Merge pull request #2333 from openstax/bookstore-purchases

generate payment codes for students

Author: Dantemss

app/controllers/admin/payments_controller.rb

@@ -16,4 +16,27 @@ def extend_payment_due_at
     redirect_to admin_payments_path, notice: "Extended payment due dates"
   end
 
+  def generate_payment_codes
+    params.require(:prefix)
+    params.require(:amount)
+
+    generator = GeneratePaymentCodes.call(
+      prefix: params[:prefix],
+      amount: params[:amount].to_i,
+      generate_csv: true
+    ).outputs
+
+    if generator.errors.any?
+      flash[:error] = generator.errors
+      redirect_to admin_payments_path
+    else
+      send_data generator.csv,
+                filename: "payment-codes-#{SecureRandom.uuid}.csv"
+    end
+  end
+
+  def download_payment_code_report
+    send_data GeneratePaymentCodeReport.call.outputs.csv,
+              filename: "payment-code-report-#{SecureRandom.uuid}.csv"
+  end
 end

app/models/payment_code.rb

@@ -0,0 +1,53 @@
+class PaymentCode < IndestructibleRecord
+  CONFUSED_CHARS = %w(B 8 G 6 I 1 O 0 S 5 Z 2)
+
+  validates_presence_of :code
+  validates_uniqueness_of :code
+
+  before_validation :set_code, on: :create
+  after_rollback :handle_collision
+
+  before_update :preserve_persisted_code
+
+  belongs_to :student, subsystem: :course_membership, inverse_of: :payment_codes, optional: true
+
+  attr_accessor :prefix
+
+  private
+
+  def preserve_persisted_code
+    throw_persisted_error if code_changed?
+  end
+
+  def code=(value)
+    throw_persisted_error if persisted?
+    super
+  end
+
+  def generate_code
+    unless prefix.present?
+      errors.add :prefix, :blank
+      raise ActiveRecord::RecordInvalid
+    end
+
+    base = [*'0'..'9', *'A'..'Z'] - CONFUSED_CHARS
+    post = Array.new(10) { base.sample }.join
+    "#{prefix.parameterize.upcase}-#{post}"
+  end
+
+  def set_code
+    throw_persisted_error if persisted?
+    self.code = generate_code
+  end
+
+  def handle_collision
+    if errors.types[:code]&.include?(:taken)
+      set_code
+      save
+    end
+  end
+
+  def throw_persisted_error
+    throw :cannot_change_persisted_code
+  end
+end

app/routines/generate_payment_code_report.rb

@@ -0,0 +1,27 @@
+class GeneratePaymentCodeReport
+  lev_routine express_output: :csv
+
+  def exec(since: 1.year.ago)
+    outputs.csv = CSV.generate(headers: true) do |csv|
+      csv << [
+        'Code',
+        'Redeemed At',
+        'Course UUID',
+        'Student Tutor ID',
+        'Student Identifier'
+      ]
+
+      range = since.midnight..DateTime::Infinity.new
+
+      PaymentCode.where(created_at: range).in_batches.each_record do |pc|
+        csv << [
+          pc.code,
+          pc.redeemed_at,
+          pc&.student&.course&.id,
+          pc&.student&.id,
+          pc&.student&.student_identifier
+        ]
+      end
+    end
+  end
+end

app/routines/generate_payment_codes.rb

@@ -0,0 +1,46 @@
+class GeneratePaymentCodes
+  lev_routine express_output: :codes, transaction: :read_committed
+
+  protected
+
+  def exec(prefix:, amount: 1, generate_csv: false)
+    codes = []
+    errors = []
+    total_retries = 0
+
+    unless amount.is_a?(Integer) && amount > 0 && amount < 1000
+      outputs.errors = ['Amount must be a whole number between 1 and 999']
+      return
+    end
+
+    amount.times do
+      retries = 0
+      pc = PaymentCode.new(prefix: prefix)
+
+      begin
+        pc.save!
+        codes << pc.code
+      rescue ActiveRecord::RecordInvalid
+        if retries < 3
+          retries += 1
+          total_retries += 1
+          retry
+        end
+
+        errors << pc.errors
+      end
+    end
+
+    outputs.retries = total_retries
+    outputs.codes = codes
+    outputs.errors = errors.map(&:full_messages).uniq
+    outputs.csv = generate_csv(codes) if generate_csv && errors.empty?
+  end
+
+  def generate_csv(codes)
+    CSV.generate(headers: true) do |csv|
+      csv << ['Code']
+      codes.map {|c| csv << [c] }
+    end
+  end
+end

