#!/usr/bin/env ruby

# Vitastor OpenNebula driver
# Copyright (c) Vitaliy Filippov, 2024+
# License: Apache-2.0 http://www.apache.org/licenses/LICENSE-2.0

ONE_LOCATION = ENV['ONE_LOCATION']

if !ONE_LOCATION
    RUBY_LIB_LOCATION = '/usr/lib/one/ruby'
    GEMS_LOCATION     = '/usr/share/one/gems'
    VMDIR             = '/var/lib/one'
    CONFIG_FILE       = '/var/lib/one/config'
else
    RUBY_LIB_LOCATION = ONE_LOCATION + '/lib/ruby'
    GEMS_LOCATION     = ONE_LOCATION + '/share/gems'
    VMDIR             = ONE_LOCATION + '/var'
    CONFIG_FILE       = ONE_LOCATION + '/var/config'
end

# %%RUBYGEMS_SETUP_BEGIN%%
if File.directory?(GEMS_LOCATION)
    real_gems_path = File.realpath(GEMS_LOCATION)
    if !defined?(Gem) || Gem.path != [real_gems_path]
        $LOAD_PATH.reject! {|l| l =~ /vendor_ruby/ }

        # Suppress warnings from Rubygems
        # https://github.com/OpenNebula/one/issues/5379
        begin
            verb = $VERBOSE
            $VERBOSE = nil
            require 'rubygems'
            Gem.use_paths(real_gems_path)
        ensure
            $VERBOSE = verb
        end
    end
end
# %%RUBYGEMS_SETUP_END%%

$LOAD_PATH << RUBY_LIB_LOCATION

require 'rexml/document'
require 'json'
require 'securerandom'

require_relative '../lib/tm_action'
require_relative '../lib/datastore'

def get_vitastor_disks(vm_xml)
    vm_xml  = REXML::Document.new(vm_xml) if vm_xml.is_a?(String)
    vm      = vm_xml.root
    vmid    = vm.elements['VMID'].text

    indexed_disks = []
    vm.elements.each('DISK[TM_MAD="vitastor"]') do |d|
        disk = new(vmid, d)
        indexed_disks[disk.id] = disk
    end

    indexed_disks
end

#-------------------------------------------------------------------------------
# RESTORE vm_id img_id inc_id disk_id
#-------------------------------------------------------------------------------
_dir      = ARGV[0].split ':'
vm_id     = ARGV[1]
bk_img_id = ARGV[2].to_i
inc_id    = ARGV[3]
disk_id   = ARGV[4].to_i

begin
    action = TransferManager::Action.new(:action_name => 'restore',
                                         :vm_id => vm_id)
    # --------------------------------------------------------------------------
    # Image & Datastore information
    # --------------------------------------------------------------------------
    bk_img = OpenNebula::Image.new_with_id(bk_img_id, action.one)

    rc = bk_img.info
    raise rc.message.to_s if OpenNebula.is_error?(rc)

    bk_ds = TransferManager::Datastore.from_image_ds(:image  => bk_img,
                                                     :client => action.one)

    # --------------------------------------------------------------------------
    # Backup information
    # sample output: {"0":"rsync://100//0:3ffce7/var/lib/one/datastores/100/1/3ffce7/disk.0.0"}
    # --------------------------------------------------------------------------
    xml_data = <<~EOS
        #{action.vm.to_xml}
        #{bk_img.to_xml}
    EOS

    rc = bk_ds.action("ls -i #{inc_id}", xml_data)

    raise 'cannot list backup contents' unless rc.code == 0

    disk_urls = JSON.parse(rc.stdout)
    disk_urls = disk_urls.select {|id, _url| id.to_i == disk_id } if disk_id != -1

    # --------------------------------------------------------------------------
    # Restore disk_urls in Host VM folder
    # --------------------------------------------------------------------------
    vitastor_disks = get_vitastor_disks(action.vm.template_xml)
    success_disks = []

    info = {}

    disk_urls.each do |id, url|
        vitastor_disk = vitastor_disks[id.to_i]
        randsuffix = SecureRandom.hex(5)

        vitastor_one_ds = OpenNebula::Datastore.new_with_id(
            action.vm["/VM/TEMPLATE/DISK[DISK_ID = #{id}]/DATASTORE_ID"].to_i, action.one
        )
        vitastor_ds = TransferManager::Datastore.new(:ds => vitastor_one_ds, :client => action.one)

        src_image = vitastor_disk.elements['SOURCE'].text
        disk_id = vitastor_disk.elements['DISK_ID'].text
        if vitastor_disk.elements['CLONE'].text == 'YES'
            src_image += '-'+vm_id+'-'+disk_id
        end

        cli = 'vitastor-cli'
        config_path = vitastor_disk.elements['VITASTOR_CONF']
        qemu_args = ''
        if config_path:
            cli += ' --config_path "'+config_path.text+'"'
            qemu_args += ':config_path='+config_path.text

        info[vitastor_disk] = {
            :br  => vitastor_ds.pick_bridge,
            :bak => "#{src_image}.backup.#{randsuffix}",
            :old => "#{src_image}.old.#{randsuffix}",
            :cli => cli,
            :img => src_image,
        }

        upload_vitastor = <<~EOS
            set -e
            tmpimg="$(mktemp -t disk#{id}.XXXX)"
            #{__dir__}/../../datastore/downloader.sh --nodecomp #{url} $tmpimg
            #{cli} create -s $(qemu-img info --output json $tmpimg | jq -r '.["virtual-size"]') #{info[vitastor_disk][:bak]}
            qemu-img convert -m 4 -O raw $tmpimg "vitastor:image=#{info[vitastor_disk][:bak]}#{qemu_args}"
            rm -f $tmpimg
        EOS

        rc = action.ssh(:host => info[vitastor_disk][:br],
                        :cmds => upload_ceph,
                        :forward  => false,
                        :nostdout => false,
                        :nostderr => false)

        break if rc.code != 0

        success_disks << vitastor_disk
    end

    # Rollback and raise error if it was unable to backup all disks
    if success_disks.length != disk_urls.length
        success_disks.each do |vitastor_disk|
            cleanup = <<~EOS
                #{info[vitastor_disk][:cli]} rm #{info[vitastor_disk][:bak]}
            EOS

            action.ssh(:host => info[vitastor_disk][:br],
                       :cmds => cleanup,
                       :forward  => false,
                       :nostdout => false,
                       :nostderr => false)
        end

        raise "error uploading backup disk to Vitastor (#{success_disks.length}/#{disk_urls.length})"
    end

    # --------------------------------------------------------------------------
    # Replace VM disk_urls with backup copies (~prolog)
    # --------------------------------------------------------------------------
    success_disks.each do |vitastor_disk|
        move = <<~EOS
            set -e
            #{info[vitastor_disk][:cli]} mv #{info[vitastor_disk][:img]} #{info[vitastor_disk][:old]}
            #{info[vitastor_disk][:cli]} mv #{info[vitastor_disk][:bak]} #{info[vitastor_disk][:img]}
            #{info[vitastor_disk][:cli]} rm --matching "#{info[vitastor_disk][:img]}@*"
            #{info[vitastor_disk][:cli]} rm #{info[vitastor_disk][:old]}
        EOS

        rc = action.ssh(:host => info[vitastor_disk][:br],
                        :cmds => move,
                        :forward  => false,
                        :nostdout => false,
                        :nostderr => false)

        warn 'cannot restore disk backup' if rc.code != 0
    end
rescue StandardError => e
    STDERR.puts "Error restoring VM disks: #{e.message}"
    exit(1)
end