Added WorkItems as a new subject for TrackedTimeEntries.

- Made TrackedTimeEntries polymorphic to belong to both Lecture and WorkItems models
- Added associated migrations for existing data
- Added to administrate UI

db/migrate/20231007144716_make_tracked_time_entry_polymorphic.rb

@@ -0,0 +1,19 @@
+class MakeTrackedTimeEntryPolymorphic < ActiveRecord::Migration[7.1]
+  def change
+    add_reference :tracked_time_entries, :subject, polymorphic: true
+
+    reversible do |dir|
+      dir.up do
+        TrackedTimeEntry.all.each do |entry|
+          entry.update!(subject: Lecture.find(entry.lecture_id))
+        end
+      end
+
+      dir.down do
+        TrackedTimeEntry.all.each do |entry|
+          entry.update!(lecture_id: entry.subject_id)
+        end
+      end
+    end
+  end
+end

db/migrate/20231007145018_remove_lecture_association.rb

@@ -0,0 +1,7 @@
+class RemoveLectureAssociation < ActiveRecord::Migration[7.1]
+  def change
+    remove_reference :tracked_time_entries, :lecture, null: false, foreign_key: true
+    change_column_null :tracked_time_entries, :subject_id, false
+    change_column_null :tracked_time_entries, :subject_type, false
+  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[7.1].define(version: 2023_10_07_144031) do
+ActiveRecord::Schema[7.1].define(version: 2023_10_07_145018) do
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
 
@@ -50,14 +50,15 @@ ActiveRecord::Schema[7.1].define(version: 2023_10_07_144031) do
   end
 
   create_table "tracked_time_entries", force: :cascade do |t|
-    t.bigint "lecture_id", null: false
     t.integer "kind"
     t.jsonb "toggl_data"
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
     t.bigint "associated_toggl_entry_id", null: false
+    t.string "subject_type", null: false
+    t.bigint "subject_id", null: false
     t.index ["associated_toggl_entry_id"], name: "index_tracked_time_entries_on_associated_toggl_entry_id", unique: true
-    t.index ["lecture_id"], name: "index_tracked_time_entries_on_lecture_id"
+    t.index ["subject_type", "subject_id"], name: "index_tracked_time_entries_on_subject"
   end
 
   create_table "work_items", force: :cascade do |t|
@@ -70,6 +71,5 @@ ActiveRecord::Schema[7.1].define(version: 2023_10_07_144031) do
   end
 
   add_foreign_key "recordings", "courses"
-  add_foreign_key "tracked_time_entries", "lectures"
   add_foreign_key "work_items", "courses"
 end