Bulk lesson creation (#853)

## Status

- Closes
[#1472](RaspberryPiFoundation/digital-editor-issues#1472 (comment))

- Related to [Experience CS #1761
](RaspberryPiFoundation/experience-cs#1761)



## What's changed?

- Add Lessons::Batch controller 
- Add a bulk create jbuilder that renders an array, echoing an
`origin_identifier` when supplied so the caller can match responses to
submitted projects
- Add a LessonsCreation concern to consolidate logic and params that are
share between batch and single lesson creation
- Update specs

Author: PetarSimonovic

app/controllers/api/lessons/batch_controller.rb

@@ -0,0 +1,65 @@
+# frozen_string_literal: true
+
+module Api
+  module Lessons
+    class BatchController < ApiController
+      include RemixSelection
+      include LessonCreation
+
+      before_action :authorize_user
+      before_action :verify_school_class_belongs_to_school
+      before_action :verify_can_create_scratch_projects
+      before_action :authorize_lesson_projects!
+
+      def create_batch
+        raise ParameterError, 'lesson_projects cannot be blank' unless lesson_projects?
+
+        @results = Lesson::CreateBatch.call(
+          lessons_params: batch_lessons_params
+        )
+        @user = current_user
+        render :create_batch, formats: [:json], status: :created
+      end
+
+      private
+
+      def verify_school_class_belongs_to_school
+        return unless lesson_projects?
+
+        params[:lesson_projects].each { |lesson_params| verify_lesson_school_class!(lesson_params) }
+      end
+
+      def verify_can_create_scratch_projects
+        return unless lesson_projects?
+
+        scratch_project_params = params[:lesson_projects].find { |lesson_params| scratch_project?(lesson_params) }
+        return unless scratch_project_params
+
+        verify_lesson_scratch!(scratch_project_params)
+      end
+
+      def batch_lessons_params
+        @batch_lessons_params ||= params[:lesson_projects].map { |lesson_params| create_batch_params(lesson_params) }
+      end
+
+      def create_batch_params(lesson_project)
+        lesson_project.permit(*LESSON_ATTRIBUTES, :origin_identifier, project_attributes: PROJECT_ATTRIBUTES).merge(user_id: current_user.id)
+      end
+
+      def lesson_projects?
+        projects = params[:lesson_projects]
+        return false unless projects.is_a?(Array)
+
+        projects.any?(&:present?)
+      end
+
+      def authorize_lesson_projects!
+        return unless lesson_projects?
+
+        batch_lessons_params.each do |lesson_params|
+          authorize! :create, Lesson.new(lesson_params.slice(:school_id, :school_class_id, :user_id))
+        end
+      end
+    end
+  end
+end

app/controllers/api/lessons_controller.rb

@@ -3,6 +3,7 @@
 module Api
   class LessonsController < ApiController
     include RemixSelection
+    include LessonCreation
 
     before_action :authorize_user, except: %i[index show]
     before_action :verify_school_class_belongs_to_school, only: :create
@@ -31,7 +32,6 @@ def show
 
     def create
       result = Lesson::Create.call(lesson_params: create_params)
-
       if result.success?
         @lesson_with_user = result[:lesson].with_user
         render :show, formats: [:json], status: :created
@@ -78,16 +78,11 @@ def filtered_lessons_scope
     end
 
     def verify_school_class_belongs_to_school
-      return if create_params[:school_class_id].blank?
-      return if school&.classes&.pluck(:id)&.include?(create_params[:school_class_id])
-
-      raise ParameterError, 'school_class_id does not correspond to school_id'
+      verify_lesson_school_class!(create_params)
     end
 
     def verify_can_create_scratch_projects
-      return unless scratch_project? && !school.scratch_enabled?
-
-      render json: { error: 'Forbidden' }, status: :forbidden
+      verify_lesson_scratch!(create_params)
     end
 
     def user_remixes(lessons)
@@ -104,10 +99,6 @@ def user_remix(lesson)
       )
     end
 
-    def scratch_project?
-      create_params.dig(:project_attributes, :project_type) == Project::Types::CODE_EDITOR_SCRATCH
-    end
-
     def update_params
       params.fetch(:lesson, {}).permit(
         :name,
@@ -119,23 +110,8 @@ def update_params
     end
 
     def create_params
-      params.fetch(:lesson, {}).permit(
-        :school_id,
-        :school_class_id,
-        :name,
-        :description,
-        :visibility,
-        :due_date,
-        {
-          project_attributes: [
-            :name,
-            :project_type,
-            :locale,
-            { components: %i[id name extension content index default] },
-            { scratch_component: {} }
-          ]
-        }
-      ).merge(user_id: current_user.id)
+      source = params.fetch(:lesson, {})
+      source.permit(*LESSON_ATTRIBUTES, project_attributes: PROJECT_ATTRIBUTES).merge(user_id: current_user.id)
     end
 
     def school_owner?

