#!/usr/bin/python2.6
#
# 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 qubes.qubes import QubesVmCollection
from qubes.qubes import QubesException
from qubes.qubes import qubes_store_filename
from qubes.qubes import qubes_base_dir
from optparse import OptionParser
import os
import time
import subprocess
import sys

def size_to_human (size):
    if size < 1024:
        return str (size);
    elif size < 1024*1024:
        return str(round(size/1024.0,1)) + ' KiB'
    elif size < 1024*1024*1024:
        return str(round(size/(1024.0*1024),1)) + ' MiB'
    else:
        return str(round(size/(1024.0*1024*1024),1)) + ' GiB'

def file_to_backup (file_path, sz = None):
    if sz is None:
        sz = os.path.getsize (qubes_store_filename)

    abs_file_path = os.path.abspath (file_path)
    abs_base_dir = os.path.abspath (qubes_base_dir) + '/'
    abs_file_dir = os.path.dirname (abs_file_path) + '/'
    (nothing, dir, subdir) = abs_file_dir.partition (abs_base_dir)
    assert nothing == ""
    assert dir == abs_base_dir
    return [ { "path" : file_path, "size": sz, "subdir": subdir} ]

def main():
    usage = "usage: %prog [options] <backup-dir-path>"
    parser = OptionParser (usage)

    (options, args) = parser.parse_args ()

    if (len (args) != 1):
        print "You must specify the target backup directory (e.g. /mnt/backup)"
        print "qvm-backup will create a subdirectory there for each individual backup."
        exit (0)

    base_backup_dir = args[0]

    if not os.path.exists (base_backup_dir):
        print "The target directory doesn't exist!"
        exit(1)

    qvm_collection = QubesVmCollection()
    qvm_collection.lock_db_for_reading()
    qvm_collection.load()

    vms_list = [vm for vm in qvm_collection.values()]
    no_vms = len (vms_list)

    files_to_backup = file_to_backup (qubes_store_filename)

    appvms_to_backup = [vm for vm in vms_list if vm.is_appvm()]
    there_are_running_vms = False

    fields_to_display = [ 
        { "name": "VM", "width": 16},
        { "name": "type","width": 12 },
        { "name": "size", "width": 12}  
    ]

    # Display the header
    s = ""
    for f in fields_to_display:
        fmt="{{0:-^{0}}}-+".format(f["width"] + 1)
        s += fmt.format('-')
    print s
    s = ""
    for f in fields_to_display:
        fmt="{{0:>{0}}} |".format(f["width"] + 1)
        s += fmt.format(f["name"]) 
    print s
    s = ""
    for f in fields_to_display:
        fmt="{{0:-^{0}}}-+".format(f["width"] + 1)
        s += fmt.format('-')
    print s

    if len (appvms_to_backup):
        for vm in appvms_to_backup:

            vm_sz = vm.get_disk_usage (vm.private_img)
            files_to_backup += file_to_backup(vm.private_img, vm_sz )

            files_to_backup += file_to_backup(vm.icon_path)
            files_to_backup += file_to_backup(vm.conf_file)
            #files_to_backup += file_to_backup(vm.dir_path + "/apps")

            if vm.is_updateable():
                sz = vm.get_disk_usage(vm.rootcow_img)
                files_to_backup += file_to_backup(vm.rootcow_img, sz)
                vm_sz += sz

            s = ""
            fmt="{{0:>{0}}} |".format(fields_to_display[0]["width"] + 1)
            s += fmt.format(vm.name) 

            fmt="{{0:>{0}}} |".format(fields_to_display[1]["width"] + 1)
            s += fmt.format("AppVM" + (" + COW" if vm.is_updateable() else "")) 

            fmt="{{0:>{0}}} |".format(fields_to_display[2]["width"] + 1)
            s += fmt.format(size_to_human(vm_sz)) 

