module Beaker
  module DSL
    module Helpers
      # Methods that help you interact and manage the state of your Beaker SUTs, these
      # methods do not require puppet to be installed to execute correctly
      module HostHelpers

        # @!macro [new] common_opts
        #   @param [Hash{Symbol=>String}] opts Options to alter execution.
        #   @option opts [Boolean] :silent (false) Do not produce log output
        #   @option opts [Array<Fixnum>] :acceptable_exit_codes ([0]) An array
        #     (or range) of integer exit codes that should be considered
        #     acceptable.  An error will be thrown if the exit code does not
        #     match one of the values in this list.
        #   @option opts [Boolean] :accept_all_exit_codes (false) Consider all
        #     exit codes as passing.
        #   @option opts [Boolean] :dry_run (false) Do not actually execute any
        #     commands on the SUT
        #   @option opts [String] :stdin (nil) Input to be provided during command
        #     execution on the SUT.
        #   @option opts [Boolean] :pty (false) Execute this command in a pseudoterminal.
        #   @option opts [Boolean] :expect_connection_failure (false) Expect this command
        #     to result in a connection failure, reconnect and continue execution.
        #   @option opts [Hash{String=>String}] :environment ({}) These will be
        #     treated as extra environment variables that should be set before
        #     running the command.
        #

        # The primary method for executing commands *on* some set of hosts.
        #
        # @param [Host, Array<Host>, String, Symbol] host    One or more hosts to act upon,
        #                            or a role (String or Symbol) that identifies one or more hosts.
        # @param [String, Command]   command The command to execute on *host*.
        # @param [Proc]              block   Additional actions or assertions.
        # @!macro common_opts
        #
        # @example Most basic usage
        #     on hosts, 'ls /tmp'
        #
        # @example Allowing additional exit codes to pass
        #     on agents, 'puppet agent -t', :acceptable_exit_codes => [0,2]
        #
        # @example Using the returned result for any kind of checking
        #     if on(host, 'ls -la ~').stdout =~ /\.bin/
        #       ...do some action...
        #     end
        #
        # @example Using TestCase helpers from within a test.
        #     agents.each do |agent|
        #       on agent, 'cat /etc/puppet/puppet.conf' do
        #         assert_match stdout, /server = #{master}/, 'WTF Mate'
        #       end
        #     end
        #
        # @example Using a role (defined in a String)  to identify the host
        #   on "master", "echo hello"
        #
        # @example Using a role (defined in a Symbol) to identify the host
        #   on :dashboard, "echo hello"
        # @return [Result]   An object representing the outcome of *command*.
        # @raise  [FailTest] Raises an exception if *command* obviously fails.
        def on(host, command, opts = {}, &block)
          block_on host do | host |
            if command.is_a? String
              cmd_opts = {}
              #add any additional environment variables to the command
              if opts[:environment]
                cmd_opts['ENV'] = opts[:environment]
              end
              command_object = Command.new(command.to_s, [], cmd_opts)
            elsif command.is_a? Command
              command_object = command
            else
              msg = "DSL method `on` can only be called with a String or Beaker::Command"
              msg << " object as the command parameter, not #{command.class}."
              raise ArgumentError, msg
            end
            @result = host.exec(command_object, opts)

            # Also, let additional checking be performed by the caller.
            if block_given?
              case block.arity
                #block with arity of 0, just hand back yourself
                when 0
                  yield self
                #block with arity of 1 or greater, hand back the result object
                else
                  yield @result
              end
            end
            @result
          end
        end

        # The method for executing commands on the default host
        #
        # @param [String, Command]   command The command to execute on *host*.
        # @param [Proc]              block   Additional actions or assertions.
        # @!macro common_opts
        #
        # @example Most basic usage
        #     shell 'ls /tmp'
        #
        # @example Allowing additional exit codes to pass
        #     shell 'puppet agent -t', :acceptable_exit_codes => [0,2]
        #
        # @example Using the returned result for any kind of checking
        #     if shell('ls -la ~').stdout =~ /\.bin/
        #       ...do some action...
        #     end
        #
        # @example Using TestCase helpers from within a test.
        #     shell('cat /etc/puppet/puppet.conf') do |result|
        #       assert_match result.stdout, /server = #{master}/, 'WTF Mate'
        #     end
        #
        # @return [Result]   An object representing the outcome of *command*.
        # @raise  [FailTest] Raises an exception if *command* obviously fails.
        def shell(command, opts = {}, &block)
          on(default, command, opts, &block)
        end

