Sort by label priority

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

2 files changed, 31 insertions, 1 deletions

diff --git a/app/models/concerns/issuable.rb b/app/models/concerns/issuable.rb
index 5d279ae602a..8871cb8a6cd 100644
--- a/app/models/concerns/issuable.rb
+++ b/app/models/concerns/issuable.rb
@@ -48,6 +48,12 @@ 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,
@@ -105,12 +111,13 @@ module Issuable
       where(t[:title].matches(pattern).or(t[:description].matches(pattern)))
     end
 
-    def sort(method)
+    def sort(method, 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)
       else
         order_by(method)
       end
diff --git a/app/models/label.rb b/app/models/label.rb
index 59e7afe53f3..4437ca393ed 100644
--- a/app/models/label.rb
+++ b/app/models/label.rb
@@ -27,11 +27,28 @@ class Label < ActiveRecord::Base
             format: { with: /\A[^&\?,]+\z/ },
             uniqueness: { scope: :project_id }
 
+  before_save :nillify_priority
+
   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
+  end
+
   alias_attribute :name, :title
 
   def self.reference_prefix
@@ -120,4 +137,10 @@ class Label < ActiveRecord::Base
       id
     end
   end
+
+  def nillify_priority
+    unless self.priority.present?
+      self.priority = nil
+    end
+  end
 end