# We may be dealing with thousands of requests a second and while Rails can
# scale to that, let's save the effort.
#
# Launch the handler by doing
#   ./script/smoked
# from the applicaiton root.
#
# TODO: Find out which is preferrable: using active_support for Hash.to_xml or
# using Hpricot to parse the XML.
require 'active_support'
require 'lib/smoke/signal_processor'
require 'lib/smoke/server/signal_router'

PROCESSOR_DIRECTORIES = [ File.dirname(__FILE__) + '/../../../etc/smoke.d/processors', '/etc/smoke.d/processors' ]
PROCESSOR_DIRECTORIES.each_with_index do |directory, index|
  directory = File.expand_path(directory)
  if directory =~ /[^\/]$/
    directory += '/'
  end
  PROCESSOR_DIRECTORIES[index] = directory  
  $: << directory
end

module Smoke
  module Server
    class SignalHandler < Mongrel::HttpHandler
      def initialize(*args)
        super
        @signal_router = Smoke::Server::SignalRouter.new
        PROCESSOR_DIRECTORIES.each do |directory|
          Dir[directory + '**/*.rb'].collect do |processor_file|
            require processor_file
            processor = processor_file.sub(directory, '').sub('.rb', '').classify
            begin
              processor_class = processor.constantize
              if processor_class.ancestors.include? Smoke::SignalProcessor
                @signal_router.register(processor_class)
              else
                puts "Expected #{processor} (#{processor_file}) to extend Smoke::SignalProcessor."
                exit 2
              end
            rescue NameError => e
              puts "Expected #{processor_file} to define #{processor}."
              puts e.message + ":\n\n" + e.backtrace.join("\n")
              exit 1
            end
          end
        end
      end

      def process(request, response)
        signal = Hash.from_xml(request.body)["signal"]
        @signal_router.route(signal)
        response.start(201) do |header, body| 
          header["Content-Type"] = "application/xml"
        end
      rescue => e
        response.start(500) do |header, body|
          STDERR.puts %Q(<errors><error>#{e.message}: #{e.backtrace}</error></errors>)
        end
      end
    end
  end
end