require 'net/ssh/transport/session'
require 'net/ssh/connection/session'
require 'net/ssh/test/kex'
require 'net/ssh/test/socket'

module Net; module SSH

  # This module may be used in unit tests, for when you want to test that your
  # SSH state machines are really doing what you expect they are doing. You will
  # typically include this module in your unit test class, and then build a
  # "story" of expected sends and receives:
  #
  #   require 'minitest/autorun'
  #   require 'net/ssh/test'
  #
  #   class MyTest < Minitest::Test
  #     include Net::SSH::Test
  #
  #     def test_exec_via_channel_works
  #       story do |session|
  #         channel = session.opens_channel
  #         channel.sends_exec "ls"
  #         channel.gets_data "result of ls"
  #         channel.gets_close
  #         channel.sends_close
  #       end
  #
  #       assert_scripted do
  #         result = nil
  #
  #         connection.open_channel do |ch|
  #           ch.exec("ls") do |success|
  #             ch.on_data { |c, data| result = data }
  #             ch.on_close { |c| c.close }
  #           end
  #         end
  #
  #         connection.loop
  #         assert_equal "result of ls", result
  #       end
  #     end
  #   end
  #
  # See Net::SSH::Test::Channel and Net::SSH::Test::Script for more options.
  #
  # Note that the Net::SSH::Test system is rather finicky yet, and can be kind
  # of frustrating to get working. Any suggestions for improvement will be
  # welcome!
  module Test
    # If a block is given, yields the script for the test socket (#socket).
    # Otherwise, simply returns the socket's script. See Net::SSH::Test::Script.
    def story
      Net::SSH::Test::Extensions::IO.with_test_extension { yield socket.script if block_given? }
      return socket.script
    end

    # Returns the test socket instance to use for these tests (see
    # Net::SSH::Test::Socket).
    def socket(options={})
      @socket ||= Net::SSH::Test::Socket.new
    end

    # Returns the connection session (Net::SSH::Connection::Session) for use
    # in these tests. It is a fully functional SSH session, operating over
    # a mock socket (#socket).
    def connection(options={})
      @connection ||= Net::SSH::Connection::Session.new(transport(options), options)
    end

    # Returns the transport session (Net::SSH::Transport::Session) for use
    # in these tests. It is a fully functional SSH transport session, operating
    # over a mock socket (#socket).
    def transport(options={})
      @transport ||= Net::SSH::Transport::Session.new(options[:host] || "localhost", options.merge(kex: "test", host_key: "ssh-rsa", paranoid: false, proxy: socket(options)))
    end

    # First asserts that a story has been described (see #story). Then yields,
    # and then asserts that all items described in the script have been
    # processed. Typically, this is called immediately after a story has
    # been built, and the SSH commands being tested are then executed within
    # the block passed to this assertion.
    def assert_scripted
      raise "there is no script to be processed" if socket.script.events.empty?
      Net::SSH::Test::Extensions::IO.with_test_extension { yield }
      assert socket.script.events.empty?, "there should not be any remaining scripted events, but there are still #{socket.script.events.length} pending"
    end
  end

end; end