import logging
from xml.etree import ElementTree as etree

import libvirt
import yaml

from ansible.plugins.inventory import BaseInventoryPlugin, Constructable

DOCUMENTATION = r'''
name: pyrocufflink
extends_documentation_fragment:
- constructed
short_description: Pyrocufflink inventory source
version_added: ''
description:
- Dynamic inventory for Pyrocufflink machines
author:
- Dustin C. Hatch <dustin@hatch.name>
options:
  plugin:
    description:
      Token that ensures this is a source file for the 'pyrocufflink' plugin.
    required: True
    choices: ['pyrocufflink']
'''

log = logging.getLogger('ansible.plugins.inventory.pyrocufflink')

METADATA_XMLNS = 'http://du5t1n.me/xmlns/libvirt/metadata/'

DOMAIN_STATES = {
    0: 'no state',
    1: 'the domain is running',
    2: 'the domain is blocked on resource',
    3: 'the domain is paused by user',
    4: 'the domain is being shut down',
    5: 'the domain is shut off',
    6: 'the domain is crashed',
    7: 'the domain is suspended by guest power management',
}

# Remove the default error handler, which prints to stderr
libvirt.registerErrorHandler(lambda *_: None, None)


class InventoryModule(BaseInventoryPlugin, Constructable):
    NAME = 'pyrocufflink'

    def parse(self, inventory, loader, path, cache=True):
        super().parse(inventory, loader, path, cache=cache)
        config_data = self._read_config_data(path)
        # set _options from config data
        self._consume_options(config_data)

        assert self.inventory
        conn = libvirt.open()
        for dom in conn.listAllDomains():
            v = {}

            name = v['name'] = dom.name()
            try:
                v['title'] = dom.metadata(1, None)
            except libvirt.libvirtError as e:
                log.debug('Could not get title for domain %s: %s', name, e)
                inventory_hostname = name
            else:
                inventory_hostname = v['title']
            self.inventory.add_host(inventory_hostname)

            try:
                v['description'] = dom.metadata(0, None)
            except libvirt.libvirtError as e:
                log.debug('Could not get description for %s: %s', name, e)

            try:
                metadata = dom.metadata(2, METADATA_XMLNS)
            except libvirt.libvirtError as e:
                log.debug(
                    'Could not get extended domain metadata for %s: %s',
                    name,
                    e,
                )
            else:
                try:
                    v['metadata'] = parse_metadata(metadata)
                except Exception as e:
                    log.error('Failed to parse metadata for %s: %s', name, e)

            state, reason = dom.state()
            v['state_code'] = state
            v['state_reason_code'] = reason
            try:
                v['state'] = DOMAIN_STATES[state]
            except KeyError:
                pass
            if state == 1:
                try:
                    guest_info = dom.guestInfo()
                except libvirt.libvirtError as e:
                    log.error('Could not get guest info for %s: %s', name, e)
                else:
                    self.inventory.set_variable(name, 'guest_info', guest_info)
            self.inventory.set_variable(inventory_hostname, 'libvirt', v)


def parse_metadata(metadata: str):
    tree = etree.fromstring(metadata)
    return yaml.safe_load(tree.text)