import logging
import re
from contextlib import contextmanager

from django.contrib.auth import get_user_model
from django.contrib.auth.models import Permission
from django.utils.text import slugify

from dcim.models import Device, DeviceRole, DeviceType, Manufacturer, Site
from extras.models import Tag
from virtualization.models import Cluster, ClusterType, VirtualMachine


def post_data(data):
    """
    Take a dictionary of test data (suitable for comparison to an instance) and return a dict suitable for POSTing.
    """
    ret = {}

    for key, value in data.items():
        if value is None:
            ret[key] = ''
        elif type(value) in (list, tuple):
            if value and hasattr(value[0], 'pk'):
                # Value is a list of instances
                ret[key] = [v.pk for v in value]
            else:
                ret[key] = value
        elif hasattr(value, 'pk'):
            # Value is an instance
            ret[key] = value.pk
        else:
            ret[key] = str(value)

    return ret


def create_test_device(name, site=None, **attrs):
    """
    Convenience method for creating a Device (e.g. for component testing).
    """
    if site is None:
        site, _ = Site.objects.get_or_create(name='Site 1', slug='site-1')
    manufacturer, _ = Manufacturer.objects.get_or_create(name='Manufacturer 1', slug='manufacturer-1')
    devicetype, _ = DeviceType.objects.get_or_create(model='Device Type 1', manufacturer=manufacturer)
    devicerole, _ = DeviceRole.objects.get_or_create(name='Device Role 1', slug='device-role-1')
    device = Device.objects.create(name=name, site=site, device_type=devicetype, role=devicerole, **attrs)

    return device


def create_test_virtualmachine(name):
    """
    Convenience method for creating a VirtualMachine.
    """
    cluster_type, _ = ClusterType.objects.get_or_create(name='Cluster Type 1', slug='cluster-type-1')
    cluster, _ = Cluster.objects.get_or_create(name='Cluster 1', type=cluster_type)
    virtual_machine = VirtualMachine.objects.create(name=name, cluster=cluster)

    return virtual_machine


def create_test_user(username='testuser', permissions=None):
    """
    Create a User with the given permissions.
    """
    user = get_user_model().objects.create_user(username=username)
    if permissions is None:
        permissions = ()
    for perm_name in permissions:
        app, codename = perm_name.split('.')
        perm = Permission.objects.get(content_type__app_label=app, codename=codename)
        user.user_permissions.add(perm)

    return user


def create_tags(*names):
    """
    Create and return a Tag instance for each name given.
    """
    tags = [Tag(name=name, slug=slugify(name)) for name in names]
    Tag.objects.bulk_create(tags)
    return tags


def extract_form_failures(content):
    """
    Given raw HTML content from an HTTP response, return a list of form errors.
    """
    FORM_ERROR_REGEX = r'<!-- FORM-ERROR (.*) -->'
    return re.findall(FORM_ERROR_REGEX, str(content))


@contextmanager
def disable_warnings(logger_name):
    """
    Temporarily suppress expected warning messages to keep the test output clean.
    """
    logger = logging.getLogger(logger_name)
    current_level = logger.level
    logger.setLevel(logging.ERROR)
    yield
    logger.setLevel(current_level)