"""Connects to AWS SFN"""
import boto3


def start_execution(sfn_arn, execution_name, input):
    """Starts an execution of an SFN"""
    client = boto3.client('stepfunctions')

    response = client.start_execution(
        stateMachineArn=sfn_arn,
        name=execution_name,
        input=input
    )
    execution_arn = response.get('executionArn')

    return execution_arn


def get_execution_log_by_arn(exec_arn, max_res=50):
    """Get an aws SFN by sfn name."""
    sfn_client = boto3.client('stepfunctions')

    full_event_list = list()
    execution_list = sfn_client.get_execution_history(
        executionArn=exec_arn,
        maxResults=50,
        reverseOrder=True,
        includeExecutionData=True
    )

    next_token = execution_list.get('nextToken')
    for event in execution_list['events']:
        full_event_list.append(event)

    while next_token:
        execution_list = sfn_client.get_execution_history(
            executionArn=exec_arn,
            maxResults=max_res,
            reverseOrder=True,
            includeExecutionData=True,
            nextToken=next_token
        )

        next_token = execution_list.get('nextToken')
        for event in execution_list['events']:
            full_event_list.append(event)

    return full_event_list


def get_exec_by_arn(exec_arn):
    """Get an aws SFN Execution by execution ARN."""
    sfn_client = boto3.client('stepfunctions')

    sfn_exec = sfn_client.describe_execution(
        executionArn=exec_arn)

    return sfn_exec


def get_sfn_arn_by_name(sfn_name):
    """Get an aws SFN by sfn name."""

    sfn_client = boto3.client('stepfunctions')

    sfn_list = sfn_client.list_state_machines()

    next_token = sfn_list.get('nextToken')
    status = next(
        (sfn for sfn in sfn_list['stateMachines']
         if sfn.get('name') == sfn_name),
        None
    )

    while not status and next_token:
        sfn_list = sfn_client.list_state_machines(nextToken=next_token)
        status = next(
            (sfn for sfn in sfn_list['stateMachines']
             if sfn.get('name') == sfn_name),
            None
        )

        next_token = sfn_list.get('nextToken')

    if not status:
        raise RuntimeError(f'No state machine found for sfn name: {sfn_name}')

    return status


def get_full_execution_count_by_arn(sfn_arn, status='RUNNING'):
    """Get the count of SFN exections by sfn name and status.

    Args:
        sfn_arn (str): The ARN of the SFN to query.
        status (str, optional): Filter by status. Defaults to 'RUNNING'.

    Returns:
        int: The count of SFN exexcutions matching the passed status.
    """

    sfn_client = boto3.client('stepfunctions')

    current_executions = sfn_client.list_executions(
        stateMachineArn=sfn_arn,
        statusFilter=status,
        maxResults=50
    )
    next_token = current_executions.get('nextToken')

    current_sfn_count = len(current_executions['executions'])

    while next_token:
        current_executions = sfn_client.list_executions(
            stateMachineArn=sfn_arn,
            statusFilter=status,
            maxResults=50,
            nextToken=next_token
        )
        current_sfn_count = current_sfn_count + len(
            current_executions['executions'])

        next_token = current_executions.get('nextToken')

    return current_sfn_count


def get_full_execution_name_list_by_arn(sfn_arn, status='RUNNING'):
    """Get a list of SFN execution names by SFN ARN matching a given status.

    Args:
        sfn_arn (str): The SFN ARN.
        status (str, optional): Only match executions of this status.
                                Defaults to 'RUNNING'.

    Returns:
        list: A list containing execution names as strings.
    """

    sfn_client = boto3.client('stepfunctions')

    current_executions = sfn_client.list_executions(
        stateMachineArn=sfn_arn,
        statusFilter=status,
        maxResults=50
    )
    next_token = current_executions.get('nextToken')

    name_list = [x['name'] for x in current_executions['executions']]

    while next_token:
        current_executions = sfn_client.list_executions(
            stateMachineArn=sfn_arn,
            statusFilter=status,
            maxResults=50,
            nextToken=next_token
        )
        name_list = name_list + [x['name'] for x in
                                 current_executions['executions']]

        next_token = current_executions.get('nextToken')

    return name_list