class BinData::Registry

def initialize
  @registry = {}
end

def is_registered?(name)
  register_dynamic_class(name) unless @registry.has_key?(name)
  @registry.has_key?(name)
end

def lookup(name, endian = nil)
  key = normalize_name(name, endian)
  @registry[key] || raise(UnRegisteredTypeError, name.to_s)
end

def name_with_endian(name, endian)
  return name if endian.nil?
  suffix = (endian == :little) ? "le" : "be"
  if /^u?int\d+$/ =~ name
    name + suffix
  else
    name + "_" + suffix
  end
end

def normalize_name(name, endian = nil)
  name = underscore_name(name)
  return name if is_registered?(name)
  name = name_with_endian(name, endian)
  return name if is_registered?(name)
  name
end

def register(name, class_to_register)
  return if class_to_register.nil?
  formatted_name = underscore_name(name)
  warn_if_name_is_already_registered(formatted_name, class_to_register)
  @registry[formatted_name] = class_to_register
end

def register_dynamic_class(name)
  if /^u?int\d+(le|be)$/ =~ name or /^s?bit\d+(le)?$/ =~ name
    class_name = name.gsub(/(?:^|_)(.)/) { $1.upcase }
    begin
      BinData::const_get(class_name)
    rescue NameError
    end
  end
end

def underscore_name(name)
  name.to_s.sub(/.*::/, "").
            gsub(/([A-Z]+)([A-Z][a-z])/,'\1_\2').
            gsub(/([a-z\d])([A-Z])/,'\1_\2').
            tr("-", "_").
            downcase
end

def unregister(name)
  @registry.delete(underscore_name(name))
end

def warn_if_name_is_already_registered(name, class_to_register)
  prev_class = @registry[name]
  if $VERBOSE and prev_class and prev_class != class_to_register
    warn "warning: replacing registered class #{prev_class} " +
         "with #{class_to_register}"
  end
end