#!/usr/bin/python
# This file is part of Ansible
#
# Ansible is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Ansible is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Ansible.  If not, see <http://www.gnu.org/licenses/>.

ANSIBLE_METADATA = {'metadata_version': '1.0',
                    'status': ['stableinterface'],
                    'supported_by': 'community'}


DOCUMENTATION = '''
---
module: route53
version_added: "1.3"
short_description: add or delete entries in Amazons Route53 DNS service
description:
     - Creates and deletes DNS records in Amazons Route53 service
options:
  state:
    description:
      - Specifies the state of the resource record. As of Ansible 2.4, the I(command) option has been changed
        to I(state) as default, but I(command) still works as well.
    required: true
    aliases: [ 'command' ]
    choices: [ 'present', 'absent', 'get', 'create', 'delete' ]
  zone:
    description:
      - The DNS zone to modify
    required: true
  hosted_zone_id:
    description:
      - The Hosted Zone ID of the DNS zone to modify
    required: false
    version_added: "2.0"
    default: null
  record:
    description:
      - The full DNS record to create or delete
    required: true
  ttl:
    description:
      - The TTL to give the new record
    required: false
    default: 3600 (one hour)
  type:
    description:
      - The type of DNS record to create
    required: true
    choices: [ 'A', 'CNAME', 'MX', 'AAAA', 'TXT', 'PTR', 'SRV', 'SPF', 'NS', 'SOA' ]
  alias:
    description:
      - Indicates if this is an alias record.
    required: false
    version_added: "1.9"
    default: False
    choices: [ 'True', 'False' ]
  alias_hosted_zone_id:
    description:
      - The hosted zone identifier.
    required: false
    version_added: "1.9"
    default: null
  alias_evaluate_target_health:
    description:
      - Whether or not to evaluate an alias target health. Useful for aliases to Elastic Load Balancers.
    required: false
    version_added: "2.1"
    default: false
  value:
    description:
      - The new value when creating a DNS record.  YAML lists or multiple comma-spaced values are allowed for non-alias records.
      - When deleting a record all values for the record must be specified or Route53 will not delete it.
    required: false
    default: null
  overwrite:
    description:
      - Whether an existing record should be overwritten on create if values do not match
    required: false
    default: null
  retry_interval:
    description:
      - In the case that route53 is still servicing a prior request, this module will wait and try again after this many seconds. If you have many
        domain names, the default of 500 seconds may be too long.
    required: false
    default: 500
  private_zone:
    description:
      - If set to true, the private zone matching the requested name within the domain will be used if there are both public and private zones.
        The default is to use the public zone.
    required: false
    default: false
    version_added: "1.9"
  identifier:
    description:
      - Have to be specified for Weighted, latency-based and failover resource record sets only. An identifier
        that differentiates among multiple resource record sets that have the
        same combination of DNS name and type.
    required: false
    default: null
    version_added: "2.0"
  weight:
    description:
      - Weighted resource record sets only. Among resource record sets that
        have the same combination of DNS name and type, a value that
        determines what portion of traffic for the current resource record set
        is routed to the associated location.
    required: false
    default: null
    version_added: "2.0"
  region:
    description:
      - Latency-based resource record sets only Among resource record sets
        that have the same combination of DNS name and type, a value that
        determines which region this should be associated with for the
        latency-based routing
    required: false
    default: null
    version_added: "2.0"
  health_check:
    description:
      - Health check to associate with this record
    required: false
    default: null
    version_added: "2.0"
  failover:
    description:
      - Failover resource record sets only. Whether this is the primary or
        secondary resource record set. Allowed values are PRIMARY and SECONDARY
    required: false
    default: null
    version_added: "2.0"
  vpc_id:
    description:
      - "When used in conjunction with private_zone: true, this will only modify records in the private hosted zone attached to this VPC."
      - This allows you to have multiple private hosted zones, all with the same name, attached to different VPCs.
    required: false
    default: null
    version_added: "2.0"
  wait:
    description:
      - Wait until the changes have been replicated to all Amazon Route 53 DNS servers.
    required: false
    default: no
    version_added: "2.1"
  wait_timeout:
    description:
      - How long to wait for the changes to be replicated, in seconds.
    required: false
    default: 300
    version_added: "2.1"
author:
  - "Bruce Pennypacker (@bpennypacker)"
  - "Mike Buzzetti <mike.buzzetti@gmail.com>"
extends_documentation_fragment: aws
'''


