#!/usr/bin/env ruby

require 'pathname'
$: << Pathname.new($0).expand_path.dirname+'lib'
require 'base'
require 'active_support/all'
require 'json'

class Tivate < Base
	def initialize
		super
		sh.alias_command :lsblk_json, *%w[lsblk --json --fs], return: :string
	end

	def listing *devices, reverse: nil, only_fs: nil, &exe
		return to_enum( __method__, *devices, reverse: reverse, only_fs: only_fs)  unless block_given?
		return nil  if devices.empty?
		reverse = false  if reverse.nil?
		only_fs = false   if only_fs.nil?
		l =
			lambda do |e|
				case e['fstype']
				when 'LVM2_member'
					e[:isfs] = false
					yield e  if not only_fs and not reverse
					(e['children']||[]).each &l
					yield e  if not only_fs and reverse
				when *%w[ext2 ext3 ext4 xfs]
					e[:isfs] = true
					yield e
				end
			end
		devices.each do |dev|
			if dev.exist?
				data = JSON.parse sh.lsblk_json( dev)
				data['blockdevices'].each &l
			end
		end
	end
end

cmd = Pathname.new $0
case ARGV[0]
when '-h', '--help'
	puts <<EOF
Usage: activate.rb -h | image    # provides all filesystem of an image as devices
       deactivate.rb -h | image  # umounts and deprovitions devices
EOF
end
image = Pathname.new ARGV[0]

case cmd.basename( '.rb').to_s.downcase.to_sym
when :activate
	Tivate.run do
		raise "Image «#{image}» does not exist"  unless image.exist?
		devs = kpartx image
		listing *devs do |dev|
			if 'LVM2_member' == dev['fstype']
				vgname = get_vgname_of_pv( "/dev/mapper/#{dev['name']}").to_a[0]
				sh.vgchange -:ay, vgname, return: :string
			end
		end
		listing *devs do |dev|
			if dev[:isfs]
				puts "/dev/mapper/#{dev['name']}"
			end
		end
	end

when :deactivate
	Tivate.run do
		raise "Image «#{image}» does not exist"  unless image.exist?
		devs = lpartx image
		listing *devs, reverse: true do |dev|
			sh.umount dev['mountpoint']  if dev['mountpoint']
			if 'LVM2_member' == dev['fstype']
				vgname = get_vgname_of_pv( "/dev/mapper/#{dev['name']}").to_a[0]
				sh.vgchange -:an, vgname
			end
		end
		departx image
	end

else
	raise "activate or deactivate?"
end