app/models/agent.rb
require 'utils'
# Agent is the core class in Huginn, representing a configurable, schedulable, reactive system with memory that can
# be sub-classed for many different purposes. Agents can emit Events, as well as receive them and react in many different ways.
# The basic Agent API is detailed on the Huginn wiki: https://github.com/huginn/huginn/wiki/Creating-a-new-agent
class Agent < ActiveRecord::Base
include AssignableTypes
include MarkdownClassAttributes
include JsonSerializedField
include RdbmsFunctions
include WorkingHelpers
include LiquidInterpolatable
include HasGuid
include DryRunnable
include SortableEvents
markdown_class_attributes :description, :event_description
load_types_in "Agents"
SCHEDULES = %w[
every_1m every_2m every_5m every_10m every_30m
every_1h every_2h every_5h every_12h
every_1d every_2d every_7d
midnight 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am
noon 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm
never
]
EVENT_RETENTION_SCHEDULES = [
["Forever", 0], ['1 hour', 1.hour], ['6 hours', 6.hours], ["1 day", 1.day],
*(
[2, 3, 4, 5, 7, 14, 21, 30, 45, 90, 180, 365].map { |n|
["#{n} days", n.days]
}
)
]
json_serialize :options, :memory
validates_presence_of :name, :user
validates_inclusion_of :keep_events_for, in: EVENT_RETENTION_SCHEDULES.map(&:last)
validates :sources, owned_by: :user_id
validates :receivers, owned_by: :user_id
validates :controllers, owned_by: :user_id
validates :control_targets, owned_by: :user_id
validates :scenarios, owned_by: :user_id
validate :validate_schedule
validate :validate_options
after_initialize :set_default_schedule
before_validation :set_default_schedule
before_validation :unschedule_if_cannot_schedule
before_save :unschedule_if_cannot_schedule
before_create :set_last_checked_event_id
after_save :possibly_update_event_expirations
belongs_to :user, inverse_of: :agents
belongs_to :service, inverse_of: :agents, optional: true
has_many :events, -> { order("events.id desc") }, dependent: :delete_all, inverse_of: :agent
has_one :most_recent_event, -> { order("events.id desc") }, inverse_of: :agent, class_name: "Event"
has_many :logs, -> { order("agent_logs.id desc") }, dependent: :delete_all, inverse_of: :agent, class_name: "AgentLog"
has_many :links_as_source, dependent: :delete_all, foreign_key: "source_id", class_name: "Link",
inverse_of: :source
has_many :links_as_receiver, dependent: :delete_all, foreign_key: "receiver_id", class_name: "Link",
inverse_of: :receiver
has_many :sources, through: :links_as_receiver, class_name: "Agent", inverse_of: :receivers
has_many :received_events, -> { order("events.id desc") }, through: :sources, class_name: "Event", source: :events
has_many :receivers, through: :links_as_source, class_name: "Agent", inverse_of: :sources
has_many :control_links_as_controller, dependent: :delete_all, foreign_key: 'controller_id',
class_name: 'ControlLink', inverse_of: :controller
has_many :control_links_as_control_target, dependent: :delete_all, foreign_key: 'control_target_id',
class_name: 'ControlLink', inverse_of: :control_target
has_many :controllers, through: :control_links_as_control_target, class_name: "Agent", inverse_of: :control_targets
has_many :control_targets, through: :control_links_as_controller, class_name: "Agent", inverse_of: :controllers
has_many :scenario_memberships, dependent: :destroy, inverse_of: :agent
has_many :scenarios, through: :scenario_memberships, inverse_of: :agents
scope :active, -> { where(disabled: false, deactivated: false) }
scope :inactive, -> { where(disabled: true).or(where(deactivated: true)) }
scope :of_type, ->(type) {
case type
when Agent
where(type: type.class.to_s)
else
where(type: type.to_s)
end
}
def short_type
type.demodulize
end
def check
# Implement me in your subclass of Agent.
end
def default_options
# Implement me in your subclass of Agent.
{}
end
def receive(events)
# Implement me in your subclass of Agent.
end
def is_form_configurable?
false
end
def receive_web_request(params, method, format)
# Implement me in your subclass of Agent.
["not implemented", 404, "text/plain", {}] # last two elements in response array are optional
end
# alternate method signature for receive_web_request
# def receive_web_request(request=ActionDispatch::Request.new( ... ))
# end
# Implement me in your subclass to decide if your Agent is working.
def working?