EXAMPLES = '''
# Add new.foo.com as an A record with 3 IPs and wait until the changes have been replicated
- route53:
      state: present
      zone: foo.com
      record: new.foo.com
      type: A
      ttl: 7200
      value: 1.1.1.1,2.2.2.2,3.3.3.3
      wait: yes

# Update new.foo.com as an A record with a list of 3 IPs and wait until the changes have been replicated
- route53:
      state: present
      zone: foo.com
      record: new.foo.com
      type: A
      ttl: 7200
      value:
        - 1.1.1.1
        - 2.2.2.2
        - 3.3.3.3
      wait: yes

# Retrieve the details for new.foo.com
- route53:
      state: get
      zone: foo.com
      record: new.foo.com
      type: A
  register: rec

# Delete new.foo.com A record using the results from the get command
- route53:
      state: absent
      zone: foo.com
      record: "{{ rec.set.record }}"
      ttl: "{{ rec.set.ttl }}"
      type: "{{ rec.set.type }}"
      value: "{{ rec.set.value }}"

# Add an AAAA record.  Note that because there are colons in the value
# that the IPv6 address must be quoted. Also shows using the old form command=create.
- route53:
      command: create
      zone: foo.com
      record: localhost.foo.com
      type: AAAA
      ttl: 7200
      value: "::1"

# Add a SRV record with multiple fields for a service on port 22222
# For more information on SRV records see:
# https://en.wikipedia.org/wiki/SRV_record
- route53:
      state: present
      zone: foo.com
      record: "_example-service._tcp.foo.com"
      type: SRV
      value: "0 0 22222 host1.foo.com,0 0 22222 host2.foo.com"

# Add a TXT record. Note that TXT and SPF records must be surrounded
# by quotes when sent to Route 53:
- route53:
      state: present
      zone: foo.com
      record: localhost.foo.com
      type: TXT
      ttl: 7200
      value: '"bar"'

# Add an alias record that points to an Amazon ELB:
- route53:
      state: present
      zone: foo.com
      record: elb.foo.com
      type: A
      value: "{{ elb_dns_name }}"
      alias: True
      alias_hosted_zone_id: "{{ elb_zone_id }}"

# Retrieve the details for elb.foo.com
- route53:
      state: get
      zone: foo.com
      record: elb.foo.com
      type: A
  register: rec

# Delete an alias record using the results from the get command
- route53:
      state: absent
      zone: foo.com
      record: "{{ rec.set.record }}"
      ttl: "{{ rec.set.ttl }}"
      type: "{{ rec.set.type }}"
      value: "{{ rec.set.value }}"
      alias: True
      alias_hosted_zone_id: "{{ rec.set.alias_hosted_zone_id }}"

# Add an alias record that points to an Amazon ELB and evaluates it health:
- route53:
    state: present
    zone: foo.com
    record: elb.foo.com
    type: A
    value: "{{ elb_dns_name }}"
    alias: True
    alias_hosted_zone_id: "{{ elb_zone_id }}"
    alias_evaluate_target_health: True

# Add an AAAA record with Hosted Zone ID.
- route53:
      state: present
      zone: foo.com
      hosted_zone_id: Z2AABBCCDDEEFF
      record: localhost.foo.com
      type: AAAA
      ttl: 7200
      value: "::1"

# Use a routing policy to distribute traffic:
- route53:
      state: present
      zone: foo.com
      record: www.foo.com
      type: CNAME
      value: host1.foo.com
      ttl: 30
      # Routing policy
      identifier: "host1@www"
      weight: 100
      health_check: "d994b780-3150-49fd-9205-356abdd42e75"

