refactor upload service

app/logical/upload_service/preprocessor.rb

@@ -0,0 +1,111 @@
+class UploadService
+  class Preprocessor
+    attr_reader :params, :original_post_id
+
+    def initialize(params)
+      @original_post_id = params.delete(:original_post_id) || -1
+      @params = params
+    end
+
+    def source
+      params[:source]
+    end
+
+    def md5
+      params[:md5_confirmation]
+    end
+
+    def in_progress?
+      if Utils.is_downloadable?(source)
+        Upload.where(status: "preprocessing", source: source).exists?
+      elsif md5.present?
+        Upload.where(status: "preprocessing", md5: md5).exists?
+      else
+        false
+      end
+    end
+
+    def predecessor
+      if Utils.is_downloadable?(source)
+        Upload.where(status: ["preprocessed", "preprocessing"], source: source).first
+      elsif md5.present?
+        Upload.where(status: ["preprocessed", "preprocessing"], md5: md5).first
+      end
+    end
+
+    def completed?
+      predecessor.present?
+    end
+
+    def delayed_start(uploader_id)
+      CurrentUser.as(uploader_id) do
+        start!
+      end
+
+    rescue ActiveRecord::RecordNotUnique
+      return
+    end
+
+    def start!
+      if Utils.is_downloadable?(source)
+        CurrentUser.as_system do
+          if Post.tag_match("source:#{source}").where.not(id: original_post_id).exists?
+            raise ActiveRecord::RecordNotUnique.new("A post with source #{source} already exists")
+          end
+        end
+
+        if Upload.where(source: source, status: "completed").exists?
+          raise ActiveRecord::RecordNotUnique.new("A completed upload with source #{source} already exists")
+        end
+
+        if Upload.where(source: source).where("status like ?", "error%").exists?
+          raise ActiveRecord::RecordNotUnique.new("An errored upload with source #{source} already exists")
+        end
+      end
+
+      params[:rating] ||= "q"
+      params[:tag_string] ||= "tagme"
+
+      upload = Upload.create!(params)
+      begin
+        upload.update(status: "preprocessing")
+
+        if source.present?
+          file = Utils.download_for_upload(source, upload)
+        elsif params[:file].present?
+          file = params[:file]
+        end
+
+        Utils.process_file(upload, file)
+
+        upload.rating = params[:rating]
+        upload.tag_string = params[:tag_string]
+        upload.status = "preprocessed"
+        upload.save!
+      rescue Exception => x
+        upload.update(status: "error: #{x.class} - #{x.message}", backtrace: x.backtrace.join("\n"))
+      end
+
+      return upload
+    end
+
+    def finish!(upload = nil)
+      pred = upload || self.predecessor()
+
+      # regardless of who initialized the upload, credit should goto whoever submitted the form
+      pred.initialize_attributes
+
+      pred.attributes = self.params
+
+      # if a file was uploaded after the preprocessing occurred,
+      # then process the file and overwrite whatever the preprocessor
+      # did
+      Utils.process_file(pred, pred.file) if pred.file.present?
+
+      pred.status = "completed"
+      pred.save
+      return pred
+    end
+  end
+
+end