#46

backend/app/controllers/posts_controller.rb

@@ -123,6 +123,7 @@ class PostsController < ApplicationController
     tag_names = params[:tags].to_s.split
     original_created_from = params[:original_created_from]
     original_created_before = params[:original_created_before]
+    parent_post_ids = parse_parent_post_ids
 
     post = Post.new(title:, url:, thumbnail_base: nil, uploaded_user: current_user,
                     original_created_from:, original_created_before:)
@@ -130,17 +131,24 @@ class PostsController < ApplicationController
 
     ApplicationRecord.transaction do
       post.save!
-      tags = Tag.normalise_tags(tag_names)
+
+      tags = Tag.normalise_tags!(tag_names)
       TagVersioning.record_tag_snapshots!(tags, created_by_user: current_user)
 
       tags = Tag.expand_parent_tags(tags)
       sync_post_tags!(post, tags)
+
+      sync_parent_posts!(post, parent_post_ids)
+
       post.resized_thumbnail!
+
       PostVersionRecorder.record!(post:, event_type: :create, created_by_user: current_user)
     end
 
     post.reload
     render json: PostRepr.base(post), status: :created
+  rescue ArgumentError => e
+    render json: { errors: [e.message] }, status: :unprocessable_entity
   rescue ActiveRecord::RecordInvalid
     render json: { errors: post.errors.full_messages }, status: :unprocessable_entity
   rescue Tag::NicoTagNormalisationError
@@ -169,6 +177,7 @@ class PostsController < ApplicationController
     tag_names = params[:tags].to_s.split
     original_created_from = params[:original_created_from]
     original_created_before = params[:original_created_before]
+    parent_post_ids = parse_parent_post_ids
 
     post = Post.find(params[:id].to_i)
 
@@ -177,12 +186,15 @@ class PostsController < ApplicationController
 
       post.update!(title:, original_created_from:, original_created_before:)
 
-      normalised_tags = Tag.normalise_tags(tag_names, with_tagme: false)
+      normalised_tags = Tag.normalise_tags!(tag_names, with_tagme: false)
       TagVersioning.record_tag_snapshots!(normalised_tags, created_by_user: current_user)
 
       tags = post.tags.nico.to_a + normalised_tags
       tags = Tag.expand_parent_tags(tags)
       sync_post_tags!(post, tags)
+
+      sync_parent_posts!(post, parent_post_ids)
+
       PostVersionRecorder.record!(post:, event_type: :update, created_by_user: current_user)
     end
 
@@ -190,6 +202,8 @@ class PostsController < ApplicationController
     json = post.as_json
     json['tags'] = build_tag_tree_for(post.tags)
     render json:, status: :ok
+  rescue ArgumentError => e
+    render json: { errors: [e.message] }, status: :unprocessable_entity
   rescue ActiveRecord::RecordInvalid
     render json: post.errors, status: :unprocessable_entity
   rescue Tag::NicoTagNormalisationError
@@ -353,4 +367,41 @@ class PostsController < ApplicationController
 
     root_ids.filter_map { |id| build_node.call(id, []) }
   end
+
+  def parse_parent_post_ids
+    raise ArgumentError, 'parent_post_ids は必須です．' unless params.key?(:parent_post_ids)
+
+    params[:parent_post_ids].to_s.split.map { |token|
+      id = Integer(token, exception: false)
+      raise ArgumentError, "親投稿 Id. が不正です: #{ token }" if id.nil? || id <= 0
+
+      id
+    }.uniq
+  end
+
+  def sync_parent_posts! post, parent_post_ids
+    if parent_post_ids.include?(post.id)
+      post.errors.add(:base, '自分自身を親投稿にはできません．')
+      raise ActiveRecord::RecordInvalid, post
+    end
+
+    existing_ids = Post.where(id: parent_post_ids).pluck(:id)
+    missing_ids = parent_post_ids - existing_ids
+
+    if missing_ids.present?
+      post.errors.add(:base, "存在しない親投稿 ID があります: #{ missing_ids.join(' ') }")
+      raise ActiveRecord::RecordInvalid, post
+    end
+
+    current_ids = post.parent_posts.pluck(:id)
+
+    ids_to_add = parent_post_ids - current_ids
+    ids_to_remove = current_ids - parent_post_ids
+
+    PostImplication.where(post_id: post.id, parent_post_id: ids_to_remove).delete_all
+
+    ids_to_add.each do |parent_post_id|
+      PostImplication.create_or_find_by!(post_id: post.id, parent_post_id:)
+    end
+  end
 end

backend/app/controllers/tags_controller.rb

@@ -374,9 +374,9 @@ class TagsController < ApplicationController
   end
 
   def update_parent_tags! tag, parent_names
-    parent_tags = Tag.normalise_tags(parent_names, with_tagme: false,
-                                                   with_no_deerjikist: false,
-                                                   deny_nico: true)
+    parent_tags = Tag.normalise_tags!(parent_names, with_tagme: false,
+                                                    with_no_deerjikist: false,
+                                                    deny_nico: true)
 
     old_parent_tags = tag.parents.to_a
 

backend/app/models/post.rb

@@ -35,6 +35,8 @@ class Post < ApplicationRecord
   validate :validate_original_created_range
   validate :url_must_be_http_url
 
+  def parent_posts = parents
+
   def as_json options = { }
     super(options).merge({ thumbnail: thumbnail.attached? ?
                                       Rails.application.routes.url_helpers.rails_blob_url(
@@ -46,6 +48,8 @@ class Post < ApplicationRecord
 
   def snapshot_tag_names = tags.joins(:tag_name).order('tag_names.name').pluck('tag_names.name')
 
+  def snapshot_parent_post_ids = parents.order(:parent_post_id).pulck(:parent_post_id)
+
   def related limit: nil
     ids = post_similarities.order(cos: :desc)
     ids = ids.limit(limit) if limit

backend/app/models/tag.rb

@@ -85,9 +85,9 @@ class Tag < ApplicationRecord
   def self.video = find_or_create_by_tag_name!('動画', category: :meta)
   def self.niconico = find_or_create_by_tag_name!('ニコニコ', category: :meta)
 
-  def self.normalise_tags tag_names, with_tagme: true,
-                                     with_no_deerjikist: true,
-                                     deny_nico: true
+  def self.normalise_tags! tag_names, with_tagme: true,
+                                      with_no_deerjikist: true,
+                                      deny_nico: true
     if deny_nico && tag_names.any? { |n| n.downcase.start_with?('nico:') }
       raise NicoTagNormalisationError
     end

backend/app/representations/post_repr.rb

@@ -2,7 +2,8 @@
 
 
 module PostRepr
-  BASE = { include: { tags: TagRepr::BASE, uploaded_user: UserRepr::BASE } }.freeze
+  BASE = { include: { tags: TagRepr::BASE, uploaded_user: UserRepr::BASE },
+           methods: [:parent_posts] }.freeze
 
   module_function
 

backend/app/services/post_version_recorder.rb

@@ -24,7 +24,7 @@ class PostVersionRecorder < VersionRecorder
       url: @record.url,
       thumbnail_base: @record.thumbnail_base,
       tags: @record.snapshot_tag_names.join(' '),
-      parent_id: @record.parent_id,
+      parent_post_ids: @record.snapshot_parent_post_ids.join(' '),
       original_created_from: @record.original_created_from,
       original_created_before: @record.original_created_before }
   end