#171

backend/app/controllers/posts_controller.rb

@@ -173,8 +173,8 @@ class PostsController < ApplicationController
     return head :unauthorized unless current_user
     return head :forbidden unless current_user.gte_member?
 
-    force = truthy_param?(params[:force])
-    merge = truthy_param?(params[:merge])
+    force = bool?(:force)
+    merge = bool?(:merge)
     return head :bad_request if force && merge
 
     base_version_no = nil
@@ -201,15 +201,14 @@ class PostsController < ApplicationController
         base_snapshot = post_snapshot_from_version(base_version)
         current_snapshot = post_snapshot_from_record(post)
       end
-      incoming_snapshot = post_incoming_snapshot(post,
-                                                 title:,
+      incoming_snapshot = post_incoming_snapshot(title:,
                                                  original_created_from:,
                                                  original_created_before:,
                                                  tag_names:,
                                                  parent_post_ids:)
 
       snapshot_to_apply =
-          if post.version_no == base_version_no || force
+          if force || post.version_no == base_version_no || current_snapshot == base_snapshot
             incoming_snapshot
           else
             changes = post_snapshot_changes(base_snapshot, current_snapshot, incoming_snapshot)
@@ -448,30 +447,36 @@ class PostsController < ApplicationController
     version_no
   end
 
-  def truthy_param?(value) = ActiveModel::Type::Boolean.new.cast(value)
-
   def post_snapshot_from_version version
     { title: version.title,
       original_created_from: snapshot_time(version.original_created_from),
       original_created_before: snapshot_time(version.original_created_before),
-      tag_names: version.tags.to_s.split.filter { !(_1.start_with?('nico:')) }.sort,
+      tag_names: editable_tag_names_from_version(version),
       parent_post_ids: snapshot_parent_post_ids_from_version(version) }
   end
 
+  def editable_tag_names_from_version version
+    version.tags.to_s.split.reject { |name| name.downcase.start_with?('nico:') }.sort
+  end
+
   def post_snapshot_from_record post
     { title: post.title,
       original_created_from: snapshot_time(post.original_created_from),
       original_created_before: snapshot_time(post.original_created_before),
-      tag_names: post.tags.joins(:tag_name).order('tag_names.name').pluck('tag_names.name'),
+      tag_names: editable_tag_names_from_post(post),
       parent_post_ids: post.parent_posts.order(:id).pluck(:id) }
   end
 
-  def post_incoming_snapshot post, title:, original_created_from:, original_created_before:,
-                                   tag_names:, parent_post_ids:
+  def editable_tag_names_from_post post
+    post.tags.not_nico.joins(:tag_name).order('tag_names.name').pluck('tag_names.name')
+  end
+
+  def post_incoming_snapshot title:, original_created_from:, original_created_before:,
+                             tag_names:, parent_post_ids:
     { title:,
       original_created_from: snapshot_time(original_created_from),
       original_created_before: snapshot_time(original_created_before),
-      tag_names: incoming_tag_names_for_snapshot(post, tag_names),
+      tag_names: incoming_tag_names_for_snapshot(tag_names),
       parent_post_ids: parent_post_ids.sort }
   end
 
@@ -494,44 +499,10 @@ class PostsController < ApplicationController
     value.to_s
   end
 
-  def incoming_tag_names_for_snapshot post, raw_tag_names
-    manual_names = normalised_manual_tag_names_for_snapshot(raw_tag_names)
+  def incoming_tag_names_for_snapshot raw_tag_names
+    tags = Tag.normalise_tags!(raw_tag_names, with_tagme: false)
 
-    existing_tags =
-        Tag
-        .joins(:tag_name)
-        .where(tag_names: { name: manual_names })
-        .to_a
-
-    expanded_names = Tag.expand_parent_tags(existing_tags).map(&:name)
-
-    (manual_names + expanded_names).uniq.sort
-  end
-
-  def normalised_manual_tag_names_for_snapshot raw_tag_names
-    if raw_tag_names.any? { |name| name.downcase.start_with?('nico:') }
-      raise Tag::NicoTagNormalisationError
-    end
-
-    pairs = raw_tag_names.map do |raw_name|
-      prefix, category =
-          Tag::CATEGORY_PREFIXES.find { |p, _| raw_name.downcase.start_with?(p) } || ['', nil]
-
-      name = TagName.canonicalise(raw_name.sub(/\A#{ Regexp.escape(prefix) }/i, '')).first
-
-      [name, category]
-    end
-
-    names = pairs.map(&:first)
-
-    has_deerjikist = pairs.any? do |name, category|
-      category == :deerjikist ||
-          Tag.joins(:tag_name).where(category: :deerjikist, tag_names: { name: }).exists?
-    end
-
-    names << Tag.no_deerjikist.name unless has_deerjikist
-
-    names.uniq.sort
+    Tag.expand_parent_tags(tags).map(&:name).uniq.sort
   end
 