            if vm.is_running():
                s +=  " <-- The VM is running, please shut it down before proceeding with the backup!"
                there_are_running_vms = True

            print s

    template_vms_worth_backingup = [ vm for vm in vms_list if (vm.is_templete() and not vm.installed_by_rpm)]
    if len (template_vms_worth_backingup):
        for vm in template_vms_worth_backingup:
            vm_sz = vm.get_disk_utilization()
            files_to_backup += file_to_backup (vm.dir_path,  vm_sz)

            s = ""
            fmt="{{0:>{0}}} |".format(fields_to_display[0]["width"] + 1)
            s += fmt.format(vm.name) 

            fmt="{{0:>{0}}} |".format(fields_to_display[1]["width"] + 1)
            s += fmt.format("Template VM") 

            fmt="{{0:>{0}}} |".format(fields_to_display[2]["width"] + 1)
            s += fmt.format(size_to_human(vm_sz)) 

            if vm.is_running():
                s +=  " <-- The VM is running, please shut it down before proceeding with the backup!"
                there_are_running_vms = True

            print s



    total_backup_sz = 0
    for file in files_to_backup:
        total_backup_sz += file["size"]

    s = ""
    for f in fields_to_display:
        fmt="{{0:-^{0}}}-+".format(f["width"] + 1)
        s += fmt.format('-')
    print s

    s = ""
    fmt="{{0:>{0}}} |".format(fields_to_display[0]["width"] + 1)
    s += fmt.format("Total size:") 
    fmt="{{0:>{0}}} |".format(fields_to_display[1]["width"] + 1 + 2 + fields_to_display[2]["width"] + 1)
    s += fmt.format(size_to_human(total_backup_sz)) 
    print s

    s = ""
    for f in fields_to_display:
        fmt="{{0:-^{0}}}-+".format(f["width"] + 1)
        s += fmt.format('-')
    print s

    stat = os.statvfs(base_backup_dir)
    backup_fs_free_sz = stat.f_bsize * stat.f_bavail
    print
    if (total_backup_sz > backup_fs_free_sz):
        print "Not enough space avilable on the backup filesystem!"
        exit (1)

    if (there_are_running_vms):
        print "Please shutdown all VMs before proceeding."
        exit (1)


    backup_dir = base_backup_dir + "/qubes-{0}".format (time.strftime("%Y-%m-%d-%H%M%S"))
    if os.path.exists (backup_dir):
        print "ERROR: the path {0} already exists?!".format(backup_dir)
        print "Aborting..."
        exit (1)

    print "-> Backup dir: {0}".format (backup_dir)
    print "-> Avilable space: {0}".format(size_to_human(backup_fs_free_sz))

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

    os.mkdir (backup_dir)

    if not os.path.exists (backup_dir):
        print "ERROR: Strange: couldn't create backup dir: {0}?!".format(backup_dir)
        print "Aborting..."
        exit (1)

    bytes_backedup = 0
    for file in files_to_backup:
        # We prefer to use Linux's cp, because it nicely handles sparse files
        progress = bytes_backedup * 100 / total_backup_sz
        print >> sys.stderr, "\r-> Backing up files: {0}%...".format (progress),
        dest_dir = backup_dir + '/' + file["subdir"]
        if file["subdir"] != "":
            retcode = subprocess.call (["mkdir", "-p", dest_dir])
            if retcode != 0:
                print "Cannot create directory: {0}?!".format(dest_dir)
                print "Aborting..."
                exit(1)

        retcode = subprocess.call (["cp", "-rp", file["path"], dest_dir])
        if retcode != 0:
            print "Error while copying file {0} to {1}".format(file["path"], dest_dir)
            exit (1)

        bytes_backedup += file["size"]
        progress = bytes_backedup * 100 / total_backup_sz
        print >> sys.stderr, "\r-> Backing up files: {0}%...".format (progress),

    print
    print "-> Backup completed."

    qvm_collection.unlock_db()
main()