# -*- coding: utf-8 -*-
'''
Managing Images in OpenStack Glance
===================================
'''
# Import python libs
from __future__ import absolute_import
import logging
import time

# Import salt libs
from salt.utils import warn_until

# Import OpenStack libs
try:
    from keystoneclient.apiclient.exceptions import \
        Unauthorized as kstone_Unauthorized
    from glanceclient.exc import \
        HTTPUnauthorized as glance_Unauthorized
    HAS_DEPENDENCIES = True
except ImportError:
    HAS_DEPENDENCIES = False

log = logging.getLogger(__name__)


def __virtual__():
    '''
    Only load if dependencies are loaded
    '''
    return HAS_DEPENDENCIES


def _find_image(name):
    '''
    Tries to find image with given name, returns
        - image, 'Found image <name>'
        - None, 'No such image found'
        - False, 'Found more than one image with given name'
    '''
    try:
        images_dict = __salt__['glance.image_list'](name=name)
    except kstone_Unauthorized:
        return False, 'keystoneclient: Unauthorized'
    except glance_Unauthorized:
        return False, 'glanceclient: Unauthorized'
    log.debug('Got images_dict: {0}'.format(images_dict))

    warn_until('Carbon', 'Starting with Carbon '
        '\'glance.image_list\' is not supposed to return '
        'the images wrapped in a separate dict anymore.')
    if len(images_dict) == 1 and 'images' in images_dict:
        images_dict = images_dict['images']

    # I /think/ this will still work when glance.image_list
    # starts returning a list instead of a dictionary...
    if len(images_dict) == 0:
        return None, 'No image with name "{0}"'.format(name)
    elif len(images_dict) == 1:
        return images_dict.values()[0], 'Found image {0}'.format(name)
    elif len(images_dict) > 1:
        return False, 'Found more than one image with given name'
    else:
        raise NotImplementedError


def image_present(name, visibility='public', protected=None,
        checksum=None, location=None, wait_for=None, timeout=30):
    '''
    Checks if given image is present with properties
    set as specified.

    An image should got through the stages 'queued', 'saving'
    before becoming 'active'. The attribute 'checksum' can
    only be checked once the image is active.
    If you don't specify 'wait_for' but 'checksum' the function
    will wait for the image to become active before comparing
    checksums. If you don't specify checksum either the function
    will return when the image reached 'saving'.
    The default timeout for both is 30 seconds.

    Supported properties:
      - visibility ('public' or 'private')
      - protected (bool)
      - checksum (string, md5sum)
      - location (URL, to copy from)
    '''
    ret = {'name': name,
            'changes': {},
            'result': True,
            'comment': '',
            }
    acceptable = ['queued', 'saving', 'active']
    if wait_for is None and checksum is None:
        wait_for = 'saving'
    elif wait_for is None and checksum is not None:
        wait_for = 'active'

    # Just pop states until we reach the
    # first acceptable one:
    while len(acceptable) > 1:
        if acceptable[0] == wait_for:
            break
        else:
            acceptable.pop(0)

    image, msg = _find_image(name)
    if image is False:
        if __opts__['test']:
            ret['result'] = None
        else:
            ret['result'] = False
        ret['comment'] = msg
        return ret
    log.debug(msg)
    # No image yet and we know where to get one
    if image is None and location is not None:
        if __opts__['test']:
            ret['result'] = None
            ret['comment'] = 'glance.image_present would ' \
                'create an image from {0}'.format(location)
            return ret
        image = __salt__['glance.image_create'](name=name,
            protected=protected, visibility=visibility,
            location=location)
        # See Salt issue #24568
        warn_until('Carbon', 'Starting with Carbon '
            '\'glance.image_create\' is not supposed to return '
            'the image wrapped in a dict anymore.')
        if len(image.keys()) == 1:
            image = image.values()[0]
        log.debug('Created new image:\n{0}'.format(image))
        ret['changes'] = {
            name:
                {
                    'new':
                        {
                        'id': image['id']
                        },
                    'old': None
                }
            }
        timer = timeout
        # Kinda busy-loopy but I don't think the Glance
        # API has events we can listen for
        while timer > 0:
            if 'status' in image and \
                    image['status'] in acceptable:
                log.debug('Image {0} has reached status {1}'.format(
                    image['name'], image['status']))
                break
            else:
                timer -= 5
                time.sleep(5)
                image, msg = _find_image(name)
                if not image:
                    ret['result'] = False
                    ret['comment'] += 'Created image {0} '.format(
                        name) + ' vanished:\n' + msg
                    return ret
                elif len(image.keys()) == 1:
                    # See Salt issue #24568
                    warn_until('Carbon', 'Starting with Carbon '
                        '\'_find_image()\' is not supposed to return '
                        'the image wrapped in a dict anymore.')
                    image = image.values()[0]
        if timer <= 0 and image['status'] not in acceptable:
            ret['result'] = False
            ret['comment'] += 'Image didn\'t reach an acceptable '+\
                    'state ({0}) before timeout:\n'.format(acceptable)+\
                    '\tLast status was "{0}".\n'.format(image['status'])

