# frozen_string_literal: true

class Subscription < ApplicationRecord
  belongs_to :user
  belongs_to :answer

  class << self
    def subscribe(recipient, target)
      existing = Subscription.find_by(user: recipient, answer: target)
      return true if existing.present?

      Subscription.create!(user: recipient, answer: target)
    end

    def unsubscribe(recipient, target)
      return nil if recipient.nil? || target.nil?

      subs = Subscription.find_by(user: recipient, answer: target)
      subs&.destroy
    end

    def destruct(target)
      return nil if target.nil?

      Subscription.where(answer: target).destroy_all
    end

    def notify(source, target)
      return nil if source.nil? || target.nil?

      muted_by = Relationships::Mute.where(target: source.user).pluck(&:source_id)

      # As we will need to notify for each person subscribed,
      # it's much faster to bulk insert than to use +Notification.notify+
      notifications = Subscription.where(answer: target)
                                  .where.not(user: source.user)
                                  .where.not(user_id: muted_by)
                                  .map do |s|
        { target_id: source.id, target_type: Comment, recipient_id: s.user_id, new: true, type: Notification::Commented }
      end

      Notification.insert_all!(notifications) unless notifications.empty? # rubocop:disable Rails/SkipsModelValidations
    end

    def denotify(source, target)
      return nil if source.nil? || target.nil?

      subs = Subscription.where(answer: target)
      Notification.where(target:, recipient: subs.map(&:user)).delete_all
    end
  end
end