#!/usr/bin/python -tt
#
# Copyright 2013 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 virtinst
from virtinst import cli
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 get_domain_and_guest(conn, domstr):
    if not domstr:
        fail("--domain must be specified")

    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))

    # XXX: Require this for first pass, but it sucks for testing
    #if domain.info()[0] != libvirt.VIR_DOMAIN_SHUTOFF:
    #    fail(_("Domain '%s' must be shutoff.") % domain.name())

    # XXX: any flags to use here? INACTIVE prob, though not secure or cpu
    xml = domain.XMLDesc(0)

    # We do this to minimize the diff, removing things like ' -> "
    xml = virtinst.Guest(conn, parsexml=xml).get_xml_config()
    return (domain, xml, virtinst.Guest(conn, parsexml=xml))


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

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

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

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

        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 options.edit == "all":
        inst = devlist[:]
    else:
        inst = parserobj.lookup_device_from_option_string(guest, options.edit)
        if not inst:
            fail(_("No matching devices found for --edit %s") % options.edit)

    return inst


def change_xml(guest, options, parsermap):
    # XXX: Make sure actions don't conflict
    # XXX: Make sure XML options don't conflict
    # XXX: Find a way to factor out whatever defaults there are
    if options.edit is -1:
        fail("--edit must be specified")

    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])
    parserobj = collisions[0]

    if parserobj.devclass:
        inst = _find_devices_to_edit(guest, options, 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))

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


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

def parse_args():
    # XXX: man page: mention introspection if it makes sense
    # XXX: expand usage
    # XXX: notes about the default actions, behavior, etc
    parser = cli.setupParser(
        "%(prog)s [options]",
        _("Edit libvirt XML using command line options."),
        introspection_epilog=True)

    cli.add_connect_option(parser)

    actg = parser.add_argument_group(_("Action Options"))
    actg.add_argument("--domain", help=_("Domain name, id, or uuid"))
    actg.add_argument("--edit", nargs='?', default=-1,
                      help=_("Edit VM XML"))

    g = parser.add_argument_group(_("XML options"))
    cli.add_disk_option(g)
    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)
    cli.add_guest_xml_options(g)
    cli.add_boot_option(g)
    cli.add_fs_option(g)
    cli.add_device_options(g)

    misc = parser.add_argument_group(_("Miscellaneous Options"))
    cli.add_misc_options(misc, prompt=False, printxml=False, dryrun=False)
    misc.add_argument("--print-diff", action="store_true",
        help=_("Only print the requested change, in diff format"))
    misc.add_argument("--print-xml", action="store_true",
        help=_("Only print the requested change, in full XML format"))
    misc.add_argument("--confirm", action="store_true",
        help=_("Require confirmation before saving any results."))
    misc.add_argument("--define", action="store_true",
        help=_("Force defining the domain, only required if a --print "
               "option was specified."))

    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:
        options.quiet = False
    if not options.print_xml and not options.print_diff:
        options.define = True
    if options.confirm and not options.print_xml:
        options.print_diff = True

    cli.setupLogging("virt-xml", options.debug, options.quiet)

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

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

    domain, origxml, guest = get_domain_and_guest(conn, options.domain)
    # XXX: do we ever need the domain?
    ignore = domain

    change_xml(guest, options, parsermap)

    newxml = guest.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 not options.define:
        return 0

    if options.confirm:
        # XXX: Message needs to depend on what action we will take
        if not prompt_yes_or_no(
            _("Define '%s' with the changed XML?" % guest.name)):
            return 0

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