Link accounts based on common authid(email)

Author: aq-ikhwa-tech

server/api-service/lowcoder-domain/src/main/java/org/lowcoder/domain/user/repository/UserRepository.java

@@ -16,6 +16,8 @@ public interface UserRepository extends ReactiveMongoRepository<User, String> {
 
     Mono<User> findByConnections_SourceAndConnections_RawId(String source, String rawId);
 
+    Flux<User> findByConnections_RawId(String rawId);
+
     Flux<User> findByConnections_SourceAndConnections_RawIdIn(String source, Collection<String> rawIds);
 
 }

server/api-service/lowcoder-domain/src/main/java/org/lowcoder/domain/user/service/UserService.java

@@ -32,14 +32,18 @@ public interface UserService {
 
     Mono<Boolean> bindEmail(User user, String email);
 
-    Mono<User> findByAuthUser(AuthUser authUser);
+    Mono<User> findByAuthUserSourceAndRawId(AuthUser authUser);
+
+    Flux<User> findByAuthUserRawId(AuthUser authUser);
 
     Mono<User> createNewUserByAuthUser(AuthUser authUser);
 
     Mono<Void> getUserAvatar(ServerWebExchange exchange, String userId);
 
     Mono<Boolean> addNewConnection(String userId, Connection connection);
 
+    Mono<User> addNewConnectionAndReturnUser(String userId, Connection connection);
+
     Mono<Void> deleteProfilePhoto(User visitor);
 
     Mono<Boolean> updatePassword(String userId, String oldPassword, String newPassword);

server/api-service/lowcoder-domain/src/main/java/org/lowcoder/domain/user/service/UserServiceImpl.java

@@ -111,6 +111,10 @@ public Mono<User> findBySourceAndId(String source, String sourceUuid) {
         return repository.findByConnections_SourceAndConnections_RawId(source, sourceUuid);
     }
 
+    public Flux<User> findByRawId(String rawUuid) {
+        return repository.findByConnections_RawId(rawUuid);
+    }
+
     @Override
     public Mono<Boolean> saveProfilePhoto(Part filePart, User user) {
         String prevAvatar = ObjectUtils.defaultIfNull(user.getAvatar(), "");
@@ -143,10 +147,15 @@ public Mono<User> update(String id, User updatedUser) {
     }
 
     @Override
-    public Mono<User> findByAuthUser(AuthUser authUser) {
+    public Mono<User> findByAuthUserSourceAndRawId(AuthUser authUser) {
         return findBySourceAndId(authUser.getSource(), authUser.getUid());
     }
 
+    @Override
+    public Flux<User> findByAuthUserRawId(AuthUser authUser) {
+        return findByRawId(authUser.getUid());
+    }
+
     @Override
     public Mono<User> createNewUserByAuthUser(AuthUser authUser) {
         User newUser = new User();
@@ -198,6 +207,13 @@ public Mono<Boolean> addNewConnection(String userId, Connection connection) {
                 .then(Mono.just(true));
     }
 
+    @Override
+    public Mono<User> addNewConnectionAndReturnUser(String userId, Connection connection) {
+        return findById(userId)
+                .doOnNext(user -> user.getConnections().add(connection))
+                .flatMap(repository::save);
+    }
+
     @Override
     public Mono<Void> deleteProfilePhoto(User visitor) {
         String userAvatar = visitor.getAvatar();

server/api-service/lowcoder-server/src/main/java/org/lowcoder/api/authentication/service/AuthenticationApiServiceImpl.java

@@ -155,14 +155,26 @@ public Mono<Void> loginOrRegister(AuthUser authUser, ServerWebExchange exchange,
     }
 
     private Mono<User> updateOrCreateUser(AuthUser authUser) {
-        return findByAuthUser(authUser)
-                .flatMap(findByAuthUser -> {
-                    if (findByAuthUser.userExist()) {
-                        User user = findByAuthUser.user();
+        return findByAuthUserSourceAndRawId(authUser).zipWith(findByAuthUserRawId(authUser))
+                .flatMap(tuple -> {
+
+                    FindByAuthUser findByAuthUserFirst = tuple.getT1();
+                    FindByAuthUser findByAuthUserSecond = tuple.getT2();
+
+                    // If the user is found for the same auth source and id, just update the connection
+                    if (findByAuthUserFirst.userExist()) {
+                        User user = findByAuthUserFirst.user();
                         updateConnection(authUser, user);
                         return userService.update(user.getId(), user);
                     }
 
+                    //If the user connection is not found with login id, but the user is
+                    // found for the same id in some different connection, then just add a new connection to the user
+                    if(findByAuthUserSecond.userExist()) {
+                        User user = findByAuthUserSecond.user();
+                        return userService.addNewConnectionAndReturnUser(user.getId(), authUser.toAuthConnection());
+                    }
+
                     // if the user is logging/registering via OAuth provider for the first time,
                     // but is not anonymous, then just add a new connection
 
@@ -183,12 +195,18 @@ private Mono<User> updateOrCreateUser(AuthUser authUser) {
                 });
     }
 
-    protected Mono<FindByAuthUser> findByAuthUser(AuthUser authUser) {
-        return userService.findByAuthUser(authUser)
+    protected Mono<FindByAuthUser> findByAuthUserSourceAndRawId(AuthUser authUser) {
+        return userService.findByAuthUserSourceAndRawId(authUser)
                 .map(user -> new FindByAuthUser(true, user))
                 .defaultIfEmpty(new FindByAuthUser(false, null));
     }
 
+    protected Mono<FindByAuthUser> findByAuthUserRawId(AuthUser authUser) {
+        return userService.findByAuthUserRawId(authUser).collectList()
+                .map(user -> new FindByAuthUser(true, user.stream().findFirst().get()))
+                .defaultIfEmpty(new FindByAuthUser(false, null));
+    }
+
     /**
      * Update the connection after re-authenticating
      */