#!/usr/bin/python

# (c) 2016, Kamil Szczygiel <kamil.szczygiel () intel.com>
#
# 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/>.

DOCUMENTATION = '''
---
module: influxdb_retention_policy
short_description: Manage InfluxDB retention policies
description:
    - Manage InfluxDB retention policies
version_added: 2.1
author: "Kamil Szczygiel (@kamsz)"
requirements:
    - "python >= 2.6"
    - "influxdb >= 0.9"
options:
    hostname:
        description:
            - The hostname or IP address on which InfluxDB server is listening
        required: true
    username:
        description:
            - Username that will be used to authenticate against InfluxDB server
        default: root
        required: false
    password:
        description:
            - Password that will be used to authenticate against InfluxDB server
        default: root
        required: false
    port:
        description:
            - The port on which InfluxDB server is listening
        default: 8086
        required: false
    database_name:
        description:
            - Name of the database where retention policy will be created
        required: true
    policy_name:
        description:
            - Name of the retention policy
        required: true
    duration:
        description:
            - Determines how long InfluxDB should keep the data
        required: true
    replication:
        description:
            - Determines how many independent copies of each point are stored in the cluster
        required: true
    default:
        description:
            - Sets the retention policy as default retention policy
        required: true
'''

EXAMPLES = '''
# Example influxdb_retention_policy command from Ansible Playbooks
- name: create 1 hour retention policy
    influxdb_retention_policy:
      hostname: "{{influxdb_ip_address}}"
      database_name: "{{influxdb_database_name}}"
      policy_name: test
      duration: 1h
      replication: 1

- name: create 1 day retention policy
    influxdb_retention_policy:
      hostname: "{{influxdb_ip_address}}"
      database_name: "{{influxdb_database_name}}"
      policy_name: test
      duration: 1d
      replication: 1

- name: create 1 week retention policy
    influxdb_retention_policy:
      hostname: "{{influxdb_ip_address}}"
      database_name: "{{influxdb_database_name}}"
      policy_name: test
      duration: 1w
      replication: 1

- name: create infinite retention policy
    influxdb_retention_policy:
      hostname: "{{influxdb_ip_address}}"
      database_name: "{{influxdb_database_name}}"
      policy_name: test
      duration: INF
      replication: 1
'''

RETURN = '''
#only defaults
'''

import re
try:
    import requests.exceptions
    from influxdb import InfluxDBClient
    from influxdb import exceptions
    HAS_INFLUXDB = True
except ImportError:
    HAS_INFLUXDB = False


def influxdb_argument_spec():
    return dict(
        hostname=dict(required=True, type='str'),
        port=dict(default=8086, type='int'),
        username=dict(default='root', type='str'),
        password=dict(default='root', type='str', no_log=True),
        database_name=dict(default=None, type='str')
    )


def connect_to_influxdb(module):
    hostname = module.params['hostname']
    port = module.params['port']
    username = module.params['username']
    password = module.params['password']
    database_name = module.params['database_name']

    client = InfluxDBClient(
        host=hostname,
        port=port,
        username=username,
        password=password,
        database=database_name
    )
    return client


def find_retention_policy(module, client):
    database_name = module.params['database_name']
    policy_name = module.params['policy_name']
    retention_policy = None

    try:
        retention_policies = client.get_list_retention_policies(database=database_name)
        for policy in retention_policies:
            if policy['name'] == policy_name:
                retention_policy = policy
                break
    except requests.exceptions.ConnectionError as e:
        module.fail_json(msg=str(e))
    return retention_policy


def create_retention_policy(module, client):
    database_name = module.params['database_name']
    policy_name = module.params['policy_name']
    duration = module.params['duration']
    replication = module.params['replication']
    default = module.params['default']

    if not module.check_mode:
        try:
            client.create_retention_policy(policy_name, duration, replication, database_name, default)
        except exceptions.InfluxDBClientError as e:
            module.fail_json(msg=e.content)
    module.exit_json(changed=True)


def alter_retention_policy(module, client, retention_policy):
    database_name = module.params['database_name']
    policy_name = module.params['policy_name']
    duration = module.params['duration']
    replication = module.params['replication']
    default = module.params['default']
    duration_regexp = re.compile('(\d+)([hdw]{1})|(^INF$){1}')
    changed = False

    duration_lookup = duration_regexp.search(duration)

    if duration_lookup.group(2) == 'h':
        influxdb_duration_format = '%s0m0s' % duration
    elif duration_lookup.group(2) == 'd':
        influxdb_duration_format = '%sh0m0s' % (int(duration_lookup.group(1)) * 24)
    elif duration_lookup.group(2) == 'w':
        influxdb_duration_format = '%sh0m0s' % (int(duration_lookup.group(1)) * 24 * 7)
    elif duration == 'INF':
        influxdb_duration_format = 'INF'

    if not retention_policy['duration'] == influxdb_duration_format or not retention_policy['replicaN'] == int(replication) or not retention_policy['default'] == default:
        if not module.check_mode:
            try:
                client.alter_retention_policy(policy_name, database_name, duration, replication, default)
            except exceptions.InfluxDBClientError as e:
                module.fail_json(msg=e.content)
        changed = True
    module.exit_json(changed=changed)


def main():
    argument_spec = influxdb_argument_spec()
    argument_spec.update(
        policy_name=dict(required=True, type='str'),
        duration=dict(required=True, type='str'),
        replication=dict(required=True, type='int'),
        default=dict(default=False, type='bool')
    )
    module = AnsibleModule(
        argument_spec=argument_spec,
        supports_check_mode=True
    )

    if not HAS_INFLUXDB:
        module.fail_json(msg='influxdb python package is required for this module')

    client = connect_to_influxdb(module)
    retention_policy = find_retention_policy(module, client)

    if retention_policy:
        alter_retention_policy(module, client, retention_policy)
    else:
        create_retention_policy(module, client)

from ansible.module_utils.basic import *

if __name__ == '__main__':
    main()