        # @deprecated
        # An proxy for the last {Beaker::Result#stdout} returned by
        # a method that makes remote calls.  Use the {Beaker::Result}
        # object returned by the method directly instead. For Usage see
        # {Beaker::Result}.
        def stdout
          return nil if @result.nil?
          @result.stdout
        end

        # @deprecated
        # An proxy for the last {Beaker::Result#stderr} returned by
        # a method that makes remote calls.  Use the {Beaker::Result}
        # object returned by the method directly instead. For Usage see
        # {Beaker::Result}.
        def stderr
          return nil if @result.nil?
          @result.stderr
        end

        # @deprecated
        # An proxy for the last {Beaker::Result#exit_code} returned by
        # a method that makes remote calls.  Use the {Beaker::Result}
        # object returned by the method directly instead. For Usage see
        # {Beaker::Result}.
        def exit_code
          return nil if @result.nil?
          @result.exit_code
        end

        # Move a file from a remote to a local path
        # @note If using {Beaker::Host} for the hosts *scp* is not
        #   required on the system as it uses Ruby's net/scp library.  The
        #   net-scp gem however is required (and specified in the gemspec).
        #
        # @param [Host, #do_scp_from] host One or more hosts (or some object
        #                                  that responds like
        #                                  {Beaker::Host#do_scp_from}.
        # @param [String] from_path A remote path to a file.
        # @param [String] to_path   A local path to copy *from_path* to.
        # @!macro common_opts
        #
        # @return [Result] Returns the result of the SCP operation
        def scp_from host, from_path, to_path, opts = {}
          block_on host do | host |
            @result = host.do_scp_from(from_path, to_path, opts)
            @result.log logger
            @result
          end
        end

        # Move a local file to a remote host using scp
        # @note If using {Beaker::Host} for the hosts *scp* is not
        #   required on the system as it uses Ruby's net/scp library.  The
        #   net-scp gem however is required (and specified in the gemspec.
        #   When using SCP with Windows it will now auto expand path when
        #   using `cygpath instead of failing or requiring full path
        #
        # @param [Host, #do_scp_to] host One or more hosts (or some object
        #                                that responds like
        #                                {Beaker::Host#do_scp_to}.
        # @param [String] from_path A local path to a file.
        # @param [String] to_path   A remote path to copy *from_path* to.
        # @!macro common_opts
        #
        # @return [Result] Returns the result of the SCP operation
        def scp_to host, from_path, to_path, opts = {}
          block_on host do | host |
            if host['platform'] =~ /windows/ && to_path.match('`cygpath')
              result = on host, "echo #{to_path}"
              to_path = result.raw_output.chomp
            end
            @result = host.do_scp_to(from_path, to_path, opts)
            @result.log logger
            @result
          end
        end

        # Move a local file or directory to a remote host using rsync
        # @note rsync is required on the local host.
        #
        # @param [Host, #do_scp_to] host A host object that responds like
        #                                {Beaker::Host}.
        # @param [String] from_path A local path to a file or directory.
        # @param [String] to_path   A remote path to copy *from_path* to.
        # @!macro common_opts
        #
        # @return [Result] Returns the result of the rsync operation
        def rsync_to host, from_path, to_path, opts = {}
          block_on host do | host |
            if host['platform'] =~ /windows/ && to_path.match('`cygpath')
              result = host.echo "#{to_path}"
              to_path = result.raw_output.chomp
            end
            @result = host.do_rsync_to(from_path, to_path, opts)
            @result
          end
        end

