#!/usr/bin/python2 -tt
#
# Copyright 2013-2014 Red Hat, Inc.
# Cole Robinson <crobinso@redhat.com>
#
# 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 difflib
import logging
import os
import sys

import libvirt
import urlgrabber.progress as progress

import virtinst
from virtinst import cli
from virtinst import util
from virtinst.cli import fail, print_stdout, print_stderr


###################
# Utility helpers #
###################

def prompt_yes_or_no(msg):
    while 1:
        printmsg = msg + " (y/n): "
        if "VIRTINST_TEST_SUITE" in os.environ:
            printmsg += "\n"
        sys.stdout.write(printmsg)
        sys.stdout.flush()

        inp = sys.stdin.readline().lower().strip()
        if inp in ["y", "yes"]:
            return True
        elif inp in ["n", "no"]:
            return False
        else:
            print_stdout(_("Please enter 'yes' or 'no'."))


def get_diff(origxml, newxml):
    ret = "".join(difflib.unified_diff(origxml.splitlines(1),
                                       newxml.splitlines(1),
                                       fromfile="Original XML",
                                       tofile="Altered XML"))

    if ret:
        logging.debug("XML diff:\n%s", ret)
    else:
        logging.debug("No XML diff, didn't generate any change.")
    return ret


def _make_guest(conn, xml):
    # We do this to minimize the diff, sanitizing XML quotes to what libxml
    # generates
    return virtinst.Guest(conn,
        parsexml=virtinst.Guest(conn, parsexml=xml).get_xml_config())


def get_domain_and_guest(conn, domstr):
    try:
        int(domstr)
        isint = True
    except ValueError:
        isint = False

    try:
        virtinst.util.validate_uuid(domstr)
        isuuid = True
    except ValueError:
        isuuid = False

    try:
        if isint:
            domain = conn.lookupByID(int(domstr))
        elif isuuid:
            domain = conn.lookupByUUIDString(domstr)
        else:
            domain = conn.lookupByName(domstr)
    except libvirt.libvirtError, e:
        fail(_("Could not find domain '%s': %s") % (domstr, e))

    state = domain.info()[0]
    active_xmlobj = None
    inactive_xmlobj = _make_guest(conn, domain.XMLDesc(0))
    if state != libvirt.VIR_DOMAIN_SHUTOFF:
        active_xmlobj = inactive_xmlobj
        inactive_xmlobj = _make_guest(conn,
            domain.XMLDesc(libvirt.VIR_DOMAIN_XML_INACTIVE))

    return (domain, inactive_xmlobj, active_xmlobj)


################
# Change logic #
################

def _find_devices_to_edit(guest, action_name, editval, parserobj):
    devlist = guest.get_devices(parserobj.devclass.virtual_device_type)
    idx = None

    if editval is None:
        idx = 1
    elif (editval.isdigit() or
          editval.startswith("-") and editval[1:].isdigit()):
        idx = int(editval)

    if idx is not None:
        if idx == 0:
            fail(_("Invalid --edit option '%s'") % editval)

        if not devlist:
            fail(_("No --%s devices found in the XML") %
                parserobj.cli_arg_name)
        if len(devlist) < abs(idx):
            fail(_("--edit %s requested but there's only %s "
                   "--%s devices in the XML") %
                (idx, len(devlist), parserobj.cli_arg_name))

        if idx > 0:
            idx -= 1
        inst = devlist[idx]
    elif editval == "all":
        inst = devlist[:]
    else:
        inst = parserobj.lookup_device_from_option_string(guest, editval)
        if not inst:
            fail(_("No matching devices found for --%s %s") %
                 (action_name, editval))

    return inst


def check_action_collision(options):
    actions = ["edit", "add-device", "remove-device", "build-xml"]

    collisions = []
    for cliname in actions:
        optname = cliname.replace("-", "_")
        if getattr(options, optname) not in [False, -1]:
            collisions.append(cliname)

    if len(collisions) == 0:
        fail(_("One of %s must be specified.") %
             ", ".join(["--" + c for c in actions]))
    if len(collisions) > 1:
        fail(_("Conflicting options %s") %
             ", ".join(["--" + c for c in collisions]))


def check_xmlopt_collision(options, parsermap):
    collisions = []
    for option_variable_name, parserobj in parsermap.items():
        if getattr(options, option_variable_name):
            collisions.append(parserobj)

    if len(collisions) == 0:
        fail(_("No change specified."))
    if len(collisions) != 1:
        fail(_("Only one change operation may be specified "
               "(conflicting options %s)") %
               ["--" + c.cli_arg_name for c in collisions])

    return collisions[0]


