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# to you under the Apache License, Version 2.0 (the
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#
#   http://www.apache.org/licenses/LICENSE-2.0
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from datetime import datetime
from typing import Optional

from superset.db_engine_specs.base import BaseEngineSpec


class AthenaEngineSpec(BaseEngineSpec):
    engine = "awsathena"

    _time_grain_expressions = {
        None: "{col}",
        "PT1S": "date_trunc('second', CAST({col} AS TIMESTAMP))",
        "PT1M": "date_trunc('minute', CAST({col} AS TIMESTAMP))",
        "PT1H": "date_trunc('hour', CAST({col} AS TIMESTAMP))",
        "P1D": "date_trunc('day', CAST({col} AS TIMESTAMP))",
        "P1W": "date_trunc('week', CAST({col} AS TIMESTAMP))",
        "P1M": "date_trunc('month', CAST({col} AS TIMESTAMP))",
        "P0.25Y": "date_trunc('quarter', CAST({col} AS TIMESTAMP))",
        "P1Y": "date_trunc('year', CAST({col} AS TIMESTAMP))",
        "P1W/1970-01-03T00:00:00Z": "date_add('day', 5, date_trunc('week', \
                                    date_add('day', 1, CAST({col} AS TIMESTAMP))))",
        "1969-12-28T00:00:00Z/P1W": "date_add('day', -1, date_trunc('week', \
                                    date_add('day', 1, CAST({col} AS TIMESTAMP))))",
    }

    @classmethod
    def convert_dttm(cls, target_type: str, dttm: datetime) -> Optional[str]:
        tt = target_type.upper()
        if tt == "DATE":
            return f"from_iso8601_date('{dttm.date().isoformat()}')"
        if tt == "TIMESTAMP":
            return f"""from_iso8601_timestamp('{dttm.isoformat(timespec="microseconds")}')"""  # pylint: disable=line-too-long
        return None

    @classmethod
    def epoch_to_dttm(cls) -> str:
        return "from_unixtime({col})"

    @staticmethod
    def _mutate_label(label: str) -> str:
        """
        Athena only supports lowercase column names and aliases.

        :param label: Expected expression label
        :return: Conditionally mutated label
        """
        return label.lower()