# 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/>.

require 'fileutils'

class TerraformWorkingDirectory
  def initialize(id, source)
    @id = id
    @source = source
  end

  def working_directory
    "tmp/terraform-working-directories/#{@id}"
  end

  def within_working_directory
    if Rails.env.development? && Dir.exist?(working_directory)
      # For the purposes of development, always clear the working
      # directory. This ensures that fresh terraform configuration
      # will be copied over
      FileUtils.remove_dir(working_directory)
    end

    source = File.expand_path(@source)
    FileUtils.mkdir_p working_directory

    Dir.chdir(working_directory) do
      if Dir.empty?('.')
        credentials = TerraformHttpBackendController.credentials

        RubyTerraform.init(
          backend: true,
          from_module: source,
          backend_config: {
            address: terraform_backend_address,
            username: credentials[:name],
            password: credentials[:password]
          },
          plugin_dir: terraform_plugin_dir
        )
      end

      yield
    end
  end

  def terraform_backend_address
    (
      Plek.new.external_url_for('mini-environment-admin') +
      Rails
        .application
        .routes
        .url_helpers
        .terraform_http_backend_path(@id)
    )
  end

  def terraform_plugin_dir
    ENV['PATH'].split(':').first
  end
end