def action_edit(guest, options, parsermap, parserobj):
    if parserobj.devclass:
        inst = _find_devices_to_edit(guest, "edit", options.edit, parserobj)
    else:
        inst = guest
        if options.edit and options.edit != '1' and options.edit != 'all':
            fail(_("'--edit %s' doesn't make sense with --%s, "
                   "just use empty '--edit'") %
            (options.edit, parserobj.cli_arg_name))

    return cli.parse_option_strings(parsermap, options,
                                    guest, inst, update=True)


def action_add_device(guest, options, parsermap, parserobj):
    if not parserobj.devclass:
        fail(_("Cannot use --add-device with --%s") % parserobj.cli_arg_name)
    return cli.parse_option_strings(parsermap, options, guest, None)


def action_remove_device(guest, options, parsermap, parserobj):
    ignore = parsermap
    if not parserobj.devclass:
        fail(_("Cannot use --remove-device with --%s") %
             parserobj.cli_arg_name)

    devs = _find_devices_to_edit(guest, "remove-device",
        getattr(options, parserobj.option_variable_name)[-1], parserobj)

    devs = util.listify(devs)
    for dev in util.listify(devs):
        guest.remove_device(dev)
    return devs


def action_build_xml(conn, options, parsermap, parserobj):
    guest = virtinst.Guest(conn)
    ret_inst = None
    inst = None

    if parserobj.devclass:
        inst = parserobj.devclass(conn)
    elif parserobj.clear_attr:
        ret_inst = getattr(guest, parserobj.clear_attr)
    else:
        fail(_("--build-xml not supported for --%s") % parserobj.cli_arg_name)

    ret = cli.parse_option_strings(parsermap, options, guest, inst)
    if ret_inst:
        return ret_inst
    return ret


def setup_device(dev):
    if getattr(dev, "virtual_device_type", None) != "disk":
        return
    if getattr(dev, "virt_xml_setup", None) is True:
        return

    logging.debug("Doing setup for disk=%s", dev)

    meter = ((cli.quiet or "VIRTINST_TEST_SUITE" in os.environ) and
             progress.BaseMeter() or
             progress.TextMeter(fo=sys.stdout))

    dev.setup(meter)
    dev.virt_xml_setup = True


def define_changes(conn, inactive_xmlobj, devs, action, confirm):
    if confirm:
        if not prompt_yes_or_no(
            _("Define '%s' with the changed XML?" % inactive_xmlobj.name)):
            return

    if action == "hotplug":
        for dev in devs:
            setup_device(dev)

    conn.defineXML(inactive_xmlobj.get_xml_config())
    print_stdout(_("Domain '%s' defined successfully." % inactive_xmlobj.name))


def update_changes(domain, devs, action, confirm):
    for dev in devs:
        xml = dev.get_xml_config()

        if confirm:
            if action == "hotplug":
                prep = "to"
            elif action == "hotunplug":
                prep = "from"
            else:
                prep = "for"

            msg = ("%s\n\n%s this device %s guest '%s'?" %
                   (xml, action.capitalize(), prep, domain.name()))
            if not prompt_yes_or_no(msg):
                continue

        if action == "hotplug":
            setup_device(dev)

        try:
            if action == "hotplug":
                domain.attachDeviceFlags(xml, libvirt.VIR_DOMAIN_AFFECT_LIVE)
            elif action == "hotunplug":
                domain.detachDeviceFlags(xml, libvirt.VIR_DOMAIN_AFFECT_LIVE)
            elif action == "update":
                domain.updateDeviceFlags(xml, libvirt.VIR_DOMAIN_AFFECT_LIVE)
        except libvirt.libvirtError, e:
            fail(_("Error attempting device %s: %s") % (action, e))

        print_stdout(_("Device %s successful.") % action)
        if confirm:
            print_stdout("")


#######################
# CLI option handling #
#######################

def parse_args():
    parser = cli.setupParser(
        "%(prog)s [options]",
        _("Edit libvirt XML using command line options."),
        introspection_epilog=True)

    cli.add_connect_option(parser, "virt-xml")

    parser.add_argument("domain", nargs='?',
        help=_("Domain name, id, or uuid"))

    actg = parser.add_argument_group(_("XML actions"))
    actg.add_argument("--edit", nargs='?', default=-1,
        help=_("Edit VM XML. Examples:\n"
        "--edit --disk ...     (edit first disk device)\n"
        "--edit 2 --disk ...   (edit second disk device)\n"
        "--edit all --disk ... (edit all disk devices)\n"
        "--edit target=hda --disk ... (edit disk 'hda')\n"))
    actg.add_argument("--remove-device", action="store_true",
        help=_("Remove specified device. Examples:\n"
        "--remove-device --disk 1 (remove first disk)\n"
        "--remove-device --disk all (remove all disks)\n"
        "--remove-device --disk /some/path"))
    actg.add_argument("--add-device", action="store_true",
        help=_("Add specified device. Example:\n"
        "--add-device --disk ..."))
    actg.add_argument("--build-xml", action="store_true",
        help=_("Just output the built device XML, no domain required."))

