#!/usr/bin/python3

# Copyright 2020, Red Hat, Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License 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 __future__ import absolute_import, division, print_function
__metaclass__ = type

from ansible.module_utils.basic import AnsibleModule
try:
    from ansible.module_utils.ca_common import generate_ceph_cmd, \
                                               pre_generate_ceph_cmd, \
                                               is_containerized, \
                                               exec_command, \
                                               exit_module
except ImportError:
    from module_utils.ca_common import generate_ceph_cmd, \
                                       pre_generate_ceph_cmd, \
                                       is_containerized, \
                                       exec_command, \
                                       exit_module


import datetime
import json
import os


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

DOCUMENTATION = '''
---
module: ceph_pool

author: Guillaume Abrioux <gabrioux@redhat.com>

short_description: Manage Ceph Pools

version_added: "2.8"

description:
    - Manage Ceph pool(s) creation, deletion and updates.
options:
    cluster:
        description:
            - The ceph cluster name.
        required: false
        default: ceph
    name:
        description:
            - name of the Ceph pool
        required: true
    state:
        description:
            If 'present' is used, the module creates a pool if it doesn't exist
            or update it if it already exists.
            If 'absent' is used, the module will simply delete the pool.
            If 'list' is used, the module will return all details about the
            existing pools. (json formatted).
        required: false
        choices: ['present', 'absent', 'list']
        default: present
    size:
        description:
            - set the replica size of the pool.
        required: false
        default: 3
    min_size:
        description:
            - set the min_size parameter of the pool.
        required: false
        default: default to `osd_pool_default_min_size` (ceph)
    pg_num:
        description:
            - set the pg_num of the pool.
        required: false
        default: default to `osd_pool_default_pg_num` (ceph)
    pgp_num:
        description:
            - set the pgp_num of the pool.
        required: false
        default: default to `osd_pool_default_pgp_num` (ceph)
    pg_autoscale_mode:
        description:
            - set the pg autoscaler on the pool.
        required: false
        default: 'on'
    target_size_ratio:
        description:
            - set the target_size_ratio on the pool
        required: false
        default: None
    pool_type:
        description:
            - set the pool type, either 'replicated' or 'erasure'
        required: false
        default: 'replicated'
    erasure_profile:
        description:
            - When pool_type = 'erasure', set the erasure profile of the pool
        required: false
        default: 'default'
    rule_name:
        description:
            - Set the crush rule name assigned to the pool
        required: false
        default: 'replicated_rule' when pool_type is 'erasure' else None
    expected_num_objects:
        description:
            -   Set the expected_num_objects parameter of the pool.
        required: false
        default: '0'
    application:
        description:
            - Set the pool application on the pool.
        required: false
        default: None
'''

EXAMPLES = '''

pools:
  - { name: foo, size: 3, application: rbd, pool_type: 'replicated',
      pg_autoscale_mode: 'on' }

- hosts: all
  become: true
  tasks:
    - name: create a pool
      ceph_pool:
        name: "{{ item.name }}"
        state: present
        size: "{{ item.size }}"
        application: "{{ item.application }}"
        pool_type: "{{ item.pool_type }}"
        pg_autoscale_mode: "{{ item.pg_autoscale_mode }}"
      with_items: "{{ pools }}"
'''

RETURN = '''#  '''


def check_pool_exist(cluster,
                     name,
                     user,
                     user_key,
                     output_format='json',
                     container_image=None):
    '''
    Check if a given pool exists
    '''

    args = ['stats', name, '-f', output_format]

    cmd = generate_ceph_cmd(cluster=cluster,
                            sub_cmd=['osd', 'pool'],
                            args=args,
                            user=user,
                            user_key=user_key,
                            container_image=container_image)

    return cmd


def generate_get_config_cmd(param,
                            cluster,
                            user,
                            user_key,
                            container_image=None):
    _cmd = pre_generate_ceph_cmd(container_image=container_image)
    args = [
        '-n',
        user,
        '-k',
        user_key,
        '--cluster',
        cluster,
        'config',
        'get',
        'mon.*',
        param
    ]
    cmd = _cmd + args
    return cmd


def get_application_pool(cluster,
                         name,
                         user,
                         user_key,
                         output_format='json',
                         container_image=None):
    '''
    Get application type enabled on a given pool
    '''

    args = ['application', 'get', name, '-f', output_format]

    cmd = generate_ceph_cmd(cluster=cluster,
                            sub_cmd=['osd', 'pool'],
                            args=args,
                            user=user,
                            user_key=user_key,
                            container_image=container_image)

    return cmd


def enable_application_pool(cluster,
                            name,
                            application,
                            user,
                            user_key,
                            container_image=None):
    '''
    Enable application on a given pool
    '''

