From cf30b7c8830b3bdaa56d0fd2e3c708da302a39a0 Mon Sep 17 00:00:00 2001
From: Rob Harrington <oeoeaio@gmail.com>
Date: Thu, 23 Nov 2017 18:20:05 +1100
Subject: [PATCH] Add service objects for summarizing outcomes of standing
 order processing jobs

---
 .../standing_order_summarizer.rb              | 43 +++++++++
 .../standing_order_summary.rb                 | 37 +++++++
 .../standing_order_summarizer_spec.rb         | 96 +++++++++++++++++++
 .../standing_order_summary_spec.rb            | 83 ++++++++++++++++
 4 files changed, 259 insertions(+)
 create mode 100644 lib/open_food_network/standing_order_summarizer.rb
 create mode 100644 lib/open_food_network/standing_order_summary.rb
 create mode 100644 spec/lib/open_food_network/standing_order_summarizer_spec.rb
 create mode 100644 spec/lib/open_food_network/standing_order_summary_spec.rb

diff --git a/lib/open_food_network/standing_order_summarizer.rb b/lib/open_food_network/standing_order_summarizer.rb
new file mode 100644
index 0000000000..9732a33fa8
--- /dev/null
+++ b/lib/open_food_network/standing_order_summarizer.rb
@@ -0,0 +1,43 @@
+require 'open_food_network/standing_order_summary'
+
+# Used by for StandingOrderPlacementJob and StandingOrderConfirmJob to summarize the
+# result of automatic processing of standing orders for the relevant shop owners.
+module OpenFoodNetwork
+  class StandingOrderSummarizer
+    def initialize
+      @summaries = {}
+    end
+
+    def record_order(order)
+      summary_for(order).record_order(order)
+    end
+
+    def record_success(order)
+      summary_for(order).record_success(order)
+    end
+
+    def record_issue(type, order, message)
+      summary_for(order).record_issue(type, order, message)
+    end
+
+    def record_failure(order)
+      line1 = "StandingOrderPlacementError: Cannot process order #{order.number} due to errors"
+      line2 = "Errors: #{order.errors.full_messages.join(', ')}"
+      Rails.logger.info("#{line1}\n#{line2}")
+      record_issue(:failure, order, line2)
+    end
+
+    def send_placement_summary_emails
+      @summaries.values.each do |summary|
+        StandingOrderMailer.placement_summary_email(summary).deliver
+      end
+    end
+
+    private
+
+    def summary_for(order)
+      shop_id = order.distributor_id
+      @summaries[shop_id] ||= StandingOrderSummary.new(shop_id)
+    end
+  end
+end
diff --git a/lib/open_food_network/standing_order_summary.rb b/lib/open_food_network/standing_order_summary.rb
new file mode 100644
index 0000000000..be445b9f0b
--- /dev/null
+++ b/lib/open_food_network/standing_order_summary.rb
@@ -0,0 +1,37 @@
+module OpenFoodNetwork
+  class StandingOrderSummary
+    attr_reader :shop_id, :order_count, :success_count, :issues
+
+    def initialize(shop_id)
+      @shop_id = shop_id
+      @order_ids = []
+      @success_ids = []
+      @issues = {}
+    end
+
+    def record_order(order)
+      @order_ids << order.id
+    end
+
+    def record_success(order)
+      @success_ids << order.id
+    end
+
+    def record_issue(type, order, message)
+      issues[type] ||= []
+      issues[type][order.id] = message
+    end
+
+    def order_count
+      @order_ids.count
+    end
+
+    def success_count
+      @success_ids.count
+    end
+
+    def issue_count
+      (@order_ids - @success_ids).count
+    end
+  end
+end
diff --git a/spec/lib/open_food_network/standing_order_summarizer_spec.rb b/spec/lib/open_food_network/standing_order_summarizer_spec.rb
new file mode 100644
index 0000000000..c01c5e0906
--- /dev/null
+++ b/spec/lib/open_food_network/standing_order_summarizer_spec.rb
@@ -0,0 +1,96 @@
+require 'open_food_network/standing_order_summarizer'
+
+module OpenFoodNetwork
+  describe StandingOrderSummarizer do
+    let(:order) { create(:order) }
+    let(:summarizer) { OpenFoodNetwork::StandingOrderSummarizer.new }
+
+    describe "#summary_for" do
+      let(:order) { double(:order, distributor_id: 123) }
+
+      context "when a summary for the order's distributor doesn't already exist" do
+        it "initializes a new summary object, and returns it" do
+          expect(summarizer.instance_variable_get(:@summaries).count).to be 0
+          summary = summarizer.send(:summary_for, order)
+          expect(summary.shop_id).to be 123
+          expect(summarizer.instance_variable_get(:@summaries).count).to be 1
+        end
+      end
+
+      context "when a summary for the order's distributor already exists" do
+        let(:summary) { double(:summary) }
+
+        before do
+          summarizer.instance_variable_set(:@summaries, { 123 => summary })
+        end
+
+        it "returns the existing summary object" do
+          expect(summarizer.instance_variable_get(:@summaries).count).to be 1
+          expect(summarizer.send(:summary_for, order)).to eq summary
+          expect(summarizer.instance_variable_get(:@summaries).count).to be 1
+        end
+      end
+    end
+
+    describe "recording events" do
+      let(:order) { double(:order) }
+      let(:summary) { double(:summary) }
+      before { allow(summarizer).to receive(:summary_for).with(order) { summary } }
+
+      describe "#record_order" do
+        it "requests a summary for the order and calls #record_order on it" do
