save context_id on lti launch

fixes: PS-1538

**test plan
configure and launch lti tool, upon lti tool launch the
lti_context_id for user should be set, and if course launch
the lti_context_id on course object, if account launch, then
lti_context_id on account.  Once these are set, api calls to the
corresponding object can be made using the syntax lti_context_id:id

Change-Id: Icdf02e4f99691be417c024adb2a2751ba2aa9335
Reviewed-on: https://gerrit.instructure.com/35380
Reviewed-by: Brad Humphrey <brad@instructure.com>
Reviewed-by: Rob Orton <rob@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>
Product-Review: Adam Phillipps <adam@instructure.com>
QA-Review: Adam Phillipps <adam@instructure.com>

app/models/account.rb

@@ -29,7 +29,7 @@ class Account < ActiveRecord::Base
     :enable_user_notes, :allowed_services, :turnitin_pledge, :turnitin_comments,
     :turnitin_account_id, :allow_sis_import, :sis_source_id, :equella_endpoint,
     :settings, :uuid, :default_locale, :default_user_storage_quota, :turnitin_host,
-    :created_by_id, :lti_guid, :default_group_storage_quota
+    :created_by_id, :lti_guid, :default_group_storage_quota, :lti_context_id
   ]
 
   EXPORTABLE_ASSOCIATIONS = [

app/models/context_external_tool.rb

@@ -541,14 +541,36 @@ class ContextExternalTool < ActiveRecord::Base
 
   def self.opaque_identifier_for(asset, shard)
     shard.activate do
-      str = asset.asset_string.to_s
-      raise "Empty value" if str.blank?
-      Canvas::Security.hmac_sha1(str, shard.settings[:encryption_key])
+      lti_context_id = context_id_for(asset, shard)
+      set_asset_context_id(asset, lti_context_id)
     end
   end
 
   private
 
+  def self.set_asset_context_id(asset, context_id)
+    lti_context_id = context_id
+    if asset.respond_to?('lti_context_id')
+      if asset.new_record?
+        asset.lti_context_id = context_id
+      else
+        asset.reload unless asset.lti_context_id?
+        unless asset.lti_context_id
+          asset.lti_context_id = context_id
+          asset.save!
+        end
+        lti_context_id = asset.lti_context_id
+      end
+    end
+    lti_context_id
+  end
+
+  def self.context_id_for(asset, shard)
+    str = asset.asset_string.to_s
+    raise "Empty value" if str.blank?
+    Canvas::Security.hmac_sha1(str, shard.settings[:encryption_key])
+  end
+
   def tool_setting(setting, hash, *keys)
     if !hash || !hash.is_a?(Hash)
       settings.delete setting

app/models/course.rb

@@ -74,7 +74,7 @@ class Course < ActiveRecord::Base
     :created_at, :updated_at, :show_public_context_messages, :syllabus_body, :allow_student_forum_attachments, :default_wiki_editing_roles, :wiki_id, :allow_student_organized_groups,
     :course_code, :default_view, :root_account_id, :enrollment_term_id, :sis_source_id, :sis_batch_id, :show_all_discussion_entries, :open_enrollment, :storage_quota,
     :tab_configuration, :allow_wiki_comments, :turnitin_comments, :self_enrollment, :license, :indexed, :restrict_enrollments_to_course_dates, :template_course_id,
-    :locale, :settings, :replacement_course_id,  :public_description, :self_enrollment_code, :self_enrollment_limit, :abstract_course_id, :course_account_associations
+    :locale, :settings, :replacement_course_id,  :public_description, :self_enrollment_code, :self_enrollment_limit, :abstract_course_id, :course_account_associations, :lti_context_id
   ]
 
