#306

backend/app/services/material_sync_importer.rb

@@ -28,6 +28,13 @@ class MaterialSyncImporter
         Material
         .unscoped
         .find_or_initialize_by(normalized_source_key: key)
+    if unchanged?(material, source)
+      return Result.new(material:,
+                        action: :unchanged,
+                        suppressed: false,
+                        suppression: nil)
+    end
+
     event_type =
         if material.new_record?
           :create
@@ -43,7 +50,7 @@ class MaterialSyncImporter
         MaterialVersionRecorder.ensure_snapshot!(material,
                                                  created_by_user: @attributes[:updated_by_user])
       end
-      material.assign_attributes(material_attributes.merge(source))
+      material.assign_attributes(material_attributes_for(material).merge(source))
       material.discarded_at = nil if material.respond_to?(:discarded_at=)
       material.file.attach(uploaded_blob) if uploaded_blob
       material.save!
@@ -81,10 +88,28 @@ class MaterialSyncImporter
                                                  source_file_id: source[:source_file_id])
   end
 
-  def material_attributes
-    @attributes.except(:source_kind, :source_uri, :source_path, :source_file_id,
-                       :file_blob, :file_tempfile, :filename, :content_type,
-                       :file_sha256, :export_path, :profile)
+  def material_attributes_for material
+    attrs =
+        @attributes
+        .except(:source_kind, :source_uri, :source_path, :source_file_id,
+                :file_blob, :file_tempfile, :file_downloader,
+                :filename, :content_type,
+                :file_sha256, :export_path, :profile, :tag, :url)
+
+    if material.new_record?
+      attrs[:tag] = @attributes[:tag] if @attributes.key?(:tag)
+      attrs[:url] = @attributes[:url] if @attributes.key?(:url)
+      return attrs
+    end
+
+    if @attributes.key?(:tag) && @attributes[:tag].present?
+      attrs[:tag] = @attributes[:tag]
+    end
+    if @attributes.key?(:url) && @attributes[:url].present?
+      attrs[:url] = @attributes[:url]
+    end
+
+    attrs
   end
 
   def suppression_for source
@@ -100,7 +125,7 @@ class MaterialSyncImporter
   def uploaded_blob!
     return @attributes[:file_blob] if @attributes[:file_blob]
 
-    tempfile = @attributes[:file_tempfile]
+    tempfile = upload_tempfile
     return nil unless tempfile
 
     tempfile.rewind
@@ -115,18 +140,22 @@ class MaterialSyncImporter
     blob
   end
 
+  def upload_tempfile
+    return @upload_tempfile if defined?(@upload_tempfile)
+
+    @upload_tempfile = @attributes[:file_tempfile]
+    if @upload_tempfile.blank? && @attributes[:file_downloader]
+      @upload_tempfile = @attributes[:file_downloader].call
+    end
+    @upload_tempfile
+  end
+
   def upsert_export_item! material
-    export_path = @attributes[:export_path].to_s.strip
+    export_path = resolved_export_path(material)
     return if export_path.blank?
 
-    profile = @attributes[:profile].presence || 'legacy_drive'
-    path = export_path
-    if export_path_taken_by_other?(material, profile, path)
-      path = MaterialSyncExportPath.uniquify(path, @attributes[:source_file_id])
-    end
-
-    item = material.material_export_items.find_or_initialize_by(profile:)
-    item.export_path = path
+    item = material.material_export_items.find_or_initialize_by(profile: effective_profile)
+    item.export_path = export_path
     item.enabled = true
     item.created_by_user ||= @attributes[:created_by_user]
     item.save!
@@ -140,11 +169,78 @@ class MaterialSyncImporter
   end
 
   def close_tempfile!
-    tempfile = @attributes[:file_tempfile]
+    tempfile = upload_tempfile
     return unless tempfile
 
     tempfile.close! unless tempfile.closed?
   rescue StandardError
     nil
   end
+
+  def unchanged? material, source
+    return false if material.new_record? || material.discarded?
+    return false unless same_source_attributes?(material, source)
+    return false unless same_export_path?(material)
+    return false unless same_material_attributes?(material)
+
+    same_file_snapshot?(material)
+  end
+
+  def same_source_attributes? material, source
+    material.source_kind == source[:source_kind] \
+      && material.source_uri == source[:source_uri] \
+      && material.source_path == source[:source_path] \
+      && material.source_file_id == source[:source_file_id]
+  end
+
+  def same_export_path? material
+    expected = resolved_export_path(material)
+    current = material.material_export_items.find { |item| item.profile == effective_profile }
+
+    return current.blank? if expected.blank?
+
+    current&.enabled && current.export_path == expected
+  end
+
+  def same_material_attributes? material
+    same_tag_attribute?(material) && same_url_attribute?(material)
+  end
+
+  def same_file_snapshot? material
+    expected_sha256 = @attributes[:file_sha256].to_s.presence
+
+    if expected_sha256.present?
+      return false unless material.file.attached?
+
+      return material.file.blob.metadata['sha256'] == expected_sha256
+    end
+
+    !material.file.attached?
+  end
+
+  def effective_profile
+    @attributes[:profile].presence || 'legacy_drive'
+  end
+
+  def resolved_export_path material
+    export_path = @attributes[:export_path].to_s.strip
+    return export_path if export_path.blank?
+    return export_path unless export_path_taken_by_other?(material, effective_profile, export_path)
+
+    MaterialSyncExportPath.uniquify(export_path, @attributes[:source_file_id])
+  end
+
+  def same_tag_attribute? material
+    return true unless @attributes.key?(:tag)
+    return true if @attributes[:tag].blank?
+
+    material.tag_id == @attributes[:tag].id
+  end
+
+  def same_url_attribute? material
+    return true unless @attributes.key?(:url)
+    return true if @attributes[:url].blank?
+
+    material.url == @attributes[:url]
+  end
 end