    args = ['application', 'enable', name, application]

    cmd = generate_ceph_cmd(cluster=cluster,
                            sub_cmd=['osd', 'pool'],
                            args=args,
                            user=user,
                            user_key=user_key,
                            container_image=container_image)

    return cmd


def disable_application_pool(cluster,
                             name,
                             application,
                             user,
                             user_key,
                             container_image=None):
    '''
    Disable application on a given pool
    '''

    args = ['application', 'disable', name,
            application, '--yes-i-really-mean-it']

    cmd = generate_ceph_cmd(cluster=cluster,
                            sub_cmd=['osd', 'pool'],
                            args=args,
                            user=user,
                            user_key=user_key,
                            container_image=container_image)

    return cmd


def get_pool_details(module,
                     cluster,
                     name,
                     user,
                     user_key,
                     output_format='json',
                     container_image=None):
    '''
    Get details about a given pool
    '''

    args = ['ls', 'detail', '-f', output_format]

    cmd = generate_ceph_cmd(cluster=cluster,
                            sub_cmd=['osd', 'pool'],
                            args=args,
                            user=user,
                            user_key=user_key,
                            container_image=container_image)

    rc, cmd, out, err = exec_command(module, cmd)

    if rc == 0:
        out = [p for p in json.loads(out.strip()) if p['pool_name'] == name][0]

    _rc, _cmd, application_pool, _err = exec_command(module,
                                                     get_application_pool(cluster,    # noqa: E501
                                                                          name,    # noqa: E501
                                                                          user,    # noqa: E501
                                                                          user_key,    # noqa: E501
                                                                          container_image=container_image))  # noqa: E501

    # This is a trick because "target_size_ratio" isn't present at the same level in the dict
    # ie:
    # {
    # 'pg_num': 8,
    # 'pgp_num': 8,
    # 'pg_autoscale_mode': 'on',
    #     'options': {
    #          'target_size_ratio': 0.1
    #     }
    # }
    # If 'target_size_ratio' is present in 'options', we set it, this way we end up
    # with a dict containing all needed keys at the same level.
    if 'target_size_ratio' in out['options'].keys():
        out['target_size_ratio'] = out['options']['target_size_ratio']
    else:
        out['target_size_ratio'] = None

    application = list(json.loads(application_pool.strip()).keys())

    if len(application) == 0:
        out['application'] = ''
    else:
        out['application'] = application[0]

    return rc, cmd, out, err


def compare_pool_config(user_pool_config, running_pool_details):
    '''
    Compare user input config pool details with current running pool details
    '''

    delta = {}
    filter_keys = ['pg_num', 'pg_placement_num', 'size',
                   'pg_autoscale_mode', 'target_size_ratio']
    for key in filter_keys:
        if (str(running_pool_details[key]) != user_pool_config[key]['value'] and
                user_pool_config[key]['value']):
            delta[key] = user_pool_config[key]

    if (running_pool_details['application'] !=
            user_pool_config['application']['value'] and
            user_pool_config['application']['value']):
        delta['application'] = {}
        delta['application']['new_application'] = user_pool_config['application']['value']  # noqa: E501
        # to be improved (for update_pools()...)
        delta['application']['value'] = delta['application']['new_application']
        delta['application']['old_application'] = running_pool_details['application']  # noqa: E501

    return delta


def list_pools(cluster,
               user,
               user_key,
               details,
               output_format='json',
               container_image=None):
    '''
    List existing pools
    '''

    args = ['ls']

    if details:
        args.append('detail')

    args.extend(['-f', output_format])

    cmd = generate_ceph_cmd(cluster=cluster,
                            sub_cmd=['osd', 'pool'],
                            args=args,
                            user=user,
                            user_key=user_key,
                            container_image=container_image)

    return cmd


def create_pool(cluster,
                name,
                user,
                user_key,
                user_pool_config,
                container_image=None):
    '''
    Create a new pool
    '''

    args = ['create', user_pool_config['pool_name']['value'],
            user_pool_config['type']['value']]

    if user_pool_config['pg_autoscale_mode']['value'] != 'on':
        args.extend(['--pg_num',
                     user_pool_config['pg_num']['value'],
                     '--pgp_num',
                     user_pool_config['pgp_num']['value']])

    if user_pool_config['type']['value'] == 'replicated':
        args.extend([user_pool_config['crush_rule']['value'],
                     '--expected_num_objects',
                     user_pool_config['expected_num_objects']['value'],
                     '--autoscale-mode',
                     user_pool_config['pg_autoscale_mode']['value']])