+          expect(summary).to receive(:record_order).with(order).once
+          summarizer.record_order(order)
+        end
+      end
+
+      describe "#record_success" do
+        it "requests a summary for the order and calls #record_success on it" do
+          expect(summary).to receive(:record_success).with(order).once
+          summarizer.record_success(order)
+        end
+      end
+
+      describe "#record_issue" do
+        it "requests a summary for the order and calls #record_issue on it" do
+          expect(summary).to receive(:record_issue).with(:type, order, "message").once
+          summarizer.record_issue(:type, order, "message")
+        end
+      end
+
+      describe "#record_failure" do
+        before do
+          allow(order).to receive(:number) { "123" }
+          allow(order).to receive(:errors) { double(:errors, full_messages: ["Some error"]) }
+          allow(summarizer).to receive(:record_issue)
+        end
+
+        it "sends error info to the rails logger" do
+          expect(Rails.logger).to receive(:info)
+          summarizer.record_failure(order)
+        end
+
+        it "calls #record_issue on itself" do
+          summarizer.record_failure(order)
+          expect(summarizer).to have_received(:record_issue)
+        end
+      end
+    end
+
+    describe "#send_placement_summary_emails" do
+      let(:summary1) { double(:summary) }
+      let(:summary2) { double(:summary) }
+      let(:summaries) { { 1 => summary1, 2 => summary2 } }
+      let(:mail_mock) { double(:mail, deliver: true) }
+
+      before do
+        summarizer.instance_variable_set(:@summaries, summaries)
+      end
+
+      it "sends a placement summary email for each summary" do
+        expect(StandingOrderMailer).to receive(:placement_summary_email).twice { mail_mock }
+        summarizer.send_placement_summary_emails
+      end
+    end
+  end
+end
diff --git a/spec/lib/open_food_network/standing_order_summary_spec.rb b/spec/lib/open_food_network/standing_order_summary_spec.rb
new file mode 100644
index 0000000000..d835a85ed1
--- /dev/null
+++ b/spec/lib/open_food_network/standing_order_summary_spec.rb
@@ -0,0 +1,83 @@
+require 'open_food_network/standing_order_summary'
+
+module OpenFoodNetwork
+  describe StandingOrderSummary do
+    let(:summary) { OpenFoodNetwork::StandingOrderSummary.new(123) }
+
+    describe "#initialize" do
+      it "initializes instance variables: shop_id, order_count, success_count and issues" do
+        expect(summary.shop_id).to be 123
+        expect(summary.order_count).to be 0
+        expect(summary.success_count).to be 0
+        expect(summary.issues).to be_a Hash
+      end
+    end
+
+    describe "#record_order" do
+      let(:order) { double(:order, id: 37) }
+      it "adds the order id to the order_ids array" do
+        summary.record_order(order)
+        expect(summary.instance_variable_get(:@order_ids)).to eq [order.id]
+      end
+    end
+
+    describe "#record_success" do
+      let(:order) { double(:order, id: 37) }
+      it "adds the order id to the success_ids array" do
+        summary.record_success(order)
+        expect(summary.instance_variable_get(:@success_ids)).to eq [order.id]
+      end
+    end
+
+    describe "#record_issue" do
+      let(:order) { double(:order, id: 1) }
+
+      context "when no issues of the same type have been recorded yet" do
+        it "adds a new type to the issues hash, and stores a new issue against it" do
+          summary.record_issue(:some_type, order, "message")
+          expect(summary.issues.keys).to include :some_type
+          expect(summary.issues[:some_type][order.id]).to eq "message"
+        end
+      end
+
+      context "when an issue of the same type has already been recorded" do
+        let(:existing_issue) { double(:existing_issue) }
+
+        before { summary.issues[:some_type] = [existing_issue] }
+
+        it "stores a new issue against the existing type" do
+          summary.record_issue(:some_type, order, "message")
+          expect(summary.issues[:some_type]).to include existing_issue
+          expect(summary.issues[:some_type][order.id]).to eq "message"
+        end
+      end
+    end
+
+    describe "#order_count" do
+      let(:order_ids) { [1,2,3,4,5,6,7] }
+      it "counts the number of items in the order_ids instance_variable" do
+        summary.instance_variable_set(:@order_ids, order_ids)
+        expect(summary.order_count).to be 7
+      end
+    end
+
+    describe "#success_count" do
+      let(:success_ids) { [1,2,3,4,5,6,7] }
+      it "counts the number of items in the success_ids instance_variable" do
+        summary.instance_variable_set(:@success_ids, success_ids)
+        expect(summary.success_count).to be 7
+      end
+    end
+
+    describe "#lissue_count" do
+      let(:order_ids) { [1,3,5,7,9] }
+      let(:success_ids) { [1,2,3,4,5] }
+
+      it "counts the number of items in order_ids that are not in success_ids" do
+        summary.instance_variable_set(:@order_ids, order_ids)
+        summary.instance_variable_set(:@success_ids, success_ids)
+        expect(summary.issue_count).to be 2 # 7 & 9
+      end
+    end
+  end
+end