From 0fa65560c43719cecbf31f6134278a5d246b8082 Mon Sep 17 00:00:00 2001
From: Dombi Attila <83396+dombesz@users.noreply.github.com>
Date: Tue, 24 Jan 2023 21:37:23 +0200
Subject: [PATCH] Simplify query for CoveringDatesAndDaysOfWeek

---
 .../scopes/covering_dates_and_days_of_week.rb | 37 +++++++++----------
 .../apply_working_days_change_job.rb          |  6 +--
 2 files changed, 21 insertions(+), 22 deletions(-)

diff --git a/app/models/work_packages/scopes/covering_dates_and_days_of_week.rb b/app/models/work_packages/scopes/covering_dates_and_days_of_week.rb
index 8641c216f0..566c45e0de 100644
--- a/app/models/work_packages/scopes/covering_dates_and_days_of_week.rb
+++ b/app/models/work_packages/scopes/covering_dates_and_days_of_week.rb
@@ -61,7 +61,6 @@ module WorkPackages::Scopes::CoveringDatesAndDaysOfWeek
               work_packages.start_date IS NOT NULL
               OR work_packages.due_date IS NOT NULL
             )
-          ORDER BY work_packages.id
         ),
         -- coalesce non-existing dates of work package to get period start/end
         work_packages_periods AS (
@@ -70,26 +69,26 @@ module WorkPackages::Scopes::CoveringDatesAndDaysOfWeek
             GREATEST(work_package_start_date, work_package_due_date) AS end_date
           FROM work_packages_with_dates
         ),
-        -- expand period into days.
-        work_packages_expaned_periods AS (
-          SELECT id, generate_series(
-            work_packages_periods.start_date,
-            work_packages_periods.end_date,
-            '1 day') AS dates,
-            -- limit to 7 days (more would be useless).
-            extract(isodow from generate_series(
-              work_packages_periods.start_date,
-              LEAST(
-                work_packages_periods.start_date + 6,
-                work_packages_periods.end_date
-              ),
-              '1 day')
-            ) AS dow
-            FROM work_packages_periods
+        -- All days between the start date of a work package and its due date
+        covered_dates AS (
+          SELECT
+           id,
+           generate_series(work_packages_periods.start_date,
+                           work_packages_periods.end_date,
+                           '1 day')          AS date
+          FROM work_packages_periods
+        ),
+        -- All days between the start date of a work package and its due date including the day of the week for each date
+        covered_dates_and_wday AS (
+          SELECT
+            id,
+            date,
+            EXTRACT(isodow FROM date) dow
+          FROM covered_dates
         )
         -- select id of work packages covering the given days
-        SELECT id FROM work_packages_expaned_periods
-        WHERE dow IN (:days_of_week) OR dates IN (:dates)
+        SELECT id FROM covered_dates_and_wday
+        WHERE dow IN (:days_of_week) OR date IN (:dates)
       SQL
 
       sanitize_sql([sql, { days_of_week:, dates: }])
diff --git a/app/workers/work_packages/apply_working_days_change_job.rb b/app/workers/work_packages/apply_working_days_change_job.rb
index 1ac855466e..2a262735ec 100644
--- a/app/workers/work_packages/apply_working_days_change_job.rb
+++ b/app/workers/work_packages/apply_working_days_change_job.rb
@@ -71,7 +71,7 @@ class WorkPackages::ApplyWorkingDaysChangeJob < ApplicationJob
 
   def applicable_work_package(previous_working_days, previous_non_working_days)
     days_of_week = changed_days(previous_working_days).keys
-    dates = changed_non_working_days(previous_non_working_days).keys
+    dates = changed_non_working_dates(previous_non_working_days).keys
     WorkPackage
       .covering_dates_and_days_of_week(days_of_week:, dates:)
       .order(WorkPackage.arel_table[:start_date].asc.nulls_first,
@@ -87,7 +87,7 @@ class WorkPackages::ApplyWorkingDaysChangeJob < ApplicationJob
     (previous ^ current).index_with { |day| current.include?(day) }
   end
 
-  def changed_non_working_days(previous_non_working_days)
+  def changed_non_working_dates(previous_non_working_days)
     previous = Set.new(previous_non_working_days)
     current = Set.new(NonWorkingDay.pluck(:date))
 
@@ -104,7 +104,7 @@ class WorkPackages::ApplyWorkingDaysChangeJob < ApplicationJob
 
   def set_journal_notice(updated_work_package_ids, previous_working_days, previous_non_working_days)
     day_changes = changed_days(previous_working_days)
-    date_changes = changed_non_working_days(previous_non_working_days)
+    date_changes = changed_non_working_dates(previous_non_working_days)
     journal_note = journal_notice_text(day_changes, date_changes)
 
     WorkPackage