Migrate service to associated objects

app/jobs/one_day_job.rb

@@ -2,6 +2,6 @@ class OneDayJob < ApplicationJob
   def perform
     Hook.delete_all
     RawHook.delete_all
-    DailyPacketService.save_to_s3
+    DailyPacket::Producer.save_to(:s3)
   end
 end

app/models/daily_packet.rb

@@ -3,7 +3,8 @@ class DailyPacket < ApplicationRecord
 
   has_object :pdf_view
 
-  delegate :pdf_data, to: :pdf_view
+  has_object :producer
+  delegate :save_to_disk, :save_to_s3, to: :producer
 
   validates :built_on, presence: true
   validates :reading_list_pace, presence: true
@@ -15,16 +16,4 @@ def built_on_phrase
   def reading_list_phrase
     "#{reading_list_pace} pages/day"
   end
-
-  def local_path
-    "tmp/daily_packet.pdf"
-  end
-
-  def s3_key
-    "daily-packets/#{built_on.strftime("%Y-%m-%d")}.pdf"
-  end
-
-  def save_locally
-    pdf_view.save_as(local_path)
-  end
 end

app/models/daily_packet/builder.rb

@@ -0,0 +1,17 @@
+class DailyPacket::Builder
+  def self.find_or_build_for(built_on)
+    daily_packet = DailyPacket.find_or_initialize_by(built_on: built_on)
+    return daily_packet if daily_packet.persisted?
+
+    reading_list = ReadingList.new
+    warm_fuzzy = WarmFuzzy.random
+
+    attributes = {
+      reading_list_pace: reading_list.pace,
+      warm_fuzzy: warm_fuzzy
+    }
+
+    daily_packet.update(attributes)
+    daily_packet
+  end
+end

app/models/daily_packet/producer.rb

@@ -0,0 +1,25 @@
+class DailyPacket::Producer < ActiveRecord::AssociatedObject
+  def self.save_to(target, date = Date.today)
+    daily_packet = DailyPacket::Builder.find_or_build_for(date)
+
+    if target == :disk
+      daily_packet.save_to_disk
+    elsif target == :s3
+      daily_packet.save_to_s3
+    else
+      raise ArgumentError
+    end
+  end
+
+  def save_to_disk
+    local_path = "tmp/daily_packet.pdf"
+    daily_packet.pdf_view.save_as(local_path)
+  end
+
+  def save_to_s3
+    timestamp = daily_packet.built_on.strftime("%Y-%m-%d")
+    s3_key = "daily-packets/#{timestamp}.pdf"
+    pdf_data = daily_packet.pdf_view.pdf_data
+    S3Api.write(s3_key, pdf_data)
+  end
+end

lib/tasks/daily_packet.rake

@@ -1,11 +1,11 @@
 namespace :daily_packet do
   desc "Produce today's packet and save locally."
   task save_locally: :environment do
-    DailyPacketService.save_locally
+    DailyPacket::Producer.save_to(:disk)
   end
 
   desc "Produce today's packet and save to S3"
   task save_to_s3: :environment do
-    DailyPacketService.save_to_s3
+    DailyPacket::Producer.save_to(:s3)
   end
 end

spec/models/daily_packet/builder_spec.rb

@@ -0,0 +1,26 @@
+require "rails_helper"
+
+describe DailyPacket::Builder do
+  describe ".find_or_build_for" do
+    let(:built_on) { Date.parse("2007-07-07") }
+
+    context "with an existing DailyPacket record" do
+      it "returns that existing record" do
+        existing_daily_packet = FactoryBot.create(:daily_packet, built_on: built_on)
+        returned_daily_packet = DailyPacket::Builder.find_or_build_for(built_on)
+        expect(returned_daily_packet.id).to eq existing_daily_packet.id
+        expect(DailyPacket.count).to eq 1
+      end
+    end
+
+    context "without an existing DailyPacket record" do
+      it "creates and returns a new record" do
+        FactoryBot.create(:warm_fuzzy)
+
+        expect do
+          DailyPacket::Builder.find_or_build_for(built_on)
+        end.to change(DailyPacket, :count).from(0).to(1)
+      end
+    end
+  end
+end

spec/models/daily_packet/producer_spec.rb

@@ -0,0 +1,36 @@
+require "rails_helper"
+
+describe DailyPacket::Producer do
+  describe ".save_to" do
+    context "with an invalid target" do
+      it "raises an ArgumentError" do
+        expect do
+          DailyPacket::Producer.save_to(:invalid)
+        end.to raise_error(ArgumentError)
+      end
+    end
+    context "when the target is disk" do
+      it "renders and writes the pdf data locally" do
+        mock_view = double(:mock_view)
+        expect(DailyPacket::PdfView).to receive(:new).and_return(mock_view)
+        expect(mock_view).to receive(:save_as).with("tmp/daily_packet.pdf").and_return(nil)
+        DailyPacket::Producer.save_to(:disk)
+      end
+    end
+
+    context "when the target is disk" do
+      it "renders and writes the pdf data to s3" do
+        mock_view = double(:mock_view, pdf_data: "PDF GOES HERE")
+        expect(DailyPacket::PdfView).to receive(:new).and_return(mock_view)
+
+        expect(S3Api).to receive(:write).with(
+          "daily-packets/2001-02-03.pdf",
+          "PDF GOES HERE"
+        )
+
+        date = Date.parse("2001-02-03")
+        DailyPacket::Producer.save_to(:s3, date)
+      end
+    end
+  end
+end