app/subsystems/course_membership/models/student.rb

@@ -19,6 +19,8 @@ class CourseMembership::Models::Student < ApplicationRecord
   has_many :research_cohorts, through: :research_cohort_members, source: :cohort,
            subsystem: :research, class_name: 'Research::Models::Cohort'
 
+  has_many :payment_codes, inverse_of: :student, class_name: 'PaymentCode'
+
   before_validation :init_first_paid_at
 
   validates :role, uniqueness: true

app/views/admin/payments/index.html.erb

@@ -12,3 +12,30 @@ time zone).</p>
                  class: 'btn btn-primary',
                  data: { confirm: "Are you sure you want to extend a whole bunch of due dates?"} %>
 <% end %>
+
+<h3>Bookstore Payment Codes</h3>
+
+<%= form_tag(generate_payment_codes_admin_payments_path, method: :post) do %>
+  <div class="row">
+    <div class="col-xs-12">
+      <div class="form-group">
+        <label for="prefix">Prefix</label>
+        <%= text_field_tag 'prefix', nil, class: 'form-control', required: 'required' %>
+      </div>
+    </div>
+    <div class="col-xs-12">
+      <div class="form-group">
+        <label for="amount">Amount</label>
+        <%= number_field_tag 'amount', nil, min: 1, max: 999, class: 'form-control' %>
+      </div>
+    </div>
+  </div>
+  <%= submit_tag 'Generate Codes', class: 'btn btn-primary' %>
+<% end %>
+
+<hr>
+
+<%= button_to 'Download Usage Report',
+    download_payment_code_report_admin_payments_path,
+    method: 'get',
+    class: 'btn btn-primary' %>

app/views/static_pages/stubbed_payments.html renamed to app/views/static_pages/stubbed_payments.html.erb

@@ -322,6 +322,8 @@
     resources :payments, only: :index do
       collection do
         put :extend_payment_due_at
+        post :generate_payment_codes
+        get :download_payment_code_report
       end
     end
 

config/routes.rb

@@ -0,0 +1,12 @@
+class CreatePaymentCodes < ActiveRecord::Migration[5.2]
+  def change
+    create_table :payment_codes do |t|
+      t.string :code
+      t.datetime :redeemed_at
+      t.references :course_membership_student
+
+      t.timestamps
+      t.index :code, unique: true
+    end
+  end
+end

db/migrate/20210623225308_create_payment_codes.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2021_06_22_152149) do
+ActiveRecord::Schema.define(version: 2021_06_23_225308) do
 
   create_sequence "active_storage_attachments_id_seq"
   create_sequence "active_storage_blobs_id_seq"
@@ -54,6 +54,7 @@
   create_sequence "oauth_applications_id_seq"
   create_sequence "openstax_accounts_accounts_id_seq"
   create_sequence "openstax_salesforce_users_id_seq"
+  create_sequence "payment_codes_id_seq"
   create_sequence "ratings_exercise_group_book_parts_id_seq"
   create_sequence "ratings_period_book_parts_id_seq"
   create_sequence "ratings_role_book_parts_id_seq"
@@ -713,6 +714,16 @@
     t.datetime "updated_at"
   end
 
+  create_table "payment_codes", force: :cascade do |t|
+    t.string "code"
+    t.datetime "redeemed_at"
+    t.bigint "course_membership_student_id"
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.index ["code"], name: "index_payment_codes_on_code", unique: true
+    t.index ["course_membership_student_id"], name: "index_payment_codes_on_course_membership_student_id"
+  end
+
   create_table "ratings_exercise_group_book_parts", force: :cascade do |t|
     t.uuid "exercise_group_uuid", null: false
     t.uuid "book_part_uuid", null: false

db/schema.rb

@@ -0,0 +1,6 @@
+FactoryBot.define do
+  factory :payment_code, class: 'PaymentCode' do
+    prefix { 'ABC' }
+    association :student, factory: :course_membership_student
+  end
+end