    outg = parser.add_argument_group(_("Output options"))
    outg.add_argument("--update", action="store_true",
        help=_("Apply changes to the running VM.\n"
               "With --add-device, this is a hotplug operation.\n"
               "With --remove-device, this is a hotunplug operation.\n"
               "With --edit, this is an update device operation."))
    outg.add_argument("--define", action="store_true",
        help=_("Force defining the domain. Only required if a --print "
               "option was specified."))
    outg.add_argument("--print-diff", action="store_true",
        help=_("Only print the requested change, in diff format"))
    outg.add_argument("--print-xml", action="store_true",
        help=_("Only print the requested change, in full XML format"))
    outg.add_argument("--confirm", action="store_true",
        help=_("Require confirmation before saving any results."))

    g = parser.add_argument_group(_("XML options"))
    cli.add_disk_option(g, editexample=True)
    cli.add_net_option(g)
    cli.add_gfx_option(g)
    cli.add_metadata_option(g)
    cli.add_memory_option(g)
    cli.vcpu_cli_options(g, editexample=True)
    cli.add_guest_xml_options(g)
    cli.add_boot_options(g)
    cli.add_device_options(g)

    misc = parser.add_argument_group(_("Miscellaneous Options"))
    cli.add_misc_options(misc, prompt=False, printxml=False, dryrun=False)

    return parser.parse_args()


###################
# main() handling #
###################

def main(conn=None):
    cli.earlyLogging()
    options = parse_args()

    if (options.confirm or options.print_xml or
        options.print_diff or options.build_xml):
        options.quiet = False
    cli.setupLogging("virt-xml", options.debug, options.quiet)

    parsermap = cli.build_parser_map(options)
    if cli.check_option_introspection(options, parsermap):
        return 0

    options.stdinxml = None
    if not options.domain and not options.build_xml:
        if not sys.stdin.closed and not sys.stdin.isatty():
            if options.confirm:
                fail(_("Can't use --confirm with stdin input."))
            if options.update:
                fail(_("Can't use --update with stdin input."))
            options.stdinxml = sys.stdin.read()
        else:
            fail(_("A domain must be specified"))

    if not options.print_xml and not options.print_diff:
        if options.stdinxml:
            if not options.define:
                options.print_xml = True
        else:
            options.define = True
    if options.confirm and not options.print_xml:
        options.print_diff = True

    if conn is None:
        conn = cli.getConnection(options.connect)

    domain = None
    active_xmlobj = None
    inactive_xmlobj = None
    if options.domain:
        domain, inactive_xmlobj, active_xmlobj = get_domain_and_guest(
            conn, options.domain)
    elif not options.build_xml:
        inactive_xmlobj = _make_guest(conn, options.stdinxml)

    origxml = None
    if inactive_xmlobj:
        origxml = inactive_xmlobj.get_xml_config()

    check_action_collision(options)
    parserobj = check_xmlopt_collision(options, parsermap)

    if options.update and not parserobj.devclass:
        fail(_("Don't know how to --update for --%s") %
             (parserobj.cli_arg_name))

    if options.edit != -1:
        devs = action_edit(inactive_xmlobj, options, parsermap, parserobj)
        action = "update"

    elif options.add_device:
        devs = action_add_device(inactive_xmlobj, options,
                                 parsermap, parserobj)
        action = "hotplug"

    elif options.remove_device:
        devs = action_remove_device(inactive_xmlobj, options,
                                    parsermap, parserobj)
        action = "hotunplug"

    elif options.build_xml:
        devs = action_build_xml(conn, options, parsermap, parserobj)
        for dev in util.listify(devs):
            print_stdout(dev.get_xml_config())
        return 0

    newxml = inactive_xmlobj.get_xml_config()
    diff = get_diff(origxml, newxml)

    if options.print_diff:
        if diff:
            print_stdout(diff)
    elif options.print_xml:
        print_stdout(newxml)

    if options.update and active_xmlobj:
        update_changes(domain, devs, action, options.confirm)
    if options.define:
        define_changes(conn, inactive_xmlobj, devs, action, options.confirm)
        if not options.update and active_xmlobj:
            print_stdout(
                _("Changes will take effect after the next domain shutdown."))

    return 0


if __name__ == "__main__":
    try:
        sys.exit(main())
    except SystemExit, sys_e:
        sys.exit(sys_e.code)
    except KeyboardInterrupt:
        logging.debug("", exc_info=True)
        print_stderr(_("Aborted at user request"))
    except Exception, main_e:
        fail(main_e)