import logging
import os
import sys
import yaml

from utils import os_client

logger = logging.getLogger(__name__)


def compile_pairs(nodes):
    result = {}
    if len(nodes) %2 != 0:
        nodes.pop(1)
    pairs = list(zip(*[iter(nodes)] * 2))
    for pair in pairs:
        result[pair[0]+'<>'+pair[1]] = pair
    return result


def get_pairs():
    config = get_configuration()
    cmp_hosts = config.get('CMP_HOSTS') or []
    skipped_nodes = config.get('skipped_nodes') or []
    if skipped_nodes:
        sys.stdout.write(("\nNotice: {} nodes will be skipped for vm2vm test"
                          "".format(",".join(skipped_nodes))))
        logger.info("Skipping nodes {}".format(",".join(skipped_nodes)))
    if not cmp_hosts:
        openstack_clients = os_client.OfficialClientManager(
            username=os.environ['OS_USERNAME'],
            password=os.environ['OS_PASSWORD'],
            project_name=os.environ['OS_PROJECT_NAME'],
            auth_url=os.environ['OS_AUTH_URL'],
            cert=False,
            domain=os.environ['OS_PROJECT_DOMAIN_NAME']
        )
        os_actions = os_client.OSCliActions(openstack_clients)
        nova_computes = os_actions.list_nova_computes()
        if len(nova_computes) < 2:
            raise BaseException(
                "At least 2 compute hosts are needed for VM2VM test, "
                "now: {}.".format(len(nova_computes)))
        cmp_hosts = [n.host_name for n in nova_computes
                     if n.host_name not in skipped_nodes]
        if len(cmp_hosts) < 2:
            raise BaseException(
                "At least 2 compute hosts are needed for VM2VM test. "
                "Cannot create a pair from {}. Please check skip list, at "
                "least 2 computes should be tested.".format(cmp_hosts))
        logger.info("CMP_HOSTS option is not set, using host pair from "
                    "Nova compute list. Pair generated: {}".format(cmp_hosts))

    return compile_pairs(cmp_hosts)


def get_configuration():
    """function returns configuration for environment
    and for test if it's specified"""

    global_config_file = os.path.join(
        os.path.dirname(os.path.abspath(__file__)), "../global_config.yaml")
    with open(global_config_file, 'r') as file:
        global_config = yaml.load(file, Loader=yaml.SafeLoader)
    for param in list(global_config.keys()):
        if param in list(os.environ.keys()):
            if ',' in os.environ[param]:
                global_config[param] = []
                for item in os.environ[param].split(','):
                    global_config[param].append(item)
            else:
                global_config[param] = os.environ[param]

    return global_config


def check_iperf_utility(actual_iperf_utility):
    valid_values = ["iperf", "iperf3"]
    if actual_iperf_utility not in valid_values:
        raise BaseException("The iperf utility for multiple threads test case "
                            "is not correct. Valid value is one of {}. Actual "
                            "value is {}. Please set the correct value in "
                            "global_config.yaml:multiple_threads_iperf_utility"
                            "".format(valid_values, actual_iperf_utility))