#!/usr/bin/python
# mclu (mini cluster)
# Copyright (C) 2014 Red Hat Inc.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

import sys
import os
import re

import libvirt
import ansible.runner
import ansible.inventory

# Get separate list of running and inactive guests.
def get_all_guests (c):
    running = {}
    inactive = {}

    # Find running guests.
    runner = ansible.runner.Runner (
        remote_user = 'root',
        module_name = 'virt',
        module_args = 'command=list_vms', # XXX ignore state=shutdown
        pattern = c['nodes_group'],
    )
    data = runner.run ()

    for node in data['contacted'].keys():
        # Get the flat list of guests from this node:
        vms = data['contacted'][node]['list_vms']
        # Store which node the guest is running on, and turn list into a map.
        for vm in vms:
            if node in running:
                sys.exit ("error: virtual machine %s is running on two nodes!" % node)
            running[vm] = { 'vm' : vm, 'node' : node }

    # Find inactive guests (XML configuration files).
    for name in get_guest_configs (c):
        if name not in running:
            inactive[name] = name

    return running, inactive

# Get the names of guests from the XML configuration files in xmls_dir.
def get_guest_configs (c):
    names = []
    for filename in sorted (os.listdir (c['xmls_dir'])):
        m = re.search (r'^(.*)\.xml$', filename)
        if m:
            names.append (m.group (1))
    return names

# Start a guest running on a given node.  The node must not be
# running anywhere already.
def start_guest (c, node_name, guest_name):
    fp = open ("%s/%s.xml" % (c['xmls_dir'], guest_name), "r")
    xml = fp.read ()
    fp.close ()

    conn = libvirt.open (uri_of_node (node_name))
    if conn == None:
        sys.exit ("error: could not open a libvirt connection to %s" %
                  node_name)
    conn.createXML (xml)

def pick_any_node_which_is_up (c):
    inventory = ansible.inventory.Inventory ()
    runner = ansible.runner.Runner (
        remote_user = 'root',
        module_name = 'ping',
        inventory = inventory,
        pattern = c['nodes_group'],
    )
    data = runner.run ()
    if len (data['contacted']) == 0:
        sys.exit ("error: no nodes are up, use mclu on")
    return data['contacted'].keys()[0]

# XXX Make this configurable.
def uri_of_node (node_name):
    return "qemu+ssh://root@%s/system" % node_name