    if (user_pool_config['size']['value'] and
            user_pool_config['type']['value'] == "replicated"):
        args.extend(['--size', user_pool_config['size']['value']])

    elif user_pool_config['type']['value'] == 'erasure':
        args.extend([user_pool_config['erasure_profile']['value']])

        if user_pool_config['crush_rule']['value']:
            args.extend([user_pool_config['crush_rule']['value']])

        args.extend(['--expected_num_objects',
                     user_pool_config['expected_num_objects']['value'],
                     '--autoscale-mode',
                     user_pool_config['pg_autoscale_mode']['value']])

    cmd = generate_ceph_cmd(cluster=cluster,
                            sub_cmd=['osd', 'pool'],
                            args=args,
                            user=user,
                            user_key=user_key,
                            container_image=container_image)

    return cmd


def remove_pool(cluster, name, user, user_key, container_image=None):
    '''
    Remove a pool
    '''

    args = ['rm', name, name, '--yes-i-really-really-mean-it']

    cmd = generate_ceph_cmd(cluster=cluster,
                            sub_cmd=['osd', 'pool'],
                            args=args,
                            user=user,
                            user_key=user_key,
                            container_image=container_image)

    return cmd


def update_pool(module, cluster, name,
                user, user_key, delta, container_image=None):
    '''
    Update an existing pool
    '''

    report = ""

    for key in delta.keys():
        if key != 'application':
            args = ['set',
                    name,
                    delta[key]['cli_set_opt'],
                    delta[key]['value']]

            cmd = generate_ceph_cmd(cluster=cluster,
                                    sub_cmd=['osd', 'pool'],
                                    args=args,
                                    user=user,
                                    user_key=user_key,
                                    container_image=container_image)

            rc, cmd, out, err = exec_command(module, cmd)
            if rc != 0:
                return rc, cmd, out, err

        else:
            rc, cmd, out, err = exec_command(module, disable_application_pool(cluster, name, delta['application']['old_application'], user, user_key, container_image=container_image))  # noqa: E501
            if rc != 0:
                return rc, cmd, out, err

            rc, cmd, out, err = exec_command(module, enable_application_pool(cluster, name, delta['application']['new_application'], user, user_key, container_image=container_image))  # noqa: E501
            if rc != 0:
                return rc, cmd, out, err

        report = report + "\n" + "{} has been updated: {} is now {}".format(name, key, delta[key]['value'])  # noqa: E501

    out = report
    return rc, cmd, out, err


def run_module():
    module_args = dict(
        cluster=dict(type='str', required=False, default='ceph'),
        name=dict(type='str', required=True),
        state=dict(type='str', required=False, default='present',
                   choices=['present', 'absent', 'list']),
        details=dict(type='bool', required=False, default=False),
        size=dict(type='str', required=False),
        min_size=dict(type='str', required=False),
        pg_num=dict(type='str', required=False),
        pgp_num=dict(type='str', required=False),
        pg_autoscale_mode=dict(type='str', required=False, default='on'),
        target_size_ratio=dict(type='str', required=False, default=None),
        pool_type=dict(type='str', required=False, default='replicated',
                       choices=['replicated', 'erasure', '1', '3']),
        erasure_profile=dict(type='str', required=False, default='default'),
        rule_name=dict(type='str', required=False, default=None),
        expected_num_objects=dict(type='str', required=False, default="0"),
        application=dict(type='str', required=False, default=None),
    )

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

    # Gather module parameters in variables
    cluster = module.params.get('cluster')
    name = module.params.get('name')
    state = module.params.get('state')
    details = module.params.get('details')
    size = module.params.get('size')
    min_size = module.params.get('min_size')
    pg_num = module.params.get('pg_num')
    pgp_num = module.params.get('pgp_num')
    pg_autoscale_mode = module.params.get('pg_autoscale_mode')
    target_size_ratio = module.params.get('target_size_ratio')
    application = module.params.get('application')

    if (module.params.get('pg_autoscale_mode').lower() in
            ['true', 'on', 'yes']):
        pg_autoscale_mode = 'on'
    elif (module.params.get('pg_autoscale_mode').lower() in
          ['false', 'off', 'no']):
        pg_autoscale_mode = 'off'
    else:
        pg_autoscale_mode = 'warn'

    if module.params.get('pool_type') == '1':
        pool_type = 'replicated'
    elif module.params.get('pool_type') == '3':
        pool_type = 'erasure'
    else:
        pool_type = module.params.get('pool_type')

    if not module.params.get('rule_name'):
        rule_name = 'replicated_rule' if pool_type == 'replicated' else None
    else:
        rule_name = module.params.get('rule_name')

