airbnb/caravel

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# 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
#
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# software distributed under the License is distributed on an
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# KIND, either express or implied.  See the License for the
# specific language governing permissions and limitations
# under the License.
from datetime import datetime
from typing import Any, Optional

from sqlalchemy import types

from superset.constants import TimeGrain
from superset.db_engine_specs.base import BaseEngineSpec, LimitMethod


class OracleEngineSpec(BaseEngineSpec):
    engine = "oracle"
    engine_name = "Oracle"
    limit_method = LimitMethod.WRAP_SQL
    force_column_alias_quotes = True
    max_column_name_length = 30

    _time_grain_expressions = {
        None: "{col}",
        TimeGrain.SECOND: "CAST({col} as DATE)",
        TimeGrain.MINUTE: "TRUNC(CAST({col} as DATE), 'MI')",
        TimeGrain.HOUR: "TRUNC(CAST({col} as DATE), 'HH')",
        TimeGrain.DAY: "TRUNC(CAST({col} as DATE), 'DDD')",
        TimeGrain.WEEK: "TRUNC(CAST({col} as DATE), 'WW')",
        TimeGrain.MONTH: "TRUNC(CAST({col} as DATE), 'MONTH')",
        TimeGrain.QUARTER: "TRUNC(CAST({col} as DATE), 'Q')",
        TimeGrain.YEAR: "TRUNC(CAST({col} as DATE), 'YEAR')",
    }

    @classmethod
    def convert_dttm(
        cls, target_type: str, dttm: datetime, db_extra: Optional[dict[str, Any]] = None
    ) -> Optional[str]:
        sqla_type = cls.get_sqla_column_type(target_type)

        if isinstance(sqla_type, types.Date):
            return f"TO_DATE('{dttm.date().isoformat()}', 'YYYY-MM-DD')"
        if isinstance(sqla_type, types.TIMESTAMP):
            return f"""TO_TIMESTAMP('{dttm
                .isoformat(timespec="microseconds")}', 'YYYY-MM-DD"T"HH24:MI:SS.ff6')"""
        if isinstance(sqla_type, types.DateTime):
            datetime_formatted = dttm.isoformat(timespec="seconds")
            return f"""TO_DATE('{datetime_formatted}', 'YYYY-MM-DD"T"HH24:MI:SS')"""
        return None

    @classmethod
    def epoch_to_dttm(cls) -> str:
        return "TO_DATE('1970-01-01','YYYY-MM-DD')+(1/24/60/60)*{col}"

    @classmethod
    def epoch_ms_to_dttm(cls) -> str:
        return "TO_DATE('1970-01-01','YYYY-MM-DD')+(1/24/60/60/1000)*{col}"

    @classmethod
    def fetch_data(
        cls, cursor: Any, limit: Optional[int] = None
    ) -> list[tuple[Any, ...]]:
        """
        :param cursor: Cursor instance
        :param limit: Maximum number of rows to be returned by the cursor
        :return: Result of query
        """
        if not cursor.description:
            return []
        return super().fetch_data(cursor, limit)