#!/usr/bin/python2
# -*- encoding: utf8 -*-
#
# The Qubes OS Project, http://www.qubes-os.org
#
# Copyright (C) 2010  Joanna Rutkowska <joanna@invisiblethingslab.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.
#
#
from multiprocessing import Event

from qubes.qubes import QubesVmCollection
from qubes.qubes import QubesException
from qubes.backup import backup_restore_header
from qubes.backup import backup_restore_prepare
from qubes.backup import backup_restore_print_summary
from qubes.backup import backup_restore_do
import qubes.backup
import sys
from optparse import OptionParser

import os
import sys
import getpass

def main():
    usage = "usage: %prog [options] <backup-dir> [vms-to-be-restored ...]"
    parser = OptionParser (usage)

    parser.add_option ("--verify-only", action="store_true",
                       dest="verify_only", default=False,
                       help="Do not restore the data, only verify backup "
                            "integrify.")

    parser.add_option ("--skip-broken", action="store_true", dest="skip_broken", default=False,
                       help="Do not restore VMs that have missing templates or netvms")

    parser.add_option ("--ignore-missing", action="store_true", dest="ignore_missing", default=False,
                       help="Ignore missing templates or netvms, restore VMs anyway")

    parser.add_option ("--skip-conflicting", action="store_true", dest="skip_conflicting", default=False,
                       help="Do not restore VMs that are already present on the host")

    parser.add_option ("--force-root", action="store_true", dest="force_root", default=False,
                       help="Force to run, even with root privileges")

    parser.add_option ("--replace-template", action="append", dest="replace_template", default=[],
                       help="Restore VMs using another template, syntax: "
                            "old-template-name:new-template-name (may be "
                            "repeated)")

    parser.add_option ("-x", "--exclude", action="append", dest="exclude", default=[],
                       help="Skip restore of specified VM (may be repeated)")

    parser.add_option ("--skip-dom0-home", action="store_false", dest="dom0_home", default=True,
                       help="Do not restore dom0 user home dir")

    parser.add_option ("--ignore-username-mismatch", action="store_true", dest="ignore_username_mismatch", default=False,
                       help="Ignore dom0 username mismatch while restoring homedir")

    parser.add_option ("-d", "--dest-vm", action="store", dest="appvm",
                       help="The AppVM to send backups to")

    parser.add_option ("-e", "--encrypted", action="store_true", dest="decrypt", default=False,
                       help="The backup is encrypted")

    parser.add_option ("-z", "--compressed", action="store_true", dest="compressed", default=False,
                       help="The backup is compressed")

    parser.add_option ("--debug", action="store_true", dest="debug",
                       default=False, help="Enable (a lot of) debug output")

    (options, args) = parser.parse_args ()

    if (len (args) < 1):
        print >> sys.stderr, "You must specify the backup directory (e.g. /mnt/backup/qubes-2010-12-01-235959)"
        exit (0)

    backup_dir = args[0]
    vmlist = args[1:]

    #if not os.path.exists (backup_dir):
    #    print >> sys.stderr, "The backup directory doesn't exist!"
    #    exit(1)

    host_collection = QubesVmCollection()
    host_collection.lock_db_for_writing()
    host_collection.load()

    restore_options = {}
    if options.ignore_missing:
        restore_options['use-default-template'] = True
        restore_options['use-default-netvm'] = True
    if options.replace_template:
        restore_options['replace-template'] = options.replace_template
    if not options.dom0_home:
        restore_options['dom0-home'] = False
    if options.ignore_username_mismatch:
        restore_options['ignore-username-mismatch'] = True
    if options.exclude:
        restore_options['exclude'] = options.exclude
    if options.verify_only:
        restore_options['verify-only'] = True
    if options.debug:
        qubes.backup.BACKUP_DEBUG = True

    appvm = None
    if options.appvm is not None:
        appvm = host_collection.get_vm_by_name(options.appvm)
        if appvm is None:
            print >>sys.stderr, "ERROR: VM {0} does not exist".format(options.appvm)
            exit(1)

    passphrase = getpass.getpass("Please enter the pass phrase that will be used to decrypt/verify the backup: ")
    passphrase = passphrase.decode(sys.stdin.encoding)

    print >> sys.stderr, "Checking backup content..."

