AI: address issue #272

backend/app/controllers/posts_controller.rb

@@ -37,7 +37,7 @@ class PostsController < ApplicationController
 
     offset = (page - 1) * limit
 
-    history_join_required = order[0] == 'updated_at' || updated_between.any?(&:present?)
+    needs_history_join = order[0] == 'updated_at' || updated_between.any?(&:present?)
 
     q =
         filtered_posts(locale)
@@ -57,8 +57,8 @@ class PostsController < ApplicationController
     q = q.where('posts.created_at >= ?', created_between[0]) if created_between[0]
     q = q.where('posts.created_at <= ?', created_between[1]) if created_between[1]
     count_scope = q
-    if history_join_required
-      history_times = PostVersion.all
+    if needs_history_join
+      history_times = HistoryAccess.visible(PostVersion.all)
           .select('post_id, MAX(created_at) AS latest_at').group(:post_id)
       q = q.joins("LEFT JOIN (#{ history_times.to_sql }) history_times " +
                   'ON history_times.post_id = posts.id')
@@ -72,7 +72,7 @@ class PostsController < ApplicationController
       q = q.where("#{ updated_at_all_sql } <= ?", updated_between[1])
     end
     count_scope = q if updated_between.any?(&:present?)
-    if history_join_required
+    if needs_history_join
       q = q.select('posts.*', "#{ updated_at_all_sql } AS updated_at")
     end
 
@@ -92,10 +92,10 @@ class PostsController < ApplicationController
              .offset(offset)
              .to_a
     latest_version_times =
-        if history_join_required
+        if needs_history_join
           { }
         else
-          PostVersion.where(post_id: posts.map(&:id))
+          HistoryAccess.visible(PostVersion.where(post_id: posts.map(&:id)))
               .group(:post_id).maximum(:created_at)
         end
 

backend/app/controllers/tag_descriptions_controller.rb

@@ -49,6 +49,7 @@ class TagDescriptionsController < ApplicationController
   private
 
   def representation description
+    HistoryAccess.require_current!(description, TagDescriptionVersion)
     description.as_json(only: [
         :tag_id,
         :language_code,

backend/app/controllers/tag_groups_controller.rb

@@ -1,7 +1,7 @@
 class TagGroupsController < ApplicationController
   def index
     locale = resolve_locale!
-    groups = TagGroup.includes(:created_by_user, :updated_by_user).order(:id)
+    groups = HistoryAccess.current(TagGroup.all, TagGroupVersion).includes(:created_by_user, :updated_by_user).order(:id)
     render json: TagGroupRepr.many(locale, groups.to_a)
   end
 

backend/app/controllers/tags_controller.rb

@@ -218,63 +218,16 @@ class TagsController < ApplicationController
     locale = resolve_locale!
 
     q = params[:q].to_s.strip.sub(/\Anot:/i, '')
-    prefix = "#{ ActiveRecord::Base.sanitize_sql_like(q) }%"
+    literal = ActiveRecord::Base.sanitize_sql_like(q)
+    nico = bool?(:nico, default: true)
+    present = bool?(:present, default: true)
 
-    with_nico = bool?(:nico, default: true)
-    present_only = bool?(:present, default: true)
-
-    alias_rows =
-        TagName
-        .where(language_code: locale.language_code, primary_flg: false)
-        .where('name LIKE ?', prefix)
-        .pluck(:tag_id, :name)
-
-    matched_alias_by_tag_id = { }
-    tag_ids = []
-    alias_rows.each do |tag_id, alias_name|
-      tag_ids << tag_id
-      matched_alias_by_tag_id[tag_id] ||= alias_name
+    rows = autocomplete_rows(locale:, pattern: "#{ literal }%", nico:, present:)
+    if rows.length < 20 && q.present?
+      suffix_rows = autocomplete_rows(locale:, pattern: "%#{ literal }", nico:, present:)
+      rows = (rows + suffix_rows).uniq { [_1['category'], _1['id']] }.first(20)
     end
 
