import re
import socket
import random
import libvirt
import paramiko
from time import sleep
from xml.etree import ElementTree
from string import ascii_letters, digits
from passlib.hash import sha512_crypt


def is_kvm_available(xml):
    tree = ElementTree.fromstring(xml)
    for dom in tree.findall('guest/arch/domain'):
        if 'kvm' in dom.get('type'):
            return True
    return False


def randomMAC():
    """Generate a random MAC address."""
    # qemu MAC
    oui = [0x52, 0x54, 0x00]

    mac = oui + [random.randint(0x00, 0xff),
                 random.randint(0x00, 0xff),
                 random.randint(0x00, 0xff)]
    return ':'.join(map(lambda x: "%02x" % x, mac))


def randomUUID():
    """Generate a random UUID."""

    u = [random.randint(0, 255) for dummy in range(0, 16)]
    return "-".join(["%02x" * 4, "%02x" * 2, "%02x" * 2, "%02x" * 2, "%02x" * 6]) % tuple(u)


def get_max_vcpus(conn, type=None):
    """@param conn: libvirt connection to poll for max possible vcpus
       @type type: optional guest type (kvm, etc.)"""
    if type is None:
        type = conn.getType()
    try:
        m = conn.getMaxVcpus(type.lower())
    except libvirt.libvirtError:
        m = 32
    return m


def xml_escape(str):
    """Replaces chars ' " < > & with xml safe counterparts"""
    if str is None:
        return None

    str = str.replace("&", "&amp;")
    str = str.replace("'", "&apos;")
    str = str.replace("\"", "&quot;")
    str = str.replace("<", "&lt;")
    str = str.replace(">", "&gt;")
    return str


def compareMAC(p, q):
    """Compare two MAC addresses"""
    pa = p.split(":")
    qa = q.split(":")

    if len(pa) != len(qa):
        if p > q:
            return 1
        else:
            return -1

    for i in range(len(pa)):
        n = int(pa[i], 0x10) - int(qa[i], 0x10)
        if n > 0:
            return 1
        elif n < 0:
            return -1
    return 0


def get_xml_data(xml, path=None, element=None):
    res = ''
    if not path and not element:
        return ''

    tree = ElementTree.fromstring(xml)
    if path:
        child = tree.find(path)
        if child is not None:
            if element:
                res = child.get(element)
            else:
                res = child.text
    else:
        res = tree.get(element)
    return res


def get_xml_findall(xml, string):
    tree = ElementTree.fromstring(xml)
    return tree.findall(string)


def pretty_mem(val):
    val = int(val)
    if val > (10 * 1024 * 1024):
        return "%2.2f GB" % (val / (1024.0 * 1024.0))
    else:
        return "%2.0f MB" % (val / 1024.0)


def pretty_bytes(val):
    val = int(val)
    if val > (1024 * 1024 * 1024):
        return "%2.2f GB" % (val / (1024.0 * 1024.0 * 1024.0))
    else:
        return "%2.2f MB" % (val / (1024.0 * 1024.0))


def gen_password(length=14):
    password = ''.join(
        [random.choice(ascii_letters + digits) for dummy in range(length)]
    )
    return password


def password_to_hash(password):
    salt = gen_password(8)
    password_hash = sha512_crypt.encrypt(password, salt=salt, rounds=5000)
    return password_hash


def similar_name(pattern, names):
    res = []
    for name in names:
        match = re.match(pattern, name)
        if match:
            res.append(name)
    return res


def check_ssh_connection(hostname, password, username='root', timeout=90):
    ssh = paramiko.SSHClient()
    ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())

    for i in range(timeout):
        try:
            ssh.connect(hostname, username=username, password=password)
            ssh.close()
            return True
        except (paramiko.BadHostKeyException,
                paramiko.AuthenticationException,
                paramiko.SSHException,
                socket.error,
                EOFError):
            sleep(1)
    return False