   EXPORTABLE_ASSOCIATIONS = [

app/models/user.rb

@@ -33,7 +33,7 @@ class User < ActiveRecord::Base
     :id, :name, :sortable_name, :workflow_state, :time_zone, :uuid, :created_at, :updated_at, :visibility, :avatar_image_url, :avatar_image_source, :avatar_image_updated_at,
     :phone, :school_name, :school_position, :short_name, :deleted_at, :show_user_services, :gender, :page_views_count, :unread_inbox_items_count, :reminder_time_for_due_dates,
     :reminder_time_for_grading, :storage_quota, :visible_inbox_types, :last_user_note, :subscribe_to_emails, :features_used, :preferences, :avatar_state, :locale, :browser_locale,
-    :unread_conversations_count, :public, :birthdate, :otp_communication_channel_id, :initial_enrollment_type, :crocodoc_id, :last_logged_out
+    :unread_conversations_count, :public, :birthdate, :otp_communication_channel_id, :initial_enrollment_type, :crocodoc_id, :last_logged_out, :lti_context_id
   ]
 
   EXPORTABLE_ASSOCIATIONS = [

db/migrate/20140519221522_add_lti_context_id_to_accounts_courses_users.rb

@@ -0,0 +1,15 @@
+class AddLtiContextIdToAccountsCoursesUsers < ActiveRecord::Migration
+  tag :predeploy
+
+  def self.up
+    add_column :accounts, :lti_context_id, :string
+    add_column :courses, :lti_context_id, :string
+    add_column :users, :lti_context_id, :string
+  end
+
+  def self.down
+    remove_column :accounts, :lti_context_id
+    remove_column :courses, :lti_context_id
+    remove_column :users, :lti_context_id
+  end
+end

db/migrate/20140519221523_add_unique_index_on_lti_context_id.rb

@@ -0,0 +1,16 @@
+class AddUniqueIndexOnLtiContextId < ActiveRecord::Migration
+  tag :postdeploy
+  disable_ddl_transaction!
+
+  def self.up
+    add_index :accounts, :lti_context_id, :unique => true, algorithm: :concurrently
+    add_index :courses, :lti_context_id, :unique => true, algorithm: :concurrently
+    add_index :users, :lti_context_id, :unique => true, algorithm: :concurrently
+  end
+
+  def self.down
+  remove_index :accounts, :lti_context_id
+  remove_index :courses, :lti_context_id
+  remove_index :users, :lti_context_id
+  end
+end

lib/api.rb

@@ -63,7 +63,6 @@ module Api
         end
       end
     end
-
     find_params = Api.sis_find_params_for_collection(collection, ids, options[:account] || @domain_root_account, @current_user)
     return [] if find_params == :not_found
     find_params[:limit] = options[:limit] unless options[:limit].nil?
@@ -91,7 +90,7 @@ module Api
 
