# Copyright (C) 2012-2024 Zammad Foundation, https://zammad-foundation.org/

class OnlineNotification < ApplicationModel
  include HasDefaultModelUserRelations

  include OnlineNotification::Assets
  include OnlineNotification::TriggersSubscriptions

  belongs_to :user, optional: true
  # rubocop:disable Rails/InverseOf
  belongs_to :object, class_name: 'ObjectLookup', foreign_key: 'object_lookup_id', optional: true
  belongs_to :type,   class_name: 'TypeLookup',   foreign_key: 'type_lookup_id', optional: true
  # rubocop:enable Rails/InverseOf

  after_create    :notify_clients_after_change
  after_update    :notify_clients_after_change
  after_destroy   :notify_clients_after_change

=begin

add a new online notification for this user

  OnlineNotification.add(
    type:          'Assigned to you',
    object:        'Ticket',
    o_id:          ticket.id,
    seen:          false,
    user_id:       2,
    created_by_id: 1,
    updated_by_id: 1,
    created_at:    Time.zone.now,
    updated_at:    Time.zone.now,
  )

=end

  def related_object
    ObjectLookup
      .by_id(object_lookup_id)
      &.safe_constantize
      &.find(o_id)
  end

  def self.add(data)

    # lookups
    if data[:type]
      type_id = TypeLookup.by_name(data[:type])
    end
    if data[:object]
      object_id = ObjectLookup.by_name(data[:object])
    end

    # check if object for online notification exists
    exists_by_object_and_id?(data[:object], data[:o_id])

    record = {
      o_id:             data[:o_id],
      object_lookup_id: object_id,
      type_lookup_id:   type_id,
      seen:             data[:seen],
      user_id:          data[:user_id],
      created_by_id:    data[:created_by_id],
      updated_by_id:    data[:updated_by_id] || data[:created_by_id],
      created_at:       data[:created_at] || Time.zone.now,
      updated_at:       data[:updated_at] || Time.zone.now,
    }

    OnlineNotification.create!(record)
  end

=begin

remove whole online notifications of an object

  OnlineNotification.remove('Ticket', 123)

=end

  def self.remove(object_name, o_id)
    object_id = ObjectLookup.by_name(object_name)
    OnlineNotification.where(
      object_lookup_id: object_id,
      o_id:             o_id,
    ).destroy_all
  end

=begin

remove whole online notifications of an object by type

  OnlineNotification.remove_by_type('Ticket', 123, type, user)

=end

  def self.remove_by_type(object_name, o_id, type_name, user)
    object_id = ObjectLookup.by_name(object_name)
    type_id = TypeLookup.by_name(type_name)
    OnlineNotification.where(
      object_lookup_id: object_id,
      type_lookup_id:   type_id,
      o_id:             o_id,
      user_id:          user.id,
    ).destroy_all
  end

=begin

return online notifications of an user.

@param user [User] to get notifications of
@param limit [Integer] of notifications to get
@param ensure_access [Boolean] to check if user still has access to referenced ticket
@param access [String] can be 'full', 'read', 'create' or 'ignore' (ignore means a selector over all tickets)

@example

  notifications = OnlineNotification.list(user, limit: 123, access: 'full')

=end

  def self.list(user, limit: 200, access: 'read')
    relation = OnlineNotification
      .where(user_id: user.id)
      .reorder(created_at: :desc)
      .limit(limit)

    return relation if access == 'ignore'

    object_id = ObjectLookup.by_name 'Ticket'

    relation
      .joins("LEFT JOIN tickets ON online_notifications.object_lookup_id = #{ActiveRecord::Base.connection.quote(object_id)} AND tickets.id = online_notifications.o_id")
      .where('online_notifications.object_lookup_id != :object_id OR (online_notifications.object_lookup_id = :object_id AND tickets.group_id IN (:group_ids))',
             object_id: object_id,
             group_ids: user.group_ids_access(access))
  end

=begin

return all online notifications of an object

  notifications = OnlineNotification.list_by_object('Ticket', 123)

=end

  def self.list_by_object(object_name, o_id)
    object_id = ObjectLookup.by_name(object_name)

    OnlineNotification
      .where(
        object_lookup_id: object_id,
        o_id:             o_id,
      )
      .reorder(created_at: :desc)
      .limit(10_000)
  end

=begin

cleanup old online notifications

  OnlineNotification.cleanup

with dedicated times

  max_age = Time.zone.now - 9.months
  max_own_seen = Time.zone.now - 10.minutes
  max_auto_seen = Time.zone.now - 8.hours

  OnlineNotification.cleanup(max_age, max_own_seen, max_auto_seen)

=end

  def self.cleanup(max_age = 9.months.ago, max_own_seen = 10.minutes.ago, max_auto_seen = 8.hours.ago)
    affected_user_ids = []

    where(created_at: ...max_age)
      .tap { |relation| affected_user_ids |= relation.distinct.pluck(:user_id) }
      .delete_all

    where(seen: true)
      .where('(user_id = updated_by_id AND updated_at < :max_own_seen) OR (user_id != updated_by_id AND updated_at < :max_auto_seen)',
             max_own_seen:, max_auto_seen:)
      .tap { |relation| affected_user_ids |= relation.distinct.pluck(:user_id) }
      .delete_all

    cleanup_notify_agents(affected_user_ids)

    true
  end

  def self.cleanup_notify_agents(user_ids)
    return if user_ids.blank?

    User
      .with_permissions('ticket.agent')
      .where(id: user_ids)
      .each do |user|
        Sessions.send_to(
          user.id,
          {
            event: 'OnlineNotification::changed',
            data:  {}
          }
        )
      end
  end

=begin

check if online notification should be shown in general as already seen with current state

  ticket = Ticket.find(1)
  seen = OnlineNotification.seen_state?(ticket, user_id_check)

returns

  result = true # or false

=end

  def self.seen_state?(ticket, user_id_check = nil)
    state      = Ticket::State.lookup(id: ticket.state_id)
    state_type = Ticket::StateType.lookup(id: state.state_type_id)

    # always to set unseen for ticket owner and users which did not the update
    return false if seen_state_not_merged_owner?(state_type, ticket, user_id_check)

    # set all to seen if pending action state is a closed or merged state
    if state_type.name == 'pending action' && state.next_state_id
      state      = Ticket::State.lookup(id: state.next_state_id)
      state_type = Ticket::StateType.lookup(id: state.state_type_id)
    end

    # set all to seen if new state is pending reminder state
    if state_type.name == 'pending reminder'
      return seen_state_pending_reminder?(ticket, user_id_check)
    end

    # set all to seen if new state is a closed or merged state
    return true if %w[closed merged].include? state_type.name

    false
  end

  def self.seen_state_pending_reminder?(ticket, user_id_check)
    return true if !user_id_check

    return false if ticket.owner_id == 1
    return false if ticket.updated_by_id != ticket.owner_id && user_id_check == ticket.owner_id

    true
  end
  private_class_method :seen_state_pending_reminder?

  def self.seen_state_not_merged_owner?(state_type, ticket, user_id_check)
    return false if state_type.name == 'merged'
    return false if !user_id_check

    user_id_check == ticket.owner_id && user_id_check != ticket.updated_by_id
  end
  private_class_method :seen_state_not_merged_owner?

  private

  def notify_clients_after_change
    Sessions.send_to(
      user_id,
      {
        event: 'OnlineNotification::changed',
        data:  {}
      }
    )
  end
end