#!/usr/bin/python
# -*- coding: utf-8 -*-

# Copyright: (c) 2013, Chatham Financial <oss@chathamfinancial.com>
# 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

DOCUMENTATION = r'''
---
module: rabbitmq_user_limits
short_description: Manage RabbitMQ user limits
description:
  - Manage the state of user limits in RabbitMQ. Supported since RabbitMQ version 3.8.10.
author: Aitor Pazos (@aitorpazos)
version_added: '1.1.0'
options:
  user:
    description:
      - Name of user to manage limits for.
    type: str
    required: true
    aliases: [username, name]
  max_connections:
      description:
          - Max number of concurrent client connections.
          - Negative value means "no limit".
          - Ignored when the I(state) is C(absent).
      type: int
      default: -1
  max_channels:
      description:
          - Max number of channels.
          - Negative value means "no limit".
          - Ignored when the I(state) is C(absent).
      type: int
      default: -1
  node:
      description:
          - Name of the RabbitMQ Erlang node to manage.
      type: str
  state:
      description:
          - Specify whether the limits are to be set or cleared.
          - If set to C(absent), the limits of both I(max_connections) and I(max_channels) will be cleared.
      type: str
      default: present
      choices: [present, absent]
notes:
  - Supports C(check_mode).
'''

EXAMPLES = r'''
- name: Limit both of the max number of connections and channels on the user 'guest'.
  community.rabbitmq.rabbitmq_user_limits:
    user: guest
    max_connections: 64
    max_channels: 256
    state: present

# This task implicitly clears the max number of channels limit using default value: -1.
- name: Limit the max number of connections on the user 'guest'.
  community.rabbitmq.rabbitmq_user_limits:
    user: guest
    max_connections: 64
    state: present

- name: Clear the limits on the user 'guest'.
  community.rabbitmq.rabbitmq_user_limits:
    user: guest
    state: absent
'''

RETURN = r''' # '''

import json
import re
from ansible_collections.community.rabbitmq.plugins.module_utils.version import LooseVersion as Version
from ansible.module_utils.basic import AnsibleModule


class RabbitMqUserLimits(object):
    def __init__(self, module):
        self._module = module
        self._max_connections = module.params['max_connections']
        self._max_channels = module.params['max_channels']
        self._node = module.params['node']
        self._state = module.params['state']
        self._user = module.params['user']
        self._rabbitmqctl = module.get_bin_path('rabbitmqctl', True)

        self._version = self._rabbit_version()

    def _exec(self,
              args,
              force_exec_in_check_mode=False):

        if not self._module.check_mode or (self._module.check_mode and force_exec_in_check_mode):
            cmd = [self._rabbitmqctl, '-q']
            if self._node is not None:
                cmd.extend(['-n', self._node])
            rc, out, err = self._module.run_command(cmd + args, check_rc=True)

            return out
        return ""

    def _rabbit_version(self):
        status = self._exec(['status'], True)

        # 3.7.x erlang style output
        version_match = re.search('{rabbit,".*","(?P<version>.*)"}', status)
        if version_match:
            return Version(version_match.group('version'))

        # 3.8.x style output
        version_match = re.search('RabbitMQ version: (?P<version>.*)', status)
        if version_match:
            return Version(version_match.group('version'))

        return None

    def _assert_version(self):
        if self._version and self._version < Version('3.8.10'):
            self._module.fail_json(changed=False,
                                   msg="User limits are only available for RabbitMQ >= 3.8.10. Detected version: %s" % self._version)

    def list(self):
        self._assert_version()

        exec_result = self._exec(['list_user_limits', '--user', self._user], False)
        max_connections = None
        max_channels = None
        if exec_result:
            user_limits = json.loads(exec_result)
            if 'max-connections' in user_limits:
                max_connections = user_limits['max-connections']
            if 'max-channels' in user_limits:
                max_channels = user_limits['max-channels']
        return dict(
            max_connections=max_connections,
            max_channels=max_channels
        )

    def set(self):
        self._assert_version()

        if self._module.check_mode:
            return

        if self._max_connections != -1:
            json_str = '{{"max-connections": {0}}}'.format(self._max_connections)
            self._exec(['set_user_limits', self._user, json_str])
        else:
            self._exec(['clear_user_limits', self._user, "max-connections"])

        if self._max_channels != -1:
            json_str = '{{"max-channels": {0}}}'.format(self._max_channels)
            self._exec(['set_user_limits', self._user, json_str])
        else:
            self._exec(['clear_user_limits', self._user, "max-channels"])

    def clear(self):
        self._assert_version()

        if self._module.check_mode:
            return

        return self._exec(['clear_user_limits', self._user, 'all'])


def main():
    arg_spec = dict(
        user=dict(required=True, type='str', aliases=['username', 'name']),
        max_connections=dict(default=-1, type='int'),
        max_channels=dict(default=-1, type='int'),
        state=dict(default='present', choices=['present', 'absent'], type='str'),
        node=dict(default=None, type='str')
    )

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

    max_connections = module.params['max_connections']
    max_channels = module.params['max_channels']
    state = module.params['state']

    module_result = dict(changed=False)
    rabbitmq_user_limits = RabbitMqUserLimits(module)
    current_status = rabbitmq_user_limits.list()

    if state == 'present':
        wanted_status = dict(
            max_connections=max_connections,
            max_channels=max_channels
        )
    else:  # state == 'absent'
        wanted_status = dict(
            max_connections=None,
            max_channels=None
        )

    if current_status != wanted_status:
        module_result['changed'] = True
        if state == 'present':
            rabbitmq_user_limits.set()
        else:  # state == 'absent'
            rabbitmq_user_limits.clear()

    module.exit_json(**module_result)


if __name__ == '__main__':
    main()