#414

backend/app/models/event.rb

@@ -0,0 +1,9 @@
+class Event < ApplicationRecord
+  has_many :post_versions
+  has_many :tag_versions
+  has_many :material_versions
+  has_many :tag_description_versions
+  has_many :tag_group_versions
+
+  belongs_to :created_by_user, class_name: 'User', optional: true
+end

backend/app/models/material_version.rb

@@ -11,7 +11,5 @@ class MaterialVersion < ApplicationRecord
   belongs_to :parent, class_name: 'Material', optional: true
   belongs_to :updated_by_user, class_name: 'User', optional: true
 
-  def export_paths_hash
-    export_paths_json || {}
-  end
+  def export_paths_hash = export_paths_json || { }
 end

backend/app/models/version_record.rb

@@ -19,6 +19,8 @@ module VersionRecord
 
     belongs_to :created_by_user, class_name: 'User', optional: true
 
+    belongs_to :event
+
     enum :event_type, event_type_map, prefix: true, validate: true
 
     validates :version_no, presence: true, numericality: { only_integer: true, greater_than: 0 }

backend/app/services/material_version_recorder.rb

@@ -1,20 +1,23 @@
 class MaterialVersionRecorder < VersionRecorder
   EVENT_TYPES = ['create', 'update', 'discard', 'restore'].freeze
 
-  def self.record! material:, event_type:, created_by_user:, file_snapshot: nil
-    new(material:, event_type:, created_by_user:, file_snapshot:).record!
+  def self.record! material:, event_type:, event:, created_by_user:, file_snapshot: nil
+    new(material:, event_type:, event:, created_by_user:, file_snapshot:).record!
   end
 
-  def initialize material:, event_type:, created_by_user:, file_snapshot: nil
+  def initialize material:, event_type:, event:, created_by_user:, file_snapshot: nil
     @file_snapshot = file_snapshot
 
-    super(record: material, event_type:, created_by_user:)
+    super(record: material, event_type:, event:, created_by_user:)
   end
 
   def self.ensure_snapshot! material, created_by_user:
     return if material.material_versions.exists?
 
-    record!(material:, event_type: :create,
+    event = Event.create!(event_type: 'materials.create',
+                          created_by_user:,
+                          created_at: material.created_at)
+    record!(material:, event_type: :create, event:,
             created_by_user: material.created_by_user || created_by_user)
   end
 

backend/app/services/post_version_recorder.rb

@@ -1,16 +1,19 @@
 class PostVersionRecorder < VersionRecorder
-  def self.record! post:, event_type:, created_by_user:
-    new(post:, event_type:, created_by_user:).record!
+  def self.record! post:, event_type:, event:, created_by_user:
+    new(post:, event_type:, event:, created_by_user:).record!
   end
 
-  def initialize post:, event_type:, created_by_user:
-    super(record: post, event_type:, created_by_user:)
+  def initialize post:, event_type:, event:, created_by_user:
+    super(record: post, event_type:, event:, created_by_user:)
   end
 
   def self.ensure_snapshot! post, created_by_user:
     return if post.post_versions.exists?
 
-    record!(post:, event_type: :create, created_by_user:)
+    event = Event.create!(event_type: 'posts.create',
+                          created_by_user:,
+                          created_at: post.created_at)
+    record!(post:, event_type: :create, event:, created_by_user:)
   end
 
   private

backend/app/services/tag_version_recorder.rb

@@ -1,13 +1,13 @@
 class TagVersionRecorder < VersionRecorder
-  def self.record! tag:, event_type:, created_by_user:, **_options
+  def self.record! tag:, event_type:, event:, created_by_user:, **_options
     Tag.transaction do
       SharedResourceIdAllocator.lock_space!(Tag, 'tags')
-      new(tag:, event_type:, created_by_user:).record!
+      new(tag:, event_type:, event:, created_by_user:).record!
     end
   end
 
-  def initialize tag:, event_type:, created_by_user:
-    super(record: tag, event_type:, created_by_user:)
+  def initialize tag:, event_type:, event:, created_by_user:
+    super(record: tag, event_type:, event:, created_by_user:)
   end
 
   private

backend/app/services/version_recorder.rb

@@ -1,9 +1,10 @@
 class VersionRecorder
   EVENT_TYPES = ['create', 'update', 'discard', 'restore'].freeze
 
-  def initialize record:, event_type:, created_by_user:
+  def initialize record:, event_type:, event:, created_by_user:
     @record = record
     @event_type = event_type.to_s
+    @event = event
     @created_by_user = created_by_user
 
     validate_event_type!
@@ -42,8 +43,9 @@ class VersionRecorder
   def base_attributes latest
     { version_no: (latest&.version_no || 0) + 1,
       event_type: @event_type,
-      created_at: Time.current,
-      created_by_user: @created_by_user }
+      event: @event,
+      created_by_user: @created_by_user,
+      created_at: Time.current }
   end
 
   def update_record_version_no! version_no