spec/factories/payment_codes.rb

@@ -0,0 +1,45 @@
+require 'rails_helper'
+
+RSpec.describe PaymentCode, type: :model do
+  subject(:pc) { FactoryBot.create :payment_code }
+
+  context 'with a new record' do
+    it 'generates codes' do
+      new_pc = described_class.new(prefix: 'NEW')
+      new_pc.save
+      expect(new_pc.code).to match(/^NEW\-[a-zA-Z0-9]{10}$/)
+    end
+
+    it 'requires a prefix' do
+      new_pc = described_class.new(prefix: '')
+      expect { new_pc.save }.to raise_error(ActiveRecord::RecordInvalid)
+      expect(new_pc.errors.types).to include(:prefix)
+    end
+
+    it 'regenerates a code when a collision occurs' do
+      new_pc = described_class.new
+      allow(new_pc).to receive(:generate_code).and_return(pc.code, pc.code, 'new-code')
+      new_pc.save
+      expect(new_pc).to have_received(:generate_code).at_least(:thrice)
+      expect(new_pc.code).not_to eq(pc.code)
+    end
+  end
+
+  context 'with a persisted record' do
+    it 'cannot change a code once persisted' do
+      expect { pc.send(:code=, 'test') }.to throw_symbol(:cannot_change_persisted_code)
+
+      expect {
+        pc.redeemed_at = 1.day.ago
+        pc.save
+      }.not_to change{ pc.code }.from(pc.code)
+
+      expect {
+        pc.write_attribute(:code, 'changed')
+        pc.save
+      }.to throw_symbol(:cannot_change_persisted_code)
+
+      expect { pc.send(:set_code) }.to throw_symbol(:cannot_change_persisted_code)
+    end
+  end
+end

spec/models/payment_code_spec.rb

@@ -34,4 +34,24 @@
       end
     end
   end
+
+  context 'generating payment codes' do
+    it 'downloads a CSV file' do
+      expect {
+         post generate_payment_codes_admin_payments_path, params: { prefix: 'abc', amount: 20 }
+      }.to change { PaymentCode.count }.by 20
+
+      expect(response.body).to match('Code')
+    end
+
+    it 'downloads a report' do
+      get download_payment_code_report_admin_payments_path
+      expect(response.body).to match('Code')
+    end
+
+    it 'returns errors' do
+      post generate_payment_codes_admin_payments_path, params: { prefix: 'ABC', amount: 'A' }
+      expect(flash[:error]).to eq(["Amount must be a whole number between 1 and 999"])
+    end
+  end
 end

spec/requests/admin/payments_controller_spec.rb

@@ -0,0 +1,34 @@
+require 'rails_helper'
+
+RSpec.describe GeneratePaymentCodeReport, type: :routine do
+  context 'when generating a report on code use' do
+    it 'generates an inline csv with codes and other data' do
+      date = 1.day.ago
+      pc = FactoryBot.create(:payment_code, redeemed_at: date)
+      rows = CSV.parse(described_class.call.outputs.csv)
+      expect(rows[0]).to eq(['Code',
+                             'Redeemed At',
+                             'Course UUID',
+                             'Student Tutor ID',
+                             'Student Identifier'])
+      expect(rows[1]).to eq ([pc.code,
+                              date.to_s,
+                              pc.student.course.id.to_s,
+                              pc.student.id.to_s,
+                              pc.student.student_identifier])
+    end
+
+    it 'can filter by a beginning date' do
+      older_code = FactoryBot.create(:payment_code, created_at: 3.days.ago).code
+      newer_code = FactoryBot.create(:payment_code, created_at: 1.day.ago).code
+      rows = CSV.parse(described_class.call(since: 2.days.ago).outputs.csv)
+      expect(rows.length).to eq(2)
+      expect(rows[1][0]).to eq(newer_code)
+
+      rows = CSV.parse(described_class.call(since: 4.days.ago).outputs.csv)
+      expect(rows.length).to eq(3)
+      expect(rows[1][0]).to eq(older_code)
+      expect(rows[2][0]).to eq(newer_code)
+    end
+  end
+end