# frozen_string_literal: true

module Notifications
  class ConsolidationPlanner
    def consolidate_or_save!(notification)
      plan = plan_for(notification)
      return :no_plan if plan.nil?

      plan.consolidate_or_save!(notification)
    end

    private

    def plan_for(notification)
      consolidation_plans = [
        liked_by_two_users,
        liked,
        group_message_summary,
        group_membership,
        new_features_notification,
      ]
      consolidation_plans.concat(DiscoursePluginRegistry.notification_consolidation_plans)

      consolidation_plans.detect { |plan| plan.can_consolidate_data?(notification) }
    end

    def liked
      ConsolidateNotifications
        .new(
          from: Notification.types[:liked],
          to: Notification.types[:liked_consolidated],
          threshold: -> { SiteSetting.notification_consolidation_threshold },
          consolidation_window: SiteSetting.likes_notification_consolidation_window_mins.minutes,
          unconsolidated_query_blk:
            Proc.new do |notifications, data|
              key = "display_username"
              value = data[key.to_sym]
              filtered = notifications.where("data::json ->> 'username2' IS NULL")

              filtered = filtered.where("data::json ->> '#{key}' = ?", value) if value

              filtered
            end,
          consolidated_query_blk: filtered_by_data_attribute("display_username"),
        )
        .set_mutations(
          set_data_blk:
            Proc.new do |notification|
              data = notification.data_hash
              data.merge(username: data[:display_username])
            end,
        )
        .set_precondition(precondition_blk: Proc.new { |data| data[:username2].blank? })
    end

    def liked_by_two_users
      DeletePreviousNotifications
        .new(
          type: Notification.types[:liked],
          previous_query_blk:
            Proc.new do |notifications, data|
              notifications.where(id: data[:previous_notification_id])
            end,
        )
        .set_mutations(
          set_data_blk:
            Proc.new do |notification|
              existing_notification_of_same_type =
                Notification
                  .where(user: notification.user)
                  .order("notifications.id DESC")
                  .where(topic_id: notification.topic_id, post_number: notification.post_number)
                  .where(notification_type: notification.notification_type)
                  .where("created_at > ?", 1.day.ago)
                  .first

              data = notification.data_hash
              if existing_notification_of_same_type
                same_type_data = existing_notification_of_same_type.data_hash
                data.merge(
                  previous_notification_id: existing_notification_of_same_type.id,
                  username2: same_type_data[:display_username],
                  count: (same_type_data[:count] || 1).to_i + 1,
                )
              else
                data
              end
            end,
        )
        .set_precondition(
          precondition_blk:
            Proc.new do |data, notification|
              always_freq = UserOption.like_notification_frequency_type[:always]

              notification.user&.user_option&.like_notification_frequency == always_freq &&
                data[:previous_notification_id].present?
            end,
        )
    end

    def group_membership
      ConsolidateNotifications
        .new(
          from: Notification.types[:private_message],
          to: Notification.types[:membership_request_consolidated],
          threshold: -> { SiteSetting.notification_consolidation_threshold },
          consolidation_window: Notification::MEMBERSHIP_REQUEST_CONSOLIDATION_WINDOW_HOURS.hours,
          unconsolidated_query_blk: filtered_by_data_attribute("topic_title"),
          consolidated_query_blk: filtered_by_data_attribute("group_name"),
        )
        .set_precondition(precondition_blk: Proc.new { |data| data[:group_name].present? })
        .set_mutations(
          set_data_blk:
            Proc.new do |notification|
              data = notification.data_hash
              post_id = data[:original_post_id]
              custom_field =
                PostCustomField.select(:value).find_by(post_id: post_id, name: "requested_group_id")
              group_id = custom_field&.value
              group_name =
                group_id.present? ? Group.select(:name).find_by(id: group_id.to_i)&.name : nil

              data[:group_name] = group_name
              data
            end,
        )
    end

    def group_message_summary
      DeletePreviousNotifications.new(
        type: Notification.types[:group_message_summary],
        previous_query_blk: filtered_by_data_attribute("group_id"),
      ).set_precondition(precondition_blk: Proc.new { |data| data[:group_id].present? })
    end

    def filtered_by_data_attribute(attribute_name)
      Proc.new do |notifications, data|
        if (value = data[attribute_name.to_sym])
          notifications.where("data::json ->> '#{attribute_name}' = ?", value.to_s)
        else
          notifications
        end
      end
    end

    def new_features_notification
      DeletePreviousNotifications.new(type: Notification.types[:new_features])
    end
  end
end