import time

def query(q, context, params={}):
    """
    Function used to execute query on database. Query results are
    set in context.result_list. If exception occurs, it is set on
    context.exception.

    @param q:
        String, database query.
    @param context:
        behave.runner.Context, context of all tests.
    @return:
        List of query results.
    """
    results_list = []

    if (context.config.database == "neo4j" or
        context.config.database == "memgraph"):
        session = context.driver.session()
        start = time.time()
        try:
            # executing query
            results = session.run(q, params)
            if not context.config.no_side_effects:
                summary = results.summary()
                add_side_effects(context, summary.counters)
            results_list = list(results)
            """
            This code snippet should replace code which is now
            executing queries when session.transactions will be supported.

            with session.begin_transaction() as tx:
                results = tx.run(q, params)
                summary = results.summary()
                if not context.config.no_side_effects:
                    add_side_effects(context, summary.counters)
                results_list = list(results)
                tx.success = True
            """
        except Exception as e:
            # exception
            context.exception = e
            context.log.info('%s', str(e))
        finally:
            end = time.time()
            if context.execution_step is not None and \
                    context.execution_step:
                context.execution_time = end - start
            session.close()
    return results_list


def add_side_effects(context, counters):
    """
    Funtion adds side effects from query to graph properties.

    @param context:
        behave.runner.Context, context of all tests.
    """
    graph_properties = context.graph_properties

    # check nodes
    if counters.nodes_deleted > 0:
        graph_properties.change_nodes(-counters.nodes_deleted)
    if counters.nodes_created > 0:
        graph_properties.change_nodes(counters.nodes_created)
    # check relationships
    if counters.relationships_deleted > 0:
        graph_properties.change_relationships(-counters.relationships_deleted)
    if counters.relationships_created > 0:
        graph_properties.change_relationships(counters.relationships_created)
    # check labels
    if counters.labels_removed > 0:
        graph_properties.change_labels(-counters.labels_removed)
    if counters.labels_added > 0:
        graph_properties.change_labels(counters.labels_added)
    # check properties
    if counters.properties_set > 0:
        graph_properties.change_properties(counters.properties_set)