module ActionView::LookupContext::ViewPaths

def args_for_lookup(name, prefixes, partial, keys, details_options) #:nodoc:
  name, prefixes = normalize_name(name, prefixes)
  details, details_key = detail_args_for(details_options)
  [name, prefixes, partial || false, details, details_key, keys]
end

def detail_args_for(options)
  return @details, details_key if options.empty? # most common path.
  user_details = @details.merge(options)
  if @cache
    details_key = DetailsKey.get(user_details)
  else
    details_key = nil
  end
  [user_details, details_key]
end

def exists?(name, prefixes = [], partial = false, keys = [], options = {})
  @view_paths.exists?(*args_for_lookup(name, prefixes, partial, keys, options))
end

def find(name, prefixes = [], partial = false, keys = [], options = {})
  @view_paths.find(*args_for_lookup(name, prefixes, partial, keys, options))
end

def find_all(name, prefixes = [], partial = false, keys = [], options = {})
  @view_paths.find_all(*args_for_lookup(name, prefixes, partial, keys, options))
end

def normalize_name(name, prefixes) #:nodoc:
  prefixes = prefixes.presence
  parts    = name.to_s.split('/')
  parts.shift if parts.first.empty?
  name     = parts.pop
  return name, prefixes || [""] if parts.empty?
  parts    = parts.join('/')
  prefixes = prefixes ? prefixes.map { |p| "#{p}/#{parts}" } : [parts]
  return name, prefixes
end

def view_paths=(paths)
  @view_paths = ActionView::PathSet.new(Array(paths))
end

def with_fallbacks
  added_resolvers = 0
  self.class.fallbacks.each do |resolver|
    next if view_paths.include?(resolver)
    view_paths.push(resolver)
    added_resolvers += 1
  end
  yield
ensure
  added_resolvers.times { view_paths.pop }
end