-    base =
-        Tag
-        .joins(:tag_names)
-        .preload(:tag_names, :materials, :deerjikists, :tag_descriptions,
-                 parents: [:tag_names, :materials, :deerjikists, :tag_descriptions])
-        .where(tag_names: { language_code: locale.language_code, primary_flg: true },
-               deprecated_at: nil)
-    base = base.where('tags.post_count > 0') if present_only
-
-    canonical_hit = base.where('tag_names.name LIKE ?', prefix)
-
-    internal_tags = canonical_hit.or(base.where(id: tag_ids.uniq))
-
-    internal_rows =
-        internal_tags
-        .order(Arel.sql('tags.post_count DESC, tag_names.name'))
-        .limit(20)
-        .map { |tag|
-          TagRepr.base(tag, language_code: locale.language_code)
-                 .merge(matched_alias: matched_alias_by_tag_id[tag.id])
-        }
-
-    return render json: internal_rows unless with_nico
-
-    external_base = ExternalTag.all
-    external_base = external_base.where('post_count > 0') if present_only
-
-    external_rows =
-        external_base
-        .where("CONCAT(platform, ':', name) LIKE ? OR name LIKE ?", prefix, prefix)
-        .order(post_count: :desc, name: :asc)
-        .limit(20)
-        .map { external_tag_json(_1) }
-
-    rows =
-    (internal_rows + external_rows)
-        .sort_by { |row| [-row['post_count'], row['name'] || row[:name]] }
-        .first(20)
-
     render json: rows
   end
 
@@ -545,6 +498,59 @@ class TagsController < ApplicationController
 
   private
 
+  def autocomplete_rows locale:, pattern:, nico:, present:
+    alias_rows =
+        TagName
+        .where(language_code: locale.language_code, primary_flg: false)
+        .where('name LIKE ?', pattern)
+        .pluck(:tag_id, :name)
+
+    matched_alias_by_tag_id = { }
+    tag_ids = []
+    alias_rows.each do |tag_id, alias_name|
+      tag_ids << tag_id
+      matched_alias_by_tag_id[tag_id] ||= alias_name
+    end
+
+    base =
+        Tag
+        .joins(:tag_names)
+        .preload(:tag_names, :materials, :deerjikists, :tag_descriptions,
+                 parents: [:tag_names, :materials, :deerjikists, :tag_descriptions])
+        .where(tag_names: { language_code: locale.language_code, primary_flg: true },
+               deprecated_at: nil)
+    base = base.where('tags.post_count > 0') if present
+
+    canonical_hit = base.where('tag_names.name LIKE ?', pattern)
+
+    internal_tags = canonical_hit.or(base.where(id: tag_ids.uniq))
+
+    internal_rows =
+        internal_tags
+        .order(Arel.sql('tags.post_count DESC, tag_names.name'))
+        .limit(20)
+        .map { |tag|
+          TagRepr.base(tag, language_code: locale.language_code)
+                 .merge(matched_alias: matched_alias_by_tag_id[tag.id])
+        }
+
+    return internal_rows unless nico
+
+    external_base = ExternalTag.all
+    external_base = external_base.where('post_count > 0') if present
+
+    external_rows =
+        external_base
+        .where("CONCAT(platform, ':', name) LIKE ? OR name LIKE ?", pattern, pattern)
+        .order(post_count: :desc, name: :asc)
+        .limit(20)
+        .map { external_tag_json(_1) }
+
+    (internal_rows + external_rows)
+        .sort_by { |row| [-row['post_count'], row['name'] || row[:name]] }
+        .first(20)
+  end
+
   def material_filter_param default:
     value = params[:material_filter].to_s.presence
     return default unless ['present', 'missing', 'any'].include?(value)

backend/app/controllers/wiki_pages_controller.rb

@@ -8,11 +8,12 @@ class WikiPagesController < ApplicationController
 
     title = params[:title].to_s.strip
     descriptions =
-        TagDescription.where(language_code: locale.language_code)
+        HistoryAccess.current(TagDescription.all, TagDescriptionVersion)
+        .where(language_code: locale.language_code)
         .includes(tag: :tag_names)
 
