favgroups: unify find by name methods.

Unify the `name_to_id`, `named`, and `find_by_name` methods into a
single `find_by_name_or_id` method that has consistent behavior in how
names are normalized.

app/logical/post_sets/post.rb

@@ -52,7 +52,7 @@ module PostSets
       name = Tag.has_metatag?(tag_array, :favgroup)
       return nil unless is_single_tag? && name.present?
 
-      @favgroup ||= FavoriteGroup.find_by_name(name)
+      @favgroup ||= FavoriteGroup.find_by_name_or_id(name, CurrentUser.user)
     end
 
     def has_explicit?

app/models/favorite_group.rb

@@ -11,22 +11,14 @@ class FavoriteGroup < ApplicationRecord
   array_attribute :post_ids, parse: /\d+/, cast: :to_i
 
   module SearchMethods
-    def for_creator(user_id)
-      where("favorite_groups.creator_id = ?", user_id)
-    end
-
     def for_post(post_id)
       where_array_includes_any(:post_ids, [post_id])
     end
 
-    def named(name)
-      where("lower(name) = ?", name.to_s.mb_chars.downcase.strip)
-    end
-
     def name_matches(name)
-      name = name.tr(" ", "_")
+      name = normalize_name(name)
       name = "*#{name}*" unless name =~ /\*/
-      where("name ilike ? escape E'\\\\'", name.to_escaped_for_sql_like)
+      where_ilike(:name, name)
     end
 
     def hide_private(user, params)
@@ -70,14 +62,6 @@ class FavoriteGroup < ApplicationRecord
 
   extend SearchMethods
 
-  def self.name_to_id(name)
-    if name =~ /^\d+$/
-      name.to_i
-    else
-      select_value_sql("SELECT id FROM favorite_groups WHERE lower(name) = ? AND creator_id = ?", name.to_s.mb_chars.downcase.tr(" ", "_"), CurrentUser.user.id).to_i
-    end
-  end
-
   def creator_can_create_favorite_groups
     if creator.favorite_group_count >= creator.favorite_group_limit
       error = "You can only keep up to #{creator.favorite_group_limit} favorite groups."
@@ -117,16 +101,18 @@ class FavoriteGroup < ApplicationRecord
     self.name = FavoriteGroup.normalize_name(name)
   end
 
-  def self.find_by_name(name)
-    if name =~ /^\d+$/
-      where("id = ?", name.to_i).first
-    elsif name
-      where("lower(name) = ?", normalize_name(name).mb_chars.downcase).first
+  def self.find_by_name_or_id(name, user)
+    if name =~ /\A\d+\z/
+      find_by(id: name)
     else
-      nil
+      user.favorite_groups.where_iequals(:name, normalize_name(name)).first
     end
   end
 
+  def self.find_by_name_or_id!(name, user)
+    find_by_name_or_id(name, user) or raise ActiveRecord::RecordNotFound
+  end
+
   def strip_name
     self.name = name.to_s.strip
   end

app/models/post.rb

@@ -820,20 +820,14 @@ class Post < ApplicationRecord
             post.update!(parent_id: id)
           end
 
-        when /^-favgroup:(\d+)$/i
-          favgroup = FavoriteGroup.where("id = ?", $1.to_i).for_creator(CurrentUser.user.id).first
-          favgroup&.remove!(self)
-
         when /^-favgroup:(.+)$/i
-          favgroup = FavoriteGroup.named($1).for_creator(CurrentUser.user.id).first
+          favgroup = FavoriteGroup.find_by_name_or_id!($1, CurrentUser.user)
+          raise User::PrivilegeError unless favgroup.editable_by?(CurrentUser.user)
           favgroup&.remove!(self)
 
-        when /^favgroup:(\d+)$/i
-          favgroup = FavoriteGroup.where("id = ?", $1.to_i).for_creator(CurrentUser.user.id).first
-          favgroup&.add!(self)
-
         when /^favgroup:(.+)$/i
-          favgroup = FavoriteGroup.named($1).for_creator(CurrentUser.user.id).first
+          favgroup = FavoriteGroup.find_by_name_or_id!($1, CurrentUser.user)
+          raise User::PrivilegeError unless favgroup.editable_by?(CurrentUser.user)
           favgroup&.add!(self)
 
         end

app/models/tag.rb

@@ -594,23 +594,15 @@ class Tag < ApplicationRecord
             q[:ordpool] = pool_id
 
           when "-favgroup"
-            favgroup_id = FavoriteGroup.name_to_id(g2)
-            favgroup = FavoriteGroup.find(favgroup_id)
-
-            if !favgroup.viewable_by?(CurrentUser.user)
-              raise User::PrivilegeError.new
-            end
+            favgroup = FavoriteGroup.find_by_name_or_id!(g2, CurrentUser.user)
+            raise User::PrivilegeError unless favgroup.viewable_by?(CurrentUser.user)
 
             q[:favgroups_neg] ||= []
             q[:favgroups_neg] << favgroup
 
           when "favgroup"
-            favgroup_id = FavoriteGroup.name_to_id(g2)
-            favgroup = FavoriteGroup.find(favgroup_id)
-
-            if !favgroup.viewable_by?(CurrentUser.user)
-              raise User::PrivilegeError.new
-            end
+            favgroup = FavoriteGroup.find_by_name_or_id!(g2, CurrentUser.user)
+            raise User::PrivilegeError unless favgroup.viewable_by?(CurrentUser.user)
 
             q[:favgroups] ||= []
             q[:favgroups] << favgroup