app/controllers/concerns/lesson_creation.rb

@@ -0,0 +1,47 @@
+# frozen_string_literal: true
+
+module LessonCreation
+  extend ActiveSupport::Concern
+
+  LESSON_ATTRIBUTES = %i[
+    school_id
+    school_class_id
+    name
+    description
+    visibility
+    due_date
+  ].freeze
+
+  PROJECT_ATTRIBUTES = [
+    :name,
+    :project_type,
+    :locale,
+    { components: %i[id name extension content index default] },
+    { scratch_component: {} }
+  ].freeze
+
+  private
+
+  def verify_lesson_school_class!(lesson_params)
+    school_class_id = lesson_params[:school_class_id]
+    return if school_class_id.blank?
+
+    school = School.find_by(id: lesson_params[:school_id])
+    return if school&.classes&.exists?(id: school_class_id)
+
+    raise ParameterError, 'school_class_id does not correspond to school_id'
+  end
+
+  def verify_lesson_scratch!(lesson_params)
+    return unless scratch_project?(lesson_params)
+
+    school = School.find_by(id: lesson_params[:school_id])
+    return if school&.scratch_enabled?
+
+    render json: { error: 'Forbidden' }, status: :forbidden
+  end
+
+  def scratch_project?(lesson_params)
+    lesson_params.dig(:project_attributes, :project_type) == Project::Types::CODE_EDITOR_SCRATCH
+  end
+end

app/views/api/lessons/batch/create_batch.json.jbuilder

@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+json.array!(@results) do |result|
+  if result.success?
+    json.partial! 'api/lessons/lesson', lesson: result[:lesson], user: @user
+  else
+    json.error result[:error]
+  end
+
+  json.origin_identifier result[:origin_identifier] if result[:origin_identifier].present?
+end

config/routes.rb

@@ -86,6 +86,7 @@
 
     resources :lessons, only: %i[index create show update destroy] do
       post :copy, on: :member, to: 'lessons#create_copy'
+      post :batch, on: :collection, to: 'lessons/batch#create_batch'
     end
 
     resources :teacher_invitations, param: :token, only: :show do

lib/concepts/lesson/operations/create_batch.rb

@@ -0,0 +1,20 @@
+# frozen_string_literal: true
+
+class Lesson
+  class CreateBatch
+    class << self
+      def call(lessons_params:)
+        lessons_params.map { |lesson| create_one(lesson) }
+      end
+
+      private
+
+      def create_one(lesson_params)
+        origin_identifier = lesson_params[:origin_identifier]
+        Lesson::Create.call(lesson_params: lesson_params.except(:origin_identifier)).tap do |result|
+          result[:origin_identifier] = origin_identifier if origin_identifier.present?
+        end
+      end
+    end
+  end
+end

spec/concepts/lesson/create_batch_spec.rb

@@ -0,0 +1,79 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe Lesson::CreateBatch, type: :unit do
+  let(:school) { create(:school) }
+  let(:teacher) { create(:teacher, school:) }
+
+  let(:lessons_params) do
+    [
+      {
+        name: 'Test Lesson',
+        user_id: teacher.id,
+        school_id: school.id,
+        origin_identifier: 'test-lesson-identifier-one',
+        project_attributes: {
+          name: 'Hello world project',
+          project_type: Project::Types::PYTHON,
+          components: [
+            { name: 'main.py', extension: 'py', content: 'print("Hello, world!")' }
+          ]
+        }
+      },
+      {
+        name: 'Test Lesson 2',
+        user_id: teacher.id,
+        school_id: school.id,
+        origin_identifier: 'test-lesson-identifier-two',
+        project_attributes: {
+          name: 'Hello world project',
+          project_type: Project::Types::PYTHON,
+          components: [
+            { name: 'main.py', extension: 'py', content: 'print("Hello, world!")' }
+          ]
+        }
+      }
+    ]
+  end
+
+  context 'with a teacher' do
+    let(:result) { described_class.call(lessons_params:) }
+
+    before do
+      allow(User).to receive(:from_userinfo).with(ids: teacher.id).and_return([teacher])
+    end
+
+    it 'returns a successful operation response for the first lesson' do
+      expect(result.first.success?).to be(true)
+    end
+
+    it 'returns a successful operation response for the second lesson' do
+      expect(result.second.success?).to be(true)
+    end
+
+    it 'creates multiple lessons' do
+      expect { described_class.call(lessons_params:) }.to change(Lesson, :count).by(2)
+    end
+
+    it 'does not pass origin_identifier to lesson creation' do
+      received_params = []
+      allow(Lesson::Create).to receive(:call).and_wrap_original do |method, lesson_params:|
+        received_params << lesson_params
+        method.call(lesson_params:)
+      end
+
+      described_class.call(lessons_params:)
+
+      expect(received_params).to all(satisfy { |params| !params.key?(:origin_identifier) })
+    end
+
+    it 'appends the origin_identifier to the first created lesson' do
+      expect(result.first[:origin_identifier]).to eq('test-lesson-identifier-one')
+    end
+
+    it 'appends the origin_identifier to the second created lesson' do
+      expect(result.second[:origin_identifier]).to eq('test-lesson-identifier-two')
+    end
+  end
+end