# frozen_string_literal: true

module API
  module Helpers
    module Packages
      module DependencyProxyHelpers
        REGISTRY_BASE_URLS = {
          npm: 'https://registry.npmjs.org/',
          pypi: 'https://pypi.org/simple/',
          maven: 'https://repo.maven.apache.org/maven2/'
        }.freeze

        APPLICATION_SETTING_NAMES = {
          npm: 'npm_package_requests_forwarding',
          pypi: 'pypi_package_requests_forwarding',
          maven: 'maven_package_requests_forwarding'
        }.freeze

        def redirect_registry_request(forward_to_registry: false, package_type: nil, target: nil, **options)
          if forward_to_registry && redirect_registry_request_available?(package_type, target) && maven_forwarding_ff_enabled?(package_type, target)
            ::Gitlab::Tracking.event(self.options[:for].name, "#{package_type}_request_forward")
            redirect(registry_url(package_type, options), body: options[:body])
            # For the requests with POST methods we need to set status 307 in order to keep request's method
            status :temporary_redirect if options[:method] == 'POST'
          else
            yield
          end
        end

        def registry_url(package_type, options)
          base_url = REGISTRY_BASE_URLS[package_type]

          raise ArgumentError, "Can't build registry_url for package_type #{package_type}" unless base_url

          case package_type
          when :npm
            "#{base_url}#{[options[:path], options[:package_name]].compact.join('/')}"
          when :pypi
            "#{base_url}#{options[:package_name]}/"
          when :maven
            "#{base_url}#{options[:path]}/#{options[:file_name]}"
          end
        end

        def redirect_registry_request_available?(package_type, target)
          application_setting_name = APPLICATION_SETTING_NAMES[package_type]

          raise ArgumentError, "Can't find application setting for package_type #{package_type}" unless application_setting_name

          if target.present?
            target.public_send(application_setting_name) # rubocop:disable GitlabSecurity/PublicSend
          else
            ::Gitlab::CurrentSettings
              .current_application_settings
              .attributes
              .fetch(application_setting_name, false)
          end
        end

        private

        def maven_forwarding_ff_enabled?(package_type, target)
          return true unless package_type == :maven
          return true if Feature.enabled?(:maven_central_request_forwarding)
          return false unless target

          Feature.enabled?(:maven_central_request_forwarding, target.root_ancestor)
        end
      end
    end
  end
end