# -*- coding: utf-8 -*-
'''
Management of PostgreSQL groups (roles)
=======================================

The postgres_group module is used to create and manage Postgres groups.

.. code-block:: yaml

    frank:
      postgres_group.present
'''
from __future__ import absolute_import

# Import Python libs

# Import salt libs
import logging

# Salt imports
from salt.modules import postgres


log = logging.getLogger(__name__)


def __virtual__():
    '''
    Only load if the postgres module is present
    '''
    return 'postgres.group_create' in __salt__


def present(name,
            createdb=None,
            createroles=None,
            createuser=None,
            encrypted=None,
            superuser=None,
            inherit=None,
            login=None,
            replication=None,
            password=None,
            refresh_password=None,
            groups=None,
            user=None,
            maintenance_db=None,
            db_password=None,
            db_host=None,
            db_port=None,
            db_user=None):
    '''
    Ensure that the named group is present with the specified privileges
    Please note that the user/group notion in postgresql is just abstract, we
    have roles, where users can be seens as roles with the LOGIN privilege
    and groups the others.

    name
        The name of the group to manage

    createdb
        Is the group allowed to create databases?

    createroles
        Is the group allowed to create other roles/users

    createuser
        Alias to create roles, and history problem, in pgsql normally
        createuser == superuser

    encrypted
        Should the password be encrypted in the system catalog?

    login
        Should the group have login perm

    inherit
        Should the group inherit permissions

    superuser
        Should the new group be a "superuser"

    replication
        Should the new group be allowed to initiate streaming replication

    password
        The Group's password
        It can be either a plain string or a md5 postgresql hashed password::

            'md5{MD5OF({password}{role}}'

        If encrypted is None or True, the password will be automatically
        encrypted to the previous
        format if it is not already done.

    refresh_password
        Password refresh flag

        Boolean attribute to specify whether to password comparison check
        should be performed.

        If refresh_password is None or False, the password will be automatically
        updated without extra password change check.

        This behaviour makes it possible to execute in environments without
        superuser access available, e.g. Amazon RDS for PostgreSQL

    groups
        A string of comma separated groups the group should be in

    user
        System user all operations should be performed on behalf of

        .. versionadded:: 0.17.0

    db_user
        database username if different from config or defaul

    db_password
        user password if any password for a specified user

    db_host
        Database host if different from config or default

    db_port
        Database port if different from config or default
    '''
    ret = {'name': name,
           'changes': {},
           'result': True,
           'comment': 'Group {0} is already present'.format(name)}

    if createuser:
        createroles = True
    # default to encrypted passwords
    if encrypted is not False:
        encrypted = postgres._DEFAULT_PASSWORDS_ENCRYPTION
    # maybe encrypt if if not already and necessary
    password = postgres._maybe_encrypt_password(name,
                                                password,
                                                encrypted=encrypted)
    db_args = {
        'maintenance_db': maintenance_db,
        'runas': user,
        'host': db_host,
        'user': db_user,
        'port': db_port,
        'password': db_password,
    }

    # check if group exists
    mode = 'create'
    group_attr = __salt__['postgres.role_get'](
        name, return_password=not refresh_password, **db_args)
    if group_attr is not None:
        mode = 'update'

    # The user is not present, make it!
    cret = None
    update = {}
    if mode == 'update':
        if (
            createdb is not None
            and group_attr['can create databases'] != createdb
        ):
            update['createdb'] = createdb
        if (
            inherit is not None
            and group_attr['inherits privileges'] != inherit
        ):
            update['inherit'] = inherit
        if login is not None and group_attr['can login'] != login:
            update['login'] = login
        if (
            createroles is not None
            and group_attr['can create roles'] != createroles
        ):
            update['createroles'] = createroles
        if (
            replication is not None
            and group_attr['replication'] != replication
        ):
            update['replication'] = replication
        if superuser is not None and group_attr['superuser'] != superuser:
            update['superuser'] = superuser
        if password is not None and (refresh_password or group_attr['password'] != password):
            update['password'] = True
    if mode == 'create' or (mode == 'update' and update):
        if __opts__['test']:
            if update:
                ret['changes'][name] = update
            ret['result'] = None
            ret['comment'] = 'Group {0} is set to be {1}d'.format(name, mode)
            return ret
        cret = __salt__['postgres.group_{0}'.format(mode)](
            groupname=name,
            createdb=createdb,
            createroles=createroles,
            encrypted=encrypted,
            login=login,
            inherit=inherit,
            superuser=superuser,
            replication=replication,
            rolepassword=password,
            groups=groups,
            **db_args)
    else:
        cret = None
    if cret:
        ret['comment'] = 'The group {0} has been {1}d'.format(name, mode)
        if update:
            ret['changes'][name] = update
    elif cret is not None:
        ret['comment'] = 'Failed to create group {0}'.format(name)
        ret['result'] = False
    else:
        ret['result'] = True

    return ret


def absent(name,
           user=None,
           maintenance_db=None,
           db_password=None,
           db_host=None,
           db_port=None,
           db_user=None):
    '''
    Ensure that the named group is absent

    name
        The groupname of the group to remove

    user
        System user all operations should be performed on behalf of

        .. versionadded:: 0.17.0

    db_user
        database username if different from config or defaul

    db_password
        user password if any password for a specified user

    db_host
        Database host if different from config or default

    db_port
        Database port if different from config or default
    '''
    ret = {'name': name,
           'changes': {},
           'result': True,
           'comment': ''}

    db_args = {
        'maintenance_db': maintenance_db,
        'runas': user,
        'host': db_host,
        'user': db_user,
        'port': db_port,
        'password': db_password,
    }
    # check if group exists and remove it
    if __salt__['postgres.user_exists'](name, **db_args):
        if __opts__['test']:
            ret['result'] = None
            ret['comment'] = 'Group {0} is set to be removed'.format(name)
            return ret
        if __salt__['postgres.group_remove'](name, **db_args):
            ret['comment'] = 'Group {0} has been removed'.format(name)
            ret['changes'][name] = 'Absent'
            return ret
    else:
        ret['comment'] = 'Group {0} is not present, so it cannot ' \
                         'be removed'.format(name)

    return ret
