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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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# specific language governing permissions and limitations
# under the License.
from datetime import datetime
from typing import Optional
from urllib import parse

from sqlalchemy.engine.url import URL

from superset.db_engine_specs.postgres import PostgresBaseEngineSpec


class SnowflakeEngineSpec(PostgresBaseEngineSpec):
    engine = "snowflake"
    force_column_alias_quotes = True
    max_column_name_length = 256

    _time_grain_functions = {
        None: "{col}",
        "PT1S": "DATE_TRUNC('SECOND', {col})",
        "PT1M": "DATE_TRUNC('MINUTE', {col})",
        "PT5M": "DATEADD(MINUTE, FLOOR(DATE_PART(MINUTE, {col}) / 5) * 5, \
                DATE_TRUNC('HOUR', {col}))",
        "PT10M": "DATEADD(MINUTE, FLOOR(DATE_PART(MINUTE, {col}) / 10) * 10, \
                 DATE_TRUNC('HOUR', {col}))",
        "PT15M": "DATEADD(MINUTE, FLOOR(DATE_PART(MINUTE, {col}) / 15) * 15, \
                 DATE_TRUNC('HOUR', {col}))",
        "PT0.5H": "DATEADD(MINUTE, FLOOR(DATE_PART(MINUTE, {col}) / 30) * 30, \
                  DATE_TRUNC('HOUR', {col}))",
        "PT1H": "DATE_TRUNC('HOUR', {col})",
        "P1D": "DATE_TRUNC('DAY', {col})",
        "P1W": "DATE_TRUNC('WEEK', {col})",
        "P1M": "DATE_TRUNC('MONTH', {col})",
        "P0.25Y": "DATE_TRUNC('QUARTER', {col})",
        "P1Y": "DATE_TRUNC('YEAR', {col})",
    }

    @classmethod
    def adjust_database_uri(
        cls, uri: URL, selected_schema: Optional[str] = None
    ) -> None:
        database = uri.database
        if "/" in uri.database:
            database = uri.database.split("/")[0]
        if selected_schema:
            selected_schema = parse.quote(selected_schema, safe="")
            uri.database = database + "/" + selected_schema

    @classmethod
    def epoch_to_dttm(cls) -> str:
        return "DATEADD(S, {col}, '1970-01-01')"

    @classmethod
    def epoch_ms_to_dttm(cls) -> str:
        return "DATEADD(MS, {col}, '1970-01-01')"

    @classmethod
    def convert_dttm(cls, target_type: str, dttm: datetime) -> Optional[str]:
        tt = target_type.upper()
        if tt == "DATE":
            return f"TO_DATE('{dttm.date().isoformat()}')"
        if tt == "DATETIME":
            return f"""CAST('{dttm.isoformat(timespec="microseconds")}' AS DATETIME)"""
        if tt == "TIMESTAMP":
            return f"""TO_TIMESTAMP('{dttm.isoformat(timespec="microseconds")}')"""
        return None