class Gitlab::QA::Component::InternetTunnel

def initialize
  @docker = Docker::Engine.new
  @volumes = {}
  key_dir = ENV['CI_PROJECT_DIR'] || Dir.tmpdir
  @ssh_key = Tempfile.new('tunnel-ssh-private-key', key_dir)
  @ssh_key.write(ENV.fetch('TUNNEL_SSH_PRIVATE_KEY'))
  @ssh_key.close
  File.chmod(0o600, @ssh_key.path)
  @volumes['/root/.ssh/id_rsa'] = @ssh_key.path
end

def instance
  raise ArgumentError, 'Please provide a block!' unless block_given?
  prepare
  start
  yield self
ensure
  teardown
end

def name
  @name ||= "ssh-tunnel-#{SecureRandom.hex(4)}"
end

def prepare
  @docker.pull(DOCKER_IMAGE, DOCKER_IMAGE_TAG)
  return if @docker.network_exists?(network)
  @docker.network_create(network)
end

def restart
  @docker.restart(name)
end

def start
  raise "Must set gitlab_hostname" unless @gitlab_hostname
  @docker.run(DOCKER_IMAGE, DOCKER_IMAGE_TAG, "-o StrictHostKeyChecking=no -N -R #{subdomain}:#{@gitlab_hostname}:80 #{ENV.fetch('TUNNEL_SSH_USER')}@#{tunnel_server_hostname}") do |command|
    command << '-d '
    command << "--name #{name}"
    command << "--net #{network}"
    @volumes.to_h.each do |to, from|
      command.volume(from, to, 'Z')
    end
  end
end

def subdomain
  @subdomain ||= rand(30_000..49_000)
end

def teardown
  raise 'Invalid instance name!' unless name
  @docker.stop(name)
  @docker.remove(name)
  @ssh_key.unlink
end

def tunnel_server_hostname
  ENV.fetch("TUNNEL_SERVER_HOSTNAME")
end

def url
  "https://#{subdomain}.#{tunnel_server_hostname}"
end