# frozen_string_literal: true

module Orchestration
  module DockerCompose
    class AppService
      def initialize(config, environment)
        @environment = environment
        @config = config
      end

      class << self
        def command
          server = env.web_server
          %w[bundle exec] + case env.web_server
                            when 'puma'
                              %w[puma -C config/puma.rb]
                            when 'unicorn'
                              %w[unicorn -c config/unicorn.rb]
                            else
                              unsupported_web_server(server)
                            end
        end

        def entrypoint
          ["/app/#{orchestration}/entrypoint.sh"]
        end

        def healthcheck
          {
            'test' => ['ruby', "/app/#{orchestration}/healthcheck.rb"],
            # Defaults according to
            # https://docs.docker.com/engine/reference/builder/#healthcheck
            # Except start_period which cannot be set to 0s
            'interval' => '30s',
            'timeout' => '30s',
            'start_period' => '5s',
            'retries' => 3
          }
        end

        private

        def orchestration
          env.orchestration_dir_name
        end

        def env
          @env ||= Environment.new
        end

        def unsupported_web_server(server)
          raise ArgumentError,
                I18n.t(
                  'orchestration.rake.app.unspported_web_server',
                  server: server,
                  expected: %w[puma unicorn]
                )
        end
      end

      def definition
        {
          'image' => image,
          'environment' => environment,
          'ports' => ports,
          'deploy' => deploy,
          'logging' => logging
        }
      end

      private

      def image
        '${DOCKER_ORGANIZATION}/${DOCKER_REPOSITORY}:${DOCKER_TAG}'
      end

      def deploy
        {
          'mode' => 'replicated',
          'replicas' => '${REPLICAS}'
        }
      end

      def logging
        {
          'driver' => 'json-file',
          'options' => {
            'max-size' => '10m',
            'max-file' => '5'
          }
        }
      end

      def environment
        {
          'RAILS_LOG_TO_STDOUT' => '1',
          'RAILS_SERVE_STATIC_FILES' => '1',
          'WEB_PRELOAD_APP' => '1',
          'WEB_HEALTHCHECK_PATH' => '/'
        }.merge(Hash[inherited_environment.map { |key| [key, nil] }])
      end

      def inherited_environment
        %w[
          DATABASE_URL
          HOST_UID
          RAILS_ENV
          SECRET_KEY_BASE
          WEB_CONCURRENCY
          WEB_TIMEOUT
          WEB_WORKER_PROCESSES
        ]
      end

      def ports
        ['${CONTAINER_PORT:?CONTAINER_PORT must be provided}:8080']
      end
    end
  end
end