private Object transformQueryCursor()

in modules/spring-data-ext/spring-data/src/main/java/org/apache/ignite/springdata/repository/query/IgniteRepositoryQuery.java [535:646]
100 lines of code
28 McCabe index (conditional complexity)

    private Object transformQueryCursor(IgniteQuery qry,
        ReturnStrategy returnStgy,
        Object[] prmtrs,
        QueryCursor qryCursor) {
        final Class<?> retCls;

        if (hasProjection) {
            if (hasDynamicProjection)
                retCls = (Class<?>)prmtrs[dynamicProjectionIndex];
            else
                retCls = returnedDomainClass;
        }
        else
            retCls = returnedDomainClass;

        if (qry.isFieldQuery()) {
            // take control over single primite result from queries, i.e. DELETE, SELECT COUNT, UPDATE ...
            boolean singlePrimitiveResult = isPrimitiveOrWrapper(retCls);

            FieldsQueryCursor<?> fieldQryCur = (FieldsQueryCursor<?>)qryCursor;

            Function<List<?>, ?> cWrapperTransformFunction = null;

            if (type.equals(retCls))
                cWrapperTransformFunction = row -> rowToEntity(row, fieldQryCur);
            else {
                if (hasProjection || singlePrimitiveResult) {
                    if (singlePrimitiveResult)
                        cWrapperTransformFunction = row -> row.get(0);
                    else {
                        // Map row -> projection class
                        cWrapperTransformFunction = row -> factory
                            .createProjection(retCls, rowToMap(row, fieldQryCur));
                    }
                }
                else
                    cWrapperTransformFunction = row -> rowToMap(row, fieldQryCur);
            }

            QueryCursorWrapper<?, ?> cWrapper = new QueryCursorWrapper<>((QueryCursor<List<?>>)qryCursor,
                cWrapperTransformFunction);

            switch (returnStgy) {
                case PAGE_OF_VALUES:
                    return new PageImpl(cWrapper.getAll(), (Pageable)prmtrs[prmtrs.length - 1], 0);
                case LIST_OF_VALUES:
                    return cWrapper.getAll();
                case STREAM_OF_VALUES:
                    return cWrapper.stream();
                case ONE_VALUE:
                    Iterator<?> iter = cWrapper.iterator();
                    if (iter.hasNext()) {
                        Object resp = iter.next();
                        U.closeQuiet(cWrapper);
                        return resp;
                    }
                    return null;
                case SLICE_OF_VALUES:
                    return new SliceImpl(cWrapper.getAll(), (Pageable)prmtrs[prmtrs.length - 1], true);
                case SLICE_OF_LISTS:
                    return new SliceImpl(qryCursor.getAll(), (Pageable)prmtrs[prmtrs.length - 1], true);
                case LIST_OF_LISTS:
                    return qryCursor.getAll();
                default:
                    throw new IllegalStateException();
            }
        }
        else {
            Function<Cache.Entry<?, ?>, ?> cWrapperTransformFunction;

            if (hasProjection && !type.equals(retCls))
                cWrapperTransformFunction = row -> factory.createProjection(retCls, row.getValue());
            else
                cWrapperTransformFunction = Cache.Entry::getValue;

            QueryCursorWrapper<Cache.Entry<?, ?>, ?> cWrapper = new QueryCursorWrapper<>(
                (QueryCursor<Cache.Entry<?, ?>>)qryCursor, cWrapperTransformFunction);

            switch (returnStgy) {
                case PAGE_OF_VALUES:
                    return new PageImpl(cWrapper.getAll(), (Pageable)prmtrs[prmtrs.length - 1], 0);
                case LIST_OF_VALUES:
                    return cWrapper.getAll();
                case STREAM_OF_VALUES:
                    return cWrapper.stream();
                case ONE_VALUE:
                    Iterator<?> iter1 = cWrapper.iterator();
                    if (iter1.hasNext()) {
                        Object resp = iter1.next();
                        U.closeQuiet(cWrapper);
                        return resp;
                    }
                    return null;
                case CACHE_ENTRY:
                    Iterator<?> iter2 = qryCursor.iterator();
                    if (iter2.hasNext()) {
                        Object resp2 = iter2.next();
                        U.closeQuiet(qryCursor);
                        return resp2;
                    }
                    return null;
                case SLICE_OF_VALUES:
                    return new SliceImpl(cWrapper.getAll(), (Pageable)prmtrs[prmtrs.length - 1], true);
                case SLICE_OF_CACHE_ENTRIES:
                    return new SliceImpl(qryCursor.getAll(), (Pageable)prmtrs[prmtrs.length - 1], true);
                case LIST_OF_CACHE_ENTRIES:
                    return qryCursor.getAll();
                default:
                    throw new IllegalStateException();
            }
        }
    }