class ActiveStorage::Service::Configurator

def self.build(service_name, configurations)
  new(configurations).build(service_name)
end

def build(service_name)
  config = config_for(service_name.to_sym)
  resolve(config.fetch(:service)).build(
    **config, configurator: self, name: service_name
  )
end

def config_for(name)
  configurations.fetch name do
    raise "Missing configuration for the #{name.inspect} Active Storage service. Configurations available for #{configurations.keys.inspect}"
  end
end

def initialize(configurations)
  @configurations = configurations.deep_symbolize_keys
end

def resolve(class_name)
  require "active_storage/service/#{class_name.to_s.underscore}_service"
  ActiveStorage::Service.const_get(:"#{class_name.camelize}Service")
rescue LoadError
  raise "Missing service adapter for #{class_name.inspect}"
end