'''

MINIMUM_BOTO_VERSION = '2.28.0'
WAIT_RETRY_SLEEP = 5  # how many seconds to wait between propagation status polls


import time
import distutils.version

# import module snippets
from ansible.module_utils.basic import AnsibleModule
from ansible.module_utils.ec2 import ec2_argument_spec, get_aws_connection_info

try:
    import boto
    import boto.ec2
    from boto import route53
    from boto.route53 import Route53Connection
    from boto.route53.record import Record, ResourceRecordSets
    from boto.route53.status import Status
    HAS_BOTO = True
except ImportError:
    HAS_BOTO = False


class TimeoutError(Exception):
    pass


def get_zone_by_name(conn, module, zone_name, want_private, zone_id, want_vpc_id):
    """Finds a zone by name or zone_id"""
    for zone in invoke_with_throttling_retries(conn.get_zones):
        # only save this zone id if the private status of the zone matches
        # the private_zone_in boolean specified in the params
        private_zone = module.boolean(zone.config.get('PrivateZone', False))
        if private_zone == want_private and ((zone.name == zone_name and zone_id is None) or zone.id.replace('/hostedzone/', '') == zone_id):
            if want_vpc_id:
                # NOTE: These details aren't available in other boto methods, hence the necessary
                # extra API call
                hosted_zone = invoke_with_throttling_retries(conn.get_hosted_zone, zone.id)
                zone_details = hosted_zone['GetHostedZoneResponse']
                # this is to deal with this boto bug: https://github.com/boto/boto/pull/2882
                if isinstance(zone_details['VPCs'], dict):
                    if zone_details['VPCs']['VPC']['VPCId'] == want_vpc_id:
                        return zone
                else:  # Forward compatibility for when boto fixes that bug
                    if want_vpc_id in [v['VPCId'] for v in zone_details['VPCs']]:
                        return zone
            else:
                return zone
    return None


def commit(changes, retry_interval, wait, wait_timeout):
    """Commit changes, but retry PriorRequestNotComplete errors."""
    result = None
    retry = 10
    while True:
        try:
            retry -= 1
            result = changes.commit()
            break
        except boto.route53.exception.DNSServerError as e:
            code = e.body.split("<Code>")[1]
            code = code.split("</Code>")[0]
            if code != 'PriorRequestNotComplete' or retry < 0:
                raise e
            time.sleep(float(retry_interval))

    if wait:
        timeout_time = time.time() + wait_timeout
        connection = changes.connection
        change = result['ChangeResourceRecordSetsResponse']['ChangeInfo']
        status = Status(connection, change)
        while status.status != 'INSYNC' and time.time() < timeout_time:
            time.sleep(WAIT_RETRY_SLEEP)
            status.update()
        if time.time() >= timeout_time:
            raise TimeoutError()
        return result

# Shamelessly copied over from https://git.io/vgmDG
IGNORE_CODE = 'Throttling'
MAX_RETRIES = 5


def invoke_with_throttling_retries(function_ref, *argv, **kwargs):
    retries = 0
    while True:
        try:
            retval = function_ref(*argv, **kwargs)
            return retval
        except boto.exception.BotoServerError as e:
            if e.code != IGNORE_CODE or retries == MAX_RETRIES:
                raise e
        time.sleep(5 * (2**retries))
        retries += 1


