new DeleteUserEvent(group, user);
+        eventStoreService.saveEvent(event);
+
+        if (validationService.checkIfGroupEmpty(group)) {
+            deleteGroup(user, group);
+        }
+    }
+
+    public void deleteGroup(User user, Group group) {
+        inviteService.destroyLink(group);
+
+        DeleteGroupEvent event = new DeleteGroupEvent(group, user);
+        eventStoreService.saveEvent(event);
+
+        log.trace("Eine Gruppe wurde gelöscht ({})", group);
+    }
+
+    //TODO: Validate title
+    public void updateTitle(User user, Group group, String title) {
+        UpdateGroupTitleEvent event = new UpdateGroupTitleEvent(group, user, title);
         eventStoreService.saveEvent(event);
     }
 
-    public void updateDescription(Account account, UUID groupId, String description) {
+    //TODO: Validate description
-        UpdateGroupDescriptionEvent event = new UpdateGroupDescriptionEvent(groupId,
+    public void updateDescription(User user, Group group, String description) {
-                                                                            account.getName(),
+        UpdateGroupDescriptionEvent event = new UpdateGroupDescriptionEvent(group, user, description);
-                                                                            description);
         eventStoreService.saveEvent(event);
     }
 
-    public void updateUserLimit(Account account, Group group, long userLimit) {
+    //TODO: Validate limit
-        UpdateUserLimitEvent event = new UpdateUserLimitEvent(group.getId(),
+    public void updateUserLimit(User user, Group group, long userLimit) {
-                                                              account.getName(),
+        UpdateUserLimitEvent event = new UpdateUserLimitEvent(group, user, userLimit);
-                                                              userLimit);
         eventStoreService.saveEvent(event);
     }
-
-    public void addUser(Account account, UUID groupId) {
-        AddUserEvent event = new AddUserEvent(groupId, new User(account));
-        eventStoreService.saveEvent(event);
-    }
-
-    public void updateTitle(Account account, UUID groupId, String title) {
-        UpdateGroupTitleEvent event = new UpdateGroupTitleEvent(groupId,
-                                                                account.getName(),
-                                                                title);
-        eventStoreService.saveEvent(event);
-    }
-
 }

src/main/java/mops/gruppen2/service/InviteService.java

@@ -1,6 +1,7 @@
 package mops.gruppen2.service;
 
 import lombok.extern.log4j.Log4j2;
+import mops.gruppen2.domain.Group;
 import mops.gruppen2.domain.dto.InviteLinkDTO;
 import mops.gruppen2.domain.exception.InvalidInviteException;
 import mops.gruppen2.domain.exception.NoInviteExistException;
@@ -20,27 +21,35 @@ public class InviteService {
     }
 
     void createLink(UUID groupId) {
-        inviteRepository.save(new InviteLinkDTO(null, groupId.toString(), UUID.randomUUID().toString()));
+        inviteRepository.save(new InviteLinkDTO(null,
+                                                groupId.toString(),
+                                                UUID.randomUUID().toString()));
     }
 
     void destroyLink(UUID groupId) {
         inviteRepository.deleteLinkOfGroup(groupId.toString());
     }
 
+    void destroyLink(Group group) {
+        inviteRepository.deleteLinkOfGroup(group.getId().toString());
+    }
+
     public UUID getGroupIdFromLink(String link) {
         try {
             return UUID.fromString(inviteRepository.findGroupIdByLink(link));
         } catch (Exception e) {
             log.error("Gruppe zu Link ({}) konnte nicht gefunden werden!", link);
+            e.printStackTrace();
             throw new InvalidInviteException(link);
         }
     }
 
