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"""This module contains AWS Athena hook"""
from time import sleep
from typing import Any, Dict, Optional

from airflow.providers.amazon.aws.hooks.base_aws import AwsBaseHook
from botocore.paginate import PageIterator


class AWSAthenaHook(AwsBaseHook):
    """
    Interact with AWS Athena to run, poll queries and return query results

    Additional arguments (such as ``aws_conn_id``) may be specified and
    are passed down to the underlying AwsBaseHook.

    .. seealso::
        :class:`~airflow.providers.amazon.aws.hooks.base_aws.AwsBaseHook`

    :param sleep_time: Time (in seconds) to wait between two consecutive calls to check query status on Athena
    :type sleep_time: int
    """

    INTERMEDIATE_STATES = (
        "QUEUED",
        "RUNNING",
    )
    FAILURE_STATES = (
        "FAILED",
        "CANCELLED",
    )
    SUCCESS_STATES = ("SUCCEEDED",)

    def __init__(self, *args: Any, sleep_time: int = 30, **kwargs: Any) -> None:
        super().__init__(client_type="athena", *args, **kwargs)  # type: ignore
        self.sleep_time = sleep_time

    def run_query(
        self,
        query: str,
        query_context: Dict[str, str],
        result_configuration: Dict[str, Any],
        client_request_token: Optional[str] = None,
        workgroup: str = "primary",
    ) -> str:
        """
        Run Presto query on athena with provided config and return submitted query_execution_id

        :param query: Presto query to run
        :type query: str
        :param query_context: Context in which query need to be run
        :type query_context: dict
        :param result_configuration: Dict with path to store results in and config related to encryption
        :type result_configuration: dict
        :param client_request_token: Unique token created by user to avoid multiple executions of same query
        :type client_request_token: str
        :param workgroup: Athena workgroup name, when not specified, will be 'primary'
        :type workgroup: str
        :return: str
        """
        params = {
            "QueryString": query,
            "QueryExecutionContext": query_context,
            "ResultConfiguration": result_configuration,
            "WorkGroup": workgroup,
        }
        if client_request_token:
            params["ClientRequestToken"] = client_request_token
        response = self.get_conn().start_query_execution(**params)
        query_execution_id = response["QueryExecutionId"]
        return query_execution_id

    def check_query_status(self, query_execution_id: str) -> Optional[str]:
        """
        Fetch the status of submitted athena query. Returns None or one of valid query states.

        :param query_execution_id: Id of submitted athena query
        :type query_execution_id: str
        :return: str
        """
        response = self.get_conn().get_query_execution(
            QueryExecutionId=query_execution_id
        )
        state = None
        try:
            state = response["QueryExecution"]["Status"]["State"]
        except Exception as ex:  # pylint: disable=broad-except
            self.log.error("Exception while getting query state %s", ex)
        finally:
            # The error is being absorbed here and is being handled by the caller.
            # The error is being absorbed to implement retries.
            return state  # pylint: disable=lost-exception

    def get_state_change_reason(self, query_execution_id: str) -> Optional[str]:
        """
        Fetch the reason for a state change (e.g. error message). Returns None or reason string.

        :param query_execution_id: Id of submitted athena query
        :type query_execution_id: str
        :return: str
        """
        response = self.get_conn().get_query_execution(
            QueryExecutionId=query_execution_id
        )
        reason = None
        try:
            reason = response["QueryExecution"]["Status"]["StateChangeReason"]
        except Exception as ex:  # pylint: disable=broad-except
            self.log.error("Exception while getting query state change reason: %s", ex)
        finally:
            # The error is being absorbed here and is being handled by the caller.
            # The error is being absorbed to implement retries.
            return reason  # pylint: disable=lost-exception

    def get_query_results(
        self,
        query_execution_id: str,
        next_token_id: Optional[str] = None,
        max_results: int = 1000,
    ) -> Optional[dict]:
        """
        Fetch submitted athena query results. returns none if query is in intermediate state or
        failed/cancelled state else dict of query output