        # Deploy packaging configurations generated by
        # https://github.com/puppetlabs/packaging to a host.
        #
        # @note To ensure the repo configs are available for deployment,
        #       you should run `rake pl:jenkins:deb_repo_configs` and
        #       `rake pl:jenkins:rpm_repo_configs` on your project checkout
        #
        # @param [Host] host
        # @param [String] path     The path to the generated repository config
        #                          files. ex: /myproject/pkg/repo_configs
        # @param [String] name     A human-readable name for the repository
        # @param [String] version  The version of the project, as used by the
        #                          packaging tools. This can be determined with
        #                          `rake pl:print_build_params` from the packaging
        #                          repo.
        def deploy_package_repo host, path, name, version
          host.deploy_package_repo path, name, version
        end

        # Create a remote file out of a string
        # @note This method uses Tempfile in Ruby's STDLIB as well as {#scp_to}.
        #
        # @param [Host, #do_scp_to] hosts One or more hosts (or some object
        #                                 that responds like
        #                                 {Beaker::Host#do_scp_from}.
        # @param [String] file_path A remote path to place *file_content* at.
        # @param [String] file_content The contents of the file to be placed.
        # @!macro common_opts
        # @option opts [String] :protocol Name of the underlying transfer method.
        #                                 Valid options are 'scp' or 'rsync'.
        #
        # @return [Result] Returns the result of the underlying SCP operation.
        def create_remote_file(hosts, file_path, file_content, opts = {})
          Tempfile.open 'beaker' do |tempfile|
            File.open(tempfile.path, 'w') {|file| file.puts file_content }

            opts[:protocol] ||= 'scp'
            case opts[:protocol]
              when 'scp'
                scp_to hosts, tempfile.path, file_path, opts
              when 'rsync'
                rsync_to hosts, tempfile.path, file_path, opts
              else
                logger.debug "Unsupported transfer protocol, returning nil"
                nil
            end
          end
        end

        # Execute a powershell script from file, remote file created from provided string
        # @note This method uses Tempfile in Ruby's STDLIB as well as {#create_remote_file}.
        #
        # @param [Host] hosts One or more hosts (or some object
        #                                 that responds like
        #                                 {Beaker::Host#do_scp_from}.
        # @param [String] powershell_script A string describing a set of powershell actions
        #
        # @return [Result] Returns the result of the powershell command execution
        def execute_powershell_script_on(hosts, powershell_script, opts = {})
          block_on hosts do |host|
            script_path = "beaker_powershell_script_#{Time.now.to_i}.ps1"
            create_remote_file(host, script_path, powershell_script, opts)
            native_path = script_path.gsub(/\//, "\\")
            on host, powershell("", {"File" => native_path }), opts
          end

        end

        # Move a local script to a remote host and execute it
        # @note this relies on {#on} and {#scp_to}
        #
        # @param [Host, #do_scp_to] host One or more hosts (or some object
        #                                that responds like
        #                                {Beaker::Host#do_scp_from}.
        # @param [String] script A local path to find an executable script at.
        # @!macro common_opts
        # @param [Proc] block Additional tests to run after script has executed
        #
        # @return [Result] Returns the result of the underlying SCP operation.
        def run_script_on(host, script, opts = {}, &block)
          # this is unsafe as it uses the File::SEPARATOR will be set to that
          # of the coordinator node.  This works for us because we use cygwin
          # which will properly convert the paths.  Otherwise this would not
          # work for running tests on a windows machine when the coordinator
          # that the harness is running on is *nix. We should use
          # {Beaker::Host#temp_path} instead. TODO
          remote_path = File.join("", "tmp", File.basename(script))

          scp_to host, script, remote_path
          on host, remote_path, opts, &block
        end

        # Move a local script to default host and execute it
        # @see #run_script_on
        def run_script(script, opts = {}, &block)
          run_script_on(default, script, opts, &block)
        end

        # Install a package on a host
        #
        # @param [Host] host             A host object
        # @param [String] package_name   Name of the package to install
        #
        # @return [Result]   An object representing the outcome of *install command*.
        def install_package host, package_name, package_version = nil
          host.install_package package_name, '', package_version
        end