def main():
    argument_spec = ec2_argument_spec()
    argument_spec.update(dict(
        state=dict(aliases=['command'], choices=['present', 'absent', 'get', 'create', 'delete'], required=True),
        zone=dict(required=True),
        hosted_zone_id=dict(required=False, default=None),
        record=dict(required=True),
        ttl=dict(required=False, type='int', default=3600),
        type=dict(choices=['A', 'CNAME', 'MX', 'AAAA', 'TXT', 'PTR', 'SRV', 'SPF', 'NS', 'SOA'], required=True),
        alias=dict(required=False, type='bool'),
        alias_hosted_zone_id=dict(required=False),
        alias_evaluate_target_health=dict(required=False, type='bool', default=False),
        value=dict(required=False, type='list'),
        overwrite=dict(required=False, type='bool'),
        retry_interval=dict(required=False, default=500),
        private_zone=dict(required=False, type='bool', default=False),
        identifier=dict(required=False, default=None),
        weight=dict(required=False, type='int'),
        region=dict(required=False),
        health_check=dict(required=False),
        failover=dict(required=False, choices=['PRIMARY', 'SECONDARY']),
        vpc_id=dict(required=False),
        wait=dict(required=False, type='bool', default=False),
        wait_timeout=dict(required=False, type='int', default=300),
    ))

    # state=present, absent, create, delete THEN value is required
    required_if = [('state', 'present', ['value']), ('state', 'create', ['value'])]
    required_if.extend([('state', 'absent', ['value']), ('state', 'delete', ['value'])])

    # If alias is True then you must specify alias_hosted_zone as well
    required_together = [['alias', 'alias_hosted_zone_id']]

    # failover, region, and weight are mutually exclusive
    mutually_exclusive = [('failover', 'region', 'weight')]

    module = AnsibleModule(argument_spec=argument_spec, required_together=required_together, required_if=required_if,
                           mutually_exclusive=mutually_exclusive)

    if not HAS_BOTO:
        module.fail_json(msg='boto required for this module')

    if distutils.version.StrictVersion(boto.__version__) < distutils.version.StrictVersion(MINIMUM_BOTO_VERSION):
        module.fail_json(msg='Found boto in version %s, but >= %s is required' % (boto.__version__, MINIMUM_BOTO_VERSION))

    if module.params['state'] in ('present', 'create'):
        command_in = 'create'
    elif module.params['state'] in ('absent', 'delete'):
        command_in = 'delete'
    elif module.params['state'] == 'get':
        command_in = 'get'

    zone_in = module.params.get('zone').lower()
    hosted_zone_id_in = module.params.get('hosted_zone_id')
    ttl_in = module.params.get('ttl')
    record_in = module.params.get('record').lower()
    type_in = module.params.get('type')
    value_in = module.params.get('value')
    alias_in = module.params.get('alias')
    alias_hosted_zone_id_in = module.params.get('alias_hosted_zone_id')
    alias_evaluate_target_health_in = module.params.get('alias_evaluate_target_health')
    retry_interval_in = module.params.get('retry_interval')

    if module.params['vpc_id'] is not None:
        private_zone_in = True
    else:
        private_zone_in = module.params.get('private_zone')

    identifier_in = module.params.get('identifier')
    weight_in = module.params.get('weight')
    region_in = module.params.get('region')
    health_check_in = module.params.get('health_check')
    failover_in = module.params.get('failover')
    vpc_id_in = module.params.get('vpc_id')
    wait_in = module.params.get('wait')
    wait_timeout_in = module.params.get('wait_timeout')

    region, ec2_url, aws_connect_kwargs = get_aws_connection_info(module)

    if zone_in[-1:] != '.':
        zone_in += "."

    if record_in[-1:] != '.':
        record_in += "."

    if command_in == 'create' or command_in == 'delete':
        if alias_in and len(value_in) != 1:
            module.fail_json(msg="parameter 'value' must contain a single dns name for alias records")
        if (weight_in is not None or region_in is not None or failover_in is not None) and identifier_in is None:
            module.fail_json(msg="If you specify failover, region or weight you must also specify identifier")
        if (weight_in is None and region_in is None and failover_in is None) and identifier_in is not None:
            module.fail_json(msg="You have specified identifier which makes sense only if you specify one of: weight, region or failover.")