        :param query_execution_id: Id of submitted athena query
        :type query_execution_id: str
        :param next_token_id:  The token that specifies where to start pagination.
        :type next_token_id: str
        :param max_results: The maximum number of results (rows) to return in this request.
        :type max_results: int
        :return: dict
        """
        query_state = self.check_query_status(query_execution_id)
        if query_state is None:
            self.log.error("Invalid Query state")
            return None
        elif (
            query_state in self.INTERMEDIATE_STATES
            or query_state in self.FAILURE_STATES
        ):
            self.log.error('Query is in "%s" state. Cannot fetch results', query_state)
            return None
        result_params = {
            "QueryExecutionId": query_execution_id,
            "MaxResults": max_results,
        }
        if next_token_id:
            result_params["NextToken"] = next_token_id
        return self.get_conn().get_query_results(**result_params)

    def get_query_results_paginator(
        self,
        query_execution_id: str,
        max_items: Optional[int] = None,
        page_size: Optional[int] = None,
        starting_token: Optional[str] = None,
    ) -> Optional[PageIterator]:
        """
        Fetch submitted athena query results. returns none if query is in intermediate state or
        failed/cancelled state else a paginator to iterate through pages of results. If you
        wish to get all results at once, call build_full_result() on the returned PageIterator

        :param query_execution_id: Id of submitted athena query
        :type query_execution_id: str
        :param max_items: The total number of items to return.
        :type max_items: int
        :param page_size: The size of each page.
        :type page_size: int
        :param starting_token: A token to specify where to start paginating.
        :type starting_token: str
        :return: PageIterator
        """
        query_state = self.check_query_status(query_execution_id)
        if query_state is None:
            self.log.error("Invalid Query state (null)")
            return None
        if (
            query_state in self.INTERMEDIATE_STATES
            or query_state in self.FAILURE_STATES
        ):
            self.log.error('Query is in "%s" state. Cannot fetch results', query_state)
            return None
        result_params = {
            "QueryExecutionId": query_execution_id,
            "PaginationConfig": {
                "MaxItems": max_items,
                "PageSize": page_size,
                "StartingToken": starting_token,
            },
        }
        paginator = self.get_conn().get_paginator("get_query_results")
        return paginator.paginate(**result_params)

    def poll_query_status(
        self, query_execution_id: str, max_tries: Optional[int] = None
    ) -> Optional[str]:
        """
        Poll the status of submitted athena query until query state reaches final state.
        Returns one of the final states

        :param query_execution_id: Id of submitted athena query
        :type query_execution_id: str
        :param max_tries: Number of times to poll for query state before function exits
        :type max_tries: int
        :return: str
        """
        try_number = 1
        final_query_state = (
            None  # Query state when query reaches final state or max_tries reached
        )
        while True:
            query_state = self.check_query_status(query_execution_id)
            if query_state is None:
                self.log.info(
                    "Trial %s: Invalid query state. Retrying again", try_number
                )
            elif query_state in self.INTERMEDIATE_STATES:
                self.log.info(
                    "Trial %s: Query is still in an intermediate state - %s",
                    try_number,
                    query_state,
                )
            else:
                self.log.info(
                    "Trial %s: Query execution completed. Final state is %s}",
                    try_number,
                    query_state,
                )
                final_query_state = query_state
                break
            if max_tries and try_number >= max_tries:  # Break loop if max_tries reached
                final_query_state = query_state
                break
            try_number += 1
            sleep(self.sleep_time)
        return final_query_state

    def stop_query(self, query_execution_id: str) -> Dict:
        """
        Cancel the submitted athena query

        :param query_execution_id: Id of submitted athena query
        :type query_execution_id: str
        :return: dict
        """
        return self.get_conn().stop_query_execution(QueryExecutionId=query_execution_id)