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"""Microsoft SQLServer hook module."""
from __future__ import annotations

from typing import Any

import pymssql

from airflow.providers.common.sql.hooks.sql import DbApiHook


class MsSqlHook(DbApiHook):
    """
    Interact with Microsoft SQL Server.

    :param args: passed to DBApiHook
    :param sqlalchemy_scheme: Scheme sqlalchemy connection.  Default is ``mssql+pymssql`` Only used for
      ``get_sqlalchemy_engine`` and ``get_sqlalchemy_connection`` methods.
    :param kwargs: passed to DbApiHook
    """

    conn_name_attr = "mssql_conn_id"
    default_conn_name = "mssql_default"
    conn_type = "mssql"
    hook_name = "Microsoft SQL Server"
    supports_autocommit = True
    DEFAULT_SQLALCHEMY_SCHEME = "mssql+pymssql"

    def __init__(
        self,
        *args,
        sqlalchemy_scheme: str | None = None,
        **kwargs,
    ) -> None:
        super().__init__(*args, **kwargs)
        self.schema = kwargs.pop("schema", None)
        self._sqlalchemy_scheme = sqlalchemy_scheme

    @property
    def connection_extra_lower(self) -> dict:
        """
        ``connection.extra_dejson`` but where keys are converted to lower case.

        This is used internally for case-insensitive access of mssql params.
        """
        conn = self.get_connection(self.mssql_conn_id)  # type: ignore[attr-defined]
        return {k.lower(): v for k, v in conn.extra_dejson.items()}

    @property
    def sqlalchemy_scheme(self) -> str:
        """Sqlalchemy scheme either from constructor, connection extras or default."""
        extra_scheme = self.connection_extra_lower.get("sqlalchemy_scheme")
        if not self._sqlalchemy_scheme and extra_scheme and (":" in extra_scheme or "/" in extra_scheme):
            raise RuntimeError("sqlalchemy_scheme in connection extra should not contain : or / characters")
        return self._sqlalchemy_scheme or extra_scheme or self.DEFAULT_SQLALCHEMY_SCHEME

    def get_uri(self) -> str:
        from urllib.parse import parse_qs, urlencode, urlsplit, urlunsplit

        r = list(urlsplit(super().get_uri()))
        # change pymssql driver:
        r[0] = self.sqlalchemy_scheme
        # remove query string 'sqlalchemy_scheme' like parameters:
        qs = parse_qs(r[3], keep_blank_values=True)
        for k in list(qs.keys()):
            if k.lower() == "sqlalchemy_scheme":
                qs.pop(k, None)
        r[3] = urlencode(qs, doseq=True)
        return urlunsplit(r)

    def get_sqlalchemy_connection(
        self, connect_kwargs: dict | None = None, engine_kwargs: dict | None = None
    ) -> Any:
        """Sqlalchemy connection object."""
        engine = self.get_sqlalchemy_engine(engine_kwargs=engine_kwargs)
        return engine.connect(**(connect_kwargs or {}))

    def get_conn(self) -> pymssql.connect:
        """Returns a mssql connection object."""
        conn = self.get_connection(self.mssql_conn_id)  # type: ignore[attr-defined]

        conn = pymssql.connect(
            server=conn.host,
            user=conn.login,
            password=conn.password,
            database=self.schema or conn.schema,
            port=conn.port,
        )
        return conn

    def set_autocommit(
        self,
        conn: pymssql.connect,
        autocommit: bool,
    ) -> None:
        conn.autocommit(autocommit)

    def get_autocommit(self, conn: pymssql.connect):
        return conn.autocommit_state
