class Protobuf::Generators::FieldGenerator

def applicable_options
  @applicable_options ||= field_options.map { |k, v| ":#{k} => #{v}" }
end

def compile
  run_once(:compile) do
    field_definition = [ "#{label} #{type_name}", name, number, applicable_options ]
    puts field_definition.flatten.compact.join(', ')
  end
end

def default_value
  @default_value ||= begin
                       if defaulted?
                         case descriptor.type.name
                         when :TYPE_ENUM then
                           enum_default_value
                         when :TYPE_STRING, :TYPE_BYTES then
                           string_default_value
                         when :TYPE_FLOAT, :TYPE_DOUBLE then
                           float_double_default_value
                         else
                           verbatim_default_value
                         end
                       end
                     end
end

def defaulted?
  descriptor.respond_to_has_and_present?(:default_value)
end

def deprecated?
  descriptor.options.try(:deprecated?) { false }
end

def enum_default_value
  "#{type_name}::#{verbatim_default_value}"
end

def extension?
  descriptor.respond_to_has_and_present?(:extendee)
end

def field_options
  @field_options ||= begin
                       opts = {}
                       opts[:default] = default_value if defaulted?
                       opts[:packed] = 'true' if packed?
                       opts[:deprecated] = 'true' if deprecated?
                       opts[:extension] = 'true' if extension?
                       opts
                     end
end

def float_double_default_value
  case verbatim_default_value
  when PROTO_INFINITY_DEFAULT then
    RUBY_INFINITY_DEFAULT
  when PROTO_NEGATIVE_INFINITY_DEFAULT then
    RUBY_NEGATIVE_INFINITY_DEFAULT
  when PROTO_NAN_DEFAULT then
    RUBY_NAN_DEFAULT
  else
    verbatim_default_value
  end
end

def label
  @label ||= descriptor.label.name.to_s.downcase.sub(/label_/, '') # required, optional, repeated
end

def name
  @name ||= ":#{descriptor.name}"
end

def number
  @number ||= descriptor.number
end

def packed?
  descriptor.options.try(:packed?) { false }
end

def string_default_value
  %Q{"#{verbatim_default_value.gsub(/'/, '\\\\\'')}"}
end

def type_name
  @type_name ||= begin
                   case descriptor.type.name
                   when :TYPE_MESSAGE, :TYPE_ENUM, :TYPE_GROUP then
                     type_name = modulize(descriptor.type_name)
                   else
                     type_name = descriptor.type.name.to_s.downcase.sub(/type_/, '')
                     type_name = ":#{type_name}"
                   end
                 end
end

def verbatim_default_value
  descriptor.default_value
end