     descriptions = descriptions.order(updated_at: :desc, id: :asc)
-    tag_groups = TagGroup.order(updated_at: :desc, id: :asc)
+    tag_groups = HistoryAccess.current(TagGroup.all, TagGroupVersion).order(updated_at: :desc, id: :asc)
     if title.present?
       pattern = "%#{ ApplicationRecord.sanitize_sql_like(title) }%"
       descriptions =
@@ -40,13 +41,13 @@ class WikiPagesController < ApplicationController
     return head :not_found unless language.is_a?(String)
     return head :not_found unless Language.exists?(code: language)
 
-    names = TagDescription.joins(tag: :tag_names)
+    names = HistoryAccess.current(TagDescription.all, TagDescriptionVersion).joins(tag: :tag_names)
         .where(language_code: locale.language_code, tag_names: { language_code: language })
         .pluck('tag_descriptions.tag_id', 'tag_descriptions.id', 'tag_names.name')
     candidates = names.map do |tag_id, description_id, name|
       WikiPageRepr.autolink_tag(locale, tag_id:, description_id:, name:, language:)
     end
-    candidates.concat(TagGroup.order(:id).pluck(:id, :name).map do |id, name|
+    candidates.concat(HistoryAccess.current(TagGroup.all, TagGroupVersion).order(:id).pluck(:id, :name).map do |id, name|
       WikiPageRepr.autolink_group(locale, id:, name:, language:)
     end)
     render json: candidates
@@ -410,7 +411,7 @@ class WikiPagesController < ApplicationController
   end
 
   def tag_description_by_title locale, title
-    TagDescription.joins(tag: :tag_names)
+    HistoryAccess.current(TagDescription.all, TagDescriptionVersion).joins(tag: :tag_names)
         .find_by(language_code: locale.language_code,
                  tag_names: { language_code: locale.language_code, name: title })
   end

backend/app/models/history_access.rb

@@ -147,6 +147,29 @@ class HistoryAccess < ActiveSupport::CurrentAttributes
     scope.where(Arel.sql(sql(scope.klass, row)))
   end
 
+  def self.current(scope, version_model)
+    return scope if admin?
+
+    table = scope.klass.table_name
+    keys = KEYS.fetch(version_model.table_name)
+    matches = keys.map do |key|
+      column = scope.klass.column_names.include?(key) ? key : 'id'
+      "current_snapshot.#{ key } = #{ table }.#{ column }"
+    end.join(' AND ')
+    boundary = "#{ matches } AND current_snapshot.version_no >= #{ table }.version_no " +
+        "AND current_snapshot.event_type = 'discard'"
+    scope = scope.where(Arel.sql("NOT EXISTS (SELECT 1 FROM #{ version_model.table_name } " +
+        "current_snapshot WHERE #{ boundary })"))
+    condition = "#{ matches } AND current_snapshot.version_no = #{ table }.version_no"
+    scope.where(Arel.sql("NOT EXISTS (SELECT 1 FROM #{ version_model.table_name } " +
+        "current_snapshot WHERE #{ condition } AND NOT (#{ sql(version_model, 'current_snapshot') }))"))
+  end
+
+  def self.require_current!(record, version_model)
+    return if admin?
+    raise Forbidden unless current(record.class.where(id: record.id), version_model).exists?
+  end
+
   def self.blob_visible?(blob, seen = [])
     return true if admin?
     return false if seen.include?(blob.id)

backend/app/representations/tag_group_repr.rb

@@ -44,6 +44,7 @@ module TagGroupRepr
   end
 
   def one locale, group
+    HistoryAccess.require_current!(group, TagGroupVersion)
     many(locale, [group]).first
   end
 

backend/app/representations/wiki_page_repr.rb

@@ -5,6 +5,7 @@ module WikiPageRepr
   module_function
 
   def tag_description locale, description
+    HistoryAccess.require_current!(description, TagDescriptionVersion)
     tag = description.tag
 
     { 'id' => description.id,