class Engine(object):

    def create_table_sql(self):
        raise NotImplementedError()


class MergeTree(Engine):

    def __init__(self, date_col, key_cols, sampling_expr=None,
                 index_granularity=8192, replica_table_path=None, replica_name=None):
        self.date_col = date_col
        self.key_cols = key_cols
        self.sampling_expr = sampling_expr
        self.index_granularity = index_granularity
        self.replica_table_path = replica_table_path
        self.replica_name = replica_name
        # TODO verify that both replica fields are either present or missing

    def create_table_sql(self):
        name = self.__class__.__name__
        if self.replica_name:
            name = 'Replicated' + name
        params = self._build_sql_params()
        return '%s(%s)' % (name, ', '.join(params))

    def _build_sql_params(self):
        params = []
        if self.replica_name:
            params += ["'%s'" % self.replica_table_path, "'%s'" % self.replica_name]
        params.append(self.date_col)
        if self.sampling_expr:
            params.append(self.sampling_expr)
        params.append('(%s)' % ', '.join(self.key_cols))
        params.append(str(self.index_granularity))
        return params


class CollapsingMergeTree(MergeTree):

    def __init__(self, date_col, key_cols, sign_col, sampling_expr=None,
                 index_granularity=8192, replica_table_path=None, replica_name=None):
        super(CollapsingMergeTree, self).__init__(date_col, key_cols, sampling_expr, index_granularity, replica_table_path, replica_name)
        self.sign_col = sign_col

    def _build_sql_params(self):
        params = super(CollapsingMergeTree, self)._build_sql_params()
        params.append(self.sign_col)
        return params


class SummingMergeTree(MergeTree):

    def __init__(self, date_col, key_cols, summing_cols=None, sampling_expr=None,
                 index_granularity=8192, replica_table_path=None, replica_name=None):
        super(SummingMergeTree, self).__init__(date_col, key_cols, sampling_expr, index_granularity, replica_table_path, replica_name)
        self.summing_cols = summing_cols

    def _build_sql_params(self):
        params = super(SummingMergeTree, self)._build_sql_params()
        if self.summing_cols:
            params.append('(%s)' % ', '.join(self.summing_cols))
        return params