storage.clj

(ns asktodon.storage
  (:require [clojure.core.async :as a]))

(defonce client-data-file "client-data.edn")
(defn- load-client-data
  "Load client data file, supposed to be done only once."
  [client-data-file]
  (try
    (read-string (slurp client-data-file))
    (catch Exception e
      (do
        (println "[WARNING] Unable to read client data: starting empty.")
        {}))))

(defn- listen-client-data
  "Intercept client-data atom and update it to file."
  [client-data-file]
  (let [channel (a/chan 10)]
    (a/go-loop []
               (when-some [data (a/<! channel)]
                 (try
                   (spit client-data-file data)
                   (catch Throwable t
                     (println "Unable to write the file" t)))
                 (recur)))
    channel))

(defonce client-data-update-chan (listen-client-data client-data-file))

(defonce client-data
  (add-watch
    (atom (load-client-data client-data-file))
    identity
    #(a/put! client-data-update-chan %4)))