class Lookbook::FileResolver

def read_file(path)
  File.exist?(path.to_s) ? File.read(path) : raise_error("The data file at '#{path}' could not be found")
end

def resolve(input)
  path = resolve_path(input, base_dir)
  content = read_file(path)
  case path.extname
  when ".json"
    JsonParser.call(content)
  when ".yml"
    YamlParser.call(content)
  end
end

def resolve_path(path, base_dir)
  Pathname(path.start_with?(".") ? File.expand_path(path, base_dir) : Rails.root.join(path))
end