   SIS_MAPPINGS = {
     'courses' =>
-      { :lookups => { 'sis_course_id' => 'sis_source_id', 'id' => 'id', 'sis_integration_id' => 'integration_id' },
+      { :lookups => { 'sis_course_id' => 'sis_source_id', 'id' => 'id', 'sis_integration_id' => 'integration_id', 'lti_context_id' => 'lti_context_id' },
         :is_not_scoped_to_account => ['id'].to_set,
         :scope => 'root_account_id' },
     'enrollment_terms' =>
@@ -99,13 +98,13 @@ module Api
         :is_not_scoped_to_account => ['id'].to_set,
         :scope => 'root_account_id' },
     'users' =>
-      { :lookups => { 'sis_user_id' => 'pseudonyms.sis_user_id', 'sis_login_id' => 'pseudonyms.unique_id', 'id' => 'users.id', 'sis_integration_id' => 'pseudonyms.integration_id' },
-        :is_not_scoped_to_account => ['users.id'].to_set,
+      { :lookups => { 'sis_user_id' => 'pseudonyms.sis_user_id', 'sis_login_id' => 'pseudonyms.unique_id', 'id' => 'users.id', 'sis_integration_id' => 'pseudonyms.integration_id', 'lti_context_id' => 'users.lti_context_id', 'lti_user_id' => 'users.lti_context_id' },
+        :is_not_scoped_to_account => ['users.id', 'users.lti_context_id'].to_set,
         :scope => 'pseudonyms.account_id',
         :joins => [:pseudonym] },
     'accounts' =>
-      { :lookups => { 'sis_account_id' => 'sis_source_id', 'id' => 'id', 'sis_integration_id' => 'integration_id' },
-        :is_not_scoped_to_account => ['id'].to_set,
+      { :lookups => { 'sis_account_id' => 'sis_source_id', 'id' => 'id', 'sis_integration_id' => 'integration_id', 'lti_context_id' => 'lti_context_id' },
+        :is_not_scoped_to_account => ['id', 'lti_context_id'].to_set,
         :scope => 'root_account_id' },
     'course_sections' =>
       { :lookups => { 'sis_section_id' => 'sis_source_id', 'id' => 'id' , 'sis_integration_id' => 'integration_id' },
@@ -127,10 +126,10 @@ module Api
     # returns column_name, column_value
     return lookups['id'], id if id.is_a?(Numeric) || id.is_a?(ActiveRecord::Base)
     id = id.to_s.strip
-    if id =~ %r{\Ahex:(sis_[\w_]+):(([0-9A-Fa-f]{2})+)\z}
+    if id =~ %r{\Ahex:(lti_[\w_]+|sis_[\w_]+):(([0-9A-Fa-f]{2})+)\z}
       sis_column = $1
       sis_id = [$2].pack('H*')
-    elsif id =~ %r{\A(sis_[\w_]+):(.+)\z}
+    elsif id =~ %r{\A(lti_[\w_]+|sis_[\w_]+):(.+)\z}
       sis_column = $1
       sis_id = $2
     elsif id =~ ID_REGEX

spec/lib/api_spec.rb

@@ -152,6 +152,26 @@ describe Api do
         end
       end
     end
+
+    it "should find user by lti_context_id" do
+      @user.lti_context_id = Canvas::Security.hmac_sha1(@user.asset_string.to_s, 'key')
+      @user.save!
+      @api.api_find(User, "lti_context_id:#{@user.lti_context_id}").should == @user
+    end
+
+    it "should find course by lti_context_id" do
+      lti_course = course
+      lti_course.lti_context_id = Canvas::Security.hmac_sha1(lti_course.asset_string.to_s, 'key')
+      lti_course.save!
+      @api.api_find(Course, "lti_context_id:#{lti_course.lti_context_id}").should == lti_course
+    end
+
+    it "should find account by lti_context_id" do
+      account = Account.create!(name: 'account')
+      account.lti_context_id = Canvas::Security.hmac_sha1(account.asset_string.to_s, 'key')
+      account.save!
+      @api.api_find(Account, "lti_context_id:#{account.lti_context_id}").should == account
+    end
   end
 
   context 'api_find_all' do

spec/models/context_external_tool_spec.rb

@@ -689,4 +689,23 @@ describe ContextExternalTool do
       expect { ContextExternalTool.find_for("horseshoes", @course, :course_navigation) }.to raise_error(ActiveRecord::RecordNotFound)
     end
   end
+
+  describe "opaque_identifier_for" do
+    it "should create lti_context_id for asset" do
+      @course.lti_context_id.should == nil
+      @tool = @course.context_external_tools.create!(:name => "a", :domain => "google.com", :consumer_key => '12345', :shared_secret => 'secret')
+      context_id = @tool.opaque_identifier_for(@course)
+      @course.reload
+      @course.lti_context_id.should == context_id
+    end
+
+    it "should not create new lti_context for asset if exists" do
+      @course.lti_context_id =  'dummy_context_id'
+      @course.save!
+      @tool = @course.context_external_tools.create!(:name => "a", :domain => "google.com", :consumer_key => '12345', :shared_secret => 'secret')
+      context_id = @tool.opaque_identifier_for(@course)
+      @course.reload
+      @course.lti_context_id.should == 'dummy_context_id'
+    end
+  end
 end