improved export - set start point for reference

app/services/exports/case_log_export_service.rb

@@ -6,8 +6,9 @@ module Exports
     end
 
     def export_case_logs
-      case_logs = retrieve_case_logs
-      export = save_export_run
+      current_time = Time.zone.now
+      case_logs = retrieve_case_logs(current_time)
+      export = save_export_run(current_time)
       write_master_manifest(export)
       write_export_data(case_logs)
     end
@@ -22,13 +23,14 @@ module Exports
 
   private
 
-    def save_export_run
+    def save_export_run(current_time)
       today = Time.zone.today
       last_daily_run_number = LogsExport.where(created_at: today.beginning_of_day..today.end_of_day).maximum(:daily_run_number)
       last_daily_run_number = 0 if last_daily_run_number.nil?
 
       export = LogsExport.new
       export.daily_run_number = last_daily_run_number + 1
+      export.started_at = current_time
       export.save!
       export
     end
@@ -49,9 +51,15 @@ module Exports
       @storage_service.write_file(file_path, string_io)
     end
 
-    def retrieve_case_logs
-      params = { from: Time.current.beginning_of_day, to: Time.current, status: CaseLog.statuses[:completed] }
-      CaseLog.where("updated_at >= :from and updated_at <= :to and status = :status", params)
+    def retrieve_case_logs(current_time)
+      recent_export = LogsExport.order("started_at").last
+      if recent_export
+        params = { from: recent_export.started_at, to: current_time, status: CaseLog.statuses[:completed] }
+        CaseLog.where("updated_at >= :from and updated_at <= :to and status = :status", params)
+      else
+        params = { to: current_time, status: CaseLog.statuses[:completed] }
+        CaseLog.where("updated_at <= :to and status = :status", params)
+      end
     end
 
     def build_manifest_csv_io

db/migrate/20220516111514_add_started_at.rb

@@ -0,0 +1,5 @@
+class AddStartedAt < ActiveRecord::Migration[7.0]
+  def change
+    add_column :logs_exports, :started_at, :datetime
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[7.0].define(version: 2022_05_13_123456) do
+ActiveRecord::Schema[7.0].define(version: 2022_05_16_111514) do
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
 
@@ -261,6 +261,7 @@ ActiveRecord::Schema[7.0].define(version: 2022_05_13_123456) do
   create_table "logs_exports", force: :cascade do |t|
     t.integer "daily_run_number"
     t.datetime "created_at", default: -> { "CURRENT_TIMESTAMP" }
+    t.datetime "started_at"
   end
 
   create_table "organisation_las", force: :cascade do |t|

spec/services/exports/case_log_export_service_spec.rb

@@ -46,10 +46,16 @@ RSpec.describe Exports::CaseLogExportService do
     end
 
     context "and case logs are available for export" do
+      let!(:time_now) { Time.now }
       before do
+        Timecop.freeze(time_now)
         case_log
       end
 
+      after do
+        LogsExport.destroy_all
+      end
+
       it "generates an XML export file with the expected filename" do
         expect(storage_service).to receive(:write_file).with(expected_data_filename, any_args)
         export_service.export_case_logs
@@ -63,6 +69,30 @@ RSpec.describe Exports::CaseLogExportService do
         export_service.export_case_logs
         expect(actual_content).to eq(expected_content)
       end
+
+      it "creates a logs export record in a database with correct time" do
+        export_service.export_case_logs
+        records_from_db = ActiveRecord::Base.connection.execute("select started_at, id from logs_exports ").to_a
+        expect(records_from_db[0]["started_at"]).to eq(time_now)
+        expect(records_from_db.count).to eq(1)
+      end
+
+      it "gets the logs for correct timeframe" do
+        start_time = Time.zone.local(2022, 4, 13, 2, 2, 2)
+        export = LogsExport.new(started_at: start_time, daily_run_number: 1)
+        export.save!
+        params = { from: start_time, to: time_now, status: CaseLog.statuses[:completed] }
+        expect(CaseLog).to receive(:where).with("updated_at >= :from and updated_at <= :to and status = :status", params).and_return([])
+        export_service.export_case_logs
+      end
+
+      context "when this is the first export" do
+        it "gets the logs for the timeframe up until the current time" do
+          params = { to: time_now, status: CaseLog.statuses[:completed] }
+          expect(CaseLog).to receive(:where).with("updated_at <= :to and status = :status", params).and_return([])
+          export_service.export_case_logs
+        end
+      end
     end
 
     context "and a previous export has run the same day" do