refactor: simple DI using callbacks

4 files changed, 44 insertions, 26 deletions

diff --git a/src/weepinbell/core.clj b/src/weepinbell/core.clj
index a8e1e6f..e865397 100644
--- a/src/weepinbell/core.clj
+++ b/src/weepinbell/core.clj
@@ -1,9 +1,28 @@
 (ns weepinbell.core
   (:require [ring.adapter.jetty :refer [run-jetty]]
-            [weepinbell.handler :refer [app]])
+            [weepinbell.processor :refer [process-webmention]]
+            [weepinbell.handler :refer [app wmc]]
+            [weepinbell.config :refer [get-config]]
+            [weepinbell.webhook :as webhook]
+            [taoensso.timbre :as timbre])
   (:gen-class)) ;; Essential for "lein uberjar"
 
+
 (defn -main [& args]
+  ;; Start webmention processor
+  (process-webmention wmc 
+    {:on-receive (fn [] 
+                   (timbre/info "Receive callback:")
+                   (webhook/trigger :on-receive (get-config :webhook)))
+     :on-update (fn [] 
+                  (timbre/info "Update callback:")
+                  (webhook/trigger :on-update (get-config :webhook)))
+     :on-delete (fn [] 
+                  (timbre/info "Delete callback:")
+                  (webhook/trigger :on-delete (get-config :webhook)))
+     :on-create (fn [] 
+                  (timbre/info "Create callback:")
+                  (webhook/trigger :on-create (get-config :webhook)))})
   ;; Check for a PORT environment variable, default to 3000
   (let [port (Integer/parseInt (or (System/getenv "PORT") "3000"))]
     (run-jetty app {:port port :join? true})))
diff --git a/src/weepinbell/handler.clj b/src/weepinbell/handler.clj
index d7067f0..29f772b 100644
--- a/src/weepinbell/handler.clj
+++ b/src/weepinbell/handler.clj
@@ -7,15 +7,11 @@
             [weepinbell.config :refer [get-config]]
             [weepinbell.receiver :refer [receive]]
             [weepinbell.retriever :as retriever]
-            [weepinbell.processor :refer [process-webmention]]
             [weepinbell.ui :as ui]
             [weepinbell.feed :as feed]
             [clojure.core.async :refer [chan]]))
 
-;; Start webmention processor
-
 (def wmc (chan))
-(process-webmention wmc)
 
 ;; Define API routes
 
diff --git a/src/weepinbell/processor.clj b/src/weepinbell/processor.clj
index d075a06..571a870 100644
--- a/src/weepinbell/processor.clj
+++ b/src/weepinbell/processor.clj
@@ -5,7 +5,6 @@
             [weepinbell.storage :as storage]
             [weepinbell.utils :refer [validate-content-types]]
             [weepinbell.wrapper :as wrapper]
-            [weepinbell.webhook :as webhook]
             [taoensso.timbre :as timbre]))
 
 (defn verify-mention
@@ -28,32 +27,32 @@
 
 (defn process-new-webmention
   "Store new webmention if verifed. Do nothing otherwise."
-  [source target]
+  [source target callbacks]
   (when (verify-mention source target)
     (timbre/info "\n🙋‍♂️ Valid webmention received: \n"
       "from " source "\n"
       "to " target "\n\n")
     (let [data (wrapper/wrap source target)]
       (storage/append-wm data)))
-  (webhook/trigger :on-create))
+  ((:on-create callbacks)))
 
 (defn process-existing-webmention
   "Update existing Webmention when verified, delete it otherwise."
-  [source target]
+  [source target callbacks]
   (timbre/info "Webmention exists.")
   (if (verify-mention source target)
     (do
       (storage/update-wm source target
                          (wrapper/wrap source target))
-      (webhook/trigger :on-update)
+      ((:on-update callbacks))
       (timbre/info "Webmention updated."))
     (do
       (storage/delete-wm source target)
-      (webhook/trigger :on-delete)
+      ((:on-delete callbacks))
       (timbre/info "Webmention no longer valid, deleted."))))
 
 (defn process-webmention
-  [wmc]
+  [wmc callbacks]
   (go-loop []
     (when-let [webmention (<! wmc)]
       (timbre/info "Webmention found in queue.")
@@ -66,10 +65,9 @@
          ;; if not, write to data
           (do
             (if (storage/get-wm s t)
-              (process-existing-webmention s t)
-              (process-new-webmention s t))
-            ;; trigger webhook
-            (webhook/trigger :on-receive))
+              (process-existing-webmention s t callbacks)
+              (process-new-webmention s t callbacks))
+            ((:on-receive callbacks)))
           ;; if content-type check fails
           (timbre/error "Source or target is not HTML or plain text; or error occurred trying to get content type."))))
     (recur)))
diff --git a/src/weepinbell/webhook.clj b/src/weepinbell/webhook.clj
index bb114cc..5a28fbc 100644
--- a/src/weepinbell/webhook.clj
+++ b/src/weepinbell/webhook.clj
@@ -1,16 +1,21 @@
 (ns weepinbell.webhook
   (:require [clj-http.client :as client]
             [taoensso.timbre :as timbre]
-            [weepinbell.config :refer [get-config]]
             [weepinbell.utils :refer [valid-http-url?]]))
 
-(defn trigger [keyw]
-  ;; keyw = on-receive, on-create, on-update, on-delete
-  (when-let [hooks (get (get-config :webhook) keyw)]
-    (->> hooks
-         (filter string?)
-         (filter valid-http-url?)
-         (map #((client/post %)
-                (timbre/info "Webhook triggered: " %)))
-         doall)))
+(defn trigger 
+  "Send requests to a list of webhooks."
+  ([urls]
+    (trigger urls nil))
+  ([keyw webhooks]
+    (when-let [hooks (if (nil? webhooks) keyw
+                         ;; if webhook list provided
+                         ;; retrieve from config
+                         (->> (get webhooks keyw)
+                              (filter string?)
+                              (filter valid-http-url?)))]
+      (->> hooks
+           (map #((client/post %)
+                  (timbre/info "Webhook triggered: " %)))
+           doall))))