case_class_proto_ripper.rb

require 'active_support/core_ext'
require 'rails/all'
class Helpers
  def self.map_type type
    case type

    when /boolean/
      'bool'
    when /java.lang.int/
      'int32'
    when /java.lang.long/
      'int64'
    else
      'string'
    end
  end

  def self.print_with_indent(string, tabs)
    puts "\t" * tabs + string
  end

end

klass = <insert_case_class_name_here>
package, message = klass.java_class.name.split('$')
puts message; puts klass.java_class.name.split('$')
message_def = "message #{message.camelize} {"
package_def = "java_package = '#{package}'"
field_map = klass.java_class.declared_fields.inject({}) do |r, m|
  r[m.name.underscore] = m
  r
end

proto_msg_fields = []

field_map.each_with_index do |v,i|
  type = Helpers.map_type (v[1].to_s)
  proto_msg_fields << "required #{type} #{v[0]} = #{proto_msg_fields.size};"
end

puts package_def
puts
puts message_def
proto_msg_fields.each{|f| Helpers.print_with_indent(f,1)}
puts "}"