import re
import os
import time

from concurrent.futures import ThreadPoolExecutor

from novaclient.client import Client as n_client
from cinderclient.v1.client import Client as c_client


def ostack_get_creds():
    env = os.environ.get
    name = env('OS_USERNAME')
    passwd = env('OS_PASSWORD')
    tenant = env('OS_TENANT_NAME')
    auth_url = env('OS_AUTH_URL')
    return name, passwd, tenant, auth_url


def nova_connect():
    return n_client('1.1', *ostack_get_creds())


def create_keypair(nova, name, key_path):
    with open(key_path) as key:
        return nova.keypairs.create(name, key.read())


def create_volume(size, name):
    cinder = c_client(*ostack_get_creds())
    vol = cinder.volumes.create(size=size, display_name=name)
    err_count = 0
    while vol.status != 'available':
        if vol.status == 'error':
            if err_count == 3:
                print "Fail to create volume"
                raise RuntimeError("Fail to create volume")
            else:
                err_count += 1
                cinder.volumes.delete(vol)
                time.sleep(1)
                vol = cinder.volumes.create(size=size, display_name=name)
                continue
        time.sleep(1)
        vol = cinder.volumes.get(vol.id)
    return vol


def wait_for_server_active(nova, server, timeout=240):
    t = time.time()
    while True:
        time.sleep(5)
        sstate = getattr(server, 'OS-EXT-STS:vm_state').lower()

        if sstate == 'active':
            return True

        print "Curr state is", sstate, "waiting for active"

        if sstate == 'error':
            return False

        if time.time() - t > timeout:
            return False

        server = nova.servers.get(server)


class Allocate(object):
    pass


def get_floating_ips(nova, pool, amount):
    ip_list = nova.floating_ips.list()

    if pool is not None:
        ip_list = [ip for ip in ip_list if ip.pool == pool]

    return [ip for ip in ip_list if ip.instance_id is None][:amount]


def create_vms_mt(nova, amount, keypair_name, img_name,
                  flavor_name, vol_sz=None, network_zone_name=None,
                  flt_ip_pool=None, name_templ='ceph-test-{}',
                  scheduler_hints=None):

    if network_zone_name is not None:
        network = nova.networks.find(label=network_zone_name)
        nics = [{'net-id': network.id}]
    else:
        nics = None

    fl = nova.flavors.find(name=flavor_name)
    img = nova.images.find(name=img_name)

    if flt_ip_pool is not None:
        ips = get_floating_ips(nova, flt_ip_pool, amount)
        ips += [Allocate] * (amount - len(ips))
    else:
        ips = [None] * amount

    print "Try to start {0} servers".format(amount)
    names = map(name_templ.format, range(amount))

    with ThreadPoolExecutor(max_workers=16) as executor:
        futures = []
        for name, flt_ip in zip(names, ips):
            params = (nova, name, keypair_name, img, fl,
                      nics, vol_sz, flt_ip, scheduler_hints,
                      flt_ip_pool)

            futures.append(executor.submit(create_vm, *params))
        return [future.result() for future in futures]


def create_vm(nova, name, keypair_name, img,
              fl, nics, vol_sz=None,
              flt_ip=False,
              scheduler_hints=None,
              pool=None):
    for i in range(3):
        srv = nova.servers.create(name,
                                  flavor=fl, image=img, nics=nics,
                                  key_name=keypair_name,
                                  scheduler_hints=scheduler_hints)

        if not wait_for_server_active(nova, srv):
            msg = "Server {0} fails to start. Kill it and try again"
            print msg.format(srv.name)
            nova.servers.delete(srv)

            while True:
                print "wait till server deleted"
                all_id = set(alive_srv.id for alive_srv in nova.servers.list())
                if srv.id not in all_id:
                    break
                time.sleep(1)
        else:
            break

    if vol_sz is not None:
        print "creating volume"
        vol = create_volume(vol_sz, name)
        print "attach volume to server"
        nova.volumes.create_server_volume(srv.id, vol.id, None)

    if flt_ip is Allocate:
        flt_ip = nova.floating_ips.create(pool)

    if flt_ip is not None:
        print "attaching ip to server"
        srv.add_floating_ip(flt_ip)
        return (flt_ip.ip, srv)
    else:
        return (None, srv)


def clear_all(nova, name_templ="ceph-test-{}"):
    deleted_srvs = set()
    for srv in nova.servers.list():
        if re.match(name_templ.format("\\d+"), srv.name):
            print "Deleting server", srv.name
            nova.servers.delete(srv)
            deleted_srvs.add(srv.id)

    while deleted_srvs != set():
        print "Waiting till all servers are actually deleted"
        all_id = set(srv.id for srv in nova.servers.list())
        if all_id.intersection(deleted_srvs) == set():
            print "Done, deleting volumes"
            break
        time.sleep(1)

    # wait till vm actually deleted

    cinder = c_client(*ostack_get_creds())
    for vol in cinder.volumes.list():
        if isinstance(vol.display_name, basestring):
            if re.match(name_templ.format("\\d+"), vol.display_name):
                if vol.status in ('available', 'error'):
                    print "Deleting volume", vol.display_name
                    cinder.volumes.delete(vol)

    print "Clearing done (yet some volumes may still deleting)"


# def prepare_host(key_file, ip, fio_path, dst_fio_path, user='cirros'):
#     print "Wait till ssh ready...."
#     wait_ssh_ready(ip, user, key_file)

#     print "Preparing host >"
#     print "    Coping fio"
#     copy_fio(key_file, ip, fio_path, user, dst_fio_path)

#     key_opts = '-o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no'
#     args = (key_file, user, ip, key_opts)
#     cmd_format = "ssh {3} -i {0} {1}@{2} '{{0}}'".format(*args).format

#     def exec_on_host(cmd):
#         print "    " + cmd
#         subprocess.check_call(cmd_format(cmd), shell=True)

#     exec_on_host("sudo /usr/sbin/mkfs.ext4 /dev/vdb")
#     exec_on_host("sudo /bin/mkdir /media/ceph")
#     exec_on_host("sudo /bin/mount /dev/vdb /media/ceph")
#     exec_on_host("sudo /bin/chmod a+rwx /media/ceph")


def main():
    image_name = 'TestVM'
    flavor_name = 'ceph'
    vol_sz = 50
    network_zone_name = 'net04'
    amount = 10
    keypair_name = 'ceph-test'

    nova = nova_connect()
    clear_all(nova)

    try:
        ips = []
        params = dict(vol_sz=vol_sz)
        params['image_name'] = image_name
        params['flavor_name'] = flavor_name
        params['network_zone_name'] = network_zone_name
        params['amount'] = amount
        params['keypair_name'] = keypair_name

        for ip, host in create_vms(nova, **params):
            ips.append(ip)

        print "All setup done! Ips =", " ".join(ips)
        print "Starting tests"
    finally:
        clear_all(nova)

if __name__ == "__main__":
    exit(main())