#306

backend/app/services/material_zip_exporter.rb

@@ -5,9 +5,19 @@ require 'zlib'
 # Keep this service boundary stable so job/cached export paths can replace it later.
 class MaterialZipExporter
   Entry = Struct.new(:path, :data, :mtime, keyword_init: true)
+  MissingFile = Struct.new(:material_id, :export_path, :blob_id, :filename, keyword_init: true)
 
   class EmptyExportError < StandardError; end
   class DuplicatePathError < StandardError; end
+  class MissingFileError < StandardError
+    attr_reader :missing_files
+
+    def initialize missing_files
+      @missing_files = missing_files
+
+      super("Missing files: #{missing_files.map(&:export_path).join(', ')}")
+    end
+  end
 
   def initialize profile: 'legacy_drive', tag_id: nil
     @profile = profile.presence || 'legacy_drive'
@@ -35,15 +45,22 @@ class MaterialZipExporter
 
     rows = rows.where(materials: { tag_id: @tag_id }) if @tag_id
 
+    missing_files = []
+
     entries = rows.filter_map do |item|
       material = item.material
       next unless material.file.attached?
 
+      data = download_blob(item, missing_files)
+      next unless data
+
       Entry.new(path: item.export_path,
-                data: material.file.blob.download,
+                data:,
                 mtime: material.updated_at || Time.current)
     end
 
+    raise MissingFileError.new(missing_files) if missing_files.any?
+
     paths = entries.map(&:path)
     duplicated = paths.find { |path| paths.count(path) > 1 }
     raise DuplicatePathError, duplicated if duplicated
@@ -51,6 +68,20 @@ class MaterialZipExporter
     entries
   end
 
+  def download_blob item, missing_files
+    blob = item.material.file.blob
+
+    blob.download
+  rescue ActiveStorage::FileNotFoundError
+    missing_files << MissingFile.new(
+        material_id: item.material_id,
+        export_path: item.export_path,
+        blob_id: blob.id,
+        filename: blob.filename.to_s,
+    )
+    nil
+  end
+
   class ZipWriter
     VERSION_NEEDED = 20
     GP_FLAG = 0x0800