#306

backend/app/representations/material_repr.rb

@@ -17,6 +17,11 @@ module MaterialRepr
                 Rails.application.routes.url_helpers.rails_storage_proxy_url(
                     material.file, host:)
               end,
+        thumbnail: thumbnail_url(material, host:),
+        thumbnail_fallback_text: thumbnail_fallback_text(material),
+        thumbnail_fallback_kind: thumbnail_fallback_kind(material),
+        media_kind: media_kind(material),
+        file_byte_size: material.file_byte_size,
         export_paths: export_paths(material),
         export_items: export_items(material))
   end
@@ -25,6 +30,28 @@ module MaterialRepr
     materials.map { |m| base(m, host:) }
   end
 
+  def list material, host:
+    { id: material.id,
+      version_no: material.version_no,
+      url: material.url,
+      tag: compact_tag(material.tag),
+      thumbnail: thumbnail_url(material, host:),
+      thumbnail_fallback_text: thumbnail_fallback_text(material),
+      thumbnail_fallback_kind: thumbnail_fallback_kind(material),
+      media_kind: media_kind(material),
+      content_type: material.content_type,
+      file_byte_size: material.file_byte_size,
+      file_suppressed_at: material.file_suppressed_at,
+      created_at: material.created_at,
+      updated_at: material.updated_at,
+      export_paths: export_paths(material),
+      export_items: export_items(material) }
+  end
+
+  def list_many materials, host:
+    materials.map { |m| list(m, host:) }
+  end
+
   def export_paths material
     material.material_export_items.each_with_object({ }) do |item, hash|
       hash[item.profile] = item.enabled ? item.export_path : ''
@@ -39,4 +66,41 @@ module MaterialRepr
         enabled: item.enabled }
     end
   end
+
+  def thumbnail_url material, host:
+    return nil if material.file_suppressed?
+    return nil unless material.thumbnail.attached?
+
+    Rails.application.routes.url_helpers.rails_storage_proxy_url(
+        material.thumbnail, host:)
+  end
+
+  def thumbnail_fallback_text material
+    material.tag&.name || material.created_at&.strftime('%Y-%m-%d')
+  end
+
+  def thumbnail_fallback_kind material
+    material.tag.present? ? 'tag_name' : 'created_at'
+  end
+
+  def media_kind material
+    return 'suppressed' if material.file_suppressed?
+    return 'url_only' unless material.file.attached?
+
+    content_type = material.file.blob.content_type.to_s
+    return 'image' if content_type.start_with?('image/')
+    return 'video' if content_type.start_with?('video/')
+    return 'audio' if content_type.start_with?('audio/')
+
+    'file_other'
+  end
+
+  def compact_tag tag
+    return nil unless tag
+
+    { id: tag.id,
+      name: tag.name,
+      category: tag.category,
+      deprecated_at: tag.deprecated_at }
+  end
 end