private Mono handleCreate()

in server/protocols/jmap-draft/src/main/java/org/apache/james/jmap/draft/methods/SetMessagesCreationProcessor.java [125:207]
80 lines of code
2 McCabe index (conditional complexity)

    private Mono<Builder> handleCreate(CreationMessageEntry create, MailboxSession mailboxSession) {
        List<MailboxId> mailboxIds = toMailboxIds(create);

        if (mailboxIds.isEmpty()) {
            return Mono.just(SetMessagesResponse.builder().notCreated(create.getCreationId(),
                SetError.builder()
                    .type(SetError.Type.INVALID_PROPERTIES)
                    .properties(MessageProperty.mailboxIds)
                    .description("Message needs to be in at least one mailbox")
                    .build()));
        }

        return assertIsUserOwnerOfMailboxes(mailboxIds, mailboxSession)
            .then(performCreate(create, mailboxSession))
            .onErrorResume(MailboxSendingNotAllowedException.class, e -> {
                LOG.debug("{} is not allowed to send a mail using {} identity", e.getConnectedUser().asString(), e.getFromField());

                return Mono.just(SetMessagesResponse.builder().notCreated(create.getCreationId(),
                    SetError.builder()
                        .type(SetError.Type.INVALID_PROPERTIES)
                        .properties(MessageProperty.from)
                        .description("Invalid 'from' field. One accepted value is " +
                            e.getConnectedUser().asString())
                        .build()));
            })
            .onErrorResume(InvalidDraftKeywordsException.class, e -> Mono.just(SetMessagesResponse.builder().notCreated(create.getCreationId(),
                SetError.builder()
                    .type(SetError.Type.INVALID_PROPERTIES)
                    .properties(MessageProperty.keywords)
                    .description(e.getMessage())
                    .build())))
            .onErrorResume(SizeExceededException.class, e -> Mono.just(SetMessagesResponse.builder().notCreated(create.getCreationId(),
                SetError.builder()
                    .type(SetError.Type.INVALID_ARGUMENTS)
                    .description(e.getMessage())
                    .build())))
            .onErrorResume(AttachmentsNotFoundException.class, e -> Mono.just(SetMessagesResponse.builder().notCreated(create.getCreationId(),
                SetMessagesError.builder()
                    .type(SetError.Type.INVALID_PROPERTIES)
                    .properties(MessageProperty.attachments)
                    .attachmentsNotFound(e.getAttachmentIds())
                    .description("Attachment not found")
                    .build())))
            .onErrorResume(InvalidMailboxForCreationException.class, e -> Mono.just(SetMessagesResponse.builder().notCreated(create.getCreationId(),
                SetError.builder()
                    .type(SetError.Type.INVALID_PROPERTIES)
                    .properties(MessageProperty.mailboxIds)
                    .description("Message creation is only supported in mailboxes with role Draft and Outbox")
                    .build())))
            .onErrorResume(MailboxInvalidMessageCreationException.class, e -> Mono.just(SetMessagesResponse.builder().notCreated(create.getCreationId(),
                buildSetErrorFromValidationResult(create.getValue().validate()))))
            .onErrorResume(MailboxNotFoundException.class, e -> Mono.just(SetMessagesResponse.builder().notCreated(create.getCreationId(),
                SetError.builder()
                    .type(SetError.Type.ERROR)
                    .description(e.getMessage())
                    .build())))
            .onErrorResume(MailboxNotOwnedException.class, e -> Mono.just(SetMessagesResponse.builder().notCreated(create.getCreationId(),
                SetError.builder()
                    .type(SetError.Type.ERROR)
                    .properties(MessageProperty.mailboxIds)
                    .description("MailboxId invalid")
                    .build())))
            .onErrorResume(OverQuotaException.class, e -> Mono.just(SetMessagesResponse.builder().notCreated(create.getCreationId(),
                SetError.builder()
                    .type(SetError.Type.MAX_QUOTA_REACHED)
                    .description(e.getMessage())
                    .build())))
            .onErrorResume(MailboxException.class, e -> Mono.just(SetMessagesResponse.builder().notCreated(create.getCreationId(),
                SetError.builder()
                    .type(SetError.Type.ERROR)
                    .description("unexpected error")
                    .build())))
            .onErrorResume(MessagingException.class, e -> Mono.just(SetMessagesResponse.builder().notCreated(create.getCreationId(),
                SetError.builder()
                    .type(SetError.Type.ERROR)
                    .description("unexpected error")
                    .build())))
            .onErrorResume(IOException.class, e -> Mono.just(SetMessagesResponse.builder().notCreated(create.getCreationId(),
                SetError.builder()
                    .type(SetError.Type.ERROR)
                    .description("unexpected error")
                    .build())));
    }