raise "Implement me in your subclass"
end
def build_event(event)
event = events.build(event) if event.is_a?(Hash)
event.agent = self
event.user = user
event.expires_at ||= new_event_expiration_date
event
end
def create_event(event)
if can_create_events?
event = build_event(event)
event.save!
event
else
error "This Agent cannot create events!"
end
end
def credential(name)
@credential_cache ||= {}
if @credential_cache.has_key?(name)
@credential_cache[name]
else
@credential_cache[name] = user.user_credentials.where(credential_name: name).first.try(:credential_value)
end
end
def reload
@credential_cache = {}
super
end
def new_event_expiration_date
keep_events_for > 0 ? keep_events_for.seconds.from_now : nil
end
def update_event_expirations!
if keep_events_for == 0
events.update_all expires_at: nil
else
events.update_all "expires_at = " + rdbms_date_add("created_at", "SECOND", keep_events_for.to_i)
end
end
def trigger_web_request(request)
params = request.params.except(:action, :controller, :agent_id, :user_id, :format)
if respond_to?(:receive_webhook)
Rails.logger.warn "DEPRECATED: The .receive_webhook method is deprecated, please switch your Agent to use .receive_web_request."
receive_webhook(params).tap do
self.last_web_request_at = Time.now
save!
end
else
handled_request =
if method(:receive_web_request).arity == 1
receive_web_request(request)
else
receive_web_request(params, request.method_symbol.to_s, request.format.to_s)
end
handled_request.tap do
self.last_web_request_at = Time.now
save!
end
end
end
def unavailable?
disabled? || dependencies_missing?
end
def dependencies_missing?
self.class.dependencies_missing?
end
def default_schedule
self.class.default_schedule
end
def cannot_be_scheduled?
self.class.cannot_be_scheduled?
end
def can_be_scheduled?
!cannot_be_scheduled?
end
def cannot_receive_events?
self.class.cannot_receive_events?
end
def can_receive_events?
!cannot_receive_events?
end
def cannot_create_events?
self.class.cannot_create_events?
end
def can_create_events?
!cannot_create_events?
end
def can_control_other_agents?
self.class.can_control_other_agents?
end
def can_dry_run?
self.class.can_dry_run?
end
def no_bulk_receive?
self.class.no_bulk_receive?
end
def log(message, options = {})
AgentLog.log_for_agent(self, message, options.merge(inbound_event: current_event))
end
def error(message, options = {})
log(message, options.merge(level: 4))
end
def delete_logs!
logs.delete_all
update_column :last_error_log_at, nil
end
def drop_pending_events
false
end
def drop_pending_events=(bool)
set_last_checked_event_id if bool
end
# Callbacks
def set_default_schedule
self.schedule = default_schedule unless schedule.present? || cannot_be_scheduled?
end
def unschedule_if_cannot_schedule
self.schedule = nil if cannot_be_scheduled?
end
def set_last_checked_event_id
if can_receive_events? && newest_event_id = Event.maximum(:id)
self.last_checked_event_id = newest_event_id
end
end
def possibly_update_event_expirations
update_event_expirations! if saved_change_to_keep_events_for?
end
# Validation Methods
private
attr_accessor :current_event
def validate_schedule
unless cannot_be_scheduled?
errors.add(:schedule, "is not a valid schedule") unless SCHEDULES.include?(schedule.to_s)
end
end
def validate_options
# Implement me in your subclass to test for valid options.
end
# Utility Methods
def boolify(option_value)
case option_value
when true, 'true'
true
when false, 'false'
false
else
nil
end
end
def is_positive_integer?(value)
Integer(value) >= 0
rescue StandardError
false
end
# Class Methods
class << self
def build_clone(original)
new(original.slice(
:type, :options, :service_id, :schedule, :controller_ids, :control_target_ids,
:source_ids, :receiver_ids, :keep_events_for, :propagate_immediately, :scenario_ids
)) { |clone|
# Give it a unique name
2.step do |i|
name = '%s (%d)' % [original.name, i]
unless exists?(name:)
clone.name = name
break
end
end
}
end
def cannot_be_scheduled!
@cannot_be_scheduled = true
end
def cannot_be_scheduled?
!!@cannot_be_scheduled
end
def default_schedule(schedule = nil)
@default_schedule = schedule unless schedule.nil?
@default_schedule
end
def cannot_create_events!
@cannot_create_events = true
end
def cannot_create_events?
!!@cannot_create_events
end
def cannot_receive_events!