    # connect to the route53 endpoint
    try:
        conn = Route53Connection(**aws_connect_kwargs)
    except boto.exception.BotoServerError as e:
        module.fail_json(msg=e.error_message)

    # Find the named zone ID
    zone = get_zone_by_name(conn, module, zone_in, private_zone_in, hosted_zone_id_in, vpc_id_in)

    # Verify that the requested zone is already defined in Route53
    if zone is None:
        errmsg = "Zone %s does not exist in Route53" % zone_in
        module.fail_json(msg=errmsg)

    record = {}

    found_record = False
    wanted_rset = Record(name=record_in, type=type_in, ttl=ttl_in,
                         identifier=identifier_in, weight=weight_in,
                         region=region_in, health_check=health_check_in,
                         failover=failover_in)
    for v in value_in:
        if alias_in:
            wanted_rset.set_alias(alias_hosted_zone_id_in, v, alias_evaluate_target_health_in)
        else:
            wanted_rset.add_value(v)

    sets = invoke_with_throttling_retries(conn.get_all_rrsets, zone.id, name=record_in,
                                          type=type_in, identifier=identifier_in)
    for rset in sets:
        # Due to a bug in either AWS or Boto, "special" characters are returned as octals, preventing round
        # tripping of things like * and @.
        decoded_name = rset.name.replace(r'\052', '*')
        decoded_name = decoded_name.replace(r'\100', '@')
        # Need to save this changes in rset, because of comparing rset.to_xml() == wanted_rset.to_xml() in next block
        rset.name = decoded_name

        if identifier_in is not None:
            identifier_in = str(identifier_in)

        if rset.type == type_in and decoded_name.lower() == record_in.lower() and rset.identifier == identifier_in:
            found_record = True
            record['zone'] = zone_in
            record['type'] = rset.type
            record['record'] = decoded_name
            record['ttl'] = rset.ttl
            record['value'] = ','.join(sorted(rset.resource_records))
            record['values'] = sorted(rset.resource_records)
            if hosted_zone_id_in:
                record['hosted_zone_id'] = hosted_zone_id_in
            record['identifier'] = rset.identifier
            record['weight'] = rset.weight
            record['region'] = rset.region
            record['failover'] = rset.failover
            record['health_check'] = rset.health_check
            if hosted_zone_id_in:
                record['hosted_zone_id'] = hosted_zone_id_in
            if rset.alias_dns_name:
                record['alias'] = True
                record['value'] = rset.alias_dns_name
                record['values'] = [rset.alias_dns_name]
                record['alias_hosted_zone_id'] = rset.alias_hosted_zone_id
                record['alias_evaluate_target_health'] = rset.alias_evaluate_target_health
            else:
                record['alias'] = False
                record['value'] = ','.join(sorted(rset.resource_records))
                record['values'] = sorted(rset.resource_records)
            if command_in == 'create' and rset.to_xml() == wanted_rset.to_xml():
                module.exit_json(changed=False)
            break

    if command_in == 'get':
        if type_in == 'NS':
            ns = record['values']
        else:
            # Retrieve name servers associated to the zone.
            z = invoke_with_throttling_retries(conn.get_zone, zone_in)
            ns = invoke_with_throttling_retries(z.get_nameservers)

        module.exit_json(changed=False, set=record, nameservers=ns)

    if command_in == 'delete' and not found_record:
        module.exit_json(changed=False)

    changes = ResourceRecordSets(conn, zone.id)

    if command_in == 'create' or command_in == 'delete':
        if command_in == 'create' and found_record:
            if not module.params['overwrite']:
                module.fail_json(msg="Record already exists with different value. Set 'overwrite' to replace it")
            command = 'UPSERT'
        else:
            command = command_in.upper()
        changes.add_change_record(command, wanted_rset)

    try:
        result = invoke_with_throttling_retries(commit, changes, retry_interval_in, wait_in, wait_timeout_in)
    except boto.route53.exception.DNSServerError as e:
        txt = e.body.split("<Message>")[1]
        txt = txt.split("</Message>")[0]
        if "but it already exists" in txt:
            module.exit_json(changed=False)
        else:
            module.fail_json(msg=txt)
    except TimeoutError:
        module.fail_json(msg='Timeout waiting for changes to replicate')

    module.exit_json(changed=True)

if __name__ == '__main__':
    main()