1 files changed, 104 insertions, 0 deletions
diff --git a/lib/puppet/face/help.rb b/lib/puppet/face/help.rb
new file mode 100644
index 000000000..1c2da9e83
--- /dev/null
+++ b/lib/puppet/face/help.rb
@@ -0,0 +1,104 @@
+require 'puppet/face'
+require 'puppet/util/command_line'
+require 'pathname'
+require 'erb'
+
+Puppet::Face.define(:help, '0.0.1') do
+  summary "Displays help about puppet subcommands"
+
+  action(:help) do
+    summary "Display help about faces and their actions."
+
+    option "--version VERSION" do
+      desc "Which version of the interface to show help for"
+    end
+
+    when_invoked do |*args|
+      # Check our invocation, because we want varargs and can't do defaults
+      # yet.  REVISIT: when we do option defaults, and positional options, we
+      # should rewrite this to use those. --daniel 2011-04-04
+      options = args.pop
+      if options.nil? or args.length > 2 then
+        raise ArgumentError, "help only takes two (optional) arguments, a face name, and an action"
+      end
+
+      version = :current
+      if options.has_key? :version then
+        if options[:version].to_s !~ /^current$/i then
+          version = options[:version]
+        else
+          if args.length == 0 then
+            raise ArgumentError, "version only makes sense when a face is given"
+          end
+        end
+      end
+
+      # Name those parameters...
+      facename, actionname = args
+
+      if facename then
+        if legacy_applications.include? facename then
+          actionname and raise ArgumentError, "Legacy subcommands don't take actions"
+          return Puppet::Application[facename].help
+        else
+          face = Puppet::Face[facename.to_sym, version]
+          actionname and action = face.get_action(actionname.to_sym)
+        end
+      end
+
+      case args.length
+      when 0 then
+        template = erb 'global.erb'
+      when 1 then
+        face or fail ArgumentError, "Unable to load face #{facename}"
+        template = erb 'face.erb'
+      when 2 then
+        face or fail ArgumentError, "Unable to load face #{facename}"
+        action or fail ArgumentError, "Unable to load action #{actionname} from #{face}"
+        template = erb 'action.erb'
+      else
+        fail ArgumentError, "Too many arguments to help action"
+      end
+
+      # Run the ERB template in our current binding, including all the local
+      # variables we established just above. --daniel 2011-04-11
+      return template.result(binding)
+    end
+  end
+
+  def erb(name)
+    template = (Pathname(__FILE__).dirname + "help" + name)
+    erb = ERB.new(template.read, nil, '%')
+    erb.filename = template.to_s
+    return erb
+  end
+
+  def legacy_applications
+    # The list of applications, less those that are duplicated as a face.
+    Puppet::Util::CommandLine.available_subcommands.reject do |appname|
+      Puppet::Face.face? appname.to_sym, :current or
+        # ...this is a nasty way to exclude non-applications. :(
+        %w{face_base indirection_base}.include? appname
+    end.sort
+  end
+
+  def horribly_extract_summary_from(appname)
+    begin
+      require "puppet/application/#{appname}"
+      help = Puppet::Application[appname].help.split("\n")
+      # Now we find the line with our summary, extract it, and return it.  This
+      # depends on the implementation coincidence of how our pages are
+      # formatted.  If we can't match the pattern we expect we return the empty
+      # string to ensure we don't blow up in the summary. --daniel 2011-04-11
+      while line = help.shift do
+        if md = /^puppet-#{appname}\([^\)]+\) -- (.*)$/.match(line) then
+          return md[1]
+        end
+      end
+    rescue Exception
+      # Damn, but I hate this: we just ignore errors here, no matter what
+      # class they are.  Meh.
+    end
+    return ''
+  end
+end