        # See Salt issue #24568
        warn_until('Carbon', 'Starting with Carbon '
            '\'_find_image()\' is not supposed to return '
            'the image wrapped in a dict anymore.')
        if len(image.keys()) == 1:
            image = image.values()[0]
            # ret[comment] +=

    # There's no image but where would I get one??
    elif location is None:
        if __opts__['test']:
            ret['result'] = None
            ret['comment'] = 'No location to copy image from specified,\n' +\
                         'glance.image_present would not create one'
        else:
            ret['result'] = False
            ret['comment'] = 'No location to copy image from specified,\n' +\
                         'not creating a new image.'
        return ret

    # If we've created a new image also return its last status:
    if name in ret['changes']:
        ret['changes'][name]['new']['status'] = image['status']

    if visibility:
        if image['visibility'] != visibility:
            old_value = image['visibility']
            if not __opts__['test']:
                image = __salt__['glance.image_update'](
                    id=image['id'], visibility=visibility)
            # See Salt issue #24568
            warn_until('Carbon', 'Starting with Carbon '
                '\'glance.image_update\' is not supposed to return '
                'the image wrapped in a dict anymore.')
            if len(image.keys()) == 1:
                image = image.values()[0]
            # Check if image_update() worked:
            if image['visibility'] != visibility:
                if not __opts__['test']:
                    ret['result'] = False
                elif __opts__['test']:
                    ret['result'] = None
                ret['comment'] += '"visibility" is {0}, '\
                    'should be {1}.\n'.format(image['visibility'],
                        visibility)
            else:
                if 'new' in ret['changes']:
                    ret['changes']['new']['visibility'] = visibility
                else:
                    ret['changes']['new'] = {'visibility': visibility}
                if 'old' in ret['changes']:
                    ret['changes']['old']['visibility'] = old_value
                else:
                    ret['changes']['old'] = {'visibility': old_value}
        else:
            ret['comment'] += '"visibility" is correct ({0}).\n'.format(
                visibility)
    if protected is not None:
        if not isinstance(protected, bool) or image['protected'] ^ protected:
            if not __opts__['test']:
                ret['result'] = False
            else:
                ret['result'] = None
            ret['comment'] += '"protected" is {0}, should be {1}.\n'.format(
                image['protected'], protected)
        else:
            ret['comment'] += '"protected" is correct ({0}).\n'.format(
                protected)
    if 'status' in image and checksum:
        if image['status'] == 'active':
            if 'checksum' not in image:
                # Refresh our info about the image
                image = __salt__['glance.image_show'](image['id'])
                warn_until('Carbon', 'Starting with Carbon '
                    '\'glance.image_show\' is not supposed to return '
                    'the image wrapped in a dict anymore.')
                if len(image.keys()) == 1:
                    image = image.values()[0]
            if 'checksum' not in image:
                if not __opts__['test']:
                    ret['result'] = False
                else:
                    ret['result'] = None
                ret['comment'] += 'No checksum available for this image:\n' +\
                        '\tImage has status "{0}".'.format(image['status'])
            elif image['checksum'] != checksum:
                if not __opts__['test']:
                    ret['result'] = False
                else:
                    ret['result'] = None
                ret['comment'] += '"checksum" is {0}, should be {1}.\n'.format(
                    image['checksum'], checksum)
            else:
                ret['comment'] += '"checksum" is correct ({0}).\n'.format(
                    checksum)
        elif image['status'] in ['saving', 'queued']:
            ret['comment'] += 'Checksum won\'t be verified as image ' +\
                'hasn\'t reached\n\t "status=active" yet.\n'
    log.debug('glance.image_present will return: {0}'.format(ret))
    return ret
