solution for retrieving completed reports from aws

solution

#per my process:  I loaded all of this data into a normal ActiveRecord Table via a migration and with proper indexing.
# I looked at the request and response data needed for AWS per the docs, and limited them to only what I knew was required though
# the sdk gives a lot of metadata that could be useful in the future. I did not test this with an actual aws bucket, but per my understanding 
# it only needs the bucket name and the name of the object in the bucket which was the report_uuid. This could obviously use an 
#integration test, stubbed responses and an end-to-end test on the business necessary features. 
# I like to write these kinds of data to temp folders if the data is likely to go stale quickly and need to be updated
# The use of private methods creates an easy to understand footprint for the report object so that a developer can quickly get 
#either a collection of completed reports, or to find out if an instance of the class is completed.  That's about it.  Thanks. 


module Reports

  class FetchPersisted

    def initialize(report)
      @report = report
      @bucket_name = SimpleStorage::GetBucketName.new(report).get
    end

    def fetch
      if @report.completed?      
        begin
          #s3 being the variable for the configured s3 instance and copy_object coming from the aws-sdk
          completed_report_response = s3.copy_object({
              bucket: @bucket_name,
              copy_source: @report.report_uuid#assuming the naming convention is same for db and aws,
            }
          )
          #write to a tmp folder so the reports can be easily cleaned up when stale,
          # depending on business needs, copy_object_result should be the only thing we care about saving to file for now
          File.write('tmp/completed_reports/#{@report.report_uuid}', completed_report_response.copy_object_result)
        rescue Aws::S3::Errors::ServiceError => e
          #keep the exception around to use in debugging later
          File.write('log/development.log', e.backtrace.inspect )
        end
      else
        return false
      end    
    end  
  end
end


class Report < ActiveRecord::Base


  validates :report_uuid, presence: true, uniqueness: true

  enum workflow_status: { open: 0,
                          completed: 1,
                          failed: 2 }



  private
    #why enumerator is handy, very easy lookup for getting all completed reports, allows for human language syntax 
    def self.open?
      where workflow_status: 0
    end

    def self.completed?
      where workflow_status: 1
    end
    
    def self.failed?
      where workflow_status: 2
    end

end

r = Report.last
f = Reports::FetchPersisted.new(r)
f.fetch