# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements.  See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership.  The ASF licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License.  You may obtain a copy of the License at
#
#   http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
# KIND, either express or implied.  See the License for the
# specific language governing permissions and limitations
# under the License.
# pylint: disable=C,R,W
from superset.db_engine_specs.base import BaseEngineSpec, LimitMethod


class Db2EngineSpec(BaseEngineSpec):
    engine = 'ibm_db_sa'
    limit_method = LimitMethod.WRAP_SQL
    force_column_alias_quotes = True
    max_column_name_length = 30

    time_grain_functions = {
        None: '{col}',
        'PT1S': 'CAST({col} as TIMESTAMP)'
                ' - MICROSECOND({col}) MICROSECONDS',
        'PT1M': 'CAST({col} as TIMESTAMP)'
                ' - SECOND({col}) SECONDS'
                ' - MICROSECOND({col}) MICROSECONDS',
        'PT1H': 'CAST({col} as TIMESTAMP)'
                ' - MINUTE({col}) MINUTES'
                ' - SECOND({col}) SECONDS'
                ' - MICROSECOND({col}) MICROSECONDS ',
        'P1D': 'CAST({col} as TIMESTAMP)'
               ' - HOUR({col}) HOURS'
               ' - MINUTE({col}) MINUTES'
               ' - SECOND({col}) SECONDS'
               ' - MICROSECOND({col}) MICROSECONDS',
        'P1W': '{col} - (DAYOFWEEK({col})) DAYS',
        'P1M': '{col} - (DAY({col})-1) DAYS',
        'P0.25Y': '{col} - (DAY({col})-1) DAYS'
                  ' - (MONTH({col})-1) MONTHS'
                  ' + ((QUARTER({col})-1) * 3) MONTHS',
        'P1Y': '{col} - (DAY({col})-1) DAYS'
               ' - (MONTH({col})-1) MONTHS',
    }

    @classmethod
    def epoch_to_dttm(cls):
        return "(TIMESTAMP('1970-01-01', '00:00:00') + {col} SECONDS)"

    @classmethod
    def convert_dttm(cls, target_type, dttm):
        return "'{}'".format(dttm.strftime('%Y-%m-%d-%H.%M.%S'))