Potential Email Schedular

study_visit_email_scheduler_service.rb

class StudyVisitMailer < BaseMailer
  def send_email(user_id, email_id)
    user = User.find(user_id)
    email = Email.find(email_id)
    
    ...

    mail(
      :to => user.email,
      :subject => email.subject(:study_visit_number_text => sv_number),
      :template_name => email.template
    )
  end
end

class Emails::AdvanceParkinsonsResearchEmail < Email
  def send_email(user_id)
    StudyVisitMailer.delay.send_email(user_id, id)
  end

  def template
    'advance_parkinsons_research'
  end

  def ganalytics_options
    {
      :utm_campaign => 'fi_feature_notifications',
      :utm_source => 'advance_parkinsons_research_email',
      :utm_medium => 'email'
    }
  end
end


class StudyVisitEmailSchedulerService
  def queue_emails(profile)
    queue(profile, email_list(profile))
  end

  def dequeue_emails(profile)
    dequeue(profile, email_list(profile))
  end

  def default_emails
    with_default([
     {:klass => Emails::StudyVisitReminderEightySevenDayEmail, :days_in => 87} 
    ])
  end

  def new_participant_baseline_emails
    with_default([
      {:klass => Emails::AdvanceParkinsonsResearchEmail, :days_in => 7},
      {:klass => , :days_in => },
      {:klass => , :days_in => },
      {:klass => , :days_in => },
      {:klass => , :days_in => },
      {:klass => , :days_in => },
      {:klass => , :days_in => },
      {:klass => , :days_in => },
      {:klass => , :days_in => },
    ])
  end

  def new_participant_second_study_visit_emails
    with_default([
      {:klass => , :days_in => },
    ])
  end

  def existing_participant_baseline_emails
    [
      {:klass => , :days_in => },
    ]
  end

  def queue(profile, emails)
    [*emails].each do |email|
      next if profile.user.emails.detect {|e| e.is_a?(email_klass) }
      profile.user.user_emails.create(
        :email => email[:klass].first,
        :send_at => email[:days_in].days.from_now.utc
      )
    end
  end

  def dequeue(profile, emails)
    [*emails].each do |email|
      profile.user.user_emails.where(:email => email).destoy_all
    end
  end

  def email_list(profile)
    if new_participant?(profile)
      case study_visit_count(profile)
      when 1
        new_participant_baseline_emails
      when 2
        new_participant_second_study_visit_emails
      end
    else
      case study_visit_count(profile)
      when 1
        existing_participant_baseline_emails
      end
    end
  end

  def new_participant?(profile)
    profile.study_visits.all? {|sv| sv.linear_study_visit? }
  end

  def study_visit_count(profile)
    profile.study_visits.map.count {|sv| sv.linear_study_visit? }
  end

  def with_default(arr)
    arr.concat(default_emails).uniq
  end
end