require 'picsolve_docker_builder/base'
require 'net/ssh'

module PicsolveDockerBuilder
  module Helpers
    # Ruby class that can forward a remote port over SSH
    class SshForward
      include PicsolveDockerBuilder::Base
      attr_reader :options
      def initialize(opts)
        @options = opts
      end

      def connection
        @connection ||= Net::SSH.start(ssh_host, ssh_user)
      end

      def bind_port
        tries = 0
        port = local_port
        begin
          connection.forward.local(port, remote_host, remote_port)
          return port
        rescue Errno::EADDRINUSE => e
          # raise after five failed tries
          raise e if tries > 5
          tries += 1
          port += 1
          retry
        end
      end

      def start
        log.debug "Connecting via ssh to host '#{ssh_user}@#{ssh_host}'"

        # bind remote service to local port
        port = bind_port

        # start thread with ssh
        @thread = Thread.new do
          connection.loop { true }
        end
        port
      end

      def stop
        return if @thread.nil?
        @thread.kill
        @thread.join
        log.debug \
          "Disconnected ssh connection to host '#{ssh_user}@#{ssh_host}'"
      end

      def ssh_user
        options[:ssh_user] = 'core'
      end

      def ssh_host
        options[:ssh_host]
      end

      def remote_host
        options[:remote_host]
      end

      def remote_port
        options[:remote_port]
      end

      def local_port
        options[:local_port] || remote_port
      end
    end
  end
end