Add upcoming_reconciliations table and model

Add the upcoming_reconciliations table and UpcomingReconciliation
model.

This table is to be used for displaying alerts to customers when
their subscription will be undergoing the quarterly reconciliation
process.

The table will hold the date when the next reconciliation is to
occur, and a date when an alert should start being displayed to the
customer. This information will be received from CustomersDot.

The table will hold a row for each relevant namespace in SaaS,
which should be about 9,000 - 10,000 rows (at time of commit). This
is because customers buy subscriptions for top-level namespaces in
SaaS.

In self-managed, the table should hold one row only, because the
entire self-managed instance uses one subscription/license.

MR: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/63054

Changelog: added

db/migrate/20210602122213_add_upcoming_reconciliations.rb

+# frozen_string_literal: true
+
+class AddUpcomingReconciliations < ActiveRecord::Migration[6.1]
+  include Gitlab::Database::MigrationHelpers
+
+  def up
+    with_lock_retries do
+      create_table :upcoming_reconciliations do |t|
+        t.references :namespace, index: { unique: true }, null: true, foreign_key: { on_delete: :cascade }
+        t.date :next_reconciliation_date, null: false
+        t.date :display_alert_from, null: false
+
+        t.timestamps_with_timezone
+      end
+    end
+  end
+
+  def down
+    with_lock_retries do
+      drop_table :upcoming_reconciliations
+    end
+  end
+end

db/schema_migrations/20210602122213

+66e50071130c2bd64be2f52d5c5f348a91883b2e9a9f4241175d1d2ad2a74434
\ No newline at end of file

db/structure.sql

@@ -18413,6 +18413,24 @@ CREATE SEQUENCE u2f_registrations_id_seq
 
 ALTER SEQUENCE u2f_registrations_id_seq OWNED BY u2f_registrations.id;
 
+CREATE TABLE upcoming_reconciliations (
+    id bigint NOT NULL,
+    namespace_id bigint,
+    next_reconciliation_date date NOT NULL,
+    display_alert_from date NOT NULL,
+    created_at timestamp with time zone NOT NULL,
+    updated_at timestamp with time zone NOT NULL
+);
+
+CREATE SEQUENCE upcoming_reconciliations_id_seq
+    START WITH 1
+    INCREMENT BY 1
+    NO MINVALUE
+    NO MAXVALUE
+    CACHE 1;
+
+ALTER SEQUENCE upcoming_reconciliations_id_seq OWNED BY upcoming_reconciliations.id;
+
 CREATE TABLE uploads (
     id integer NOT NULL,
     size bigint NOT NULL,
@@ -20279,6 +20297,8 @@ ALTER TABLE ONLY trending_projects ALTER COLUMN id SET DEFAULT nextval('trending
 
 ALTER TABLE ONLY u2f_registrations ALTER COLUMN id SET DEFAULT nextval('u2f_registrations_id_seq'::regclass);
 
+ALTER TABLE ONLY upcoming_reconciliations ALTER COLUMN id SET DEFAULT nextval('upcoming_reconciliations_id_seq'::regclass);
+
 ALTER TABLE ONLY uploads ALTER COLUMN id SET DEFAULT nextval('uploads_id_seq'::regclass);
 
 ALTER TABLE ONLY user_agent_details ALTER COLUMN id SET DEFAULT nextval('user_agent_details_id_seq'::regclass);
@@ -21927,6 +21947,9 @@ ALTER TABLE ONLY trending_projects
 ALTER TABLE ONLY u2f_registrations
     ADD CONSTRAINT u2f_registrations_pkey PRIMARY KEY (id);
 
+ALTER TABLE ONLY upcoming_reconciliations
+    ADD CONSTRAINT upcoming_reconciliations_pkey PRIMARY KEY (id);
+
 ALTER TABLE ONLY uploads
     ADD CONSTRAINT uploads_pkey PRIMARY KEY (id);
 
@@ -24675,6 +24698,8 @@ CREATE INDEX index_unit_test_failures_failed_at ON ci_unit_test_failures USING b
 
 CREATE UNIQUE INDEX index_unit_test_failures_unique_columns ON ci_unit_test_failures USING btree (unit_test_id, failed_at DESC, build_id);
 
+CREATE UNIQUE INDEX index_upcoming_reconciliations_on_namespace_id ON upcoming_reconciliations USING btree (namespace_id);
+
 CREATE INDEX index_uploads_on_checksum ON uploads USING btree (checksum);
 
 CREATE INDEX index_uploads_on_model_id_and_model_type ON uploads USING btree (model_id, model_type);
@@ -26519,6 +26544,9 @@ ALTER TABLE ONLY user_custom_attributes
 ALTER TABLE ONLY ci_pending_builds
     ADD CONSTRAINT fk_rails_480669c3b3 FOREIGN KEY (project_id) REFERENCES projects(id) ON DELETE CASCADE;
 
