#!/usr/bin/env ruby
# encoding: binary

# This file is supposed to make inspecting AMQ protocol easier.

# How does it work:
# 1) This file is executed.
# 2) We load irb, redefine where IRB looks for .irbrc and start IRB.
# 3) IRB loads .irbrc, which we redefined, so it loads this file again.
#    However now the second branch of "if __FILE__ == $0" gets executed,
#    so it runs our custom code which loads the original .irbrc and then
#    it redefines some IRB settings. In this case it add IRB hook which
#    is executed after IRB is started.

# Although it looks unnecessarily complicated, I can't see any easier
# solution to this problem in case that you need to patch original settings.
# Obviously in case you don't have the need, you'll be happy with simple:

# require "irb"
#
# require_relative "lib/amq/protocol/client.rb"
# include AMQ::Protocol
#
# IRB.start(__FILE__)

require "irb"

if __FILE__ == $0
  puts "~ Using #{__FILE__} as an executable ..."


  def IRB.rc_file_generators
    yield Proc.new { |_| __FILE__ }
  end

  IRB.start(__FILE__)
else
  begin
    irbrc = File.join(ENV["HOME"], ".irbrc")
    puts "~ Using #{__FILE__} as a custom .irbrc .."
    puts "~ Loading original #{irbrc} ..."
    load irbrc

    file = ENV["FILE"] || "client"
    require_relative "lib/amq/protocol/#{file}.rb"
    include AMQ::Protocol

    begin
      require "amq/client/io/string"

      class AMQ::Protocol::Frame
        def self.decode(string)
          AMQ::Client::StringAdapter::Frame.decode(string)
        end
      end
    rescue LoadError
      warn "~ AMQ Client isn't available."
    end

    # "0123456789".chunks(1, 1, 2, 3)
    # => ["0", "1", "23", "456"]
    class String
      def chunks(*parts)
        offset = 0
        parts.map do |number_of_characters|
          self[offset..(offset + number_of_characters - 1)].tap do
            offset += number_of_characters
          end
        end << self[offset..-1]
      end
    end

    require "stringio"

    def fd(data)
      Frame.decode(StringIO.new(data))
    end
  rescue Exception => exception # it just discards all the exceptions!
    abort exception.message + "\n  - " + exception.backtrace.join("\n  - ")
  end
end