# -*- coding: utf-8 -*-
'''
Management of PostgreSQL tablespace
===================================

A module used to create and manage PostgreSQL tablespaces.

.. code-block:: yaml

    ssd-tablespace:
      postgres_tablespace.present:
        - name: indexes
        - directory: /mnt/ssd-data

.. versionadded:: 2015.8.0

'''

# Import python libs
from __future__ import absolute_import, unicode_literals, print_function

# Import salt libs
import salt.utils.dictupdate as dictupdate

# Import 3rd-party libs
from salt.ext.six import iteritems


def __virtual__():
    '''
    Only load if the postgres module is present and is new enough (has ts funcs)
    '''
    if 'postgres.tablespace_exists' not in __salt__:
        return (False, 'Unable to load postgres module.  Make sure `postgres.bins_dir` is set.')
    return True


def present(name,
            directory,
            options=None,
            owner=None,
            user=None,
            maintenance_db=None,
            db_password=None,
            db_host=None,
            db_port=None,
            db_user=None):
    '''
    Ensure that the named tablespace is present with the specified properties.
    For more information about all of these options run ``man 7
    create_tablespace``.

    name
        The name of the tablespace to create/manage.

    directory
        The directory where the tablespace will be located, must already exist

    options
        A dictionary of options to specify for the tablespace.
        Currently, the only tablespace options supported are ``seq_page_cost``
        and ``random_page_cost``. Default values are shown in the example below:

        .. code-block:: yaml

            my_space:
              postgres_tablespace.present:
                - directory: /srv/my_tablespace
                - options:
                    seq_page_cost: 1.0
                    random_page_cost: 4.0

    owner
        The database user that will be the owner of the tablespace.
        Defaults to the user executing the command (i.e. the `user` option)

    user
        System user all operations should be performed on behalf of

    maintenance_db
        Database to act on

    db_user
        Database username if different from config or default

    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': 'Tablespace {0} is already present'.format(name)}
    dbargs = {
        'maintenance_db': maintenance_db,
        'runas': user,
        'host': db_host,
        'user': db_user,
        'port': db_port,
        'password': db_password,
    }
    tblspaces = __salt__['postgres.tablespace_list'](**dbargs)
    if name not in tblspaces:
        # not there, create it
        if __opts__['test']:
            ret['result'] = None
            ret['comment'] = 'Tablespace {0} is set to be created'.format(name)
            return ret
        if __salt__['postgres.tablespace_create'](name, directory, options,
                                                  owner, **dbargs):
            ret['comment'] = 'The tablespace {0} has been created'.format(name)
            ret['changes'][name] = 'Present'
            return ret

    # already exists, make sure it's got the right config
    if tblspaces[name]['Location'] != directory and not __opts__['test']:
        ret['comment'] = """Tablespace {0} is not at the right location. This is
            unfixable without dropping and recreating the tablespace.""".format(
                name)
        ret['result'] = False
        return ret

    if owner and not tblspaces[name]['Owner'] == owner:
        if __opts__['test']:
            ret['result'] = None
            ret['comment'] = 'Tablespace {0} owner to be altered'.format(name)
        if (__salt__['postgres.tablespace_alter'](name, new_owner=owner)
            and not __opts__['test']):
            ret['comment'] = 'Tablespace {0} owner changed'.format(name)
            ret['changes'][name] = {'owner': owner}
            ret['result'] = True

    if options:
        # options comes from postgres as a sort of json(ish) string, but it
        # can't really be parsed out, but it's in a fairly consistent format
        # that we should be able to string check:
        # {seq_page_cost=1.1,random_page_cost=3.9}
        # TODO remove options that exist if possible
        for k, v in iteritems(options):
            # if 'seq_page_cost=1.1' not in '{seq_page_cost=1.1,...}'
            if '{0}={1}'.format(k, v) not in tblspaces[name]['Opts']:
                if __opts__['test']:
                    ret['result'] = None
                    ret['comment'] = """Tablespace {0} options to be
                        altered""".format(name)
                    break  # we know it's going to be altered, no reason to cont
                if __salt__['postgres.tablespace_alter'](name,
                                                         set_option={k: v}):
                    ret['comment'] = 'Tablespace {0} opts changed'.format(name)
                    dictupdate.update(ret['changes'], {name: {'options': {k: v}}})
                    ret['result'] = True

    return ret


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

    name
        The name of the tablespace to remove

    user
        System user all operations should be performed on behalf of

    maintenance_db
        Database to act on

    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 tablespace exists and remove it
    if __salt__['postgres.tablespace_exists'](name, **db_args):
        if __opts__['test']:
            ret['result'] = None
            ret['comment'] = 'Tablespace {0} is set to be removed'.format(name)
            return ret
        if __salt__['postgres.tablespace_remove'](name, **db_args):
            ret['comment'] = 'Tablespace {0} has been removed'.format(name)
            ret['changes'][name] = 'Absent'
            return ret

    # fallback
    ret['comment'] = 'Tablespace {0} is not present, so it cannot ' \
                     'be removed'.format(name)
    return ret