    erasure_profile = module.params.get('erasure_profile')
    expected_num_objects = module.params.get('expected_num_objects')
    user_pool_config = {
        'pool_name': {'value': name},
        'pg_num': {'value': pg_num, 'cli_set_opt': 'pg_num'},
        'pgp_num': {'value': pgp_num, 'cli_set_opt': 'pgp_num'},
        'pg_autoscale_mode': {'value': pg_autoscale_mode,
                              'cli_set_opt': 'pg_autoscale_mode'},
        'target_size_ratio': {'value': target_size_ratio,
                              'cli_set_opt': 'target_size_ratio'},
        'application': {'value': application},
        'type': {'value': pool_type},
        'erasure_profile': {'value': erasure_profile},
        'crush_rule': {'value': rule_name, 'cli_set_opt': 'crush_rule'},
        'expected_num_objects': {'value': expected_num_objects},
        'size': {'value': size, 'cli_set_opt': 'size'},
        'min_size': {'value': min_size}
    }

    if module.check_mode:
        module.exit_json(
            changed=False,
            stdout='',
            stderr='',
            rc=0,
            start='',
            end='',
            delta='',
        )

    startd = datetime.datetime.now()
    changed = False

    # will return either the image name or None
    container_image = is_containerized()

    user = "client.admin"
    keyring_filename = cluster + '.' + user + '.keyring'
    user_key = os.path.join("/etc/ceph/", keyring_filename)

    if state == "present":
        rc, cmd, out, err = exec_command(module,
                                         check_pool_exist(cluster,
                                                          name,
                                                          user,
                                                          user_key,
                                                          container_image=container_image))  # noqa: E501
        if rc == 0:
            running_pool_details = get_pool_details(module,
                                                    cluster,
                                                    name,
                                                    user,
                                                    user_key,
                                                    container_image=container_image)  # noqa: E501
            user_pool_config['pg_placement_num'] = {'value': str(running_pool_details[2]['pg_placement_num']), 'cli_set_opt': 'pgp_num'}  # noqa: E501
            delta = compare_pool_config(user_pool_config,
                                        running_pool_details[2])
            if len(delta) > 0:
                keys = list(delta.keys())
                details = running_pool_details[2]
                if details['erasure_code_profile'] and 'size' in keys:
                    del delta['size']
                if details['pg_autoscale_mode'] == 'on':
                    delta.pop('pg_num', None)
                    delta.pop('pgp_num', None)

                if len(delta) == 0:
                    out = "Skipping pool {}.\nUpdating either 'size' on an erasure-coded pool or 'pg_num'/'pgp_num' on a pg autoscaled pool is incompatible".format(name)  # noqa: E501
                else:
                    rc, cmd, out, err = update_pool(module,
                                                    cluster,
                                                    name,
                                                    user,
                                                    user_key,
                                                    delta,
                                                    container_image=container_image)  # noqa: E501
                    if rc == 0:
                        changed = True
            else:
                out = "Pool {} already exists and there is nothing to update.".format(name)  # noqa: E501
        else:
            rc, cmd, out, err = exec_command(module,
                                             create_pool(cluster,
                                                         name,
                                                         user,
                                                         user_key,
                                                         user_pool_config=user_pool_config,  # noqa: E501
                                                         container_image=container_image))  # noqa: E501
            if user_pool_config['application']['value']:
                rc, _, _, _ = exec_command(module,
                                           enable_application_pool(cluster,
                                                                   name,
                                                                   user_pool_config['application']['value'],  # noqa: E501
                                                                   user,
                                                                   user_key,
                                                                   container_image=container_image))  # noqa: E501
            if user_pool_config['min_size']['value']:
                # not implemented yet
                pass
            changed = True

    elif state == "list":
        rc, cmd, out, err = exec_command(module,
                                         list_pools(cluster,
                                                    name, user,
                                                    user_key,
                                                    details,
                                                    container_image=container_image))  # noqa: E501
        if rc != 0:
            out = "Couldn't list pool(s) present on the cluster"

    elif state == "absent":
        rc, cmd, out, err = exec_command(module,
                                         check_pool_exist(cluster,
                                                          name, user,
                                                          user_key,
                                                          container_image=container_image))  # noqa: E501
        if rc == 0:
            rc, cmd, out, err = exec_command(module,
                                             remove_pool(cluster,
                                                         name,
                                                         user,
                                                         user_key,
                                                         container_image=container_image))  # noqa: E501
            changed = True
        else:
            rc = 0
            out = "Skipped, since pool {} doesn't exist".format(name)

    exit_module(module=module, out=out, rc=rc, cmd=cmd, err=err, startd=startd,
                changed=changed)


def main():
    run_module()


if __name__ == '__main__':
    main()