Replace incompatible babe_squeel

Baby Squeel is incompatible with Rails >5.2.1 when using polymorphic
associations. This commit removes baby_squeel and replaces all usages
with plain where statements and some new scopes.

Most squeel clauses are replaces with AR where clauses with a little bit
SQL as string. Values are passed as placeholders. The more complex feed
logic is extracted into three scopes on the Feed model.

Gemfile

@@ -37,7 +37,6 @@ gem 'will_paginate'
 gem 'paginate-responder', '~> 2.0'
 gem 'decorate-responder', '~> 2.0'
 gem 'api-responder'
-gem 'baby_squeel'
 
 gem 'pg', '~> 1.0' # missing compability with rails
 

Gemfile.lock

@@ -57,10 +57,6 @@ GEM
     ast (2.4.0)
     autoprefixer-rails (9.6.1.1)
       execjs
-    baby_squeel (1.3.1)
-      activerecord (>= 4.2.0)
-      join_dependency (~> 0.1.2)
-      polyamorous (~> 1.3)
     bcrypt (3.1.13)
     bourbon (6.0.0)
       thor (~> 0.19)
@@ -147,8 +143,6 @@ GEM
     i18n (1.6.0)
       concurrent-ruby (~> 1.0)
     jaro_winkler (1.5.3)
-    join_dependency (0.1.4)
-      activerecord (>= 4.2.0)
     jquery-rails (4.3.5)
       rails-dom-testing (>= 1, < 3)
       railties (>= 4.2.0)
@@ -227,8 +221,6 @@ GEM
       capybara (>= 2.1, < 4)
       cliver (~> 0.3.1)
       websocket-driver (>= 0.2.0)
-    polyamorous (1.3.3)
-      activerecord (>= 3.0)
     powerpack (0.1.2)
     pry (0.12.2)
       coderay (~> 1.1.0)
@@ -399,7 +391,6 @@ DEPENDENCIES
   accept_values_for (>= 0.7.4)
   api-responder
   autoprefixer-rails (~> 9.6)
-  baby_squeel
   bcrypt
   bourbon (~> 6.0)
   brakeman

app/models/feed.rb

@@ -4,8 +4,21 @@ class Feed < ApplicationRecord
   belongs_to :source
   has_many :fetches, class_name: 'FeedFetch'
   has_many :messages, as: :messageable
+
   scope :fetch_needed, -> {
-    where.has { next_fetch_at < Time.zone.now }.order(:next_fetch_at)
+    where('next_fetch_at < ?', Time.zone.now).order(:next_fetch_at)
+  }
+
+  scope :archived, lambda {
+    joins(source: :canteen).where(sources: {canteens: {state: 'archived' }})
+  }
+
+  scope :inactive, lambda {
+    where('(schedule IS NULL OR id IN (?))', Feed.archived.select(:id))
+  }
+
+  scope :active, lambda {
+    where('(schedule IS NOT NULL AND id NOT IN (?))', Feed.archived.select(:id))
   }
 
   def canteen
@@ -14,8 +27,8 @@ def canteen
 
   def feed_timespans
     {
-      lastday: fetches.where.has { executed_at > 1.day.ago },
-      lastweek: fetches.where.has { executed_at > 1.week.ago },
+      lastday: fetches.where('executed_at > ?', 1.day.ago),
+      lastweek: fetches.where('executed_at > ?', 1.week.ago),
       total: fetches
     }
   end

lib/open_mensa/update_feeds_task.rb

@@ -13,22 +13,13 @@ def do
   private
 
   def fix_next_fetch_ats
-    disabled_feeds = Feed
-      .joins(source: :canteen)
-      .where.has { source.canteen.state == 'archived' }
-      .select(:id)
+    changes = Feed.inactive.where.not(next_fetch_at: nil).update_all(next_fetch_at: nil)
 
-    changes = Feed
-      .where.has { ((schedule == nil) | id.in(disabled_feeds)) & (next_fetch_at != nil) }
-      .update_all(next_fetch_at: nil)
-
-    Feed
-      .where.has { (schedule != nil) & id.not_in(disabled_feeds) & (next_fetch_at == nil) }
-      .each do |feed|
-        feed.next_fetch_at = process_schedule(feed, :last)
-        feed.save!
-        changes += 1
-      end
+    Feed.active.where(next_fetch_at: nil).each do |feed|
+      feed.next_fetch_at = process_schedule(feed, :last)
+      feed.save!
+      changes += 1
+    end
 
     changes
   end