class ActionDispatch::Routing::PolymorphicRoutes::HelperMethodBuilder

def self.build(action, type)
  prefix = action ? "#{action}_" : ""
  suffix = type
  if action.to_s == "new"
    HelperMethodBuilder.singular prefix, suffix
  else
    HelperMethodBuilder.plural prefix, suffix
  end
end

def self.get(action, type)
  type = type.to_sym
  CACHE[type].fetch(action) { build action, type }
end

def self.path; CACHE[:path][nil]; end

def self.plural(prefix, suffix)
  new(->(name) { name.route_key }, prefix, suffix)
end

def self.polymorphic_method(recipient, record_or_hash_or_array, action, type, options)
  builder = get action, type
  case record_or_hash_or_array
  when Array
    record_or_hash_or_array = record_or_hash_or_array.compact
    if record_or_hash_or_array.empty?
      raise ArgumentError, "Nil location provided. Can't build URI."
    end
    if record_or_hash_or_array.first.is_a?(ActionDispatch::Routing::RoutesProxy)
      recipient = record_or_hash_or_array.shift
    end
    method, args = builder.handle_list record_or_hash_or_array
  when String, Symbol
    method, args = builder.handle_string record_or_hash_or_array
  when Class
    method, args = builder.handle_class record_or_hash_or_array
  when nil
    raise ArgumentError, "Nil location provided. Can't build URI."
  else
    method, args = builder.handle_model record_or_hash_or_array
  end
  if options.empty?
    recipient.public_send(method, *args)
  else
    recipient.public_send(method, *args, options)
  end
end

def self.singular(prefix, suffix)
  new(->(name) { name.singular_route_key }, prefix, suffix)
end

def self.url;  CACHE[:url][nil]; end

def get_method_for_class(klass)
  name = @key_strategy.call klass.model_name
  get_method_for_string name
end

def get_method_for_string(str)
  "#{prefix}#{str}_#{suffix}"
end

def handle_class(klass)
  [get_method_for_class(klass), []]
end

def handle_class_call(target, klass)
  target.public_send get_method_for_class klass
end

def handle_list(list)
  record_list = list.dup
  record      = record_list.pop
  args = []
  route = record_list.map do |parent|
    case parent
    when Symbol
      parent.to_s
    when String
      raise(ArgumentError, "Please use symbols for polymorphic route arguments.")
    when Class
      args << parent
      parent.model_name.singular_route_key
    else
      args << parent.to_model
      parent.to_model.model_name.singular_route_key
    end
  end
  route <<
  case record
  when Symbol
    record.to_s
  when String
    raise(ArgumentError, "Please use symbols for polymorphic route arguments.")
  when Class
    @key_strategy.call record.model_name
  else
    model = record.to_model
    if model.persisted?
      args << model
      model.model_name.singular_route_key
    else
      @key_strategy.call model.model_name
    end
  end
  route << suffix
  named_route = prefix + route.join("_")
  [named_route, args]
end

def handle_model(record)
  args  = []
  model = record.to_model
  named_route = if model.persisted?
    args << model
    get_method_for_string model.model_name.singular_route_key
  else
    get_method_for_class model
  end
  [named_route, args]
end

def handle_model_call(target, record)
  if mapping = polymorphic_mapping(target, record)
    mapping.call(target, [record], suffix == "path")
  else
    method, args = handle_model(record)
    target.public_send(method, *args)
  end
end

def handle_string(record)
  [get_method_for_string(record), []]
end

def handle_string_call(target, str)
  target.public_send get_method_for_string str
end

def initialize(key_strategy, prefix, suffix)
  @key_strategy = key_strategy
  @prefix       = prefix
  @suffix       = suffix
end

def polymorphic_mapping(target, record)
  if record.respond_to?(:to_model)
    target._routes.polymorphic_mappings[record.to_model.model_name.name]
  else
    target._routes.polymorphic_mappings[record.class.name]
  end
end