module RackGraphql
  class HealthResponseBuilder
    def initialize(app_name:, env: {})
      @app_name = app_name
      @request = Rack::Request.new(env)
    end

    def build
      [200, headers, [body]]
    end

    private

    attr_reader :app_name, :request

    def headers
      { 'Content-Type' => 'application/json' }
    end

    def body
      JSON.generate(
        status:     :ok,
        request_ip: request.ip,
        app_name:   app_name,
        app_env:    ENV['RACK_ENV'],
        host:       ENV['HOSTNAME'],
        revision:   ENV['REVISION']
      )
    end
  end
end