    error_detected = Event()
    def error_callback(message):
        error_detected.set()
        print >> sys.stderr, message

    restore_info = None
    try:
        restore_info = backup_restore_prepare(
                backup_dir,
                passphrase=passphrase,
                options=restore_options,
                host_collection=host_collection,
                encrypted=options.decrypt,
                compressed=options.compressed,
                appvm=appvm,
                error_callback=error_callback)
    except QubesException as e:
        print >> sys.stderr, "ERROR: %s" % str(e)
        exit(1)

    if len(vmlist) > 0:
        for vm in restore_info.keys():
            if vm.startswith('$'):
                continue
            if not vm in vmlist:
                restore_info.pop(vm)

    backup_restore_print_summary(restore_info)

    there_are_conflicting_vms = False
    there_are_missing_templates = False
    there_are_missing_netvms = False
    dom0_username_mismatch = False

    for vm_info in restore_info.values():
        if 'excluded' in vm_info and vm_info['excluded']:
            continue
        if 'missing-template' in vm_info.keys():
            there_are_missing_templates = True
        if 'missing-netvm' in vm_info.keys():
            there_are_missing_netvms = True
        if 'already-exists' in vm_info.keys():
            there_are_conflicting_vms = True
        if 'username-mismatch' in vm_info.keys():
            dom0_username_mismatch = True

    print

    if hasattr(os, "geteuid") and os.geteuid() == 0:
        print >> sys.stderr, "*** Running this tool as root is strongly discouraged, this will lead you in permissions problems."
        if options.force_root:
            print >> sys.stderr, "Continuing as commanded. You have been warned."
        else:
            print >> sys.stderr, "Retry as unprivileged user."
            print >> sys.stderr, "... or use --force-root to continue anyway."
            exit(1)

    if there_are_conflicting_vms:
        print >> sys.stderr, "*** There VMs with conflicting names on the host! ***"
        if options.skip_conflicting:
            print >> sys.stderr, "Those VMs will not be restored, the host VMs will not be overwritten!"
        else:
            print >> sys.stderr, "Remove VMs with conflicting names from the host before proceeding."
            print >> sys.stderr, "... or use --skip-conflicting to restore only those VMs that do not exist on the host."
            exit (1)

    print "The above VMs will be copied and added to your system."
    print "Exisiting VMs will not be removed."

    if there_are_missing_templates:
        print >> sys.stderr, "*** One or more template VM is missing on the host! ***"
        if not (options.skip_broken or options.ignore_missing):
            print >> sys.stderr, "Install it first, before proceeding with backup restore."
            print >> sys.stderr, "Or pass: --skip-broken or --ignore-missing switch."
            exit (1)
        elif options.skip_broken:
            print >> sys.stderr, "... VMs that depend on it will not be restored (--skip-broken used)"
        elif options.ignore_missing:
            print >> sys.stderr, "... VMs that depend on it will be restored anyway (--ignore-missing used)"
        else:
            print >> sys.stderr, "INTERNAL ERROR?!"
            exit (1)

    if there_are_missing_netvms:
        print >> sys.stderr, "*** One or more network VM is missing on the host! ***"
        if not (options.skip_broken or options.ignore_missing):
            print >> sys.stderr, "Install it first, before proceeding with backup restore."
            print >> sys.stderr, "Or pass: --skip_broken or --ignore_missing switch."
            exit (1)
        elif options.skip_broken:
            print >> sys.stderr, "... VMs that depend on it will not be restored (--skip-broken used)"
        elif options.ignore_missing:
            print >> sys.stderr, "... VMs that depend on it be restored anyway (--ignore-missing used)"
        else:
            print >> sys.stderr, "INTERNAL ERROR?!"
            exit (1)

    if 'dom0' in restore_info.keys() and options.dom0_home:
        if dom0_username_mismatch:
            print >> sys.stderr, "*** Dom0 username mismatch! This can break some settings ***"
            if not options.ignore_username_mismatch:
                print >> sys.stderr, "Skip dom0 home restore (--skip-dom0-home)"
                print >> sys.stderr, "Or pass: --ignore-username-mismatch to continue anyway"
                exit(1)
            else:
                print >> sys.stderr, "Continuing as directed"
        print >> sys.stderr, "While restoring user homedir, existing files/dirs will be backed up in 'home-pre-restore-<current-time>' dir"

    prompt = raw_input ("Do you want to proceed? [y/N] ")
    if not (prompt == "y" or prompt == "Y"):
        exit (0)


    try:
        backup_restore_do(restore_info,
                host_collection=host_collection,
                error_callback=error_callback)
    except QubesException as e:
        print >> sys.stderr, "ERROR: %s" % str(e)

    host_collection.unlock_db()

    if error_detected.is_set():
        print "-> Completed with errors!"
        exit(1)
    else:
        print "-> Done."
main()