contextualizer.clj

(ns stats-service.handlers.contextualizer
  "Contextualizes incoming source events, duplicating and delegating throughout the cluster as needed."
  (:refer-clojure :exclude [promise await])
  (:require [zinn.log :as log]
            [stats-service.handlers.event :as e]
            [co.paralleluniverse.pulsar.core :refer :all]))

(defn delegate-contextualized-events
  "Interacts with the [store] (dynamodb?) to find which node handles a particular source event. For now, throws things
  directly on the processing queue of this node until we are actually doing delegation."
  [events]
  (doseq [event events]
    (snd e/message-queue event)))

(defn annotate-event
  "Applies the context and id field to the provided source event."
  [source-event id context]
  (merge source-event {:id id :context context}))

(defn contextualize
  "Parses a source event for identifiers that are representative of contexts (interactions, queues, resources, etc) and
  annotates + replicates the event based on these contexts."
  [source-event]
  (log/debug "SE" source-event)
  (let [{:keys [resource-id queue-id interaction-id]} source-event
        replicated-events (cond-> []
                            resource-id (conj (annotate-event source-event resource-id :resource))
                            queue-id (conj (annotate-event source-event resource-id :queue))
                            interaction-id (conj (annotate-event source-event resource-id :interaction)))]
    (delegate-contextualized-events replicated-events)))