+ALTER TABLE ONLY upcoming_reconciliations
+    ADD CONSTRAINT fk_rails_497b4938ac FOREIGN KEY (namespace_id) REFERENCES namespaces(id) ON DELETE CASCADE;
+
 ALTER TABLE ONLY ci_pipeline_artifacts
     ADD CONSTRAINT fk_rails_4a70390ca6 FOREIGN KEY (project_id) REFERENCES projects(id) ON DELETE CASCADE;
 

ee/app/models/ee/namespace.rb

@@ -27,6 +27,7 @@ module EE
       has_one :namespace_limit, inverse_of: :namespace
       has_one :gitlab_subscription
       has_one :elasticsearch_indexed_namespace
+      has_one :upcoming_reconciliation, inverse_of: :namespace, class_name: "GitlabSubscriptions::UpcomingReconciliation"
 
       has_many :compliance_management_frameworks, class_name: "ComplianceManagement::Framework"
 

ee/app/models/gitlab_subscriptions/upcoming_reconciliation.rb

+# frozen_string_literal: true
+
+module GitlabSubscriptions
+  class UpcomingReconciliation < ApplicationRecord
+    belongs_to :namespace, inverse_of: :upcoming_reconciliation, optional: true
+
+    validates :namespace, uniqueness: true, presence: { if: proc { ::Gitlab.com? } }
+
+    def self.for_self_managed
+      self.find_by(namespace_id: nil)
+    end
+
+    def display_alert?
+      next_reconciliation_date >= Date.current && display_alert_from <= Date.current
+    end
+  end
+end

ee/spec/factories/upcoming_reconciliations.rb

+# frozen_string_literal: true
+
+FactoryBot.define do
+  factory :upcoming_reconciliation, class: 'GitlabSubscriptions::UpcomingReconciliation' do
+    next_reconciliation_date { Date.current + 7.days }
+    display_alert_from { Date.current.beginning_of_day }
+
+    trait :self_managed do
+      namespace { nil }
+    end
+
+    trait :saas do
+      namespace
+    end
+  end
+end

ee/spec/models/ee/namespace_spec.rb

@@ -17,6 +17,7 @@ RSpec.describe Namespace do
   it { is_expected.to have_one(:namespace_statistics) }
   it { is_expected.to have_one(:namespace_limit) }
   it { is_expected.to have_one(:elasticsearch_indexed_namespace) }
+  it { is_expected.to have_one :upcoming_reconciliation }
 
   it { is_expected.to delegate_method(:shared_runners_seconds).to(:namespace_statistics) }
   it { is_expected.to delegate_method(:shared_runners_seconds_last_reset).to(:namespace_statistics) }

ee/spec/models/gitlab_subscriptions/upcoming_reconciliation_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe GitlabSubscriptions::UpcomingReconciliation do
+  describe 'associations' do
+    it { is_expected.to belong_to(:namespace).optional }
+  end
+
+  describe 'validations' do
+    # This is needed for the validate_uniqueness_of expectation.
+    let_it_be(:upcoming_reconciliation) { create(:upcoming_reconciliation, :saas) }
+
+    it { is_expected.to validate_uniqueness_of(:namespace) }
+
+    it 'does not allow multiple rows with namespace_id nil' do
+      create(:upcoming_reconciliation, :self_managed)
+
+      expect { create(:upcoming_reconciliation, :self_managed) }.to raise_error(
+        ActiveRecord::RecordInvalid,
+        'Validation failed: Namespace has already been taken'
+      )
+    end
+
+    context 'when gitlab.com' do
+      before do
+        allow(Gitlab).to receive(:com?).and_return(true)
+      end
+
+      it { is_expected.to validate_presence_of(:namespace) }
+    end
+
+    context 'when not gitlab.com' do
+      it { is_expected.not_to validate_presence_of(:namespace) }
+    end
+  end
+
+  describe '#display_alert?' do
+    let(:upcoming_reconciliation) { build(:upcoming_reconciliation, :saas) }
+
+    subject(:display_alert?) { upcoming_reconciliation.display_alert? }
+
+    context 'with next_reconciliation_date in future' do
+      it { is_expected.to eq(true) }
+    end
+
+    context 'with next_reconciliation_date in past' do
+      before do
+        upcoming_reconciliation.next_reconciliation_date = Date.yesterday
+      end
+
+      it { is_expected.to eq(false) }
+    end
+
+    context 'with display_alert_from in future' do
+      before do
+        upcoming_reconciliation.display_alert_from = 2.days.from_now
+      end
+
+      it { is_expected.to eq(false) }
+    end
+
+    context 'with display_alert_from in past' do
+      it { is_expected.to eq(true) }
+    end
+  end
+
+  describe '.for_self_managed' do
+    it 'returns row where namespace_id is nil' do
+      upcoming_reconciliation = create(:upcoming_reconciliation, :self_managed)
+
+      expect(described_class.for_self_managed).to eq(upcoming_reconciliation)
+    end
+
+    it 'returns nil when there is no row with namespace_id nil' do
+      expect(described_class.for_self_managed).to eq(nil)
+    end
+  end
+end