#399

backend/app/controllers/posts_controller.rb

@@ -732,6 +732,7 @@ class PostsController < ApplicationController
 
   def post_incoming_snapshot title:, original_created_from:, original_created_before:,
                              tag_names:, video_ms_param:, duration_param:, parent_post_ids:
+    validate_original_created_values!(original_created_from, original_created_before)
     Tag.normalise_tags!(tag_names, with_tagme: false, deny_deprecated: true,
                                         with_sections: true) =>
         { tags:, sections: }
@@ -769,6 +770,23 @@ class PostsController < ApplicationController
     value.to_s
   end
 
+  def validate_original_created_values! original_created_from, original_created_before
+    candidate = Post.new(
+        url: 'https://example.invalid/original-created-validation',
+        original_created_from:,
+        original_created_before:)
+    candidate.valid?
+    fields = [:original_created_from, :original_created_before, :original_created_at]
+    relevant_errors = candidate.errors.select { fields.include?(_1.attribute) }
+    return if relevant_errors.empty?
+
+    invalid_post = Post.new
+    relevant_errors.each { |error|
+      invalid_post.errors.add(error.attribute, error.message)
+    }
+    raise ActiveRecord::RecordInvalid, invalid_post
+  end
+
   def section_literal section
     "[#{ Post.ms_to_time(section[0]) }-#{ section[1] ? Post.ms_to_time(section[1]) : '' }]"
   end

backend/app/services/post_create_plan.rb

@@ -201,7 +201,7 @@ class PostCreatePlan
 
   def serialised_tags direct_tag_specs, tag_sections
     direct_tag_specs.map { |spec|
-      "#{ spec[:name] }#{ tag_sections[spec[:name]].to_a.map { Post.section_literal(_1) }.join }"
+      "#{ spec[:name] }#{ tag_sections[spec[:name]].to_a.map { section_literal(_1) }.join }"
     }.sort.join(' ')
   end
 
@@ -210,10 +210,15 @@ class PostCreatePlan
       {
           name: spec[:name],
           category: spec[:category].to_s,
-          section_literals: tag_sections[spec[:name]].to_a.map { Post.section_literal(_1) } }
+          section_literals: tag_sections[spec[:name]].to_a.map { section_literal(_1) } }
     }.sort_by { _1[:name] }
   end
 
+  def section_literal range
+    begin_ms, end_ms = range
+    "[#{ Post.ms_to_time(begin_ms) }-#{ end_ms ? Post.ms_to_time(end_ms) : '' }]"
+  end
+
   def normalise_video_ms snapshot_tag_specs
     return nil unless snapshot_tag_specs.any? { _1[:name] == VIDEO_TAG_NAME }