Improve Issuable.order_labels_priority

Signed-off-by: Rémy Coutable <remy@rymai.me>

3 files changed, 30 insertions, 29 deletions

diff --git a/app/models/concerns/issuable.rb b/app/models/concerns/issuable.rb
index 8871cb8a6cd..92526a99147 100644
--- a/app/models/concerns/issuable.rb
+++ b/app/models/concerns/issuable.rb
@@ -48,12 +48,6 @@ module Issuable
     scope :non_archived, -> { join_project.where(projects: { archived: false }) }
 
 
-    def self.order_priority(labels)
-      select("#{table_name}.*, (#{Label.high_priority(name, table_name, labels).to_sql}) AS highest_priority")
-        .group("#{table_name}.id")
-        .reorder(nulls_last('highest_priority', 'ASC'))
-    end
-
     delegate :name,
              :email,
              to: :author,
@@ -111,18 +105,24 @@ module Issuable
       where(t[:title].matches(pattern).or(t[:description].matches(pattern)))
     end
 
-    def sort(method, labels = [])
+    def sort(method, excluded_labels: [])
       case method.to_s
       when 'milestone_due_asc' then order_milestone_due_asc
       when 'milestone_due_desc' then order_milestone_due_desc
       when 'downvotes_desc' then order_downvotes_desc
       when 'upvotes_desc' then order_upvotes_desc
-      when 'priority' then order_priority(labels)
+      when 'priority' then order_labels_priority(excluded_labels: excluded_labels)
       else
         order_by(method)
       end
     end
 
+    def order_labels_priority(excluded_labels: [])
+      select("#{table_name}.*, (#{highest_label_priority(excluded_labels).to_sql}) AS highest_priority").
+        group(arel_table[:id]).
+        reorder(Gitlab::Database.nulls_last_order('highest_priority', 'ASC'))
+    end
+
     def with_label(title, sort = nil)
       if title.is_a?(Array) && title.size > 1
         joins(:labels).where(labels: { title: title }).group(*grouping_columns(sort)).having("COUNT(DISTINCT labels.title) = #{title.size}")
@@ -146,6 +146,20 @@ module Issuable
 
       grouping_columns
     end
+
+    private
+
+    def highest_label_priority(excluded_labels)
+      query = Label.select(Label.arel_table[:priority].minimum).
+        joins(:label_links).
+        where(label_links: { target_type: name }).
+        where("label_links.target_id = #{table_name}.id").
+        reorder(nil)
+
+      query.where.not(title: excluded_labels) if excluded_labels.present?
+
+      query
+    end
   end
 
   def today?
diff --git a/app/models/issue.rb b/app/models/issue.rb
index bd0fbc96d18..235922710ad 100644
--- a/app/models/issue.rb
+++ b/app/models/issue.rb
@@ -75,10 +75,10 @@ class Issue < ActiveRecord::Base
     @link_reference_pattern ||= super("issues", /(?<issue>\d+)/)
   end
 
-  def self.sort(method)
+  def self.sort(method, excluded_labels: [])
     case method.to_s
     when 'due_date_asc' then order_due_date_asc
-    when 'due_date_desc'  then order_due_date_desc
+    when 'due_date_desc' then order_due_date_desc
     else
       super
     end
diff --git a/app/models/label.rb b/app/models/label.rb
index 4437ca393ed..7fd77880558 100644
--- a/app/models/label.rb
+++ b/app/models/label.rb
@@ -19,7 +19,6 @@ class Label < ActiveRecord::Base
 
   validates :color, color: true, allow_blank: false
   validates :project, presence: true, unless: Proc.new { |service| service.template? }
-  validates :priority, presence: false, default: false
 
   # Don't allow '?', '&', and ',' for label titles
   validates :title,
@@ -32,21 +31,11 @@ class Label < ActiveRecord::Base
   default_scope { order(title: :asc) }
 
   scope :templates, ->  { where(template: true) }
-  scope :prioritized, ->(value = true) { where(priority: value) }
-
-  def self.high_priority(name, table_name, labels)
-    unfiltered = unscoped
-      .select("MIN(labels.priority)")
-      .joins("INNER JOIN label_links ON label_links.label_id = labels.id")
-      .where("label_links.target_type = '#{name}'")
-      .where("label_links.target_id = #{table_name}.id")
-      .where("labels.project_id = #{table_name}.project_id")
-
-    if labels.empty?
-      unfiltered
-    else
-      unfiltered.where("labels.title NOT IN (?)", labels)
-    end
+
+  def self.prioritized(bool = true)
+    query = bool ? where.not(priority: nil) : where(priority: nil)
+
+    query.reorder(Gitlab::Database.nulls_last_order(:priority), :title)
   end
 
   alias_attribute :name, :title
@@ -139,8 +128,6 @@ class Label < ActiveRecord::Base
   end
 
   def nillify_priority
-    unless self.priority.present?
-      self.priority = nil
-    end
+    self.priority = nil if priority.blank?
   end
 end