#306

backend/db/migrate/20260626010000_backfill_initial_material_versions.rb

@@ -0,0 +1,159 @@
+class BackfillInitialMaterialVersions < ActiveRecord::Migration[8.0]
+  class MigrationMaterial < ActiveRecord::Base
+    self.table_name = 'materials'
+  end
+
+  class MigrationMaterialExportItem < ActiveRecord::Base
+    self.table_name = 'material_export_items'
+  end
+
+  class MigrationMaterialVersion < ActiveRecord::Base
+    self.table_name = 'material_versions'
+  end
+
+  class MigrationStorageAttachment < ActiveRecord::Base
+    self.table_name = 'active_storage_attachments'
+  end
+
+  class MigrationStorageBlob < ActiveRecord::Base
+    self.table_name = 'active_storage_blobs'
+  end
+
+  class MigrationTag < ActiveRecord::Base
+    self.table_name = 'tags'
+  end
+
+  class MigrationTagName < ActiveRecord::Base
+    self.table_name = 'tag_names'
+  end
+
+  def up
+    say_with_time 'Backfilling initial material versions' do
+      materials_without_versions.find_in_batches(batch_size: 500) do |materials|
+        material_ids = materials.map(&:id)
+        tags_by_id = load_tags(materials.map(&:tag_id).compact.uniq)
+        export_paths_by_material_id = load_export_paths(material_ids)
+        file_snapshots_by_material_id = load_file_snapshots(material_ids)
+
+        rows = materials.map do |material|
+          tag = tags_by_id[material.tag_id]
+          file_snapshot = file_snapshots_by_material_id[material.id] || empty_file_snapshot
+
+          { material_id: material.id,
+            version_no: 1,
+            event_type: 'create',
+            url: material.url,
+            parent_id: material.parent_id,
+            tag_id: material.tag_id,
+            tag_name: tag&.fetch(:name, nil),
+            tag_category: tag&.fetch(:category, nil),
+            source_kind: material.source_kind,
+            source_uri: material.source_uri,
+            source_path: material.source_path,
+            source_file_id: material.source_file_id,
+            normalized_source_key: material.normalized_source_key,
+            export_paths_json: export_paths_by_material_id[material.id] || { },
+            discarded_at: material.discarded_at,
+            file_blob_id: file_snapshot[:file_blob_id],
+            file_filename: file_snapshot[:file_filename],
+            file_content_type: file_snapshot[:file_content_type],
+            file_byte_size: file_snapshot[:file_byte_size],
+            file_checksum: file_snapshot[:file_checksum],
+            file_sha256: file_snapshot[:file_sha256],
+            created_by_user_id: material.created_by_user_id,
+            updated_by_user_id: material.updated_by_user_id,
+            created_at: material.created_at,
+            updated_at: material.created_at }
+        end
+
+        MigrationMaterialVersion.insert_all!(rows) if rows.present?
+      end
+    end
+
+    execute <<~SQL.squish
+      UPDATE materials
+      SET version_no = COALESCE(
+        (
+          SELECT MAX(material_versions.version_no)
+          FROM material_versions
+          WHERE material_versions.material_id = materials.id
+        ),
+        1
+      )
+    SQL
+  end
+
+  def down
+    raise ActiveRecord::IrreversibleMigration
+  end
+
+  private
+
+  def materials_without_versions
+    MigrationMaterial.where.not(id: MigrationMaterialVersion.select(:material_id))
+  end
+
+  def load_tags tag_ids
+    return { } if tag_ids.empty?
+
+    tag_name_ids_by_tag_id = MigrationTag.where(id: tag_ids).pluck(:id, :tag_name_id).to_h
+    tag_names_by_id =
+        MigrationTagName
+        .where(id: tag_name_ids_by_tag_id.values.uniq)
+        .pluck(:id, :name)
+        .to_h
+    categories_by_tag_id = MigrationTag.where(id: tag_ids).pluck(:id, :category).to_h
+
+    tag_ids.each_with_object({ }) do |tag_id, hash|
+      hash[tag_id] = { name: tag_names_by_id[tag_name_ids_by_tag_id[tag_id]],
+                       category: categories_by_tag_id[tag_id] }
+    end
+  end
+
+  def load_export_paths material_ids
+    MigrationMaterialExportItem
+      .where(material_id: material_ids)
+      .order(:material_id, :profile)
+      .pluck(:material_id, :profile, :export_path)
+      .each_with_object({ }) do |(material_id, profile, export_path), hash|
+        hash[material_id] ||= { }
+        hash[material_id][profile] = export_path
+      end
+  end
+
+  def load_file_snapshots material_ids
+    attachments_by_material_id =
+        MigrationStorageAttachment
+        .where(record_type: 'Material', name: 'file', record_id: material_ids)
+        .pluck(:record_id, :blob_id)
+        .to_h
+
+    blobs_by_id =
+        MigrationStorageBlob
+        .where(id: attachments_by_material_id.values.uniq)
+        .index_by(&:id)
+
+    attachments_by_material_id.each_with_object({ }) do |(material_id, blob_id), hash|
+      blob = blobs_by_id[blob_id]
+      next unless blob
+
+      hash[material_id] = {
+        file_blob_id: blob.id,
+        file_filename: blob.filename.to_s,
+        file_content_type: blob.content_type,
+        file_byte_size: blob.byte_size,
+        file_checksum: blob.checksum,
+        file_sha256: blob.metadata['sha256']
+      }
+    end
+  end
+
+  def empty_file_snapshot
+    { file_blob_id: nil,
+      file_filename: nil,
+      file_content_type: nil,
+      file_byte_size: nil,
+      file_checksum: nil,
+      file_sha256: nil }
+  end
+end