-    public String getLinkByGroupId(UUID groupId) {
+    public String getLinkByGroup(UUID groupId) {
         try {
             return inviteRepository.findLinkByGroupId(groupId.toString());
         } catch (Exception e) {
             log.error("Link zu Gruppe ({}) konnte nicht gefunden werden!", groupId);
+            e.printStackTrace();
             throw new NoInviteExistException(groupId.toString());
         }
     }

src/main/java/mops/gruppen2/service/ProjectionService.java

@@ -48,7 +48,6 @@ public class ProjectionService {
         Map<UUID, Group> groupMap = new HashMap<>();
 
         events.forEach(event -> event.apply(getOrCreateGroup(groupMap, event.getGroupId())));
-        log.trace("{} Events wurden projiziert!", events.size());
 
         return new ArrayList<>(groupMap.values());
     }
@@ -66,7 +65,6 @@ public class ProjectionService {
         Group group = new Group();
 
         events.forEach(event -> event.apply(group));
-        log.trace("{} Events wurden projiziert!", events.size());
 
         return group;
     }
@@ -175,6 +173,7 @@ public class ProjectionService {
     /**
      * Gibt die Gruppe zurück, die zu der übergebenen Id passt.
      * Enthält alle verfügbaren Informationen, also auch User (langsam).
+     * Gibt eine leere Gruppe zurück, falls die Id leer ist.
      *
      * @param groupId Die Id der gesuchten Gruppe
      *
@@ -183,11 +182,16 @@ public class ProjectionService {
      * @throws GroupNotFoundException Wenn die Gruppe nicht gefunden wird
      */
     public Group projectSingleGroup(UUID groupId) throws GroupNotFoundException {
+        if (IdService.idIsEmpty(groupId)) {
+            return new Group();
+        }
+
         try {
             List<Event> events = eventStoreService.findGroupEvents(groupId);
             return projectGroups(events).get(0);
         } catch (IndexOutOfBoundsException e) {
             log.error("Gruppe {} wurde nicht gefunden!", groupId.toString());
+            e.printStackTrace();
             throw new GroupNotFoundException(ProjectionService.class.toString());
         }
     }

src/main/java/mops/gruppen2/service/ValidationService.java

@@ -41,6 +41,7 @@ public class ValidationService {
         return groups;
     }
 
+    //TODO: what the fuck
     public void throwIfGroupNotExisting(String title) {
         if (title == null) {
             throw new GroupNotFoundException("@details");
@@ -69,10 +70,15 @@ public class ValidationService {
         }
     }
 
+    //TODO: necessary?
     boolean checkIfGroupEmpty(UUID groupId) {
         return projectionService.projectSingleGroup(groupId).getMembers().isEmpty();
     }
 
+    boolean checkIfGroupEmpty(Group group) {
+        return group.getMembers().isEmpty();
+    }
+
     public void throwIfNoAdmin(Group group, User user) {
         throwIfNoAccessToPrivate(group, user);
         if (group.getRoles().get(user.getId()) != ADMIN) {
@@ -93,15 +99,15 @@ public class ValidationService {
         return false;
     }
 
-    void throwIfLastAdmin(Account account, Group group) {
+    void throwIfLastAdmin(User user, Group group) {
-        if (checkIfLastAdmin(account, group)) {
+        if (checkIfLastAdmin(user, group)) {
             throw new NoAdminAfterActionException("Du bist letzter Admin!");
         }
     }
 
-    boolean checkIfLastAdmin(Account account, Group group) {
+    boolean checkIfLastAdmin(User user, Group group) {
         for (Map.Entry<String, Role> entry : group.getRoles().entrySet()) {
-            if (entry.getValue() == ADMIN && !(entry.getKey().equals(account.getName()))) {
+            if (entry.getValue() == ADMIN && !(entry.getKey().equals(user.getId()))) {
                 return false;
             }
         }

src/test/java/mops/gruppen2/service/GroupServiceTest.java

@@ -58,7 +58,7 @@ class GroupServiceTest {
 
     @BeforeEach
     void setUp() {
-        groupService = new GroupService(eventStoreService, validationService, inviteService, projectionService);
+        groupService = new GroupService(eventStoreService, validationService, inviteService);
         eventRepository.deleteAll();
         //noinspection SqlResolve
         template.execute("ALTER TABLE event ALTER COLUMN event_id RESTART WITH 1");