        # Check to see if a package is installed on a remote host
        #
        # @param [Host] host             A host object
        # @param [String] package_name   Name of the package to check for.
        #
        # @return [Boolean] true/false if the package is found
        def check_for_package host, package_name
          host.check_for_package package_name
        end

        # Upgrade a package on a host. The package must already be installed
        #
        # @param [Host] host             A host object
        # @param [String] package_name   Name of the package to install
        #
        # @return [Result]   An object representing the outcome of *upgrade command*.
        def upgrade_package host, package_name
          host.upgrade_package package_name
        end

        # Configure a host entry on the give host
        # @example: will add a host entry for forge.puppetlabs.com
        #   add_system32_hosts_entry(host, { :ip => '23.251.154.122', :name => 'forge.puppetlabs.com' })
        #
        # @return nil
        def add_system32_hosts_entry(host, opts = {})
          if host.is_powershell?
            hosts_file = "C:\\Windows\\System32\\Drivers\\etc\\hosts"
            host_entry = "#{opts['ip']}`t`t#{opts['name']}"
            on host, powershell("\$text = \\\"#{host_entry}\\\"; Add-Content -path '#{hosts_file}' -value \$text")
          else
            raise "nothing to do for #{host.name} on #{host['platform']}"
          end
        end

        # Back up the given file in the current_dir to the new_dir
        #
        # @param host [Beaker::Host] The target host
        # @param current_dir [String] The directory containing the file to back up
        # @param new_dir [String] The directory to copy the file to
        # @param filename [String] The file to back up. Defaults to 'puppet.conf'
        #
        # @return [String, nil] The path to the file if the file exists, nil if it
        #   doesn't exist.
        def backup_the_file host, current_dir, new_dir, filename = 'puppet.conf'

          old_location = current_dir + '/' + filename
          new_location = new_dir + '/' + filename + '.bak'

          if host.file_exist? old_location
            host.exec( Command.new( "cp #{old_location} #{new_location}" ) )
            return new_location
          else
            logger.warn "Could not backup file '#{old_location}': no such file"
            nil
          end
        end

        #Run a curl command on the provided host(s)
        #
        # @param [Host, Array<Host>, String, Symbol] host    One or more hosts to act upon,
        #                            or a role (String or Symbol) that identifies one or more hosts.
        # @param [String, Command]   cmd The curl command to execute on *host*.
        # @param [Proc]              block   Additional actions or assertions.
        # @!macro common_opts
        #
        def curl_on(host, cmd, opts = {}, &block)
          on host, "curl --tlsv1 %s" % cmd, opts, &block
        end

        def curl_with_retries(desc, host, url, desired_exit_codes, max_retries = 60, retry_interval = 1)
          opts = {
            :desired_exit_codes => desired_exit_codes,
            :max_retries => max_retries,
            :retry_interval => retry_interval
          }
          retry_on(host, "curl -m 1 #{url}", opts)
        end

        # This command will execute repeatedly until success or it runs out with an error
        #
        # @param [Host, Array<Host>, String, Symbol] host    One or more hosts to act upon,
        #                            or a role (String or Symbol) that identifies one or more hosts.
        # @param [String, Command]   command The command to execute on *host*.
        # @param [Hash{Symbol=>String}] opts Options to alter execution.
        # @param [Proc]              block   Additional actions or assertions.
        #
        # @option opts [Array<Fixnum>, Fixnum] :desired_exit_codes (0) An array
        #   or integer exit code(s) that should be considered
        #   acceptable.  An error will be thrown if the exit code never
        #   matches one of the values in this list.
        # @option opts [Fixnum] :max_retries (60) number of times the
        #   command will be tried before failing
        # @option opts [Float] :retry_interval (1) number of seconds
        #   that we'll wait between tries
        # @option opts [Boolean] :verbose (false)
        #
        # @return [Result] Result object of the last command execution
        def retry_on(host, command, opts = {}, &block)
          option_exit_codes     = opts[:desired_exit_codes]
          option_max_retries    = opts[:max_retries].to_i
          option_retry_interval = opts[:retry_interval].to_f
          desired_exit_codes    = option_exit_codes ? [option_exit_codes].flatten : [0]
          desired_exit_codes    = [0] if desired_exit_codes.empty?
          max_retries           = option_max_retries == 0 ? 60 : option_max_retries  # nil & "" both return 0
          retry_interval        = option_retry_interval == 0 ? 1 : option_retry_interval
          verbose               = true.to_s == opts[:verbose]

