#!/usr/bin/python
# Copyright: Ansible Project
# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)

from __future__ import absolute_import, division, print_function
__metaclass__ = type


ANSIBLE_METADATA = {'metadata_version': '1.1',
                    'status': ['preview'],
                    'supported_by': 'community'}


DOCUMENTATION = '''
module: ec2_vpc_nat_gateway_facts
short_description: Retrieves AWS VPC Managed Nat Gateway details using AWS methods.
description:
  - Gets various details related to AWS VPC Managed Nat Gateways
version_added: "2.3"
requirements: [ boto3 ]
options:
  nat_gateway_ids:
    description:
      - Get details of specific nat gateway IDs
    required: false
    default: None
  filters:
    description:
      - A dict of filters to apply. Each dict item consists of a filter key and a filter value.
        See U(http://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_DescribeNatGateways.html)
        for possible filters.
    required: false
    default: None
author: Karen Cheng(@Etherdaemon)
extends_documentation_fragment:
  - aws
  - ec2
'''

EXAMPLES = '''
# Simple example of listing all nat gateways
- name: List all managed nat gateways in ap-southeast-2
  ec2_vpc_nat_gateway_facts:
    region: ap-southeast-2
  register: all_ngws

- name: Debugging the result
  debug:
    msg: "{{ all_ngws.result }}"

- name: Get details on specific nat gateways
  ec2_vpc_nat_gateway_facts:
    nat_gateway_ids:
      - nat-1234567891234567
      - nat-7654321987654321
    region: ap-southeast-2
  register: specific_ngws

- name: Get all nat gateways with specific filters
  ec2_vpc_nat_gateway_facts:
    region: ap-southeast-2
    filters:
      state: ['pending']
  register: pending_ngws

- name: Get nat gateways with specific filter
  ec2_vpc_nat_gateway_facts:
    region: ap-southeast-2
    filters:
      subnet-id: subnet-12345678
      state: ['available']
  register: existing_nat_gateways
'''

RETURN = '''
result:
  description: The result of the describe, converted to ansible snake case style.
    See http://boto3.readthedocs.io/en/latest/reference/services/ec2.html#EC2.Client.describe_nat_gateways for the response.
  returned: success
  type: list
'''

import json

try:
    import botocore
except ImportError:
    pass  # will be detected by imported HAS_BOTO3

from ansible.module_utils.basic import AnsibleModule
from ansible.module_utils.ec2 import (ec2_argument_spec, get_aws_connection_info, boto3_conn,
                                      camel_dict_to_snake_dict, ansible_dict_to_boto3_filter_list, HAS_BOTO3)


def date_handler(obj):
    return obj.isoformat() if hasattr(obj, 'isoformat') else obj


def get_nat_gateways(client, module, nat_gateway_id=None):
    params = dict()

    params['Filter'] = ansible_dict_to_boto3_filter_list(module.params.get('filters'))
    params['NatGatewayIds'] = module.params.get('nat_gateway_ids')

    try:
        result = json.loads(json.dumps(client.describe_nat_gateways(**params), default=date_handler))
    except Exception as e:
        module.fail_json(msg=str(e.message))

    return [camel_dict_to_snake_dict(gateway) for gateway in result['NatGateways']]


def main():
    argument_spec = ec2_argument_spec()
    argument_spec.update(
        dict(
            filters=dict(default={}, type='dict'),
            nat_gateway_ids=dict(default=[], type='list'),
        )
    )

    module = AnsibleModule(argument_spec=argument_spec,
                           supports_check_mode=True)

    # Validate Requirements
    if not HAS_BOTO3:
        module.fail_json(msg='botocore/boto3 is required.')

    try:
        region, ec2_url, aws_connect_params = get_aws_connection_info(module, boto3=True)
        if region:
            connection = boto3_conn(module, conn_type='client', resource='ec2', region=region, endpoint=ec2_url, **aws_connect_params)
        else:
            module.fail_json(msg="region must be specified")
    except botocore.exceptions.NoCredentialsError as e:
        module.fail_json(msg=str(e))

    results = get_nat_gateways(connection, module)

    module.exit_json(result=results)


if __name__ == '__main__':
    main()
