"""Helper for DynamoDB requests."""

import boto3
from boto3.dynamodb.conditions import Attr, Key
from ddtrace import tracer

from users import config


@tracer.wrap(name='dynamodb_get_social_auth_item')
def get_social_auth_item(participant_id, identity_id, platform, dynamodb=None):
    """Query social auth db for participant's social auth info.

    Query social auth table in dynamodb to get the participant and
    related info. This helps us determine whether the user with
    id `identity_id` is the one who linked the participant with id `participant_id`.

    Args:
        participant_id (str): The id of the participant to query
        identity_id (str): The id of the user trying to unlink the participant's
                           social account
        platform (str): The platform of the participant to query

    Returns:
        The participant record or None if not found

    """
    if not participant_id:
        return None
    if not identity_id:
        return None
    if not platform:
        return None
    if not dynamodb:
        dynamodb = boto3.resource('dynamodb', region_name=config.AWS_REGION)
    table = dynamodb.Table(config.DYNAMODB_SOCIAL_AUTH_TABLE)
    response = table.query(
        KeyConditionExpression=Key('PK').eq(participant_id)
        & Key('SK').eq('{}#{}'.format(identity_id, platform.upper())),
        FilterExpression=Attr('linked').eq(True),
        Limit=1,
    )
    items = response.get('Items', [])
    if not items:
        return None
    return items[0]


@tracer.wrap(name='dynamodb_update_social_auth_item_linked_status')
def update_social_auth_item_linked_status(
    participant_id, identity_id, platform, link_status, dynamodb=None
):
    """Update social auth item's link status.

    Update the social auth item in the table to set the link status to `link_status`.

    Args:
        participant_id (str): The id of the participant to query
        identity_id (str): The id of the user trying to unlink the participant's
                           social account
        platform (str): The platform of the participant to query
        link_status (bool): The link status to set for the item

    Returns:
        The participant record or None if not found

    """
    if not participant_id:
        return None
    if not identity_id:
        return None
    if not platform:
        return None
    if not dynamodb:
        dynamodb = boto3.resource('dynamodb', region_name=config.AWS_REGION)
    table = dynamodb.Table(config.DYNAMODB_SOCIAL_AUTH_TABLE)
    response = table.update_item(
        Key={'PK': participant_id, 'SK': '{}#{}'.format(identity_id, platform.upper())},
        UpdateExpression='SET linked = :val',
        ExpressionAttributeValues={':val': link_status},
        ReturnValues='ALL_NEW',
    )
    attributes = response.get('Attributes', {})
    if not attributes:
        return None
    return attributes