"""Lambda test module."""

from unittest.mock import patch

import boto3
import moto

import lambda_retention


def _create_fake_volume_with_snapshots(tag):
    """Create fake volume with provided tag for snapshot creation testing.

     Args:
        tag (str): tag value.
    Returns:
        str, list: volume id, list of snapshot ids.

    """
    ec2_client = boto3.client('ec2', region_name='us-east-1')
    response = ec2_client.create_volume(
        AvailabilityZone='us-east-1a',
        Size=80,
        VolumeType='gp2',
    )
    ec2_client.create_tags(
        Resources=[
            response['VolumeId'],
        ],
        Tags=[
            {
                'Key': tag,
                'Value': '1'
            },
        ]
    )
    snapshot_ids = []
    for i in range(3):
        snapshot = ec2_client.create_snapshot(VolumeId=response['VolumeId'])
        snapshot_ids.append(snapshot['SnapshotId'])
    return response['VolumeId'], snapshot_ids


@moto.mock_ec2
@patch('os.environ', {'VOLUME_TAG': 'mock_tag'})
def test_handler_via_moto_mock():
    """Test handler function."""
    # preparation
    mock_tag = 'mock_tag'
    volume_id, snapshot_ids = _create_fake_volume_with_snapshots(mock_tag)
    fake_event_string = 'event-data/{0}'.format(snapshot_ids[0])
    ec2_client = boto3.client('ec2', region_name='us-east-1')
    result_snapshot = ec2_client.describe_snapshots(
        Filters=[
            {
                'Name': 'volume-id',
                'Values': [
                    volume_id
                ]
            }
        ]
    )
    assert len(result_snapshot['Snapshots']) == 3
    # test functional call
    lambda_retention.handler(fake_event_string, None)
    # checking
    result_snapshot = ec2_client.describe_snapshots(
        Filters=[
            {
                'Name': 'volume-id',
                'Values': [
                    volume_id
                ]
            }
        ]
    )
    assert len(result_snapshot['Snapshots']) == 1