changed schema, and added create/delete waitlist

app/models/sign_up_sheet.rb

@@ -79,6 +79,11 @@ def self.create_SignUpTeam(assignment_id, sign_up, topic_id, user_id)
       ExpertizaLogger.info LoggerMessage.new('SignUpSheet', user_id, "Sign up sheet created with teamId #{team_id}")
     else
       sign_up.is_waitlisted = true
+      team_id = TeamsUser.team_id(assignment_id, user_id)
+      unless WaitlistTeam.add_team_to_topic_waitlist(team_id, topic_id, user_id)
+        # flash[:error] = "Error occured while waitlisting to topic #{topic_id}"
+        raise ActiveRecord::Rollback 
+      end
     end
     [team_id, topic_id]
   end

app/models/sign_up_topic.rb

@@ -98,6 +98,7 @@ def self.reassign_topic(session_user_id, assignment_id, topic_id)
           end
         end
       end
+      WaitlistTeam.remove_team_from_topic_waitlist(users_team[0].t_id, topic_id, session_user_id)
       signup_record.destroy unless signup_record.nil?
       ExpertizaLogger.info LoggerMessage.new('SignUpTopic', session_user_id, "Topic dropped: #{topic_id}")
     else

app/models/waitlist_team.rb

@@ -3,6 +3,32 @@ class WaitlistTeam < ApplicationRecord
   belongs_to :team, class_name: 'Team'
 
   validates :topic_id, :team_id, presence: true
+  validates :topic_id, uniqueness: { scope: :team_id }
   scope :by_team_id, ->(team_id) { where('team_id = ?', team_id) }
   scope :by_topic_id, ->(topic_id) { where('topic_id = ?', topic_id) }
+
+  def self.add_team_to_topic_waitlist(team_id, topic_id, user_id)
+    new_waitlist = WaitlistTeam.new
+    new_waitlist.topic_id = topic_id
+    new_waitlist.team_id = team_id
+    if new_waitlist.valid?
+      WaitlistTeam.create(topic_id: topic_id, team_id: team_id)
+    else
+      ExpertizaLogger.info LoggerMessage.new('WaitlistTeam', user_id, "Team #{team_id} cannot be added to waitlist for the topic #{topic_id}")
+      ExpertizaLogger.info LoggerMessage.new('WaitlistTeam', user_id, new_waitlist.errors.full_messages.join(" "))
+      return false
+    end
+    return true
+  end
+
+  def self.remove_team_from_topic_waitlist(team_id, topic_id, user_id)
+    waitlisted_team_topic = WaitlistTeam.find_by(topic_id: topic_id, team_id: team_id)
+    unless waitlisted_team_topic.nil?
+      waitlisted_team_topic.destroy
+    else
+      ExpertizaLogger.info LoggerMessage.new('WaitlistTeam', user_id, "Cannot find Team #{team_id} in waitlist for the topic #{topic_id} to be deleted.")
+    end
+    return true
+  end
+
 end

db/migrate/20220420015915_create_waitlist_teams.rb

@@ -1,10 +1,10 @@
 class CreateWaitlistTeams < ActiveRecord::Migration[5.1]
 
   def self.up
-    create_table 'waitlist_teams', id: false do |t|
+    create_table 'waitlist_teams' do |t|
       t.column 'team_id', :integer
       t.column 'topic_id', :integer
-      t.timestamps
+      t.column 'created_at', :datetime
     end
 
     add_index 'waitlist_teams', ['team_id'], name: 'fk_waitlist_teams'
@@ -18,8 +18,9 @@ def self.up
     execute "alter table waitlist_teams
                add constraint fk_waitlist_teams_sign_up_topics
                foreign key (topic_id) references sign_up_topics(id)"
+
+    add_index 'waitlist_teams', ["team_id", "topic_id"], unique: true
 
-    execute "ALTER TABLE waitlist_teams ADD PRIMARY KEY (team_id, topic_id);"
   end
 
   def self.down