# Copyright 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"). You
# may not use this file except in compliance with the License. A copy of
# the License is located at
#
#     http://aws.amazon.com/apache2.0/
#
# or in the "license" file accompanying this file. This file is
# distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF
# ANY KIND, either express or implied. See the License for the specific
# language governing permissions and limitations under the License.

from argparse import Namespace
import sys


def get_instance_data(session, instance_id):
    """
    Calls EC2 DescribeInstances API to get the DNS Names and IP addresses of the instance both Public and Private
    and also gets the Availability Zone of an instance

    :param session: A Botocore session to use to generate the EC2 client
    :type session: Botocore.session.Session
    :param instance_id: InstanceID of the instance
    :type instance_id: basestring
    :return: Namespace with Public DNS Name, Private DNS Name, Public IP, Private IP and Availability Zone
    :rtype: argparse.Namespace
    """

    try:
        client = session.create_client('ec2')
        instance_id = [instance_id]
        response = client.describe_instances(InstanceIds=instance_id)
        availability_zone = response['Reservations'][0]['Instances'][0]['Placement']['AvailabilityZone']
        try:
            public_dns_name = response['Reservations'][0]['Instances'][0]['PublicDnsName']
        except:
            public_dns_name = None
            pass
        try:
            private_dns_name = response['Reservations'][0]['Instances'][0]['PrivateDnsName']
        except:
            private_dns_name = None
            pass
        try:
            public_ip = response['Reservations'][0]['Instances'][0]['PublicIpAddress']
        except:
            public_ip = None
            pass
        try:
            private_ip = response['Reservations'][0]['Instances'][0]['PrivateIpAddress']
        except:
            private_ip = None
            pass
    except Exception as e:
        print(str(e))
        sys.exit(1)
    else:
        if len(availability_zone) == 0:
            print("Instance zone information not found")
            sys.exit(7)
        if not (public_dns_name or private_dns_name or public_ip or private_ip):
            print("No hostname or IPs found")
            sys.exit(8)
        else:
            instance_info = Namespace(public_dns_name=public_dns_name,
                                      private_dns_name=private_dns_name,
                                      public_ip=public_ip,
                                      private_ip=private_ip,
                                      availability_zone=availability_zone
                                      )

    return instance_info