          log_prefix = host.log_prefix
          logger.debug "\n#{log_prefix} #{Time.new.strftime('%H:%M:%S')}$ #{command}"
          logger.debug "  Trying command #{max_retries} times."
          logger.debug ".", add_newline=false

          result = on host, command, {:accept_all_exit_codes => true, :silent => !verbose}, &block
          num_retries = 0
          until desired_exit_codes.include?(result.exit_code)
            sleep retry_interval
            result = on host, command, {:accept_all_exit_codes => true, :silent => !verbose}, &block
            num_retries += 1
            logger.debug ".", add_newline=false
            if (num_retries > max_retries)
              logger.debug "  Command \`#{command}\` failed."
              fail("Command \`#{command}\` failed.")
            end
          end
          logger.debug "\n#{log_prefix} #{Time.new.strftime('%H:%M:%S')}$ #{command} ostensibly successful."
          result
        end

        # FIX: this should be moved into host/platform
        # @visibility private
        def run_cron_on(host, action, user, entry="", &block)
          block_on host do | host |
            platform = host['platform']
            if platform.include?('solaris') || platform.include?('aix') then
              case action
                when :list   then args = '-l'
                when :remove then args = '-r'
                when :add
                  on( host,
                     "echo '#{entry}' > /var/spool/cron/crontabs/#{user}",
                      &block )
              end

            else # default for GNU/Linux platforms
              case action
                when :list   then args = '-l -u'
                when :remove then args = '-r -u'
                when :add
                   on( host,
                      "echo '#{entry}' > /tmp/#{user}.cron && " +
                      "crontab -u #{user} /tmp/#{user}.cron",
                       &block )
              end
            end

            if args
              case action
                when :list, :remove then on(host, "crontab #{args} #{user}", &block)
              end
            end
          end
        end

        # Create a temp directory on remote host owned by specified user.
        #
        # @param [Host, Array<Host>, String, Symbol] host    One or more hosts to act upon,
        #                            or a role (String or Symbol) that identifies one or more hosts.
        # @param [String] path_prefix A remote path prefix for the new temp
        # directory.
        # @param [String] user The name of user that should own the temp
        # directory. If no username is specified defaults to the currently logged in user
        # per host
        #
        # @return [String, Array<String>] Returns the name of the newly-created dir, or an array
        #                                of names of newly-created dirs per-host
        def create_tmpdir_on(host, path_prefix = '', user=nil)

          block_on host do | host |
            # use default user logged into this host
            if not user
              user = host['user']
            end

            if not on(host, "getent passwd #{user}").exit_code == 0
              raise "User #{user} does not exist on #{host}."
            end

            if defined? host.tmpdir
              dir = host.tmpdir(path_prefix)
              on host, "chown #{user}:#{user} #{dir}"
              dir
            else
              raise "Host platform not supported by `create_tmpdir_on`."
            end
          end
        end

        # 'echo' the provided value on the given host(s)
        # @param [Host, Array<Host>, String, Symbol] hosts    One or more hosts to act upon,
        #                            or a role (String or Symbol) that identifies one or more hosts.
        # @param [String] val The string to 'echo' on the host(s)
        # @return [String, Array<String> The echo'ed value(s) returned by the host(s)
        def echo_on hosts, val
          block_on hosts do |host|
            if host.is_powershell?
              host.exec(Command.new("echo #{val}")).stdout.chomp
            else
              host.exec(Command.new("echo \"#{val}\"")).stdout.chomp
            end
          end
        end
      end
    end
  end
end