From 31d1a798f42823948f510db2b977ab8469cc181b Mon Sep 17 00:00:00 2001
From: Andrei Prigorshnev <a.prigorshnev@gmail.com>
Date: Wed, 14 Dec 2022 12:42:17 +0400
Subject: [PATCH] FEATURE: do not suggest users on vacation (#395)

---
 .../discourse_assign/assign_controller.rb     | 42 ++++++++++++-------
 lib/discourse_calendar.rb                     |  7 ++++
 plugin.rb                                     |  1 +
 spec/requests/assign_controller_spec.rb       | 37 +++++++++++++++-
 4 files changed, 70 insertions(+), 17 deletions(-)
 create mode 100644 lib/discourse_calendar.rb

diff --git a/app/controllers/discourse_assign/assign_controller.rb b/app/controllers/discourse_assign/assign_controller.rb
index 4bd5e12..3678e10 100644
--- a/app/controllers/discourse_assign/assign_controller.rb
+++ b/app/controllers/discourse_assign/assign_controller.rb
@@ -6,22 +6,7 @@ module DiscourseAssign
     before_action :ensure_logged_in, :ensure_assign_allowed
 
     def suggestions
-      users = [current_user]
-      users +=
-        User
-          .where("users.id <> ?", current_user.id)
-          .joins(<<~SQL)
-          JOIN(
-            SELECT assigned_to_id user_id, MAX(created_at) last_assigned
-            FROM assignments
-            WHERE assignments.assigned_to_type = 'User'
-            GROUP BY assigned_to_id
-            HAVING COUNT(*) < #{SiteSetting.max_assigned_topics}
-          ) as X ON X.user_id = users.id
-        SQL
-          .assign_allowed
-          .order("X.last_assigned DESC")
-          .limit(6)
+      users = [current_user, *recent_assignees]
 
       render json: {
                assign_allowed_on_groups:
@@ -279,5 +264,30 @@ module DiscourseAssign
     def user_menu_limit
       UsersController::USER_MENU_LIST_LIMIT
     end
+
+    def recent_assignees
+      User
+        .where("users.id <> ?", current_user.id)
+        .joins(<<~SQL)
+          JOIN(
+            SELECT assigned_to_id user_id, MAX(created_at) last_assigned
+            FROM assignments
+            WHERE assignments.assigned_to_type = 'User'
+            GROUP BY assigned_to_id
+            HAVING COUNT(*) < #{SiteSetting.max_assigned_topics}
+          ) as X ON X.user_id = users.id
+        SQL
+        .joins(<<~SQL)
+          LEFT JOIN(
+            SELECT DISTINCT ON (user_id) name, user_id
+            FROM user_custom_fields
+            WHERE name = '#{DiscourseCalendar::HOLIDAY_CUSTOM_FIELD}'
+          ) AS ucf on ucf.user_id = users.id
+        SQL
+        .where("ucf.name is NULL")
+        .assign_allowed
+        .order("X.last_assigned DESC")
+        .limit(6)
+    end
   end
 end
diff --git a/lib/discourse_calendar.rb b/lib/discourse_calendar.rb
new file mode 100644
index 0000000..3e7f36f
--- /dev/null
+++ b/lib/discourse_calendar.rb
@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+module DiscourseAssign
+  module DiscourseCalendar
+    HOLIDAY_CUSTOM_FIELD ||= 'on_holiday'
+  end
+end
diff --git a/plugin.rb b/plugin.rb
index 29b62ff..d8eeb02 100644
--- a/plugin.rb
+++ b/plugin.rb
@@ -17,6 +17,7 @@ register_asset "stylesheets/mobile/assigns.scss", :mobile
 load File.expand_path("../lib/discourse_assign/engine.rb", __FILE__)
 load File.expand_path("../lib/discourse_assign/helpers.rb", __FILE__)
 load File.expand_path("../lib/validators/assign_statuses_validator.rb", __FILE__)
+load File.expand_path("../lib/discourse_calendar.rb", __FILE__)
 
 Discourse::Application.routes.append do
   mount ::DiscourseAssign::Engine, at: "/assign"
diff --git a/spec/requests/assign_controller_spec.rb b/spec/requests/assign_controller_spec.rb
index 6f2d840..d36b4cf 100644
--- a/spec/requests/assign_controller_spec.rb
+++ b/spec/requests/assign_controller_spec.rb
@@ -94,11 +94,39 @@ RSpec.describe DiscourseAssign::AssignController do
 
   describe "#suggestions" do
     before do
-      SiteSetting.max_assigned_topics = 1
       sign_in(user)
     end
 
+    it "suggests the current user + the last 6 previously assigned users" do
+      assignees = 10.times.map { |_| assign_user_to_post.username }
+
+      get "/assign/suggestions.json"
+
+      suggestions = response.parsed_body["suggestions"].map { |u| u["username"] }
+      expect(suggestions).to contain_exactly(user.username, *assignees[4..9])
+    end
+
+    it "doesn't suggest users on holiday" do
+      user_on_vacation = assign_user_to_post
+      user_on_vacation.upsert_custom_fields(DiscourseAssign::DiscourseCalendar::HOLIDAY_CUSTOM_FIELD => "t")
+
+      get "/assign/suggestions.json"
+
+      suggestions = response.parsed_body["suggestions"].map { |u| u["username"] }
+      expect(suggestions).to_not include(user_on_vacation.username)
+    end
+
+    it "suggests the current user even if they're on holiday" do
+      user.upsert_custom_fields(DiscourseAssign::DiscourseCalendar::HOLIDAY_CUSTOM_FIELD => "t")
+
+      get "/assign/suggestions.json"
+
+      suggestions = response.parsed_body["suggestions"].map { |u| u["username"] }
+      expect(suggestions).to include(user.username)
+    end
+
     it "excludes other users from the suggestions when they already reached the max assigns limit" do
+      SiteSetting.max_assigned_topics = 1
       another_admin = Fabricate(:admin, groups: [default_allowed_group])
       Assigner.new(post.topic, user).assign(another_admin)
 
@@ -107,6 +135,13 @@ RSpec.describe DiscourseAssign::AssignController do
 
       expect(suggestions).to contain_exactly(user.username)
     end
+
+    def assign_user_to_post
+      assignee = Fabricate(:user, groups: [default_allowed_group])
+      post = Fabricate(:post)
+      Assigner.new(post.topic, user).assign(assignee)
+      assignee
+    end
   end
 
   describe "#assign" do