   def post_conflict_json post:, base_version_no:, base_snapshot:,
@@ -618,29 +589,53 @@ class PostsController < ApplicationController
                  original_created_from: snapshot[:original_created_from],
                  original_created_before: snapshot[:original_created_before])
 
-    tags = Tag.normalise_tags!(snapshot[:tag_names], with_tagme: false)
-    TagVersioning.record_tag_snapshots!(tags, created_by_user: current_user)
+    editable_tags = Tag.normalise_tags!(snapshot[:tag_names], with_tagme: false)
+    TagVersioning.record_tag_snapshots!(editable_tags, created_by_user: current_user)
 
+    readonly_tags = post.tags.nico.to_a
+
+    tags = readonly_tags + editable_tags
     tags = Tag.expand_parent_tags(tags)
-    sync_post_tags!(post, tags)
 
+    sync_post_tags!(post, tags)
     sync_parent_posts!(post, snapshot[:parent_post_ids])
 
     PostVersionRecorder.record!(post:, event_type: :update, created_by_user: current_user)
   end
 
   def merge_post_snapshots base_snapshot, current_snapshot, incoming_snapshot
-    [:title, :original_created_from, :original_created_before, :tag_names, :parent_post_ids].map {
-      [_1, merge_scaler_snapshot_value(base_snapshot[_1],
+    [:title, :original_created_from, :original_created_before].map {
+      [_1, merge_scalar_snapshot_value(base_snapshot[_1],
                                        current_snapshot[_1],
                                        incoming_snapshot[_1])]
-    }.to_h
+    }.to_h.merge([:tag_names, :parent_post_ids].map {
+      [_1, merge_set_snapshot_value(base_snapshot[_1],
+                                    current_snapshot[_1],
+                                    incoming_snapshot[_1])]
+    }.to_h)
   end
 
-  def merge_scaler_snapshot_value base, current, mine
+  def merge_scalar_snapshot_value base, current, mine
     return mine if current == base
     return current if mine == base || current == mine
 
     raise ArgumentError, '競合してゐる項目はマージできません．'
   end
+
+  def merge_set_snapshot_value base, current, mine
+    base = base.to_a
+    current = current.to_a
+    mine = mine.to_a
+
+    added_by_current = current - base
+    removed_by_current = base - current
+    added_by_me = mine - base
+    removed_by_me = base - mine
+
+    merged = base + added_by_current + added_by_me
+    merged -= removed_by_current
+    merged -= removed_by_me
+
+    merged.uniq.sort
+  end
 end

backend/app/models/post.rb

@@ -28,6 +28,8 @@ class Post < ApplicationRecord
 
   has_one_attached :thumbnail
 
+  attribute :version_no, :integer, default: 1
+
   before_validation :normalise_url
 
   validates :url, presence: true, uniqueness: true

backend/app/models/tag.rb

@@ -40,6 +40,8 @@ class Tag < ApplicationRecord
   belongs_to :tag_name
   delegate :wiki_page, to: :tag_name
 
+  attribute :version_no, :integer, default: 1
+
   delegate :name, to: :tag_name, allow_nil: true
   validates :tag_name, presence: true
 
@@ -136,7 +138,6 @@ class Tag < ApplicationRecord
     tn = tn.canonical if tn.canonical_id?
 
     Tag.find_undiscard_or_create_by!(tag_name_id: tn.id) do |t|
-      t.version_no = TagVersion.where(tag_id: t.id).order(version_no: :desc).first || 1
       t.category = category
     end
   rescue ActiveRecord::RecordNotUnique

backend/app/models/wiki_page.rb

@@ -15,6 +15,8 @@ class WikiPage < ApplicationRecord
 
   has_many :wiki_versions
 
+  attribute :version_no, :integer, default: 1
+
   belongs_to :tag_name
   validates :tag_name, presence: true
   validates :body, presence: true