# GOV.UK Mini Environment Admin
# Copyright © 2018  Christopher Baines <mail@cbaines.net>
#
# This file is part of the GOV.UK Mini Environment Admin.
#
# The GOV.UK Mini Environment Admin is free software: you can
# redistribute it and/or modify it under the terms of the GNU Affero
# General Public License as published by the Free Software Foundation,
# either version 3 of the License, or (at your option) any later
# version.
#
# The GOV.UK Mini Environment Admin 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 Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public
# License along with the GOV.UK Mini Environment Admin.  If not, see
# <http://www.gnu.org/licenses/>.

module GovukGuix::UpdateGcrootsDirectory
  extend ::ShellUtils

  DIRECTORY = '/var/guix/gcroots/govuk-mini-environment-admin'

  def self.set_in_use_store_paths(store_paths, options = {})
    current_store_paths = list_store_paths(options)

    (current_store_paths - store_paths).each do |store_path|
      remove_store_path(store_path, options)
    end

    (store_paths - current_store_paths).each do |store_path|
      add_store_path(store_path, options)
    end
  end

  def self.add_store_path(store_path, options = {})
    run_command(
      'ln', '-s',
      store_path,
      File.join(DIRECTORY, store_path['/gnu/store/'.length..-1]),
      run_remotely_on_host: options[:run_remotely_on_host]
    )
  end

  def self.remove_store_path(store_path, options = {})
    run_command(
      'rm', File.join(DIRECTORY, store_path['/gnu/store/'.length..-1]),
      run_remotely_on_host: options[:run_remotely_on_host]
    )
  end

  def self.list_store_paths(options = {})
    run_command(
      'ls', '-1', DIRECTORY,
      run_remotely_on_host: options[:run_remotely_on_host]
    ).map do |store_path_suffix|
      "/gnu/store/#{store_path_suffix.strip}"
    end
  end
end