@cannot_receive_events = true
end
def cannot_receive_events?
!!@cannot_receive_events
end
def can_control_other_agents!
@can_control_other_agents = true
end
def can_control_other_agents?
!!@can_control_other_agents
end
def can_dry_run!
@can_dry_run = true
end
def can_dry_run?
!!@can_dry_run
end
def no_bulk_receive!
@no_bulk_receive = true
end
def no_bulk_receive?
!!@no_bulk_receive
end
def gem_dependency_check
@gem_dependencies_checked = true
@gem_dependencies_met = yield
end
def dependencies_missing?
@gem_dependencies_checked && !@gem_dependencies_met
end
# Find all Agents that have received Events since the last execution of this method. Update those Agents with
# their new `last_checked_event_id` and queue each of the Agents to be called with #receive using `async_receive`.
# This is called by bin/schedule.rb periodically.
def receive!(options = {})
Agent.transaction do
scope = Agent
.select("agents.id AS receiver_agent_id, sources.type AS source_agent_type, agents.type AS receiver_agent_type, events.id AS event_id")
.joins("JOIN links ON (links.receiver_id = agents.id)")
.joins("JOIN agents AS sources ON (links.source_id = sources.id)")
.joins("JOIN events ON (events.agent_id = sources.id AND events.id > links.event_id_at_creation)")
.where("NOT agents.disabled AND NOT agents.deactivated AND (agents.last_checked_event_id IS NULL OR events.id > agents.last_checked_event_id)")
if options[:only_receivers].present?
scope = scope.where("agents.id in (?)", options[:only_receivers])
end
sql = scope.to_sql
agents_to_events = {}
Agent.connection.select_rows(sql).each do |receiver_agent_id, source_agent_type, receiver_agent_type, event_id|
begin
Object.const_get(source_agent_type)
Object.const_get(receiver_agent_type)
rescue NameError
next
end
agents_to_events[receiver_agent_id.to_i] ||= []
agents_to_events[receiver_agent_id.to_i] << event_id
end
Agent.where(id: agents_to_events.keys).each do |agent|
event_ids = agents_to_events[agent.id].uniq
agent.update_attribute :last_checked_event_id, event_ids.max
if agent.no_bulk_receive?
event_ids.each { |event_id| Agent.async_receive(agent.id, [event_id]) }
else
Agent.async_receive(agent.id, event_ids)
end
end
{
agent_count: agents_to_events.keys.length,
event_count: agents_to_events.values.flatten.uniq.compact.length
}
end
end
# This method will enqueue an AgentReceiveJob job. It accepts Agent and Event ids instead of a literal ActiveRecord
# models because it is preferable to serialize jobs with ids.
def async_receive(agent_id, event_ids)
AgentReceiveJob.perform_later(agent_id, event_ids)
end
# Given a schedule name, run `check` via `bulk_check` on all Agents with that schedule.
# This is called by bin/schedule.rb for each schedule in `SCHEDULES`.
def run_schedule(schedule)
return if schedule == 'never'
types = where(schedule:).group(:type).pluck(:type)
types.each do |type|
next unless valid_type?(type)
type.constantize.bulk_check(schedule)
end
end
# Schedule `async_check`s for every Agent on the given schedule. This is normally called by `run_schedule` once
# per type of agent, so you can override this to define custom bulk check behavior for your custom Agent type.
def bulk_check(schedule)
raise "Call #bulk_check on the appropriate subclass of Agent" if self == Agent
where("NOT disabled AND NOT deactivated AND schedule = ?", schedule).pluck("agents.id").each do |agent_id|
async_check(agent_id)
end
end
# This method will enqueue an AgentCheckJob job. It accepts an Agent id instead of a literal Agent because it is
# preferable to serialize job with ids, instead of with the full Agents.
def async_check(agent_id)
AgentCheckJob.perform_later(agent_id)
end
end
public def to_liquid
Drop.new(self)
end
class Drop < LiquidDroppable::Drop
def type
@object.short_type
end
METHODS = %i[
id
name
type
options
memory
sources
receivers
schedule
controllers
control_targets
disabled
keep_events_for
propagate_immediately
]
METHODS.each { |attr|
define_method(attr) {
@object.__send__(attr)
} unless method_defined?(attr)
}
def working
@object.working?
end
def url
Rails.application.routes.url_helpers.agent_url(
@object,
Rails.application.config.action_mailer.default_url_options
)
end
end
end